Litter production, decomposition and nutrient release of woody tree species in Dhanaulti region of temperate forest in Gahwal Himalaya

Eurasscience Journals Eurasian Journal of Forest Science (2016) 4(1): 17-30 LITTER PRODUCTION, DECOMPOSITION AND NUTRIENT RELEASE OF WOODY TREE SPECIES IN DHANAULTI REGION OF TEMPERATE FOREST IN GARHWAL HIMALAYA Sushil Saha, G.S.Rajwar and Munesh Kumar* and Kalidas Upadhaya Department of Botany Govt. Post Graduate College, Rishikesh 249201, Uttarakhand, India Department of Forestry, HNB Garhwal University, Srinagar-Garhwal, Uttarakhand, India (*Author for correspondence, email:) Abstract The study has been carried out in Dhanaulity region of temperate forest of Garhwal Himalaya to understand litter production, their decomposition and concentration of nutrients release by leaf litter at different altitudes. The results indicate that the litter production with altitude in each season reduced in order of Lower>middle>upper altitudes, while in each altitudes the seasonal litter production reduced in order of summer>rainy>winter. The value of decomposition constant (k) was reduced as 0.511, 0.438 and 0.256 at lower, upper, middle altitude respectively. The concentration of nutrients seasonally (irrespective altitude), potassium reduced from summer (0.92%), rainy (0.90%) and winter (0.84%) however, phosphorus shown reverse trend with potassium as summer (0.104%), rainy (0.108%) and winter (0.203%) whereas nitrogen was highest in rainy (1.13%) followed by winter (1.11%) and summer (1.01%). The nutrient concentration with altitude (irrespective season), potassium increased with increasing altitudes, whereas, phosphorus and nitrogen have not shown any trend with altitude. Keywords: Himalaya, Forest floor, Nutrient elements, NPK. Özet Bu çalışma Garhwal Himalaya’nın Dhanaulity bölgesindeki ılıman kuşak ormanlarındaki ölü örtü birikimi, ölü örtü ayrışması ve böylece ölü örtüden besin maddelerinin salımı miktarlarını belirlemek amacıyla yapılmıştır. Araştrıma sonuçları, ölü örtü miktarları en yüksekten en düşüğe doğru alt>orta>üst yükseltilerde olduğu ve herbir yükselti basamağında yaz>yağmurlu mevsim>kış sıralamasına göre oluştuğu tespit edilmiştir. Ayrışma sabiti (k) alt, üst ve orta yükseltilerde sırasıyla 0.511, 0.438 ve 0.256 şeklinde değişmiştir. Yükseltiye bağlı olmaksızın potasyum yaz>yağmurlu mevsim>kış (sırasıyla %0.92, 0.90 ve 0.84), fosfor potasyumun tersine kış>yağmurlu mevsim>yaz (%0.203, 0.108, 0.104) şeklinde bir değişim göstermiş, azot ise mevsimlere göre yağmurlu mevsim>kış>yaz (%1.13, 1.11 ve 1.01) bir seyir izlemiştir. Mevsimlere bağlı kalmaksızın bakıldığında ise potasyum yükselti arttıkça artış göstermiş, fosfor ve azot ise yükseltiye bağlı belirgin bir değişim göstermemiştir. Anahtar Kelimeler: Himalay, Ölü örtü, Besin elementleri, NPK. INTRODUCTION Litter production and nutrient cycle in terrestrial ecosystem plays an important role in turnover of nutrient and maintenance of soil fertility and productivity. The accumulation and decomposition of plant litter has been considered as complex and important factor in controlling both vegetation structure and ecosystem function (Grime, 1979). Organic matter in the mineral soil is composed of close physical and chemical relationship with the mineral function of the soil. Litter fall on the forest floor occurs in the form of leaves, twigs, fruits, bark and small Litter production, decomposition and nutrient release in Garhwal Himalaya Saha et al. 2016 4(1): 17-30 branches. The interactive and sequential process of litter fall, its decomposition and subsequent mineralization are essential in substaining a dynamic ecosystem. Litter of forest floor minimizes the soil erosion, runoff and increases the percolation rates as well as nutrient taken up by the tree which is held in the green foliage. A sub-sequential amount of nutrient taken up by the aboveground component of the tree is returned to the soil through litter fall. . Litter decomposition plays a crucial role in the nutrient budget of forest ecosystems where vegetation depends mainly on the recycling of nutrients contained in the plant detritus. During this process plant nutrients become available for recycling within the ecosystem. Litter decomposition is influenced by environmental factors and also by physicochemical properties of the parts such as stem wood, leaves, root, etc. of the species studied and decomposer organisms present in the soil. Woody debris in the form of standing dead trees, fallen boles, large branches and roots is abundant in many forest ecosystems, and plays an important ecological role in the recycling of nutrients within the forest. This woody debris also reduces soil erosion, acts as a reservoir for nutrient and water storage, seed bed for plant establishment, and a habitat for fungi, bacteria, arthropods and a variety of vertebrates. Decomposition of leaf litter is a major source of nutrients in forest ecosystems. As leaves are broken down by insect and microbial decomposers, organically-bound nutrients are released as free ions to the soil solution which are then available for uptake by plants. Decomposition of coniferous forest is very slow. Slow rate of decay can result in the accumulation of large nutrients stocks on the soil horizons (Melillo et al., 1982). Forest release of nutrient from a forest may help an assemblage of different types of communities in the ecosystem. The rate of litter decomposition is determined by nature or plant and microclimatic conditions. The decomposer substratum performs two major functions i.e., the mineralization of essential elements and formation of soil organic matter. However, studies on litter dynamics of tree species and its contribution to nutrient status in the soil in Dhanaulti area of Tehri Garhwal, Uttarakhand, India, have not been conducted so far; therefore, present study was undertaken with the objective of understanding Seasonal pattern of litter production, decomposition and nutrient release of woody tree species in selected forest along altitudinal gradient. MATERIALS AND METHODS Location and climate of study area The present study was carried out on litter production decomposition and nutrients concentration of litter release at three different altitudes of woody tree species forest near Dhanaulti in Garhwal Himalaya of Uttarakhand. Dhanaulti is located in the Garhwal Hills between 30’ 45o N and 78’ 25o E, at an altitude of 2286m. The forests have thick trees covers of Cedrus deodara, Quercus leucotrichophora, Rhododendron arboreum Pinus roxburghii, etc. The moist Cedrus deodara Deodar forest (Type – 12/C1C; Champion and Seth 1968) is found between altitudes 1750-2150 m a.s.l. Cedrus deodara is mainly observed in pure patches, while few scattered individuals of other associated species such as Quercus leucotrichophora, Pinus wallichiana, Cupressus torulosa and Rhododendron arboreum are also found. Three sites were selected for the present study (Figure.1) at three different altitudes i.e., upper, middle and lower (Table 1). Soils of Dhanaulti area belongs to mollisols and (...truncated)