Journal of Forestry Research (2009) 20(3): 205−212 DOI 10.1007/s11676-009-0040-0 Status and distribution pattern of coarse woody debris along an alti- tudinal gradient in Askot Wildlife Sanctuary, Uttarakhand, West Hi- malaya Bhupendra Singh Adhikari Department of Habitat Ecology, Wildlife Institute of India, Chandrabani, Dehradun 248 001, Uttarakhand, India Abstract: A rapid assessment on the status and distribution patterns of coarse woody debris (CWD) was conducted by laying five curvilin- ear transects (transects A, B, C, D and E; major trails), along an altitudinal gradient starting from 900 to 2 600 m, in three major watersheds (Charigad, Dogarhigad and upper Gosigad) of Goriganga catchment in Askot Wildlife Sanctuary, India. At every 100 m rise in altitude a hectare plot (100 m x 100 m) was selected. Results showed that the percentage contribution by different succession phases was in the de- creasing order: phase I > phase II > phase IV > phase III for snags, and phase III > phase II > phase IV > phase I for logs. Snag density in chir pine forest was high in transect A (11 snags·ha -1 ) at 1 500 m, and the value in rianj oak forest was high in transect B (10 snags·ha -1 ) at 2 300 m. The total available mass of snags and logs in chir pine forest was 13.9 t, of which snags mass accounted for 41% of the total mass and logs mass for 59%. While the total value was 5.6 t in rianj oak forest, of which snags and logs accounted for 60% and 40% of the total mass, respectively. Moreover, the presence of CWD in the study area if not harvested, would provide a great opportunity to the orchids in future to flourish by providing protection. The high densities of snags and logs in chir pine forest at mid-altitudinal zone led to less species richness and lower density of ground flora as the zone receives more light, accompanying with lower soil moisture, and thus only the domi- nant species occupy the habitat. Keywords: Askot Wildlife Sanctuary; chir pine; coarse woody debris; rianj oak; Pinus roxburghii; Quercus lanata Introduction Despite the large amount of organic matter, the coarse woody debris (CWD) still has not been considered as an important fea- ture of a forest ecosystem by the ecologists due to lower concen- tration of nutrients in cycling and energy flow. However, in fact the input of CWD into the natural ecosystem is a common phe- nomenon due to the natural catastrophes, such as wind storms, which uproot the tree and blow or break the top of the tree (Falinski 1978; Cline et al. 1980), and landslides due to heavy rains. The CWD includes a wide variety of types, such as snags or logs, chunk of snags or logs (in a particular regime), larger branches and coarse roots or dry attached branches in living trees (Ferris-Kaan et al. 1993). Some of the causes, such as disease, drought, water logging or pollution, as well as shade effect in Received: 2008-12-02; Accepted: 2009-02-28 © Northeast Forestry University and Springer-Verlag 2009 The online version is available at http://www.springerlink.com Biography: Bhupendra Singh Adhikari (1966-), male, scientist, research interest in high altitude forest dynamics, biodiversity monitoring, me- dicinal plant conservation, climate change. E-mail: adhikaribs@wii.gov.in Responsible editor: Hu Yanbo densely stocked stands of small trees in their early growth period are responsible for death of the individuals (Kirby et al. 1998). The CWD has many crucial ecological functions as habitat for organisms (Harmon et al. 1986). The CWD forms an ideal habi- tat for many plant taxa, viz. bryophytes, pteridophytes, angio- sperms, lichens and fungi, which acts as "Nurse Snag or Log", and thus enriches the plant diversity. Snags provide an abode to many avian for nesting, roosting and vantage point to birds of prey, as well as major sites for the establishment of tree seedlings (on logs) and strengthen the fertility of soil at every succession phase/decay class. Moreover, CWD also plays a major role in energy flow and nutrient cycling in some special ecosystem (Harmon et al. 1986). In global perspective, many researches have been carried out on various topics related to CWD, including dynamics, decom- position rate, nutrient cycling, water relations, geomorphic func- tions, animal and insect use and as substrate for fungi and plants (Falinski 1978 & 1986; Triska & Cromack 1979; Cline et al. 1980; Maser & Trappe 1984; Harmon et al. 1986; Spies et al. 1988; Harmon and Chen 1991; Warren and Key 1991; Fer- ris-Kaan et al. 1993; Freedman et al. 1996; Stevens 1997; Daniels et al. 1997; Frangi et al. 1997; Kirby et al. 1998; Hagan & Grove 1999; McComb & Lindenmayer 1999). In recent years, studies on CWD were mainly focused on the role of CWD in an ecosystem and biogeochemical cycle (Chen et al. 1992; Dai et al. 2002; Zhao et al. 2002; Tang et al. 2003; Timothy and Mark 2004; Zhou et al. 2007). However, only few studies have been RESEARCH PAPER