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Vegetation monitoring of the Vegetation monitoring of the wetland reconstruction area in wetland reconstruction area in
Hanság (Hungary)Hanság (Hungary)
Katalin Katalin MargócziMargóczi ((University of Szeged, Department of EcologyUniversity of Szeged, Department of Ecology))
Gábor Gábor TakácsTakács ((Fertő-Hanság National Park DirectoratFertő-Hanság National Park Directorate)e)
László László KörmöcziKörmöczi ((University of Szeged, Department of EcologyUniversity of Szeged, Department of Ecology))
The hiStory of Hanság
Till the 19th century Hanság was a 50 000 ha large wetland, connected
with the Lake Fertő.
Lake Fertő
(Neusiedler see)
Wien Bratislava
HanságHanság
Today only the Fertő is indicated as wetland on the map.
There are tree plantations, meadows, ploughlands on the former fen area (outlined by red line)
The blue line shows the outline of wetland reconstruction.
The area of wetland reconstruction (red line) on the military map from
1783-84.
The ancient Hanság was a large, mostly floating fen, with small lakes, sedges, reeds and some alder forest patches.
In 1883-1884 the main drainage channels can be seen on the map, and mainly wet meadows instead of floating fen
The drastic drying-out of the fen was „successful” only in the early 20th century, using machines to dig channels. Secondary meadows formed in the place of the fen, and most of the lakes disappeared. A large part of the area was ploughed, afforested, and peat mines were opened.
Nature protectionNature protection
In spite of drainage and a lot of human disturbance, the Hanság could save a relatively large part of its natural values. Patches of natural vegetation survived in the wet meadows and forests, and the aquatic communities partly survived in drainage channels.
Hanság became a protected natural area in 1976, and since 1994 it has been a part of the Fertő-Hanság National Park.
Hottonia palustris in a channel
The most serious deficiency of the protected area is the very few remaining wetland, so the National Park Directorate decided to
restore wetland areas.
Restoration of a larger area of the former fen by closing the channels would be nice, but present human activities, demands and the changes of hydrology make it impossible.
Technical possibilities, safety, ownership and economical criteria were considered in priority when choosing the 400 ha area to be flooded.
The restoration was supported by Hungarian and Dutch Governments
The main goals of restoration:
• To create wetland with open water, suitable habitat for water-birds and fen-plants.
• To have a model area, and to get experiencies of rewetting.
• To decrease invasive plant species (Solidago gigantea).
A habitat map were made before flooding.
Large sedges (57%) (Carex riparia, C. acutiformis), and wet meadows (28%) (Alopecurus pratensis, Festuca arundinacea) were the dominant vegetation types and some reeds (5%) (Phragmites australis, Glyceria maxima) also occured.
Technical aspects of reconstruction
Dikes were built around the planned wetland pools, and water was transported by gravitation through sluices from the river Rábca and the channel Kismetszés. The 1st and 2nd unit was flooded in spring 2001, and the 3rd unit in autumn.
tszf 112_6m-es vízállásnálElevation Range
SzárazulatSzárazulatSzárazulatSzárazulatSzárazulatSzárazulatSzárazulatIdõszakos vízborítás (0-0,4m)Sekély víz(>0,4m)
Rekonstrukció határa
The water-level is intended to keep constant. The water depth is between 0-100 cm.
tszf 113m-es vízállásnálElevation Range
SzárazulatSzárazulatSzárazulatSzárazulatSzárazulatSzárazulatIdõszakos vízborítás (0-0,4m)Sekély víz (0,4-1,8m)Mélyvíz (>0,8m)
Rekonstrukció határa
The year 2001 and 2003 was very dry, so the water level was about 20 cm lower.
tszf 113.4m-es vízállásnál Elevation Range
SzárazulatSzárazulatSzárazulatSzárazulatSzárazulatIdõszakos vízborítás (0-0,4m)Sekély víz (0,4-0,8m)Sekély víz (0,8-1,2m)Mélyvíz (>1,2m)
Rekonstrukció határatszf 113m-es vízállásnálElevation Range
SzárazulatSzárazulatSzárazulatSzárazulatSzárazulatSzárazulatIdõszakos vízborítás (0-0,4m)Sekély víz (0,4-1,8m)Mélyvíz (>0,8m)
Rekonstrukció határa
Aerial photos from the first year of flooding.
2001.04.27. 2001.06.15.
2001.09.19.
The landscape of the reconstructed area is really beautiful, it is one of the main „attractions” of the National Park.
Autumn wiev of sedges Open water area
Tussoks of sedges Persicaria amphibia field
Monitoring methods
• Small scale monitoring: 5x5 m phytosociological relevés along 21+4 permanent transects every year.
• Large scale monitoring: vegetation mapping using aerial ortophotos in every 3rd year, and developing GIS database.
Location of permanent transectsLocation of permanent transects
Small scale monitoring method: Small scale monitoring method: permanent transectspermanent transects
The end of the transects were marked by wooden sticks, and positioned using GPS.
The percent cover of plant species were recorded in 20 pieces of 5x5 m quadrates along each transect.
100 m
5 m
Results of small scale monitoring
Transects (2003)
0%
20%
40%
60%
80%
100%
1st unit 2nd unit 3rd unit
Open water
Water-plants
Sedges
Typha
Phragmites
Glyceria
Other
Each of the 420 relevés were categorized into vegetation types, named according to the dominant species. The vegetation is slightly different in the three units of restoration area.
The main vegetation categories
Water-plants Glyceria (maxima) Phragmites (australis)
Typha (latifolia, angustifolia) Sedges (Carex acutiformis, C. riparia)
The depth of the water is one of the main environmental factor affecting vegetation development
Occuring vegetation types at different water depths
0
10
20
30
40
50
60
70
TlPh
CrCa Tl Tl
TlTa Cr Cr Ca
TlTa
TlCr Cr Cr
SaBa Cr
UvC
d Ph Pa Ca
MsN
m Ph
Ta(U
) Ph Pa Gm Ba Gm
Gm
Gm Pa Pa Pa Pa
Wat
er d
epth
(cm
)
Glyceria
Phragmites (?)
Sedges
Typha
Water-plants
Finer categories, differentiated by cluster analysis
Changes of vegetation in the first 3 years after flooding
First unit
0%10%20%30%40%50%60%70%80%90%
100%
2001 2002 2003
Open water
Water-plants
Sedges
Typha
Phragmites
Glyceria
Other
Second unit
0%
20%
40%
60%
80%
100%
2001 2002 2003
Open water
Water-plants
Sedges
Typha
Phragmites
Glyceria
Other
Third unit
0%
20%
40%
60%
80%
100%
2001 2002 2003
Open water
Water-plants
Sedges
Typha
Phragmites
Glyceria
Other
• Dryland vegetation disappears (2nd year)
•Typha increases
•Open water and water-plants increase
•Sedges decrease (3rd year)
The permanent transect method is suitable for fine detection of local vegetation changes
0
10
20
30
40
50
60
70
80
90
100
1 3 5 7 9 11 13 15 17 19
Persicaria amphibia
Iris pseudochorus
Phalaroides arundinacea
Glyceria maxima
Carex gracilis (0,5cm)
Carex ac+rip
Egyéb
Sequence of individual relevés
SpeciesPercent cover of species
Sample
Transect 1.2 Glyceria overgrows in the deep water, Carex survives at 50 cm water
depth.
0
10
20
30
40
50
60
70
80
90
100
1 3 5 7 9 11 13 15 17 19
Persicaria amphibia
Iris pseudochorus
Phalaroides arundinacea
Glyceria maxima
Carex gracilis (0,5cm)
Carex ac+rip
Egyéb
0
20
40
60
80
100
120
1 3 5 7 9 11 13 15 17 19
Persicaria amphibia
Iris pseudochorus
Phalaroides arundinacea
Glyceria maxima
Carex gracilis (0,5cm)
Carex ac+rip
Egyéb
0
10
20
30
40
50
60
70
80
90
100
1 3 5 7 9 11 13 15 17 19
Persicaria amphibia
Iris pseudochorus
Phalaroides arundinacea
Glyceria maxima
Carex gracilis (0,5cm)
Carex riparia
Egyéb
Vízmélység
0
20
40
60
80
100
1 3 5 7 9 11 13 15 17 19
2001 2002
2003 Water depth (cm)
Transect 1.5Glyceria overgrows Phalaroides, but disappears in the 3rd year in 80
cm deep water
0
20
40
60
80
100
120
1 3 5 7 9 11 13 15 17 19
Typha angustifolia
Phragmites australis
Carex ac+rip
Persicaria amphibia
Phalaroides arundinacea
Glyceria maxima
Egyéb
0
10
20
30
40
50
60
70
80
90
100
1 3 5 7 9 11 13 15 17 19
Typha angustifolia
Phragmites australis
Carex riparia
Persicaria amphibia
Phalaroides arundinacea
Glyceria maxima
Egyéb
0
5
10
15
20
25
1 3 5 7 9 11 13 15 17 19
Typha angustifolia
Phragmites australis
Carex riparia
Persicaria amphibia
Phalaroides arundinacea
Glyceria maxima
Egyéb
0102030405060708090
100
1 3 5 7 9 11 13 15 17 19
2003 Water depth (cm)
2001 2002
Transect 2.4 Carex disapperars in the 3rd year from 80 cm deep water, Persicaria
grow up in the open place.
0
20
40
60
80
100
120
1 3 5 7 9 11 13 15 17 19
Ceratophyllum demersum
Glyceria f luitans
Phalaris arundinacea
Persicaria amphibia
Carex riparia
Egyéb
0
20
40
60
80
100
120
1 3 5 7 9 11 13 15 17 19
Ceratophyllum demersum
Glyceria maxima
Phalaris arundinacea
Persicaria amphibia
Carex riparia
Egyéb
0
20
40
60
80
100
120
140
1 3 5 7 9 11 13 15 17 19
Ceratophyllum demersum
Glyceria maxima
Phalaris arundinacea
Persicaria amphibia
Carex riparia
Egyéb
0
20
40
60
80
100
120
140
1 3 5 7 9 11 13 15 17 19
2001 2002
2003 Water depth (cm)
Transect 2.3 Typha latifolia outcompetes Carex riparia in the 3rd year at 40-50 cm
water depth.
0
20
40
60
80
100
120
1 3 5 7 9 11 13 15 17 19
Phalaris arundinacea
Typha angustifolia
Typha latifolia
Ceratophyllum demersum
Phragmites australis
Carex ac+rip
Egyéb
0
10
20
30
40
50
60
70
80
90
100
1 3 5 7 9 11 13 15 17 19
Phalaris arundinacea
Typha angustifolia
Typha latifolia
Ceratophyllum demersum
Phragmites australis
Carex riparia
Egyéb
0
10
20
30
40
50
60
70
80
90
1 3 5 7 9 11 13 15 17 19
Phalaris arundinacea
Typha angustifolia
Typha latifolia
Ceratophyllum demersum
Phragmites australis
Carex ac+rip
Egyéb
0
10
20
30
40
50
60
70
1 3 5 7 9 11 13 15 17 19
2001 2002
2003 Water depth (cm)
Large scale monitoring
Parameters of the aerial photograph:
• Service: Telecopter Kft.• Date of flight: 2003.07.15.
(12:00 – 12:15)• Film material: K color III
2444• Flying height: 1200m• Camera: Wild RC-10
(f=153,1mm)• Overlap: 60%• Resolution: 1 m
Processing of the aerial photoghraph
• Scanning with 18μm resolution and 16 bit color depth. Ortorectification with field reference points by ERMAPPER 6.1 and DIGITERRA (Hungary) softwares.
• Outline the possible patch contours in the computer.
Developing GIS data base (ESRI ArcView 3.2)
• Identification and correction in the field. (vegetation category, main species and their cover, total vegetation cover)
• Data processing by raster analysis (One pixel is 1x1 m)
• GRID statistics
Results of large scale monitoring
• Detailed description of vegetation categories.
• Thematic maps about the restored area.
• Statistics.
Detailed description of vegetation categories
Code: CaCr
National habitat category:
B5
Association: Caricetum acutiformis és Caricetum ripariae
Alliance: Magnocaricion
Short decription: Sűrű, általában erősen zárt magassásos (60-100%). A Carex riparia és a Carex acutiformis változó arányban fordul elő. Mellette a gyékények és egyéb fajok csak max. 1-5%-ban fordulnak elő. A sások helyenként zsombékolnak.
Species:
Dominant: Carex riparia, Carex acutiformis
Subdominant: Typha angustifolia, Typha latifolia
Abundant: Lythrum salicaria, Phalaroides arundinacea, Typha angustifolia, Typha latifolia, Phragmites australis
Sample
62 vegetation types were distinguished and described
Thematic maps about the restored area.
Total plant cover above the water level
Total plant cover under the water level
Glyceria maxima
Phragmites australis
Carex riparia
Typha latifolia
Raster statistics
109.21
104.04968.46
57.621
16.27
15.98412.047 11.67
Open water
Aquatic plants
Sedges
Typha
Phragmites
Glyceria
Islands
Other
Area (in ha) of vegetation categories in the whole restored area in 2003.
Vegetation map
0%
20%
40%
60%
80%
100%
1st unit 2nd unit 3rd unit
Open ater
Water-plants
Sedges
Typha
Phragmites
Glyceria
Other
Transects (2003)
0%
20%
40%
60%
80%
100%
1st unit 2nd unit 3rd unit
Open water
Water-plants
Sedges
Typha
Phragmites
Glyceria
Other
Do the permanent transects represent appropriately the whole restored area ?
Glyceria is overrepresented
Water plants are underrepresented
Evaluation of restorationEvaluation of restoration
Natural wetland communities are developing in the area. The landscape is beautiful. It is a very important breeding and feeding area of birds.
(Zoological monitoring is being made as well!) The hydrology is considerably different from the original
situation. Natural communities are not the same, than before
drainage of the ancient fen.
Attributes of restored ecosystems (SER 2002)
Present situation in Hanság restoration project
1.The restored ecosystems contains a characteristic assemblage of the species that occur in the reference ecosystem
The dominant species after flooding were abundant before drainage as well.
2. The restored ecosystems consist of indigenous species
There are no abundant exotic species, Solidago gigantea decreased strongly after flooding.
3. All functional groups are represented. Certain groups are underrepresented (e.g. hydato-helophyta species)
4. The physical environment is capable of sustaining reproducing populations.
The water quality is not very good. 5. The restored ecosystem apparently functions normally
Further study is necessary to find out. ?6. The restored ecosystem is suitably integrated into a larger ecological matrix.
The new reconstructed wetland improves the landscape level habitat diversity.
7. Potential threats have been eliminated. Desiccation have been eliminated, but eutrophication not.
8. The restored ecosystem is sufficiently resilient.
The revegetation was spontaneous, so resilience is quite good.
9. The restored ecosystem is self-sustaining.
Further study is necessary to find out. ?
Evaluation of restoration according to the SER PrimerEvaluation of restoration according to the SER Primer
Future
The National Park is ready to follow wetland restoration!
Forestry and agriculture cause severe soil degradation in this area, so wetland restoration would become soon the only logic land use in Hanság!
The change of the water management in the whole area of Hanság is necessary for saving the natural values.
Katalin MARGÓCZI
Gábor TAKÁCS
László KÖRMÖCZI Thank you for your attention!