Deforestation Rate in Southeast Asia

1674 Words7 Pages
Estimation of population density or abundance of arboreal primates such as Hylobates agilis is generally difficult due to their highly mobile nature and accessibility to sampling area can be very difficult. Conventional methods such as distance sampling or mark- recapture method requires big amount of effort, funding and man power. Alternatively, presence-absence method can be used which is relatively easy, less costly and requires lesser personnel The presence-absence method used in this study is one of the approach developed for estimating occupancy of single species within single season(MacKenzie, Nichols, Gideon, Droege, Royle and Langtimm, 2002). Occupancy is the proportion of a randomly selected sampling unit in an area under study is occupied with interested species. Occupancy modeling allows us to estimate the probability that a sampling unit is occupied, given that species are imperfectly detected or in other words probability that a site is within a group of sites is occupied with species of interest. Occupancy model has wide range of applications such as species occurrence, range, distribution, habitat selection and wild life monitoring (MacKenzie et al, 2005). In this, study we used single season single species occupancy model and carried out based on presence – absence data or detection –non detection data. In the single season model, populations are assumed to be closed no migration, birth of new individual, death take place during the period of study. If x and s represents the number of occupied sites and total number of surveyed site, then occupancy of particular species is: Ψ=x/s However, x count may be lower than expected due to absence of species in the occupied site which leads to false absence. Theref... ... middle of paper ... ...e third unique difference is occurrence of epiphythe. (Smith and Smith, 2003) Deforestation rate in Southeast Asia is one of the highest globally. It is a primary threat to loss of biodiversity. Most of exploitations are focused on lowland due to ease of access compare to its counterpart montane forest. Besides this, intense logging in lowland may bring major threat to flora and fauna in lowland dipterocarp forest.(Soh, Sodhi and Lim, 2006).From year 1981 to 1990 deforestation rate in Malaysia reached 1.8% per year between 1981 and 1990, this is notably regarded as among the highest in the world. Most of the virgin lowland forests are exploited for timber and land clearing for commercial crops and estate development. It is suggested that degraded area if allowed to regenerate could possibly provide home for some forest biota.(Peh, Jong, Sodhi, Lim and Yap, 2005)
Open Document