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PROCEEDINGS OF THE
ADVANCED FIELDCOURSE IN ECOLOGY AND
CONSERVATION – XTBG 2010
XISHUANGBANNA TROPICAL BOTANICAL GARDEN, YUNNAN, CHINA 20 NOV – 18 DEC 2010
EDITED BY LAN QIE, YALOU LIU AND RHETT HARRISON
Preface
i
Preface
The AFEC-X Field Biology Course is an annual, graduate-level field course in tropical forest biology run by the Program for Field Studies in Tropical Asia (PFS-TropAsia; www.pfs-tropasia.org), Xishuangbanna Tropical Botanical Garden, Chinese Academy of Science, in collaboration with institutional partners in the region. The course is held at Xishuangbanna Tropical Botanical Garden in Yunnan, China and at field sites in Xishunagbanna. AFEC-X 2010 Field Biology Course was held from from 20 November to 18 December, and was the second such course to be organised by PFS-TropAsia after launching the course in 2009. The aim of these courses is to provide high-level training in the biology and conservation of forests in tropical Asia. The courses are aimed at entry-level graduate students from the region, who are at the start of their thesis research or professional careers in forest biology. During the course topics in forest biology are taught by a wide range of experts in tropical forest science. There is also a strong emphasis on the development of independent research projects. Students are exposed to different ecosystem types through course excursions. The AFEC-X 2010 Field Biology Course was attended by 20 students from 10 countries (China, Thailand, Indonesia, India, Sri Lanka, Cambodia, Cameroon, Benin, Argentina and DPR Korea) and a total of 15 resource staff from a variety of national and international institutions gave lectures and practical instruction. Twelve participants received fellowships, including travel awards, to attend the field course. The course was run by Professor Ferry Slik (Laboratory of Plant Geography, XTBG), Dr. Lan Qie (PFS-TropAsia, XTBG), and Professor Chuck Cannon (Laboratory of Ecological Evolution, XTBG). Due to their efforts the course proved to be a huge success. The following report illustrates the hard work of the organizers and the enthusiasm and commitment of the students. Rhett D. Harrison
Director, Program for Field Studies in Tropical Asia
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences
Acknowledgement
ii
Acknowledgement
The AFEC-X China 2010 organizers wish to thank all resource staff listed at the end of this proceedings, who generously gave their time to teach the field course, especially Dr. Doug Schaefer, Dr Jacob Wickham, Ms. Shi Lingling and Ms. Vivian Fu, who invested enormous amount of time into the course. A field course like this will not be possible without the commitment and support from these researchers. We thank Professor Ding Wenjun, the vice dean of the School Life Sciences, Chinese Academy of Sciences and Director Chen Jin of Xishuangbanna Tropical Botanical Garden (XTBG) for attending the Opening Ceremony of AFEC-X China 2010 and giving guest lectures to the participants. We give our sincere thanks to our Program Coordinator Liu Yalou (Allen) whose role in this course was absolutely indispensable. We would like to thank the supporting staff from the XTBG Personnel and Education Office: Mr. Chen Zhiyun and Ms. Liu Zhiqiu, from the Project Management Office: Mr. Yang Qing and Ms. Fang Chunyan, for their wonderful help to make sure the administration and logistics of this course went smoothly. We are very grateful for the kind help from the XTBG Student Union in taking care of the international participants upon their arrival and in putting on a wonder performance at the course farewell party. The organizers acknowledge the support and assistance of the Xishuangbanna Nature Reserve management, in particular Mr. Ai Jiao and Mr. Li Zhonghua, who accompanied the class during our field trip at Mengsong. We give out special thanks to the local Hani people at Mengsong, the Village Head Mr. He Yongneng, San Tu, and Ah Dong. Their great hospitality made all the international participants feel just at home. The wonderful and authentic Hani dinner we had at He’s house was one of the most memorable experiences during the field course. AFEC-X China 2010 was funded by XTBG and the Key Lab of Tropical Forest Ecology. Thanks to all.
Ferry Slik
Professor, Plant Geography Lab
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences
Lan Qie
Scientific Coordinator, Program for Field Studies in Tropical Asia
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences
CONTENT
iii
CONTENT
Preface................................................................................................................................... i
Acknowledgement ................................................................................................................ ii
CONTENT........................................................................................................................... iii
AFEC-X 2010 Schedule........................................................................................................ 1
Group Reports....................................................................................................................... 1
The Effect of Distance from Stream Edge on Insect Diversity in a Mengsong Meadow......... 1
Relationship between Soil Macrofauna and Soil Respiration in Two Different Vegetation
Types .................................................................................................................................... 7
Soil Respiration Responses to Forest Density and Elevation Gradients in the Rainforests of
Mengsong ........................................................................................................................... 14
Do Environmental Factors Influence the Density of Invasive Species? ................................ 21
The Distribution Patterns of Birds in Tropical Riparian Forest of Mengsong ....................... 29
Changes in Plant Community Trait Composition of Understory Trees: Mengsong Seasonal
Tropical Rainforests, Yunnan, China:.................................................................................. 35
Participants ......................................................................................................................... 50
People ................................................................................................................................. 55
Resource Staff..................................................................................................................... 55
Teaching Assistants............................................................................................................. 58
AFEC 2010 Schedule
1
AFEC-X 2010 Schedule
Day Month Time Activity Lecturer
20 Nov Arrival Participants
21 Nov 9:00 Registration (Kunming XTBG office)
10:00 L1: Course introduction Chuck Cannon
11:00 L2: Introduction to the tropics Chuck Cannon
12:00 Lunch
13:00 L3: Mutualisms Doug Yu
14:00 L4: Amerindians and conservation Doug Yu
15:00 Student introductions
18:00 Dinner
22 Nov 8:00 Bus trip to XTBG
23 Nov 8:30 CAS delegation of graduate school
9:30 L5: Conservation crisis in Asia and new developments
Ferry Slik
10:00 L6: Conservation Chuck Cannon
11:00 L7: DNA developments Chuck Cannon
12:00 Lunch
13:30 L8: Ecophysiology Cao Kunfang
14:30 L9: Seed dispersal Chen Jin
15:30 L14: Invasive plants Feng Yulong
18:00 Dinner
19:30 Student introductions
24 Nov 9:00 L17: Statistics day Rhett Harrison
12:00 Lunch
13:30 L17: Statistics day Rhett Harrison
18:00 Dinner
19:30 L12: Plant animal interactions Rhett Harrison
20:30 L23: Getting published Rhett Harrison
25 Nov 9:00 L11: Biodiversity Ferry Slik
10:00 L30: Biogeography Ferry Slik
11:00 L13: Wood ring research Fan Zexin
12:00 Lunch
13:30 L32: Modeling and climate change Ferry Slik
14:30 L15: Soil litter fauna Yang Xiaodong
15:30 L31: Introduction to Mengsong Ferry Slik
16:30 L27: Project design / Devide students in groups Chuck Cannon
18:00 Dinner
26 Nov 9:00 L10: Plant taxonomy Ferry Slik
10:00 Move to rainforest site (plant collecting) Ferry Slik
AFEC 2010 Schedule
14:00 Identify plants in lecture hall Ferry Slik
16:00 Introduce short term projects / Devide students in groups
Ferry Slik, Qie Lan
18:00 Dinner
27 Nov 9:00 Visit to CTFS 20 ha plot Ferry Slik, Qie Lan
18:00 Dinner
28 Nov 9:00 L18: DNA Applications Shi Lingling
10:00 L19: Molecular Ecology Shi Lingling
11:00 L31: Community ecology Ferry Slik
12:00 Lunch
13:30 L21: Insects Jacob Wickham
14:30 L22: Insects Jacob Wickham
15:30 L29: Forest restoration Tang Yong
16:30 L28: amphibians and birds Vivian Fu
18:00 Dinner
29 Nov 9:00 L16: Soil Ecology Douglas Scheaffer
10:00 Visit to forest restoration site Tang Yong
30 Nov 8:00 Move to Mengsong
13:00 Round trip through Mengsong Ferry Slik, Qie Lan
1 Dec Mensong field survey: Students start thinking about projects
Ferry Slik, Qie Lan
2 Dec Morning: preparation of proposals; Afternoon: presentation of proposals
Ferry Slik, Qie Lan
3 Dec Field projects Ferry Slik, Qie Lan
4 Dec Field projects Ferry Slik, Qie Lan
5 Dec Field projects Ferry Slik, Qie Lan
6 Dec Field projects Ferry Slik, Qie Lan
7 Dec Field projects Ferry Slik, Qie Lan
8 Dec Field projects Ferry Slik, Qie Lan
9 Dec Field projects Ferry Slik, Qie Lan
10 Dec Field projects Ferry Slik, Qie Lan
11 Dec 8:00 Return to XTBG
12:00 Lunch + free afternoon
12 Dec 9:00 Data analysis
13 Dec 9:00 L24: Energy plants Zeng-Fu Xu
10:00 Data analysis rest of day
14 Dec 9:00 Presentation try-outs (rest of day)
15 Dec 9:00 Prepare final presentation
16 Dec 9:00 Whole day symposium
18:00 Goodbye dinner in bamboo restaurant
17 Dec 8:00 Back to Kunming
18 Dec Everybody leaves for home
Group Reports
1
Group Reports
The Effect of Distance from Stream Edge on Insect Diversity in a Mengsong Meadow
Eka A.P. Iskandar
1, Duan Qiong
2 and Sophany Phauk
3
1Cibodas Botanical Garden, Indonesian Institute of Sciences, Cibodas, Cianjur, Indonesia 43253. 2Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China 3 Department of Biology, Faculty of Sciences, Royal University of Phnom Penh, Phnom Penh 12000. Cambodia
Abstract
This study examined the effect of stream edge on diversity of insects in a meadow in Mengsong, Yunnan Province, China. The meadow was located between a stream and a forest. Insect sampling was conducted over the course of ten days at five distances from the stream: 0 m, 6.25 m, 12.5 m, 18.75 m and 25 m (at the forest edge). Insects were captured using pitfall traps and a sweep net, and identified to order and morph species. Vegetation analyses were performed using point transects. Diversity index for insect and plant were counted using shanon-Weaver index. The results showed that the insect diversity was not affected by distance from the stream, but insect abundance was affected. Plant diversity was correlated with distance from stream edge. However there was no correlation between insect diversity and plant diversity. And there was no correlation between plant diversity and insect abundance. Keywords: edge effect, insect diversity, insect abundance, meadow, pitfall, plant diversity
INTRODUCTION
In tropical dry forests, water resources
have the potential to influence local insect
diversity, abundance, and composition
(Janzen, 1967).Edge effects result from the
interplay between two spatially contiguous
ecosystems (Murcia, 1995). Edge effect
hypothesis states that diversity is higher in
ecotones than in adjacentassemblages
(Odum 1971), which influences
invertebrate assemblage patterns (Majer et
al.1997). Insect assemblages are very
important components of biodiversity
because they accumulate considerable
biomass and show high species richness
(Erwin, 1991). Insect plays a very
important role in the food web of
ecosystem. For these reasons, insects are
valuable ecological indicators of edge
effects in natural landscapes (Pinheiro et al.
2010).
A meadow in Mengsong was
chosen to investigate whether there was a
The Effect of Distance from Stream Edge on Insect Diversity in a Mengsong Meadow
significant change in insect diversity and
abundance at increasing distances from the
stream. Our hypothesis was that the
walking insect diversity would decrease
with distance from the stream because of
the moisture, and the jumping and flying
insect diversity would increase with
distance from the stream because of the
insect resource from forest.
METHODS
STUDY AREA. –An even meadow in
Mengsong, Yunnan, China adjacent to a
stream and a forest was chosen for this
study (100o24’48”-100o40’25”E;
21o56’54” - 22o16’56” N; 1640 m a.s.l.). It
was formed due to the drying process of
the dam downstream earlier (c.a. one year
ago).The grass vegetation of the meadow
was almost the same, dominated by
grasses of knee height. There were some
herbs by the stream edge which can reach
until 75 cm height. The maximum distance
from the edge of the secondary forest to
the edge of the stream was approximately
30 m.
INSECT SAMPLING. –The study was
conducted from December 4th to 10th, 2010.
Five parallel line transects, one located at
the stream edge (line A), three on the
grassland (line B, C and D), and one at the
forest edge (line E), separated by at least 5
m were laid out. Five pitfalls were placed
along each line at 5m distance from each
other, to capture ground-favoring insects.
Each pitfall trap consisted of a white
plastic glass, buried to its rim in soil and
partly filled with a 30:70 ethylene glycol:
water mixture. Each trap was covered with
a small plastic sheet roof supported with a
stick to prevent either desiccation or
flooding, but left the sides open so that
insects could enter the pitfall unhindered.
Traps were inspected and collected every
48 hours over two periods. Trapped insects
were separated, identified to
morphospecies, and counted. Species
richness and abundance of taxa at each
pitfall was recorded by counting species.
Additionally, a sweep net method was
used in line A, C, and E, to capture more
mobile, none ground-favoring insects.
Because of the vegetation of the meadow
was almost grass, we used the point
transect method. Using a stick, we pointed
along the one meter line at 20 cm distance
on each side of the pitfall, where pitfalls
acted as its center. Plant species that
touches the stick was recorded and
identified to as specific as possible taxa or
to morphospecies if it was unidentified.
DATA ANALYSIS. –Diversity was
characterised by the Shannon-Weaver
Index. Statistical estimation of species
richness was performed using the Estimate
S 8.0.0 program [reference]. Chao 2was
Group Reports
3
used to estimate species richness in the
study area. Statistical analyses were
performed using the statistics program R
2.12.0 (R Development Core Team 2010).
The effect of distance category (Line A-E)
from the stream on insect species richness
was analyzed using one-wayANOVA. The
effects of distance and plant diversity on
the insect diversity and abundance were
analyzed using linear regressions, with
some modifications, and the pitfall and
sweep netting result were analyzed
separately.
RESULTS
We collected 68 and 53 morphospecies
from the pitfalls and sweep netting, with
82% and 72% completeness, respectively
based on the Chao2. Vegetation was
dominated by Ageratina adenophora,
Poaceae sp.1, and Polygonum sp.2 for
stream edge, meadow center, and forest
edge, respectively. According to a
one-way ANOVA test, distance had a
significant effect on themean total number
of plantmorphospecies per line (DF-4, 20,
F=5.07, P=0.0055).
For both pitfalls and sweep net,
insect diversity was not correlated with
distance from the stream, and insect
diversity was also not correlated with plant
diversity. However, plant diversity
showed a quadratic relationship with
distance from the stream (r2=
0.54,p<0.0001 (fig.1), and a linear
relationship for sweep net: r2= 0.78, p =
0.02 (fig.2)). A quadratic relationship also
exists between insect abundance and
distance from the stream (r2= 0.20, p =
0.002 (fig.3)).
The Effect of Distance from Stream Edge on Insect Diversity in a Mengsong Meadow
0 5 10 15 20 25
0.0
0.5
1.0
1.5
2.0
pitfall$distance.stream
Fig.1. Linear and quadratic regression of plant diversity with distance from the stream (pitfall).
0 5 10 15 20 25
0.6
0.8
1.0
1.2
1.4
1.6
sweep$distance.stream
Fig.2. Linear and regression of plant diversity with distance from the stream (sweep net).
R2=0.54, p<0.0001
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0 5 10 15 20 25
10
20
30
40
50
pitfall$distance.stream
Fig.3. Quadratic regression of insect abundance with distance from the stream (pitfall)
DISCUSSION
Our study showed that the insect diversity
was not correlated with distance from the
stream. This was probably due to the study
area that may have been too small to detect
the effects of distance. The period of
study was also short, and was in dry
whether where most insects were less
active. This result supports Bruneau &
Lee (2003) who found that distance has no
significant effect on insect diversity. Their
study was conducted on the dry tropical
forest dominated by low growing
vegetation near the water and grasses on
further distance from the water.
We found that plant diversity was
correlated with distance from the stream,
where both edges had higher diversity in
comparison with the center of the meadow.
By the stream, the moisture is a very
important effect factor; by the forest, the
insect resource may be the effect factor.
This is clearly supported Odum’s
hypothesis (1971). Higher plant diversity
on the edges would influence the
invertebrate assemblages’ patterns (Majer
et al.1997). Because a diversity of
resources should support a diversity of
consumers, most models predict that
increasing plant diversity increases animal
diversity. Analyses of relations among
The Effect of Distance from Stream Edge on Insect Diversity in a Mengsong Meadow
plants and arthropod trophic groups
indicated that herbivore diversity was
influenced by plant(Stein et al. 2010).In
general, trees have richer insect faunas
than herbs(Whipple et al. 2010)
ACKNOWLEDGEMENTS
We would like to thank to our sponsor and
organizer, the Xishuangbanna Tropical
Botanical Garden (XTBG) for hosting this
AFEC 2010. Special thanks to Dr. Ferry
Slik, Dr. Charles Cannon, Dr. Jacob D.
Wickham, Dr. Rhett D. Harrison, Dr.
Doug Schaefer, Qie Lan, Liu Yalou and
all the staff in XTBG for great warm
welcome and facilitation. Thanks to all our
friends in the course with sharing
knowledge, culture and happiness.
LITERATURE CITED
BRUNEAU, L. & M. Lee. 2003. The affects of distance from water holes on insect diversity in tropical dry forests in Deinert, E., K. Gastreich, M. Sasa, A.C. Villegas (eds.) Undergraduate Semester Abroad Program. Organization of Tropical Studies.
ERWIN, T.L.1991.How many species are there?Revisited.Conserv.Biol.5:330-333.
JANZEN, D.H., T.W. Schoener. 1967. Differences in insect abundance anddiversity between wetter and drier sites during a tropical dry season. Ecology 49: 96-110.
MAJER,J.D., J.H.C. Delabie , N.L. McKenzie. 1997. Ant litter fauna of forest, forest edges and adjacent grassland in the Atlantic rainforest region of Bahia, Brazil. Insect Soc. 44:255-266.
MURCIA, C. 1995. Edge effects in fragmented forests: implications for conservation. TREE 10:58-62.
ODUM, E.P.1971.Fundamentals of
Ecology. Saunders, London.
PINHEIRO, R.S., L.S. Duarte, E. Diehl, S.M. Hartz. 2010. Edge effects on epigeic ant assemblages in a grassland forest mosaic in southern Brazil. Acta
Oecologica36:365-371.
R Development Core Team (2010). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0, URL http://www.R-project.org/.
STEIN, C., S. Unsicker, A. Kahmen, M. Wagner, V. Audorff, H. Auge, D. Prati, and W. Weisser. 2010. Impact of invertebrate herbivory in grasslands depends on plant species diversity. Ecology91:1639-1650.
WHIPPLE, S., M. Brust, W. Hoback, and K. Farnsworth-Hoback. 2010. Sweep Sampling Capture Rates for Rangeland Grasshoppers (Orthoptera: Acrididae) Vary During Morning Hours. Journal
of Orthoptera Research19:75-80.
Group Reports
7
Relationship between Soil Macrofauna and Soil Respiration in Two Different
Vegetation Types
Iogna Patricia A.1, Liu Xiamo
2, Jo Won Ju
3
1GEBEF (Ecophysiological and Biophysical Research Group), Natural Sciences Faculty, National University of Patagonia San Juan Bosco (UNPSJB). National Council on Scientifics and Technical research (CONICET). Ciudad Universitaria Km4, Comodoro Rivadavia, 9005, Argentina. 2Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China. 3Geographical Information Group, Land Use Planning Institute under the Ministry of Land Environment Protection (MoLEP). Abstract
There is an extremely high diversity of organisms living in the soil that contribute in returning the carbon fixed in photosynthesis to the atmosphere. This study compares the CO2 release, and macrofauna from the soil in secondary forest and adjacent tea plantation of Mengsong Nature Reserve, Yunnan, China. Soil CO2 measurements were made on soil samples taken from each site. Soil macrofauna were classified into 130 morphospecies and the number of individuals counted for each soil sample. While CO2 release was not significantly different between the two vegetation types, we found 30% higher species richness, and more than twice abundance, of soil macrofauna, in the secondary forest compared to tea plantation. Key words: carbon dioxide, decomposition, secondary forest, soil fauna, tea plantation. DECOMPOSITION OF DEAD PLANT
material is an important process by which
carbon fixed during photosynthesis is
returned to the atmosphere and is critical
for nutrient cycling (Swift et al. 1979).
This process is driven by interacting
physical factors, such as climate, substrate,
soil organisms, and physical and chemical
properties of soils (Dyer et al. 1990;
Pausas et al. 2004).
Soils host an extremely high
diversity of organisms. In one hectare of
temperate forest, several hundred species
of soil invertebrates may coexist (Schaefer
and Schauerman, 1990). This soil fauna
can be classified into microfauna,
mesofauna and macrofauna. Macrofauna
include organisms between 2 and 20 mm
(e.g., millipedes, woodlice, fly larvae,
beetles, snails and earthworms). They have
body sizes large enough to disrupt the
physical structure of the soil through their
feeding and/or burrowing activities.
These organisms contribute to litter
decomposition by digestion of substrates,
increase of surface area through
fragmentation, and acceleration of
microbial inoculation to materials (Swift et
Relationship between Soil Macrofauna and Soil Respiration in Two Different Vegetation Types
al.1979; Coleman and Crossley, 1996).
Soil microarthropods, as prevalent
components of the soil fauna, have been
shown to increase the rates of litter
decomposition, nutrient cycling and
primary productivity in forest ecosystems
(Seastedt,1984) through digestion and
breakdown of the litter, stimulation of
microbial activity and transport of fungal
and bacterial propagules (Moore et al.
1988; Read and Perez-Moreno, 2003). Soil
fauna can also influence microbial species
composition or biomass (Visser, 1985;
Groffman et al. 2004), thus altering
decomposition rates and nutrient cycles
(Moore et al. 1988; Lavelle, 2002).
Moreover, litter fragmentation and passage
through the guts of microarthropods such
as millipedes and isopods favor the
establishment of soil microbial populations
(Griffiths and Bardgett, 1997).
This soil macrofauna can be affected
by land use. Most land use practices
reduce the abundance or diversity of soil
macroinvertebrate communities by
disturbing their physical environment and
reducing the diversity and abundance of
organic inputs that they normally use for
feeding (Curry, 1987; Decaëns et al.
1994).
The objective of this study was to
compare the CO2 release from the soil
between secondary forest and adjacent tea
plantation macrofauna of Mengsong
Nature Reserve, Yunnan, China. Our
hypothesis was that soil macrofauna
diversity and abundance would be higher
in the secondary forest than in the tea
plantation for the human disturbance of the
site, and that these differences in soil
macrofauna will be reflected in a higher
CO2 release by the secondary forest soil.
In this study, we asked whether
forest type affect soil fauna richness and
abundance. If secondary forest and rubber
plantation have different physical and
chemical soil properties. It may have
altered CO2 production and different soil
fauna diversity.
METHODS
STUDY SITE AND SAMPLES. –The
study was carried out in Mengsong,
Xishuangbanna, Yunnan province, China.
Soil samples were extracted from
secondary forest and adjacent tea
plantation.
The study site has a typical monsoon
climate with three distinct seasons
distributed throughout the year as follows:
1. A humid hot rainy season that runs from
May to October,
2. A foggy cool-dry season from
November to February, and
3. A hot-dry season from March to April.
Mean annual temperature ranges
between 15.1°C and 21.7°C, and
Group Reports
9
precipitation between 1200 and 2500 mm.
Rainfall during the wet season between
May and October accounts for over 80
percent of total annual precipitation. Water
deposition from fog accounts for over
one-third of total water input during the
dry season in the forests, suggesting an
important role that fog may play in
pushing up the northern limit of tropical
rain forest in Southeast Asia (Cao et al.
2006). The soil is classified as latosol (pH
4.5 5.5) developed from purple sandstone.
In the secondary forest, 4 plots of
20x20 m were selected with 100 m
intervals. In the tea plantation, due to the
limited size of the area, 4 plots of 10x10 m
were selected with 50 m intervals. In each
plot 4 soil samples of 15 cm diameter and
6 - 8 cm depth were extracted from each
corner of the plot. Soil extraction was done
inside a metal cylinder pushed into the
ground to prevent the soil fauna from
escaping during sampling. Soil mass of
each sample was measured in the
laboratory.
Tea plantation
Secondary forest
SOIL CO2 MEASUREMENTS. – Soil CO2 release was measured from each soil sample with a LI-820 (Licor, Licoln, NEUSA) in the laboratory.
SOIL MACROFAUNA - Winkler bags
were used to extract the soil macrofauna of
the soil samples. This fauna extraction
method works through the desiccation of
the soil samples inside the bag, which
makes the macrofauna to move out of the
soil sample, after which they end up in a
cup at the bottom of the bag. The cup was
partially filled with soapy water with salt
to drown and preserve the insects that fell
in the cup. Soil samples were first passed
through a 1 cm sieve to remove big
Relationship between Soil Macrofauna and Soil Respiration in Two Different Vegetation Types
material present in the soil and then placed
in the winkler bag. After 24 hrs the soil
sample was taken out and remixed to
enhance desiccation, and placed back in
the winkler bag. After 48 hrs the water in
the cup was passed through a 2 mm mesh
to remove the micro- and mesofauna. The
remaining macrofauna were then sorted.
Soil macrofauna was classified in
morphospecies under a microscope and the
number of individuals counted for each
soil sample.
DATA ANALYSES – R software (R
Development Core Team 2010) was used
for data analyses. One-way analyses of
variances (ANOVA) were used to test the
significance of difference in CO2
production, abundance, richness and forest
type. Analysis of covariance (ANCOVA)
were used to test the significance of
difference between abundance, richness
and forest type was consistent CO2
production.
RESULTS
For all samples combined we identified
130 macrofauna morphospecies, of which
94 were found in the secondary forest and
64 in the tea plantation. The total number
of individuals found in the secondary
forest was 495, more than twice the
number in the tea plantation (202
individuals).
1. CO2 production rate was not
significantly different between
secondary forest and tea plantation
(Fig. 1; one factor ANOVA, p-value =
0.7508, adjusted R-squared = 0.02981).
The reason maybe that the secondary
forest site is not far away from the tea
plantation, and the tea plantation has
low management intensity.
secondary tea
10
00
30
00
50
00
forest.type
Fig. 1 One factor ANOVA showing that
CO2 production (μmoles/h-1) is not
significantly different between secondary
forest and tea plantation.
2. Abundance was not significantly
different between the two forest types
(Fig. 2; p-value = 0.7508 adjusted
R-squared = 0.03087)
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secondary tea
51
01
52
02
53
0
forest type
Fig. 2 One factor ANOVA showing
abundance of soil macrofauna is not
significantly different between secondary
forest and tea plantation.
secondary tea
10
20
30
40
forest type
richness
Fig. 3 One factor ANOVA showing that
the richness of insect is significantly
higher in secondary forest than in tea
plantation.
3.Richness was found to differ
significantly between different vegetation
types. (p-value = 0.001182, adjusted
R-squared = 0.2933)
DISCUSSION
Our study investigated whether forest type
affects soil fauna richness and abundance
and CO2 production. We found that CO2
production rate is not significantly
different between secondary forest and tea
plantation. We also found that Abundance
and richness is higher in secondary forest
than tea plantation. However this may
have to do with the fact that the tea
plantation is in the vicinity of the
secondary forest. Our data collection was
also limited to a single season of the year,
while ideally CO2 production needs to be
measured at different times of the year to
be able to detect its variability.
There may be many other factors
affecting CO2 production, such as root
respiration, surface-litter respiration and
soil organic matter. CO2 production from
soil surface is approximately equal to the
soil respiration. Which part of CO2
production comes from soil fauna is
difficult to measure, however, CO2
production from soil surface is
approximately equal to the soil respiration.
Because of limited time we did not
consider the associations between soil
fauna and litter quantity and quality. Soil
Relationship between Soil Macrofauna and Soil Respiration in Two Different Vegetation Types
fauna represent a sensitive link between
plant detritus and plant-available nutrients.
Changes in litter quality could affect the
abundance of some faunal species either
directly or indirectly through their food
supply. In secondary forest, both litter
quality and quantity are expected to be
higher than in tea plantation.
Also, land use change may affect
soil fauna through modified environmental
conditions, such as soil temperature,
moisture, nutrients, heat and light, thereby
triggering changes in plant competitive
interactions, community composition and
disturbance regimes. Future studies should
take these environmental factors into
consideration.
ACKNOWLEDGEMENTS
We would like to thanks Lainie (Qie lan),
Douglas Schaefer, Chuck Cannon, Ferry
Slik, Rhett Harrison, Jacob Wickham,
Vivian Fu, Shi Lingling, Allen (Liu
Yalou) and the AFEC-2010 Group.
LITERATURED CITED
COLEMAN, D.C., CROSSLEY, D.A. (1996). Fundamentals of Soil Ecology. Academic Press,San Diego, California, USA.
CURRY, J.P. (1987). The invertebrate
fauna of grassland and its influence on productivity. 1. The composition of the fauna. Grass For Sci 42: 103–120.
DECAËNS, T., LAVELLE, P., JIMENEZ JAEN, J.J., ESCOBAR, G. & RIPSTEIN, G. (1994). Impact of land management on soil macrofauna in the Oriental Llanos of Colombia. Eur J Soil Biol 30(4): 157–168.
DYER, M.L., MEENTEMEYER, V., BERG, B., (1990). Apparent controls of mass loss rate of leaf litter on a regional scale: litter quality vs. climate. Scandinavian Journal of Forest Research 5, 311–323.
GRIFFITHS, B.S., BARDGETT, R.D. (1997). Modern Soil Microbiology: Interactions Between Microbe-feeding Invertebrate and Soil Microorganisms. Marvel Dekker lnc., New York, pp. 165–182.
GROFFMAN, P.M., BOHLEN, P.J., FISK,
M.C., FAHEY, T.J. (2004). Exotic earthworm invasion and microbial biomass in temperate forest soils. Ecosystems 7, 45–54.
LAVELLE, P. (2002). Functional domains
in soils. Ecology Resource 17, 441–450.
MOORE, J.C., WALTER, D.E., HUNT,
H.W. (1988). Arthropod regulation of micro- and mesobiota in below-ground detrital food webs. Annual Review of Entomology 33, 419–439.
PAUSAS, J.G., CASALS, P., ROMANYA,
J. (2004). Litter decomposition and faunal activity in Mediterranean forest soils: effects of N content and the moss layer. Soil Biology and
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Biochemistry 36, 989–997. READ, D.J., PEREZ-MORENO, J. (2003).
Mycorrhizas and nutrient cycling in ecosystems– a journey towards relevance? New Phytologist 157, 475–492.
SCHAEFER, M. AND SCHAUERMANN,
J. (1990). The soil fauna of beech forests: comparison between a mull and a moder soil. Pedobiologia 34(5), 299-314.
SEASTEDT, T.R. (1984). The role of
microarthropods in the decomposition and mineralization of
N. Annual Review of Ecology and Systematics 29, 25–46.
SWIFT, M.J., HEAL, O.W., ANDERSON,
J.M. (1979). Decomposition in Terrestrial Ecosystems. Blackwell Science, Oxford, UK.
VISSER, S. (1985). Role of the soil
invertebrates in determining the composition of soil microbial communities. In: Fitter, A.H., Atkinson, D., Read, D.J., Usher, M.B. (Eds.), Ecological Interactions in Soil. Blackwells, Oxford, pp. 297–317.
Soil Respiration Responses to Forest Density and Elevation Gradients in the Rainforests of Mengsong
Soil Respiration Responses to Forest Density and Elevation Gradients in the Rainforests
of Mengsong
Orou Augustin1, Chemboli Sreenivasan Dhanya
2, Liu Yanjie
3, Ri Kum Ran
4
1Hokkaido University, Japan 2M S Swaminathan Research Foundation, India 3Graduate University of Chinese Academy of Science, China 4Environment and Development Centre, DPR Korea
Abstract
A study was carried out looking at the effect of basal area and topography (elevation and slope) on CO2 production in the litter zone of the rain forests of Mengsong, Yunnan Province, China. Basal area was calculated from the dbh measured in 20 x 20 m quadrats at both upper and lower parts of the mountain, and CO2 production was measured in the field using a Co2 gas analyzer (Li-820). It was found that Soil respiration increased with increasing basal area and elevation, and basal area increased with increasing elevation. Slope didn’t affect either soil respiration or basal area in the Mengsong forest.
Key words: basal area, CO2 production, elevation, slope, tropical forest, Yunnan
INTRODUCTION
ESTIMATION OF CARBON STOCK IN
tropical forests and the factors influencing
the production of CO2 is a widely
discussed topic in the current era of
climate change. The past century has
witnessed a marked increase in
atmospheric carbon dioxide concentrations
and a concomitant ‘greenhouse warming’
that has drawn scientific attention to the
link between global carbon stocks and
climate change (Cox et al. 2000). And
there has been increasing interest in the
quantification of the biomass of forest
ecosystems and its potential carbon
fixation (Chave et al. 2005, Fearnside,
1996, Schulp et al. 2008 and Sierra et al.
2007).
Soil organic matter is an important
component that represents a carbon (C)
pool three times larger than that of the
atmosphere (GCTE 1996). The litter from
trees is one of the major factors that
contribute to the CO2 production in the soil
surface of tropical forests. Contribution to
soil respiration of different factors that are
related to plants, especially the Above
Ground Biomass (Kanowski, 2010), root
(Matamala, 2000) soil and litter
(Phillipson, 1975, Witkamp, 1961), have
caught the attention of many researchers.
Carbon stocks of forest trees are
well studied in terms of carbon
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sequestration (Brown S., Lugo A.E. 1982,
Clark D.A. et al. 2001, Dixon R.K.,
Houghton R.A., 1994, Huet S. et al. 2004,
Kraenzel M. et al. 2003, Le Goff N. et al.
2004, Wu Z.M. et al. 1998). Also there
have been efforts to determine the accurate
characterization of tree carbon (TC), forest
floor carbon (FFC) and soil organic carbon
(SOC) in tropical forests so as to estimate
their contribution to global carbon stocks
(Juan Carlos et al 2010). But the factors
that affect the soil carbon production in
natural forests and the relationship
between different factors such as
topography, species diversity and plant
density, remain little studied.
Hence the present study was carried
out to examine the correlation between
CO2 production in the litter and (1) the
basal area of trees, and (2) the topography
(elevation and slope) in the tropical rain
forest of Mengsong, Yunnan, China. We
hypothesized that he basal area of tropical
forest trees increases the CO2 production
in the litter zone.
MATERIALS and METHODS
STUDY AREA. –The study was
conducted at the forests of Mengsong,
which is a part of Xishuangbanna
Administrative region in Southern Yunnan,
China (fig. 1). The study site is located at
21.510 N, 100.510 E at an altitude that
ranges from 1600m to 1780m above sea
level. The region has tropical rainforest
vegetation comprising both primary and
secondary forest elements and has a
typical monsoon climate (fig. 2).
Fig. 1 Map showing the study site
Fig. 2 Forest site at Mengsong
METHODS.–A total of 6 sites were
selected, of which 4 sites were at the east
side and 2 sites at the west part of the
Mengsong forest. In each site, 2 quadrats
(20x20m each) were set up, one in the
upper part of the mountain and the second
in the lower part of the mountain, close to
the river, keeping an inter-distance of 50m.
The distance between sites was kept at
Xishuangbanna
Soil Respiration Responses to Forest Density and Elevation Gradients in the Rainforests of Mengsong
100m along a trail that followed the same
elevation along the mountain side (fig. 3).
The twelve quadrats were surveyed over a
seven-day period.
Fig. 3 The plot design.
BASAL AREA. –All trees with
dbh>10cm were measured in each 20 X
20m quadrat. The basal area of each
quadrat was calculated by summing up the
basal area of the individual trees (BA of a
tree = 3.14 x (DBH/2)2) and dividing it by
0.04 to get the value per ha. For
multi-stemmed trees, the bole diameter
was measured separately, and then
summed and the basal area was calculated.
MEASUREMENT OF CO2
PRODUCTION IN THE LITTER
ZONE.–The rate of CO2 production in the
litter zone of the forest floor was measured
at five points in each quadrat using a CO2
Gas Analyser (Li-820) with a static
ventilated chamber. The temperature of the
litter zone was also recorded at each
sample point using a digital soil
thermometer. Then the rate of CO2
production was calculated from the slope
of the regression curve, as
micromoles/hr/m2.
SLOPE AND ALTITUDE.–The
slope of each quadrat was measured by
calculating the angle of inclination using a
stick of 1m length (Trigonometry).
Elevation of all the quadrats was also
recorded using a GPS.
STATISTICAL
ANALYSIS.–ANOVA and linear
regression have been adopted for
analyzing the data using R (Version 2.12.0)
software (R Development Core Team
2010). The factorial design was done, to
accommodate the errors.
RESULTS
VARIATION OF NUMBER OF TREES
AND BASAL AREA PER PLOT.–We
measured 352 trees in 12 quadrats
covering both the east and west parts of
Mensong Forest. The upper plots had a
significantly higher number of trees than
the lower plots (Fig. 4A). The basal area
was also higher in the upper plots
compared with the lower plots (Fig.4B).
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Fig. 4 A. Number of trees per quadrat
Fig. 4 B. Basal area per quadrat
VARIATION IN CO2 PRODUCTION
AMONG SITES.–CO2 production was
significantly higher for upper plots than
lower plots (Fig. 5) (Factorial
AnovaP<0.001). The highest CO2
production was ~400 micromoles/hr/m2
(site 2, Fig. 6) while the lowest was 180
micromoles/hr/m2 (site 1).
Fig. 5. CO2 production along elevation.
Soil Respiration Responses to Forest Density and Elevation Gradients in the Rainforests of Mengsong
Fig. 6. CO2 production among sites in Mensong forest.
Fig. 7 Correlation between BA and CO2 production
SLOPE EFFECT ON C02 PRODUCTION
AND BASAL AREA.–Slope didn’t show
a significant correlation between either soil
respiration or basal area in Mengsong
forest.
DISCUSSION
Our results show a very clear positive
relationship between CO2 production and
basal area. When the gradient factor was
considered, there still exist a positive
correlation between CO2 production and
basal area (Prevost-Boure et al. 2009).
Potential causative factor behind this could
be the occurrence of higher basal area and
more number of trees in the upper plots.
The more amount of organic matter
produced in the upper part can cause an
increase in the CO2 production in the litter
zone.
The reason for occurrence of more
number of trees and higher basal area in
the upper part could be attributed to the
history of the forest, as the lower part is
always vulnerable to disturbance.
Another possibility is that there could be
more light available in the upper part than
the lower that could promote better tree
growth. Hence, further research
concerning trees and soil respiration, in the
Mensong forest could consider the effects
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of light and litter depth on soil respiration,
which were not measured in the present
study.
ACKNOWLEDGEMENTS
We would like to place on record our
sincere gratitude to Dr Chen Jin, Director,
XTBG, for providing us the opportunity to
do this study. We thank Dr Chuck Cannon,
Dr Ferry Slik and Dr Rhett Harrison for
their support and comments on our project.
We are deeply indebted to Dr Douglas
Schaefer for his lessons, continuous
encouragement and support during the
field work as well as analysis and
interpretation. We are grateful to Ms Qie
Lan for her advice, comments, critics and
wholehearted support that helped us to
complete this work.
LITERITURE CITED
Brown S., Lugo A.E., The storage and production of organic matter in tropical forests and their role in the global carbon cycle, Biotropica 14 (1982) 161–87. Chave et al. 2005 J. Chave, C. Andalo, S. Brown, M. Cairns, J. Chambers, D. Eamus, H. Fölster, F. Fromard, N. Higuchi and T. Kira, Tree allometry and improved estimation of carbon stocks and balance in tropical forests, Oecologia 145 (2005), pp. 87–99. Clark D.A., Brown S., Kicklighter D.W., Chambers J.Q., Thomlinson J.R., Ni J., Holland E.A., Net primary production in tropical forests: an evaluation and synthesis of existing field data, Ecol. Appl. 11 (2001) 371–384. Cox, P.M., Betts, R.A., Jones, C.D., Spall, S.A., Totterdell, I.J., 2000. Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model. Nature 408, 184–187.
Dixon R.K., Houghton R.A., Carbon pools and flux of global forest ecosystems, Science 263 (1994) 185–190. Fearnside, 1996 P. Fearnside, Amazonian deforestation and global warming: carbon
stocks in vegetation replacing Brazil's Amazon forest, Forest Ecology and Management 80 (1996), pp. 21–34. GCTE (1996) Effects of Global Change on
Soils: Implementation Plan. Activity 3.3, Report no. 12. GCTE Huet S., Forgeard F., Nys C., Above- and belowground distribution of dry matter and carbon biomass of Atlantic beech (Fagus
sylvatica L.) in a time sequence, Ann. For. Sci. 61 (2004) 683–694. Juan Carlos Loaiza Usugaa, Jorge Andrés Rodríguez Torob, Mailing Vanessa Ramírez Alzateb, Álvaro de Jesús Lema Tapiasc, Estimation of biomass and carbon stocks in plants, soil and forest floor in different tropical forests, Forest Ecology and Management 260 (2010) 1906-1913. Kanowski, J & Catterall P., 2010. Carbon stocks in above-ground biomass monoculture plantations, mixed species plantations and environmental restoration plantings in north-east Australia. Research Report 1442, 119-125. Kraenzel M., Castillo A., Moore T., Potvin C., Carbon storage of harvest-age teak (Tectona grandis) plantations, Panama, For. Ecol. Manage. 173 (2003) 213–225. Le Goff N., Granier A., Ottorini J., Peiffer
Soil Respiration Responses to Forest Density and Elevation Gradients in the Rainforests of Mengsong
M., Biomass increment and carbon balance of ash (Fraxinus excelsior) trees in an experimental stand in northeastern France, Ann. For. Sci. 61 (2004) 577– 588. Matamala, R. & Schlesinger, W., 2001. Effects of elevated atmospheric On root production and activity in an intact temperate forest ecosystem. Global Change Biology 6, 967-979. Phillipson, J. ,Putman,J. & Woodell R. J., 1975. Litter input, litter decomposition and the evolution of carbon dioxide in a beech woodland-wythman woods. Oecologia 20, 203-217. Prevost-Boure C. N., Soudania, K., Damesina, C., Lata J.C.& Dufresne E, 2009. Increase in aboveground fresh litter quantity over-stimulates soil respiration in a temperate deciduous forest. Applied of Soil Ecology 46, 26-34. Schulp et al. 2008 C. Schulp, G. Nabuurs,
P. Verburg and R. de Waal, Effect of tree species on carbon stocks in forest floor and mineral soil and implications for soil carbon inventories, Forest Ecology and Management 256 (2008), pp. 482–490. Sierra et al. 2007 C. Sierra, J. del Valle, S. Orrego, F. Moreno, M. Harmon, M. Zapata, G. Colorado, M. Herrera, W. Lara and D. Restrepo, Total carbon stocks in a tropical forest landscape of the Porce region, Colombia, Forest Ecology and Management 243 (2007), pp. 299–309. Witkamp,M. & Van der Drift, J.,1961. Breakdown of forest litter in relation to environmental factors. Institute for Biological Research 4, 295-311. Wu Z.M., Li Y.D., Zeng Q.B., Zhou G.Y., Chen B.F., Du Z.H., Lin M.X., Carbon pool of tropical mountain rain forests in Jianfengling and effect of clear-cutting on it, Chinese J. Appl. Ecol. 9 (1998) 341–344.
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Do Environmental Factors Influence the Density of Invasive Species?
Yayan Wahyu C Kusuma1, Luo Yahuang
2, Choe Kumchol
3
1Bogor Botanic Garden, Jl. Ir. H. Juanda No. 13, Bogor, West Java, Indonesia 2 Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China 3 Kunming Institute of Botany,
Abstract
China is especially vulnerable to the establishment of invasive species of foreign origin due to its increasing international trade that facilitate the weed dispersal. Rapid expansion of invasive plants in agricultural land and natural ecosystems is threatening biodiversity, productivity, and ecosystem health. The objective of this study is to determine which environmental factors influence the density of invasive plant species. Single factor ANOVA, and Linear Model Regression were employed to analyze the relationship between invasive and native plant density and environmental factors, as well as possible competition between invasive and native plants. We did this study in Bulong Nature Reserve, in the forest and stream area. The results show that canopy cover plays an important role in determining A.
adenophora density in two different habitat types. Competition among plants did not significantly affect the density of A. adenophora. However, other environmental factors such as precipitation and moisture might be important and should be considered in further research. Keywords: Ageratina adenopohora, canopy cover, forest edge, Mengsong, soil compaction
INTRODUCTION
CHINA CURRENTLY UNDERGOES A
rapid economic development and
increasing international trade, which may
lead to the spread of weeds and invasive
species. Such activities include the
construction of new roads and railways,
increased disturbance, nonecological
construction had increased (intentional)
species introduction (Liu et al.2003;
Lo´pez-Pujol et al. 2006). With a wide
range of habitats and environmental
conditions, China is especially vulnerable
to the establishment of invasive species of
foreign origin (Xie et al. 2000). Rapid
expansion of invasive plants in agricultural
land and natural ecosystems is threatening
biodiversity, productivity, and ecosystem
health.
In China, a total of 108 plant species
have been identified as alien weeds, of
which 15 are distributed throughout most
regions or the whole country (Qiang and
Cao 2000). One of the most notable
invasive plants is crofton weed (Ageratina
adenophora Spreng (King & Robinson), a
perennial herb native to Mexico, Central
Do Environmental factors Influence the Density of Invasive Species
America. It naturally spread into southern
Yunnan province of China from Myanmar
around the 1940s (Xie et al. 2001). An
extremely rapidly growing perennial shrub,
A. adenophora survives and proliferates
under harsh conditions. When it invades a
new habitat it can cause degeneration of
native plant communities in the new
habitat, changing it into an A. adenophora
mono-culture (Wang, 2005). Another
noxious weed is Ageratum conyzoides L.,
an invasive species that also originate from
South America. This harmful species not
only have bad impact in China but also in
Shivalik Hills, India. It has been reported
that A. conyzoides invasion had reduced
plant diversity significantly (Dogra et al.
2009). However, it still becomes a
question why those invasive species can
spread widely and invade many different
areas. With this research we aimed to
determine which environmental factors
influence the density of this highly
invasive plant species.
METHOD
This study was conducted in a stream and
forest area of Mengsong (21o 29’N, 100o
29’E: 1620 m asl.), which is located in
Bulong Nature Reserve, Yunnan Province,
China. Within the study area three
different habitats were chosen: (1) river
bank (high disturbance level), forest edge
(intermediate disturbance level) and forest
interior (low disturbance level). This river
bank was recently established as new
habitat due to the dam construction in the
downstream. Thus, it can also be called
human induced disturbances. Most of its
species consist of pioneer, grass and
invasive species. A line transect was
established for each disturbance level.
Transect in the river bank followed the
flow of the river. Transect in the forest
edge also followed the shape of the edge.
And transect in the forest was located 20
m from the forest edge transect. At each
transect, points were established in every
100 m distance. Thus, for each transect we
selected 34 points, 100 m from each other.
Plant surveys were carried out using point
centered quarter method.
Densities of the invasive alien plants
Ageratina adenophora Spreng (King &
Robinson) and Ageratum conyzoides L and
that of native plants and grasses were
measured at each sampling point using the
point centered quarter method. At each
point, four quadrants were specified using
a compass, and in each quadrant, the
distance from the mid-point to the nearest
individual of each plant category (native
plant, grasses and invasive plant) was
measured. At each point, environmental
variables (canopy cover, soil toughness,
and soil moisture) were also measured
with four replicates (Fig. 1). Each replicate
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located in each quadrant (there were 4
quadrants at each point).
Density was estimated using this
formula:
where, D = Density
A = specified area (i.e. 1 m2)
d = average distance the plant
from point center (m)
Fig. 1. Transect and plot layout for vegetation sampling.
Canopy cover was estimated using an
improvised aluminum can with 9 holes in
its bottom. The observer held the can
straight up and counted the number of
shaded holes as an estimate of the canopy
cover. Soil toughness was estimated using
a soil penetrometer. The one-kilogram
metal weight was dropped three times and
the depth of penetration was recorded,
which is inversely correlated with the soil
toughness.
Soil moisture was measured by
collecting a (approximately 20 g.) soil
sample from each point. Fresh and dry
weight of the soil sample was measured
using an electric balance. Water content
(soil moisture) was calculated using the
following formula: Water content = (Fresh
weight – Dry weight)/Fresh weight.
DATA ANALYSES
Single factor ANOVA was employed to
compare the density of plants (A.
adenophora, A. conyzoides, native plant,
and grasses) between habitats. The same
analysis was also applied for the
environmental factors. A quasi-Poisson
GLMs was used to detect the correlation
among variables due to non normal
distribution and overdispersion, especially
between plant densities and environmental
factors and between different plant
densities. Model selection was done in
Do Environmental factors Influence the Density of Invasive Species
backward selection using Akaike’s
Information Criterion (AIC). Started with
the most complex model and reduce the
most insignificant variable, and at last
compare the whole model based on AIC.
Then, Nonmetric Multi Dimensional
Scaling (NMDS) was also employed to
explore the dissimilarities among sites,
based on plant community composition
and environmental factors in order to
support and explain the GLMs model in
ordination.
All analyses were conducted in R
software version 2.12.0 (R Development
Core Team 2010).
RESULT
Densities of all plant types were
significantly different among habitats
except for A. conyzoides (Table 1). Native
plants had the highest density in all habitat
sites. Most of these native plants were
represented by pioneer species, such as
Sida sp, Polygonum spp, and other
creeping herbs. Both invasive plant
species had highest densities in the forest
edge, while A.conyzoides did especially
bad in the forested area.
Table 1. Comparison of mean density and standard error of all plants in each site.
Sites
A.
adenophora***
A.
conyzoides
Native
plant** Grasses**
Bank 0.34±0.09a 0.88±0.28ns 58.90±18.39b 2.86±0.47a
Edge 6.35±1.33b 2.50±1.26ns 12.18±2.73a 2.15±0.27a
Forest 0.40±0.24a 0.04±0.03ns 13.79±2.01a 0.67±0.12b
* p<0.05, ** p<0.01, ***p<0.001
The result of a quasi-Poisson GLMs
showed that environmental factors had
significant effect on the invasive plant
density. Density of A. adenophorum was
significantly affected by canopy cover and
interaction between canopy cover and soil
toughness (Table 2). Whilst, A. conyzoides
only significantly affected by soil
toughness (Table 3). Density correlation
among plants that correspond to
competition was not detected.
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Table 2. GLM with a quasi Poisson distribution of the effect of canopy cover, soil moisture, soil toughness, and interaction between them on Density of A. adenophorum.
GLM Model selection Predictor variable
t df P
intercept 1.771 101 0.07968
Can_cov (CC) 3.273 101 0.00147
So_moi (SM) 0.061 101 0.952
So_tou (ST) -0.750 101 0.4554
CC x SM -1.323 101 0.18889
SM x ST 0.330 101 0.7418
CC x ST -3.220 101 0.00173
SM x CC x ST 0.655 101 0.51416
Variables included in the final model are in bold. Significant P-values are in italic
Table 3. GLM with a quasi Poisson distribution of the effect of canopy cover, soil moisture, soil toughness, and interaction between them on Density of A. conyzoides.
GLM Model selection Source
t df P
intercept 2.419 101 0.0174
Can_cov (CC) -1.342 101 0.1826
So_moi (SM) -1.400 101 0.16478
So_tou (ST) -2.163 101 0.0329
CC x SM -1.273 101 0.2059
SM x ST 0.409 101 0.6835
CC x ST 1.013 101 0.3138
SM x CC x ST -0.523 101 0.602
Variables included in the final model are in bold. Significant P-values are in italic
For NMDS analysis forest data were
excluded due a lot of zero which caused by
inconsistent condition of the forest itself.
Most of the area inside the forest was
already converted into tea plantation with
varying environmental conditions. The
result showed that density of all plant
types were difference indicated by clearly
separated cluster for each plant type. Each
plant types also had different preference
on environmental factors. The density of A.
adenophora was influenced by canopy
cover and interaction between canopy
cover and soil toughness as suggested by
quasi Poisson GLMs. While, density of A.
conyzoides was only influenced by soil
toughness (Fig. 1). This was also in line
with the result of quasi poisson GLMs.
Do Environmental factors Influence the Density of Invasive Species
Fig. 1. NMDS of plant density and environmental factors in bank and edge
DISCUSSION
The study by Wang et al. (1994) suggested
that light stimulates germination of A.
adenophora seeds, thus it is highly
effective in invading heavily disturbed
areas such as river banks and forest edges.
However, Lu et al. (2006) found that in the
invaded regions A. adenophora seeds
preferred to germinate under relatively
cool conditions. Our study confirmed that
A. adenophora is most abundance in the
forest edge area, which is considerably
cooler and more shaded than in the river
bank (open) area. Nevertheless, once
established A. adenopohora will also grow
well in shaded areas (Sang et al. 2010).
This also confirms what Fang Hao et al
(2010) found, that A. adenophora is highly
adaptable to environmental extremes such
as (low) temperatures and drought.
Competition did not seem to be a
significant factor for the distribution of A.
adenophora. Hao (2010) and Yang (2008)
found that A. adenophora is allelopathic.
Its allochemicals can inhibit the growth
and development of the native plants. It
can thus effectively neutralize the
competition by other plant species.
However, the abundance and
distribution of invasive plant species such
as A. adenophora or A. conyzoides are not
only affected by light intensity, other
environmental factors such as precipitation
and moisture (Zhu et al. 2007, Sang, 2010)
may also play a role. Moreover, our result
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confirmed previous research that
environmental factors have influence on
the density of invasive plant which
improve their ability to spread and invade
many parts of the world. Nevertheless,
more precise measurement and more
environmental variable are needed in
future research to better explain which and
how environmental factor affect the
density and distribution of invasive plant.
ACKNOWLEDGEMENT
We are greatly indebted to Prof. Chen Jin
(Director of XTBG) for providing us the
great opportunity to attend the AFEC 2010
course. A big bunch of thanks to Prof.
Chuck, Prof. Ferry, Dr. Doug, also Lainie,
and Allen for giving us a lot of help and
suggestion during this project. We also
want to thankful to Dr. Rhett, Dr. Jacob,
and Professors in XTBG for all the
lectures. To all of AFEC 2010 students,
thanks so much for the joyful moment that
we shared during the course.
LITERATURE CITED
Dogra, K.S, R. K. Kohli, S. K. Sood, & P. K. Dobhal. 2009. Impact of Ageratum conyzoides L. on the diversity and composition of vegetation in the Shivalik hills of Himachal Pradesh (Northwestern Himalaya), India. International Journal of Biodiversity and Conservation Vol. 1(4) pp. 135-145
Fang Hao, W., L. Wan Xue, G. Jian Ying, Q. Sheng, L. Bao Ping, W. Jin Jun, Y. Guo Qing, N. Hong Bang, G. Fu Rong, H. Wen Kun, J. Zhi Lin, W. Wen Qi. (2010). Invasive mechanism and control strategy of Ageratina adenophora (Sprengel). Sci China Life Sci (53)11: 1291-1298.
Lo´pez-Pujol J, Zhang FM, Ge S (2006) Plant biodiversity inChina: richly varied, endangered, and in need of conservation. Biodivers Conserv 15:3983–4026
Lu P, Sang W, Ma K (2006) Effects of environmental factors on germination and emergence of Crofton weed (Eupatorium
adenophorum). Weed Sci 54:452–457
Qiang, S., X. Y Cao. 2000. Survey and analysis of exotic weeds in China. J Plant Resour Environ 9:34–38
Qing Yang, Q., F. Hao Wan, W Xue Liu, J Guo. 2008. Influence of two allelochemicals from Ageratina
adenophora Sprengel on ABA, IAA and ZR contents in roots of upland rice seedlings. Allelopathy journal 21 (2):253-262.
R Development Core Team (2010). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL http://www.R-project.org.
Ren, D. R. 2000. Atlas of China. China Cartographic Publishing House, Beijing
Sang, W., L. Zhu, J. C. Axmacher. 2010. Invasion pattern of Eupatorium
adenophorum Spreng in southern China. Biol Invasions (12).1721-1730
Wang HJ, He P, Ma JL (1994) An investigation and research report on the dissemination of Ageratina
adenophora on rangeland areas in Liangshan District of
Do Environmental factors Influence the Density of Invasive Species
Sichuan Province. Grassland China 1:62–64
Wang, J.J. 2005. Ageratina adenophora (Spreng.). In: Wan FH, Zheng XB, Guo JY (eds) Biology and management of invasive alien species in agriculture and forestry. Science Press, Beijing, pp 651–661
Xie, Y., Y.Z. Li, W. P. Gregg, D. M.
Li.2001. Invasive species in China - an overview. Biodivers Conser 10:1317–1341
Zhu, L., O. J. Sun, W. Sang, Z. Li, K. Ma. 2007. Predicting the spatial distribution of an invasive plant species (Eupatorium
adenophorum) in China. Landscape Ecol (22): 22=1143-1154
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The Distribution Patterns of Birds in Tropical Riparian Forest of Mengsong
Liu Xiaohu 1, Peabotuwage Indika umara 2, O InYong 3 1Kumming Institute of Zoology, Chinese Academy of Sciences, Kunming, China 2 The Open University of Srilanka 3 Central Forest Design and Technical Institute. DPR Korea Abstract
In this study we conducted a preliminary survey on birds in one primary and one secondary forest sites in Mengsong, Yunnan province, China. To test for the effect of distance from river on the bird abundance, point transects of 200 m were set up from the river to the forest. At each point, we also recorded the number of flowering and fruiting trees, basal area, and canopy cover as covariates. Results suggest that bird abundance decreased with increasing distance from river. Although limited by sample size, our study suggests that the forest riparian zone is of particular importance for bird conservation.
Keywords: Avian diversity, Frugivory, Hunting, Point count, Riparian habitat
INTRODUCTION
The study was conducted in the forest
area of Mengsong, Yunnan province
(From 6th December to 10th December).
The annual rainfall is 1600-1800 mm
and the annual temperature is 18-19°C
(Z.Wang & C.Chris, 1998). Natural
vegetation types are tropical evergreen
rain forest, Mountain rain forest and
secondary forest. In Mengsong, the
indigenous people living in close
vicinity of the forest are Hani people,
and most of them live from agricultural
activities. They are combing with the
Mengsong forest from many years ago
and it has a long history.
Tropical forest forms a main
resource for the conservation of
biodiversity. Especially, tropical
riparian areas are often important
habitats for birds, particularly in
semi-arid of seasonally dry
environments (Woinarski et al. 2000).
So far, many studies have usually
focused on large streams or rivers over
broad geographical scales, where
riparian zones are often associated with
The Distribution Patterns of Birds in Tropical Riparian Forest of Mengsong
distinctive vegetation (Lock& Naiman
1998,Woinarski et al.2000, Harvey et
al.2006). However, riparian zones
along small streams within a tropical
forest matrix may also be important
habitats for birds (Naiman et al.2005,
Ballinger & Lake 2006).
Through this research, we
compared and analyzed the diversity of
birds in riparian areas of primary forest
& secondary forest, Mensong in
Yunnan Province.
METHOD
STUDY AREA. –The study was
conducted in the tropical rain forest
area of Mengsong, Yunnan province
china, From 6th December to 10th
December 2010
(100°28’26.5”-100°28’38.1”E,
21°30’35.8”-21°30’59.7”N). This
mountain range is a part of the
Indo-Burma biodiversity hotspot and is
recognized as a high priority area for
biodiversity conservation.
Sampling plot was situated in the
primary and secondary forest in
Mengsong. (Fig. 1).
Fig. 1
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Fig. 2
BIRD SURVEY. –We set up four
point transects each within primary and
secondary forest. Each transect was
200 m long, approximately
perpendicular to the stream, consisting
of five points, 50 m apart (Fig. 2). At
each point, birds seen and heard within
25 m from the observers were recorded
for 10 min duration. Bird species and
number of individuals were recorded.
We also recorded all flowering and
fruiting trees with 25 m from each
point. Birds were surveyed every day
between 9 am and 12 am for five days.
All point transects were surveyed on
each day following a random order.
For each point, we also measured
distance from river, basal area, canopy
cover, elevation and Geographical
position.
Data analyzed using R software 2.6.0
(R Development core team 2005).
RESULT
We recorded nine bird genera in the
primary forest and 13 genera in the
secondary forest. There were 17
common bird species with more than
10 individuals recorded, including
mainly barbets (Megalima spp.) and
bubuls (Hypsipetes spp.).
We tested the effects of canopy
openness, basal area, distance from
fruiting and flowering trees, number of
fruiting and flowering trees on number
of bird species at survey points, but
found no significant patterns. The
distance from stream was the most
significant factor and bird abundance
decreased with increasing distance
from river (Fig. 3), and effect of the
The Distribution Patterns of Birds in Tropical Riparian Forest of Mengsong
distance is not affected by forest type.
The distance from the stream was also
correlated to the number of flowering
and fruiting trees.
Fig. 3
DISCUSSION
Riparian zones are frequently
characterized as ecologically
significant corridors that contribute to
the maintenance of high biodiversity in
landscapes (e.g., Gregory et al. 1991,
Naiman et al. 2005). Fruit and nectar
feeding birds are dominant species in
the study area in winter. We found that
fruiting and flowering trees were
distributed in higher abundance closer
to the riparian zone in Mengsong.
Resource availability is likely to be a
significant factor affecting the
diversity and abundance of birds in
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primary and secondary forest. Our
results suggest the importance of
riparian zone as important area for the
conservation of forest birds.
Local peoples in Mengsong still
hunt birds in this area and three species.
Great Barbet (Megalaima virens),
Blue-throated Barbet (Megalaima
asiatica ), and Black Bulbul
(Hypsipetes leucocephalus) and among
the most hunted species. Populations
of these species are believed to be
stable at present; however, their
numbers may decrease in the future.
This study was limited by time
and sample size. More extensive
studies should be conducted to
determine the value of other riparian
habitats for forest birds, in which the
effect of hunting should be taken into
consideration.
ACKNOWLEDGEMENT
We wish to thanks Prof: Chen Jin
(Director XTBG), Prof: Ferry Slik
(AFEC-X organizer), Prof. Chuck
Cannon, Prof. Rhet Harrison, Prof.
Douglas Schaefer and Dr Jacob
Wiekham for gave this opportunity.
We also thank to Dr Qie Lan, Mr. Liu
Yalou, Ms Vivian Fu, Ms Shi Lingling,
in AFEC-X organizing committee
2010. Finally, we thank Mr Ai Jiao for
his kind help (forest manager in
mongsong).
LITERITURE CITED
W.Zhijun and C. Carpenter.1999., Forest landscape and bird diversity in mountain region, Xishuangbanna, Yunnan, Chinese geographical science, Vol: 09, No: 02, pp 172-176.
E.K.W. Chan, Y.T. Yu, Y. Zhang and
D. Dudgeon, 2008., Distribution patterns of birds and insect prey in a tropical riparian forest., Boitropica., pp1-7.
D.M.S. Karunarathna, A.A.T. Amarasinghe, P.I.K. Peabotuwage and A.A.D.A.Udayakumara., 2007. A study of the non-captive Avifaunal diversity in the National Zoological Gardens, Dehiwala, Sri Lanka. Siyoth. Vol 2 2 pp25-29.
M.Pliosungnoen. 2007., Lantana fruit
removal by birds in Xishuangbanna Tropical Botanical Garden, China., CTFC . AA International Field Biology Course. XTBG.,
The Distribution Patterns of Birds in Tropical Riparian Forest of Mengsong
pp106-111. L. Boonsong and R.D. Phillip., A guide to the birds of Thailand.
J. Mackinnon & K. Phillipps., 2000.A field guide to the birds of China.
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Changes in Plant Community Trait Composition of Understory Trees:
Mengsong Seasonal Tropical Rainforests, Yunnan, China.
Beng Kingsly Chuo 1, Ryom Song Hwan 2, Wu Junjie3 , Amornrat Pitakpong4 1Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China 2Central Forest Design and Technical Institute. DPR Korea, 3Kumming Institute of Botany, Chinese Academy of Sciences, Kunming, China 4School of Biology, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand. Abstract Tropical forests serve as biodiversity storehouses, providers of ecosystem services and sequestration of carbon among other functions. To fully understand the roles played by plant communities in these forests, knowledge about plant traits at the species, individual, population and community levels is required. These traits have been proven to vary with changes in environmental conditions. Understanding how and why they vary is important because they represent the fundamental basis of species survival and reproduction. Changes in plant community trait composition remain an interesting research topic despite many years of intensive research. Although trait variation has been widely studied, with different researchers working at different scales and focusing on different components of variation in different environmental conditions, much still needs to be done on this field. To address this problem, we studied changes in average tree height, dbh, leaf length, width, thickness, fresh weight, petiole length, margin, tip and base across 20 plots in the east and west tropical rainforests of Mengsong, Yunnan, China. In each forest, we established 10 plots on both sides along a small forest trail (topographic gradient). Each plot had a 20m transect perpendicular to the trail (east forest) and parallel to the dam (west) in a 20X10m area (disturbance gradient/edge effect). 20 plants were sampled along (20m) and within 1m on both sides of the transect. Two leaves were collected from the 3rd node of 2 separate branches for each tree. We measured light intensity (canopy opening), soil litter thickness and elevation in the field. From our correlation results using SPSS 17.0, leaf length, fresh weight and basal area correlated negatively with light; leaf width, fresh weight and basal area had a positive correlation with length; while DBH and tree height were positively correlated. These findings suggest that plant communities reduce their leaf sizes at high light intensities and increase leaf sizes at low light intensities. Keywords: functional traits, leaf length, light, plant community, tropical forest,
Changes in Plant Community Trait Composition of Understory Trees: Mengsong Seasonal Tropical Rainforest, Yunnan, China
understory trees
INTRODUCTION
Leaves are above-ground plant organs
specialized for the process of
photosynthesis. As such, they are very
essential for plant growth,
development and survival in different
habitats. However, they occur in
various shapes and sizes. This wide
variety of morphological features
equally accounts for the world’s plant
diversity. Plant functional traits are
features that determine the adaptations
and survivor of plants in various
environments and to different
conditions. Leaf traits on the other
hand are characteristics that assist in
the proper functioning of leaves and
include; area, length, width, thickness,
fresh weight, dry weight, petiole length,
margin, base, tip, venation etc. Many
studies have proven that plants alter
their leaf shape and sizes as a result of
changes in their environmental
conditions (e.g. Deschamp & Cooke,
1985; Emery et al 1994). Meanwhile
Givnish (1987) reported variation in
leaf morphology with changing light
intensity between species; Winn &
Evans (1991) also proved that light
availability is an essential
environmental condition that varies
both within and between populations;
and Winn (1999) reported the ability of
individual plants to appropriately
modify their morphological traits
under different moisture conditions.
Understanding how and why
these traits vary across plant
communities is as important as their
role in plant productivity and ecology.
Therefore, we must link the different
components of trait variation with
variation across communities so as to
bridge the gap between other aspects
of trait variation and changes in plant
community variation. This will give us
a common and wider scope of
knowledge on this subject. As a step
towards addressing this issue, we
studied changes in plant community
trait composition for some selected
traits across 20 plots in the east and
west tropical rainforests of Mengsong,
Xishuangbanna, Yunnan, Southwest
China.
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QUESTIONS. –How do light intensity,
topography, elevation and litter
thickness affect leaf functional traits of
understory plant communities? Does
low light intensity account for
decreased leaf thickness in understory
trees? What relationship exists
between leaf dimensions and light
intensity in understory plants?
OBJECTIVES . –To investigate the
effect of light intensity, topography,
elevation and litter thickness on
understory community leaf trait
variability.
HYPOTHESIS . –Variation in canopy
cover and subtle changes in light
availability in the forest understory
affect leaf traits and we hypothesize
that smaller-leaved species turn to
occur in higher-light environments.
EXPERIMENTAL DESIGN
STUDY SITES . –Mengsong is located
in Menghai county, Xishuanbanna,
Yunnan province, Southwest China.
This area borders Myanmar, Laos and
Vietnam with a subtropical climate
influenced by the Indian monsoon. The
annual mean temperature is about
18°C while the annual mean rainfall is
between 1600–1800 mm, 80% of
which occurs between May–October
(Xu et al 2009). The three main forest
types in this area include; (1)
South-subtropical evergreen broadleaf
forest, (2) Tropical-montane rainforest
and (3) Tropical-seasonal rainforest
(Zhang and Cao 1995). The Mengsong
forest area lies at elevations between
approximately 1500 and 1800m with
an undulating topography. Several tea
plantation patches occur around and
within the forest stands while a large
dam is situated near the west forest.
This dam is normally full of water
(almost same level as the forest flow)
flowing from the Mekong river but
was opened last year to release the
water for reconstruction. This has
created a huge edge effect at the forest
edge. However, a small quantity of the
water was retained in the dam during
the reconstruction period. This created
a disturbance gradient along the forest
and a kind of new habitat for plant
species now growing in and around the
Changes in Plant Community Trait Composition of Understory Trees: Mengsong Seasonal Tropical Rainforest, Yunnan, China
dam.
PLOT SAMPLING . –We selected two
forest stands in the Mengsong seasonal
rainforest, one in the east and another
in the west (near the dam) to determine
the influence of disturbance gradient
on leaf traits. In each forest, we
established 10 plots on both sides
(left=top and right=valley/ridge) of a
small forest trail to investigate the
effects of topography on leaf traits.
Each plot had a 20m transect
perpendicular to the trail (in the east
forest) and parallel to the dam (in the
west forest) and a 20X10m area. For
each transect, we sampled the first 20
understory trees within 1m on either
sides from the transect line and with
dhb 5cm and height 5m. In each
20X10m area, we measured the
diameter of all trees with dbh 10cm to
estimate the basal area for that plot.
The distance between the plots and the
trail was at least 5m while the distance
between 2 plots was at least 100m.
Provincial capital
Mengsong, Xishuangbanna
Provincial and International boundaries
Mekong River
Dam
Tropical forest
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TRAIL
dbh 10cm tree
understory tree
transect
Dam
Island (area of land surrounded by water.
Small plants (grasses, herbs, shrubs)
Small stream/ water flow
SAMPLE COLLECTION . –We
collected 2 leaves (photosynthetic units)
each from the 3rd node of 2 separate
branches on the same tree and measured
their length, width, fresh weight, thickness,
petiole, etc immediately after field
collection.
20m 20m
10m
2m
100m T
RA
IL
LEFT
TOP
RIGHT
VALLEY/RIDGE
• Water
Island
FOREST
EDGE
N
Changes in Plant Community Trait Composition of Understory Trees: Mengsong Seasonal Tropical Rainforest, Yunnan, China
MEASUREMENTS AND
EQUIPMENT . –Tape/ruler: leaf
length, width, petiole length, tree
height, litter thickness and GBH
1. Digital caliper: DBH, leaf
thickness
2. Precision scale: fresh weight
3. GPS: elevation (single)
4. Beer can: We completely cut out
one end of the can and used a nail
to bore 10 small holes on the other
end. Each small hole therefore
represented 10%. During
observation, we used transparent
tissue paper to cover the open end,
then look directly into the canopy
using a single eye repeatedly at
different points along the transect.
We counted the number of holes
open (not blocked by the canopy)
for each point and calculated the
average per plot.
DATA ANALYSIS
For each leaf trait, an arithmetic
average was calculated per tree from
Alternate Compound Opposite Whorled
Tape/ruler
DBH Beer can
Digital
caliper
Precision
scale
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two sampled leaves and then the final
arithmetic average was computed per
plot. A correlation analysis was
performed between the leaf traits and
environmental variables based on
overall plant community changes,
disturbance and topographic gradients
using the SPSS 17.0 statistical
software. We used a dendrogram
according to Minitab 16.0 statistical
software to visually represent our
correlation data. The individual plots
and variables are arranged along the
bottom of the dendrogram according to
their level of correlation. Highly
correlated variable clusters had a
correlation value close to 1 and thus
D=1-C was close to zero
(D=correlation distance and
C=correlation coefficient/value). As
such, highly correlated clusters are
nearer the bottom of the dendrogram.
Variable clusters that are not correlated
had a correlation value close to zero
and a corresponding distance value
close to 1. We did Principal
Component Analysis tests for all the
leaf traits, all the environmental
variables and for both traits and
environmental factors combined.
RESULTS
Variations in leaf length were
correlated with light, basal area, leaf
width and fresh weight (Pearson
correlation, p 0.005) when overall
plant community changes were
considered. Fresh weight equally
correlated with light and the relative
distance between the plants along the 20m
transect (Table 1).
Though light intensity is
significantly negatively correlated with
leaf length and fresh weight, it might
not be the only factor affecting these
traits. It was therefore necessary to
further investigate the level of
disturbance (disturbance gradient) and
the type of habitat (topographic
gradient) occupied by these plant
communities. According to our results
and with respect to the history of
disturbance in the east and west forests,
neither leaf length nor fresh weight
correlated with light intensity in the
east forest plant communities.
However, in the west forest, leaf length
correlated with light and basal area,
fresh weight and leaf width correlated
Changes in Plant Community Trait Composition of Understory Trees: Mengsong Seasonal Tropical Rainforest, Yunnan, China
with soil litter thickness while
elevation correlated with DBH (Table
2).
With respect to their habitats,
plant communities did not show any
significant changes in traits with light
intensity or basal area in the top
topography but elevation was rather
correlated with leaf length, tree height
and light intensity. Meanwhile a more
usual pattern was observed in the
ridge/valley plant communities where
leaf length correlated with light and
basal area, and petiole length
correlated with soil litter thickness and
leaf width (Table 3).
Table 1 Combined east and west forests plant community changes
Variables Pearson correlation Sig. (2-tailed) Width .675** .001 Fresh weight .711** .000 Light -.605** .005
Length
Basal area .689** .001 Width .791** .000 Light -.460* .041
Fresh weight
Trans-X .533* .015
Height DBH .812** .000
Basal area Light -.636** .003 **Correlation is significant at the 0.01 level (2-tailed)
*Correlation is significant at the 0.05 level (2-tailed)
Trans-X is the relative distance between the plants along the 20m transect (X-axis)
Table 2 East forest plant community variations
Variables Pearson correlation Sig. (2-tailed) Width .947** .000 Length
Fresh weight .732** .016 Width .860** .001
Petiole length -.683* .029
Fresh weight
Trans-X .660* .038 Height DBH .770** .009
West forest plant community variations
Light -.650* .042 Length Basal area .724* .018
Width .703* .023 Fresh weight
Litter thickness -.797** .006
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Trans-Y .702* .024 Width Litter thickness -.647* .043
Height .882** .001
-.707* .022
DBH
Elevation
Trans-Y is the relative distance between the plants within 1m on both sides of the 20m transect.
Table 3 Top topography plant community trait variation
Variables Pearson correlation Sig. (2-tailed) Width .958** .000 Fresh weight .755* .019 Height .672* .048
Length
Elevation .721* .029 Width .784* .012 DBH .833** .005
Height
Elevation .690* .040 Fresh weight .676* .045 Trans-X
Petiole length -.718* .030
Light -.756* .018 Elevation
Trans-Y -.825** .006 Trans-Y Fresh weight -783* .013
Ridge/valley plant community trait variation
Fresh weight .615* .044
Light -.786** .004
Length
Basal area .748** .008 Fresh weight .837** .001 Width
Petiole length .683* .021
Petiole length Litter thickness -.709* .015
Height DBH .918** .000
Basal area Light -.667* .025
PLANT COMMUNTY TRAITS AND
LIGHT INTENSITY . –Plant
community traits and light
environment had a large effect on leaf
morphology. All leaf traits differed
strongly among communities (P <
0.001), and light had a significant
effect on 2 of 5 leaf traits. It appears
there was a significant basal area and
light as well as fresh weight and light
interactive effects for 3 of 5 leaf traits.
Light did not have a significant direct
Changes in Plant Community Trait Composition of Understory Trees: Mengsong Seasonal Tropical Rainforest, Yunnan, China
or interactive effect on leaf thickness
and petiole length; tree height and
DBH. This indicates that these traits
had similar responses to light in the
different plant communities (Fig. 1).
Fig. 1: Cluster diagram showing the correlation patterns between plant traits and
environmental factors.
Apart from the correlations obtained between plant traits and environmental factors, there were also significant
correlations among the traits (Fig. 2) and among the environmental factors (Fig. 3).
Variables
Deg
ree
of
corr
ela
tio
n
Complete Linkage, Absolute Correlation Coefficient Distance
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Fig. 2: Cluster diagram showing correlations among plant traits
Fig. 3: Cluster diagram showing the correlation pattern among environmental conditions.
Plant traits
Deg
ree
of
corr
ela
tio
n
Complete Linkage, Absolute Correlation Coefficient Distance
Environmental factors
Deg
ree
of
corr
ela
tio
n
Complete Linkage, Absolute Correlation Coefficient Distance
Changes in Plant Community Trait Composition of Understory Trees: Mengsong Seasonal Tropical Rainforest, Yunnan, China
It was equally important to know how
these plant communities vary or have
similar/common patterns across all the
plots despite their disturbance history
and habitat differences (Fig. 4).
Fig. 4: Cluster diagram show the degree of similarity among the 20 plots studied.
DISCUSSION
Leaf trait variation was mainly related
to differences in light availability.
According to Whitmore (1996), light is
considered to be the most limiting
resource for tree growth and survival
in tropical wet forests and a major axis
of differentiation for tropical tree
species (Lars Markesteijn et al 2007).
Our results showed a clear pattern of
decreasing leaf length with increasing
light intensity. Since light is a limiting
factor for growth in shaded understory
plant communities, trees growing in
these shaded areas enhance their light
interception by producing relatively
large leaves (Evans & Poorter, 2001).
Plant communities studied equally
demonstrated increasing fresh weight
Plots
Deg
ree
of
sim
ila
rity
Complete Linkage, Pearson Distance
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and basal area values with decreasing
light intensity. Chazdon and Kaufmann
(1993) reported that light acclimation
may be mediated by distinct processes
that involve structural, physiological
and biochemical changes.Though plant
communities may show variation in
leaf traits, these changes may be
important ecological adaptations
relative to environmental conditions
(Andrea et al 2000).
All the leaf traits examined did not
significantly vary with elevation but
when we used a classification matrix
based on variables, top and
ridge/valley communities, leaf length,
tree height and light correlated
positively with elevation. This might
be partly due to the fact that the
elevational gradients (1500-1800m)
were not high enough to influence
these traits. Velázquez-Rosas et al
(2002) analyzed the variation in leaf traits
of dominant tree species in six montane
rain forest communities along an
elevational gradient ranging from 1220 to
2560 m within a single basin at La
Chinantla, Oaxaca, México and found that
leaf area was the only variable that
significantly decreased with elevation.
CONCLUSIONS
Leaf trait variations in plant
communities of seasonal tropical
forests reveal important information
about the complex interactions
between abiotic factors and survival
mechanisms of trees in response to
mechanical stress and increased
resource acquisition. Changes in plant
community traits may not necessarily
be an advantage or a setback. These
might be structurally, biologically or
chemically initiated by the plants to
stabilize their ecosystem and maximize
the resources available.
Changes in Plant Community Trait Composition of Understory Trees: Mengsong Seasonal Tropical Rainforest, Yunnan, China
LITERITURE CITED
C. Li, X. Zhang, X. Liu, O. Luukkanen and F. Berninger, Leaf morphological and physiological responses of Quercus aquifolioides along an altitudinal gradient, Silva
Fenn 40 (2006), pp. 5–13.
Chazdon R. L. Fetcher N.. 1984. Light environments of tropical forests. In E. Medina, H. A. Mooney, C. Vasquez-Yanes, [eds.], Physiological ecology
of plants in the wet tropics, 27-36. W. Junk, The Hague, Netherlands.
Chazdon R. L. Kaufmann S.. 1993.
Plasticity in leaf anatomy of two rainforest scrubs in relation to photosynthetic light acclimation. Functional
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Deschamp, P.A., and Cooke, T.J.
(1985). Leaf dimorphism in the aquatic angiosperm Callitriche heterophylla. Am. J. Bot. 72, 1377-1387.
Emery RJN, Chinnappa CC,
Chmielewski JG (1994) Specialization, plant strategies, and phenotypic plasticity in populations of Stellaria
longipes along an elevation gradient.
Evans J. R. Poorter H.. 2001.
Photosynthetic acclimation of
plants to growth irradiance: the relative importance of specific leaf area and nitrogen partitioning in maximizing carbon gain. Plant, Cell and
Environment 24: 755-767..[CrossRef]
Fonseca CR, Overton JC, Collins B,
Westoby M (2000) Shifts in trait-combinations along rainfall and phosphorus gradients. J Ecol 88:964-977. dio:10.1046/j
Givnish, T.J. (1979) On the adaptive
significance of leaf form. Topics in Plant Population Biology (eds O.T. Solbrig, S. Jain, G.B. Johnson & P.H. Raven), pp. 375¨C407. Columbia University Press, NewYork.
Knight CA, Ackerly DD (2003)
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Patticipants
Participants
Miss Amornrat Pitakpong Thailand
Suranaree University of Technology 829 Dech-udom Road, Naimuang, Muang, Nakhon Ratchasima, Thailand. 30000 Email: [email protected] [email protected]
OROU MATILO TIMOTHEE BIO Augustin Benin
Hokkaido University 001-0020, Kitaku-Kita 20, Nishi7-101, Sapporo, Japan. Email: [email protected]
Chemboli Sreenivasan Dhanya India
M S Swaminathan Research Foundation, Community Agrobiodiversity Centre, Puthoorvayal Post office, Kalpetta, Wayanad District, 673121, Kerala, India Email: [email protected]
Eka Aditya Putri Iskandar Indonesia
Indonesian Institute of Sciences, Cibodas Botanic Garden Jl. Kebun Raya Cibodas, Cipanas, Cianjur 43253, Indonesia Email: [email protected]
Participants
51
Peabotuwage Indika Kumara Sri Lanka
The Open University of Sri Lanka NO 143, Hettipola RD, Piduma, Pansal Watta, Kuliyapitiya, Sri Lanka Email: [email protected] / [email protected]
Ryom SongHwan Democratic People's Republic of Korea
Central Forest Design and Technical Institute, Pyongyang, DPRK Email: [email protected]
O InYong Democratic People's Republic of Korea
Central Forest Design and Technical Institute, Pyongyang, DPRK Email: [email protected]
Ri KumRan Democratic People's Republic of Korea
Environment and Development Center, Pyongyang, DPRK Email:[email protected]
Participants
Jo WonJu Democratic People's Republic of Korea
Land Use Planning Institute, Pyongyang, DPRK Email: [email protected]
Choe KumChol Democratic People's Republic of Korea
Land Use Planning Institute, Pyongyang, DPRK Email: [email protected]
Sophany Phauk Cambodia
Royal University of Phnom Penh 63EoD Street 118, Sangkat Tuk Laak I, Khan Toul Kok, Phnom Penh, 12000, Cambodia Email: [email protected]
Luo Yahuang China
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences , Menglun, Mengla, Yunnan, 666303,China Email: [email protected]
Participants
53
Liu Xiamo China
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences , Menglun, Mengla, Yunnan, 666303,China Email:[email protected]
Wu Junjie China Kunming Institute of
Botany, Chinese Academy of Sciences 132# Lanhei Road, Heilongtan, Kunming 650204, Yunnan, China Email: [email protected]
Kingsly Chuo Beng Cameroon
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences , Menglun, Mengla, Yunnan, 666303,China Email: [email protected]
Duan Qiong China
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences , Menglun, Mengla, Yunnan, 666303,China Email:[email protected]
Participants
Iogna Patricia Araceli Argentina U.N.P.S.J.B. –
CONICET Gral Roca 3094/B - B° San Martin Eete KM3 - CP 9005 - Comodoro Rivadavia - Chubut – Argentina Email: [email protected]
Liu Yanjie China
Graduate University of Chinese Academy of Sciences, No.19(A), Yuquan Road, Shijingshan District, Beijing100049 Email:[email protected]
Liu Xiaohu China
Kunming Institute of Zoology, Chinese Aademy of Sciences, NO.32, Jiao Chang east road, Wu Hua district, Kunming, Yunnan province, China Email:[email protected]
Yayan Wahyu Candra Kusuma Indonesia
Bogor Botanic Garden, Indonesian Institute of Sciences (LIPI) Jl. Ir. H. Juanda No. 13 PO BOX 309 Bogor 16003, Indonesia Email: [email protected]
People
55
People
Resource Staff
Rhett D HARRISON (PhD)
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences , Menglun, Mengla, Yunnan, 666303,China Email: [email protected]
Lan QIE a.k.a. Lainie (PhD)
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences , Menglun, Mengla, Yunnan, 666303,China Email: [email protected]
Liu Yalou (MSc) Xishuangbanna
Tropical Botanical Garden, Chinese Academy of Sciences , Menglun, Mengla, Yunnan, 666303,China Email: [email protected]
Chuck CANNON (PhD)
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences , Menglun, Mengla, Yunnan, 666303,China Email: [email protected]
Resource Staff
Kunfang CAO (PhD)
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences , Menglun, Mengla, Yunnan, 666303,China Email: [email protected]
Jin CHEN (PhD)
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences , Menglun, Mengla, Yunnan, 666303,China Email: [email protected]
Ze-Xin FAN (PhD)
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences , Menglun, Mengla, Yunnan, 666303,China Email: [email protected]
Yulong FENG (PhD)
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences , Menglun, Mengla, Yunnan, 666303,China Email: [email protected]
People
57
Douglas SCHAEFER (PhD)
Associate Professor of Soil Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan, 666303, China Email: [email protected]
Ferry SLIK (PhD)
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences , Menglun, Mengla, Yunnan, 666303,China Email: [email protected]
Jacob D. WICKHAM (PhD)
NSF International Research Fellow (USA), Institute of Chemistry, Chinese Academy of Sciences, Beijing, China Email: [email protected]
Douglas YU (PhD)
Researcher, Principal Investigator of Ecology, Conservation, & Environment Center (ECEC), Kunming Institute of Zoology, Chinese Academy of Sciences Email: [email protected]
Resource Staff
TANG Yong (PhD)
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences , Menglun, Mengla, Yunnan, 666303,China Email: [email protected]
Teaching Assistants
FU Wing Kan, Vivian (MPhil)
China Programme Officer, The Hong Kong Bird Watching Society/BirdLife International Email: [email protected]
SHI Lingling (PhD candidate)
Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences , Menglun, Mengla, Yunnan, 666303,China Email: [email protected]