Leaf litter decomposition and nutrient release patterns of six multipurpose tree species of central Himalaya, India

Biomass and Bioenergy 24 (2003) 3–11

Leaf litter decomposition and nutrient release patterns of sixmultipurpose tree species of central Himalaya, India

R.L. Semwala, R.K. Maikhuria ;∗, K.S. Raob, K.K. Senb, K.G. Saxenac

aG.B. Pant Institute of Himalayan Environment and Development, Garhwal Unit, P.B. 92, Srinagar, Garhwal 246174, IndiabSustainable Development and Rural Ecosystems Programme, G.B. Pant Institute of Himalayan Environment and Development,

Kosi-Katarmal, Almora 263643, IndiacSchool of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India

Received 5 October 2001; received in revised form 6 June 2002; accepted 28 June 2002

Abstract

Chemical characteristics and decomposition patterns of six multipurpose tree species, viz.,Alnus nepalensis,Albizzia lebbek,Boehmeria rugulosa, Dalbergia sissoo, Ficus glomerata and F. roxburghii were analysed in a mixed plantation establishedon an abandoned agricultural land site in a village at 1200 m altitude in Central Himalaya, India. Di4erences in chemicalquality of litter species were most marked in polyphenol and N concentrations. A. lebbek, A. nepalensis and D. sissoo showedhigher N (2.2–2.6%) but lower polyphenol concentrations (3.2–4.7%) than B. rugulosa, F. glomerata and F. roxburghii(0.96–1.97% N and 5.68–11.64% polyphenol). Signi:cant e4ects of species, incubation time and species× incubation timeinteraction on monthly mass, N, P and K release rates were observed. A linear combination of rainfall and temperatureexplained the variation in monthly mass loss better than rainfall and temperature independently. Percentage mass remainingafter 1 year of incubation varied from 30 to 50, N remaining from 40 to 86, P remaining from 33 to 56 and K remainingfrom 1 to 3. Annual decomposition constants of mass and N were positively correlated with C and N concentrations andnegatively correlated with C/N, lignin/N, polyphenol/N and lignin+polyphenol/N ratios of fresh litter. As all the speciesstudied showed the highest rates of N and P release during the rainy season, rainy season crops are not likely to be as muchnutrient stressed as winter season crops if leaf litter of these species is assumed to be the sole source of nutrients to crops intree-crop mixed agroforestry. A. lebbek, A. nepalensis, D. sissoo and F. glomerata seem to be more appropriate for rapidrecovery in degraded lands as their litter decomposed faster than B. rugulosa and F. roxburghii. A diverse multipurpose treecommunity provides not only diverse products but may also render stable nutrient cycling.? 2002 Elsevier Science Ltd. All rights reserved.

Keywords: Agroforestry; Decomposition constant; Lignin; Polyphenol; Soil fertility in degraded lands

1. Introduction

Land degradation is a major problem all throughthe Himalayan mountain system covering eight

∗ Corresponding author. Tel.: +91-138852424.E-mail address: [email protected] (R.K. Maikhuri).

developing countries of South Asia includingAfghanistan, Bangladesh, Bhutan, China, India,Myanmar, Nepal and Pakistan. Plantations of mul-tipurpose trees alone or combined with agriculturalcrops could be an e4ective land rehabilitation strategy[1–3]. Litter production, decomposition and nutri-ent release patterns determine the potential of tree

0961-9534/03/$ - see front matter ? 2002 Elsevier Science Ltd. All rights reserved.PII: S0961 -9534(02)00087 -9

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4 R.L. Semwal et al. / Biomass and Bioenergy 24 (2003) 3–11

species to improve soil fertility and productivity indegraded lands. Though many studies on decompo-sition and nutrient release from agroforestry speciesare available [4–10], e4orts in the Himalayan regionare limited [11–13]. The aim of this study was tocompare decomposition and nutrient release patternsof six multipurpose tree species in Indian CentralHimalaya.

2. Materials and methods

2.1. Study area

The study was carried out in village Ban-swara (1200 m above mean sea level) in DistrictRudraprayag, Garhwal (latitude 30◦27′N and longi-tude 79◦5′E). This area experiences a typical mon-soon climate. Monthly mean minimum and maxi-mum temperatures vary in the range of 6–21◦C and18–35◦C, respectively. The average annual rainfall is1700 mm. The soil is derived from felspathic quartzschist, quartz muscovite schist and quartz chloriteschist [14] and 30–80 cm deep.

2.2. Multipurpose tree species

The traditional multipurpose tree species selectedfor this study could be categorized by their products,litter fall patterns, nitrogen :xing ability and habi-tat. Local people value Boehmeria rugulosa, Ficusglomerata and Ficus roxburghii as the best qualityfodder species, Albizzia lebbek and Dalbergia sissooas the best quality timber species, and Alnus nepalen-sis as a medium quality fuelwood and timber species.Alnus nepalensis and Dalbergia sissoo are more fre-quent in forests and the remaining four on farms.B. rugulosa and F. roxburghii are evergreen speciesexhibiting peak leaf litter fall during April–June(summer season). F. glomerata and all the threenitrogen :xing species A. nepalensis, A. lebbek andD. sissoo are deciduous species showing peak litterfall during December–January (winter season).

2.3. Plantation

Five rectangular plots (10 m×7 m) were laid out onan abandoned agricultural land site. Two individuals

of each of six species were planted at 3 m distance inJuly 1991 such that neighbouring individuals did notbelong to the same species. After 3.5 years of growth,A. lebbek, A. nepalensis, B. rugulosa, D. sissoo,F. glomerata and F. roxburghii showed mean cir-cumference and breast height as 19.9, 26.5, 20.5, 24.0,32.0 and 21:5 cm, respectively, and height 4.9, 7.2,3.9, 5.1, 6.0 and 3:9 m, respectively. The soil is sandyloam (17% clay, 36% silt and 47% sand) and mildlyacidic (pH 6.25) with 1.4% organic carbon, 0.22%nitrogen, 0.08% total phosphorus and 0:05 g kg−1

exchangeable potassium.

2.4. Methods of study

Decomposition was studied using the litter bagtechnique [15]. Leaf litter was collected in traps setup at 15 cm above ground level during the peakfall period of each species. Air dried leaf material(5 g) of a species was kept in 15 cm × 15 cm ny-lon bags (mesh size 1 mm permitting movement ofmicro-arthropods). Fifteen bags of each species wererandomly placed in direct contact with soil in eachplot within 2 weeks after litter collection. Thus, litterof A. nepalensis, D. sissoo and F. glomerata was in-cubated on December 31, 1994, A. lebbek on January31, 1995 and B. rugulosa and F. roxburghii on April30, 1995. One bag of each species from each plot wasrecovered at monthly intervals over a period of 1 year.Litter was removed from each sampled bag, brushedgently to remove soil and oven dried at 70+5◦C.Three bulk samples of fresh litter and decomposed

litter recovered from three randomly selected litterbags out of :ve sampled for mass loss estimationfor each species were chemically analysed. The ovendried material was ground and passed through a 1 mmsieve. Lignin and cellulose concentrations were de-termined following Clancy and Wilson [16], carbonfollowing Schlesinger [17] and Taylor et al. [18], andpolyphenols extracted in hot 50% aqueous methanol[19] using tannic acid as a standard only in freshlitter. In all samples, nitrogen was estimated by themicro-kjeldahl method, phosphorus by the molybde-num blue method and potassium by an atomic absorp-tion spectrophotometer [20]. Maximum and minimumtemperatures and rainfall were recorded daily duringthe period of study (January 1995–April 1996) andaggregated to obtain monthly means.

R.L. Semwal et al. / Biomass and Bioenergy 24 (2003) 3–11 5

The annual decomposition constant (k) [21] forthe exponential relationship was calculated usingthe equation: ln(x0=xt) = kt, where x0 is the originalbiomass or nutrient content of litter, xt is the massor nutrient content remaining after time t (in years).Analysis of variance and regressions were performedfollowing Sokal and Rohlf [22].

3. Results

3.1. Climate

The year could be di4erentiated into a warm-dry summer season (March–May), warm-wet rainy

0

100

200

300

400

500

600

700

J M A M J J A S O N D J M A

Months

Rai

nfa

ll (m

m)

0510152025303540

Tem

per

atu

re (

°C)

Rainfall Max. temp. Min. temp.

1995 1996F F

Fig. 1. Monthly rainfall and maximum and minimum temperatures during the study period (January 1995–April 1996).

Table 1Characteristics (mean ± standard deviation) of leaf litter of multipurpose tree species planted in degraded land at Banswara, CentralHimalaya, India

Characteristics Tree species Least signi:cantdi4erence

Albizzia Alnus Boehmeria Dalbergia Ficus Ficus (P = 0:05)lebbek nepalensis rugulosa sissoo glomerata roxburghii

Moisturea(%) 4:40± 0:20 5:90± 0:25 8:00± 0:30 5:02± 0:20 7:71± 0:37 8:70± 0:46 0.55Lignin 9:78± 0:70 15:11± 0:20 13:78± 0:70 9:42± 0:52 13:82± 2:45 12:14± 0:24 1.97Cellulose 20:23± 0:40 31:79± 2:42 23:19± 0:34 21:43± 0:51 25:92± 1:00 23:20± 1:44 2.23C (%) 43:00± 0:50 44:17± 0:28 35:83± 0:28 43:00± 0:50 39:16± 0:76 38:00± 0:50 0.88N (%) 2:62± 0:06 2:51± 0:08 1:16± 0:06 2:19± 0:08 1:97± 0:07 0:96± 0:06 0.12P (%) 0:15± 0:01 0:13± 0:01 0:18± 0:01 0:18± 0:01 0:17± 0:01 0:13± 0:01 0.01K (%) 0:60± 0:06 0:60± 0:04 0:92± 0:08 1:12± 0:10 1:10± 0:07 0:98± 0:09 0.14Polyphenol (%) 3:20± 0:44 4:70± 0:77 5:68± 0:46 4:50± 0:53 7:10± 1:06 11:64± 2:56 2.17C/N ratio 16:41± 0:53 17:59± 0:57 30:88± 1:87 19:63± 0:48 19:88± 0:50 39:58± 2:26 2.26Lignin/N ratio 3:73± 0:25 6:02± 0:13 11:88± 0:77 4:30± 0:37 7:01± 1:25 12:64± 0:58 1.20Polyphenol/N ratio 1:22± 0:14 1:87± 0:30 4:90± 0:14 2:05± 0:17 3:60± 0:66 12:12± 3:20 1.39Lignin + polyphenol/ 4:95± 0:37 7:89± 0:36 16:77± 0:67 6:35± 0:30 10:62± 1:49 24:77± 3:70 1.97

N ratio

a% Moisture in air dried litter kept for incubation.

season (mid June–September) and cold-dry win-ter season (October–February). Minor variationsin monthly means between years are evident fromJanuary–April data recorded in 2 years (Fig. 1).

3.2. Litter quality

Di4erences between species were most markedin polyphenol and N concentrations (Table 1).A. lebbek, A. nepalensis and D. sissoo showedhigher N (2.62%, 2.51% and 2.19%, respectively)but lower polyphenol concentrations (3.2%, 4.7% and4.5%, respectively) than B. rugulosa, F. glomerataandF. roxburghii (1.16%, 1.97%, 0.96%N and 5.68%,


0

20

40

60

80

100

120

10 11 12

Months after incubation

% m

ass

rem

aini

ng

Albizzia lebbekAlnus nepalensisBoehmeria rugulosaDalbergia sissooFicus glomerataFicus roxburghii

0

20

40

60

80

100

120

% to

tal N

rem

aini

ng

Albizzia lebbekAlnus nepalensisBoehmeria rugulosaDalbergia sissoo

Ficus glomerataFicus roxburghii

1 2 3 4 5 6 7 8 9 10 11 12


1 2 3 4 5 6 7 8 9

(a)(b)

0

20

40

60

80

100

120

10 11 12


% to

tal P

rem

aini

ng


0

20

40

60

80

100

120

% to

tal K

rem

aini

ng


1 2 3 4 5 6 7 8 9 10 11 12


1 2 3 4 5 6 7 8 9

(c) (d)

Fig. 2. (a)–(d) Percent biomass and nutrient (N,P,K) mass remaining in di4erent months during one year of incubation of six multipurposetrees. The vertical lines represent least signi:cant di4erence (P = 0:05).

7.1% and 11.64% polyphenol concentration, respec-tively). B. rugulosa and F. roxburghii had the highestC/N, lignin/N, polyphenol/N and lignin+polyphenol/Nratios. A. lebbek and A. nepalensis, and D. sissooand F. glomerata had similar C/N and polyphe-nol/N ratios but di4ered in respect of lignin andlignin+polyphenol/N ratios.

3.3. Monthly mass loss and nutrient release patterns

Analysis of variance revealed signi:cant (P¡ 0:01)di4erences in decomposition rates due to species,incubation time and species × incubation time in-teraction. A. nepalensis, A. lebbek, D. sissoo andF. glomerata showed three phases in mass loss andN and P release (Fig. 2a–c): a slow loss in the initialperiod of incubation, rapid loss during intermediatephase and again a slow loss during the end of the year.B. rugulosa and F. roxburghii showed two phases inmass loss and P release: a rapid loss during the :rst

5 months followed by a slow loss phase. Such phaseswere not marked in N release pattern of these twospecies. F. roxburghii showed a prolonged immobi-lization and started mineralizing N after 10 monthsof incubation. All species showed fast release of K(Fig. 2d) soon after incubation. Di4erences betweenspecies were more marked after 7 months onwards inmass, N and P remaining and during initial 6 monthsin K remaining. Percentage mass remaining after1 year of incubation varied from 30.32 to 50.38, Nremaining from 40.05 to 86.04, P remaining from33.39 to 55.71 and K remaining from 1.01 to 3.08.F. roxburghii and B. rugulosa showed signi:cantly(P¡ 0:05) higher mass, N and P remaining thanother species after 8 months of incubation.

3.4. Mass loss in relation to rainfall andtemperature

Monthly mass loss was positively related withrainfall and temperature but these linear relationships

R.L. Semwal et al. / Biomass and Bioenergy 24 (2003) 3–11 7Table2

Regressionbetweenmonthlyrainfall(mm),meantemperature(◦C)andmonthlymassloss(y)fordi4erentmultipurposetreespeciesplantedindegradedland

atBanswara,

CentralHimalaya,India

Species

Regression

Rainfall

Airtemperature

Rainfall+airtemperature

Albizia

lebb

eky=0:021x+2:63

(R2=0:73;P¡0:01)

y=0:50x−4:39

(R2=0:51;P¡0:01)

y=0:016x1+0:29x 2

−2:50

(R2=0:87;P¡0:01)

Alnus

nepa

lensis

y=0:012x+4:23

(R2=0:40;P¡0:05)

y=0:344x

−0:90

(R2=0:40;P¡0:05)

y=0:009x1+0:22x 2+0:34

(R2=0:33;P¡0:05)

Boehm

eria

rugu

losa

y=0:011x+2:99

(R2=0:65;P¡0:01)

y=0:231x

−0:13

(R2=0:38;P¡0:05)

y=0:009x1+0:12x 2+0:71

(R2=0:75;P¡0:01)

Dalbergia

sissoo

y=0:013x+3:65

(R2=0:61;P¡0:01)

y=0:313x

−0:82

(R2=0:46;P¡0:05)

y=0:010x1+0:18x 2+0:49

(R2=0:73;P¡0:01)

Ficus

glom

erata

y=0:015x+3:19

(R2=0:82;P¡0:01)

y=0:239x+0:53

(R2=0:24;P¿0:05)

y=0:015x1+0:05x 2+2:34

(R2=0:83;P¡0:01)

Ficus

roxb

urgh

iiy=0:005x+3:52

(R2=0:20;P¿0:05)

y=0:126x+1:68

(R2=0:17;P¿0:05)

y=0:004x1+0:08x 2+2:02

(R2=0:28;P¿0:05) were not signi:cant (P¿ 0:05) for temperature in

all species and for both temperature and rainfall inF. roxburghii (P¿ 0:05). A linear combination ofrainfall and temperature explained the variation inmonthly mass loss better than rainfall and temperatureindependently, but the degree of improvement due tomultiple regression varied between species (Table 2).

3.5. Annual decomposition constants

A single exponential decay model showed a fairlygood :t in all species (R2 = 0:79–0.98) except for Nrelease from F. roxburghii (R2 = 0:25) (Table 3). Allspecies showed the highest decomposition constantfor K. B. rugulosa and F. roxburghii showed decom-position constant of P higher and other species lowerthan that of N. A. nepalensis showed the highest andF. roxburghii the lowest constants for mass, N and P.The highest constant for K was observed in A. lebbekand the lowest in B. rugulosa, F. glomerata andF. roxburghiiwith no signi:cant di4erence (P¿ 0:05)between them.

3.6. Decomposition and nutrient release rates inrelation to litter quality

Annual decomposition constants of mass andN were positively correlated with C and N con-centrations and negatively correlated with C/N,lignin/N, polyphenol/N and lignin+polyphenol/Nratios of fresh litter. The decomposition constantfor N showed stronger correlations with N%, C/N,lignin/N and lignin+polyphenol/N (P¡ 0:01) ascompared to other litter quality parameters. How-ever, non-signi:cant (P¿ 0:05) relationships werenoted between these chemical attributes and P and Kdecomposition constants (Table 4).

4. Discussion

4.1. Litter quality

The key litter quality characteristics, viz., C, N,lignin and polyphenol concentrations and ratios in-tegrating two characteristics observed in this studyare within the reported range of values [5,7,8,23–25].Litter quality may vary within a species growing in


Table 3Annual decomposition constants (k) of mass and nutrients for leaf litter of multipurpose tree species planted in degraded land at Banswara,Central Himalaya, India

Attributes Species Least signi:cantdi4erence

Albizzia Alnus Boehmeria Dalbergia Ficus Ficus (P = 0:05)lebbek nepalensis rugulosa sissoo glomerata roxburghii

Massk 1.02 1.16 0.74 0.99 0.99 0.63 0.03R2 0.89 0.92 0.98 0.93 0.93 0.97

Nitrogenk 0.83 0.91 0.22 0.71 0.66 0.05 0.03R2 0.87 0.89 0.80 0.91 0.91 0.25

Phosphorusk 0.73 1.09 0.63 0.83 0.78 0.53 0.04R2 0.79 0.92 0.98 0.93 0.85 0.98

Potassiumk 4.66 4.04 3.84 4.28 3.70 3.64 1.30R2 0.96 0.95 0.97 0.98 0.97 0.96

(k) is calculated using the equation ln x0=xt = kt. R2 expresses the variance explained by the exponential model.

Table 4Correlation coeKcients from linear regression of leaf litter quality parameters and annual decomposition constants (k) for litter mass andnutrients of multipurpose trees planted in degraded land at Banswara, Central Himalaya, India

Litter quality Correlation coeKcients

Mass Nitrogen Phosphorous Potassium

N (%) 0.959∗∗ 0.985∗∗ 0.769 0.752Lignin (%) −0:001 −0:093 0.255 −0:664Polyphenol (%) −0:777 −0:783 −0:589 −0:799C/N −0:936∗∗ −0:975∗∗ −0:761 −0:667Lignin/N −0:877∗ −0:932∗∗ −0:662 −0:792Polyphenol/N −0:867∗ −0:887∗ −0:707 −0:692Lignin+polyphenol/N −0:906∗ −0:945∗∗ −0:713 −0:770

∗P¡ 0:05.∗∗P¡ 0:01.

di4erent environments [26,27]. Nitrogen and phos-phorus concentrations of A. nepalensis were compara-ble, but polyphenol concentration was 1.4 times lowerthan the values reported by Sharma et al. [13] for thisspecies in more humid and cooler climate of East-ern Himalaya. Mineral and lignin concentration ofD. sissoo are comparable and polyphenol concentra-tion about two times higher than the values reportedin a more arid and warm climate [28]. N concentration

in leaf litter of nitrogen :xing tree species was higherthan non-nitrogen :xing species [5,25,28].

4.2. Litter quality, litter fall period anddecomposition patterns

In strongly seasonal climates, as in this study,contribution of leaf litter of agroforestry trees to soilfertility through decomposition would be determined


by litter quality as well as the timing of litterfall.A. nepalensis, A. lebbek, D. sissoo and F. glomeratashowing a high-quality litter shed leaves in winterand thus face relatively higher moisture and temper-ature stresses for a period of about 6 months afterlitterfall, while low-quality litter of B. rugulosa andF. roxburghii is not exposed to these abiotic stressesas leaves are shed in the beginning of rainy season. Inall species, rapid mass loss occurred during warm-wetrainy season evident from a positive correlation ofmonthly mass loss with a linear combination of rain-fall and temperature. The more important role of rain-fall as compared to temperature deduced from regres-sion analysis is supported from other studies [11,29].However, the e4ect of these abiotic factors was notas pronounced in very low-quality material, likeF. roxburghii, as in the better quality ones [8,11].Interaction of litter quality and peak litter fall period(incubation timing) was such that species e4ects wereless marked in monthly mass, N and P release ratesduring the initial phase of decomposition. K did showmarked species e4ects during early period suggestingthat this element could be easily leached [30] by evenlow sporadic rainfall events occurring during summerand winter months.Three-phase decomposition pattern (initial slow

phase, intermediate fast phase and terminal slow phaseof decomposition) in A. lebbek, A. nepalensis, D.sissoo and F. glomerata incubated long before rainyseason and two-phase pattern (initial fast followed bya slow phase) in B. rugulosa and F. roxburghii incu-bated in the beginning of rainy season are observedin other studies in a monsoon climate [11,29,31].Available studies suggest that plant materials with

N ¿ 1:7%, lignin ¡ 15%, polyphenol ¡ 3% andC/N ratio ¡ 20 generally mineralize while those ex-ceeding these limits immobilize N [7,25,32,33]. Thisgeneralization is supported from this study exceptthat species like A. nepalensis, A. lebbek, D. sissoo,F. glomerata having ¿ 3% polyphenol and B. rugu-losa having C/N ratio¿ 20 did not immobilize N andF. roxburghii with ¡ 15% lignin concentrationshowed prolonged immobilization.

4.3. Annual decomposition constants

While monthly decomposition and nutrient releaserates from litter incubated at the time of litter fall in-

dicates contribution from trees to nutrients demandedby crops, annual decomposition constants would re-Lect species potential in long-term soil fertility man-agement. Annual decay constants or mass and nutrientrelease in 1 year reported in this study are lower thanthe values reported for other agroforestry tree leaf lit-ter in relatively more humid regions in the Himalaya[11–13] and elsewhere in the tropics [4,9,34]. Sharmaet al. [13] found decomposition constant of P about1.5 times higher than that of N in A. nepalensis, whilethere was no signi:cant di4erence between the two inthis study. These variations could be attributed to vari-ation in decomposer community, environmental con-ditions, litter quality and bag mesh size [27,35,36].A strong correlation of annual decomposition con-

stant of N with litter quality parameters indicates theimportance of litter quality in determining N releaseon an annual time scale. The data show that abso-lute lignin and polyphenol concentration were not asstrongly correlated with annual N release as their con-centrations in relation to N, as also observed by Con-stantinides and Fownes [25] in their laboratory basedstudies. Di4erences among studies in best predictorof N mineralization/immobilization arise partly fromvariation in methods used to measure these processesand partly from variation in ranges of chemical com-position of the litter materials used [25]. Relationshipsbetween decomposition constants of P and K with lit-ter quality parameters analysed were not signi:cant(P¿ 0:05) suggesting that processes determining Pand K release may not be correlated with N release.

4.4. Synchrony between nutrient release from treeleaf litter and crop demand

In Central Himalayan agroforestry systems, tradi-tionally two crops are grown in a year, one duringthe rainy season (sowing in May and harvesting inSeptember/October) and the other during the winterseason (sowing in October/November and harvestingin April/May) [37]). As all species studied showedthe highest rates of N and P release during the rainyseason, rainy season crops are not likely to be nutri-ent stressed as much as winter season crops if treeleaf litter is assumed to be the sole source of nutri-ents to crops. F. roxburghii litter immobilizes andB. rugulosa litter releases N at slow rates but this ef-fect is likely to be minimized due to their low litter


production as they are lopped for fodder. A. lebbek,A. nepalensis, D. sissoo and F. glomerata litter onaccount of their fast decomposition seem to be moreappropriate for rapid recovery in soil fertility in de-graded lands. A diverse multipurpose tree communityprovides not only diverse products but may also ren-der stable nutrient cycling. Further studies are neededto evaluate the potential of multipurpose trees in pureand various combinations of mixed plantations in re-spect of soil fertility management.

Acknowledgements

We are grateful to the Director, G.B. Pant Instituteof Himalayan Environment and Development for thefacilities and to the Tropical Soil Biology and Fertil-ity (TSBF) Programme, Nairobi for partial :nancialsupport.

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Documents

Leaf litter decomposition and nutrient release patterns of six multipurpose tree species of central Himalaya, India