An analysis of altitudinal behavior of tree species in Subansiri district, Eastern Himalaya

Abstract

Plant species diversity and endemism demonstrate a definite trend along altitude. We analyzed the (i) pattern of tree diversity and its endemic subset (ii) frequency distribution of altitudinal range and (iii) upper & lower distributional limits of each tree species along altitudinal gradients in eastern Himalaya. The study was conducted in Subansiri district of Arunachal Pradesh. Data on the tree species (cbh ‡ 15 cm) were gathered every 200 m steps between 200 m and 2200 m gradients. Tree diversity demonstrated a greater variation along the gradients. A total of 336 species (of which 26 are endemic) were recorded belonging to 185 genera and 78 families. The alpha diversity demonstrated a decreasing pattern with two maxima (i.e., elevational peaks) along the gradients; one in 601-1000 m and the other in 1601-1800 m, corresponding to transition zones between tropical-subtropical and subtropical-temperate forests. Pattern diversity revealed a narrow range along the gradients. Frequency of altitudinal range was distributed between 1 and 41. Only one species (Altingia excelsa) showed widest amplitude, occurring over the entire range. Highest level of species turnover was found in 400-600 m step at lower elevational limit whereas for upper elevational limit, the highest turn over was recorded between 800 and 1000 m. Tree diversity decreased and its endemic subset increased along the gradients. Two maximas in tree diversity pattern correspond to forest transition zones with subtropical-temperate transition is narrower than tropical-subtropical. The pattern observed here could be attributed to varied microclimates or environmental heterogeneity. If altitudinal amplitude of a species is considered as an aspect of its niche breadth, it is clear from these results that niche breadth in these organisms is in fact independent of the diversity of the assemblage in which they occur. This analysis calls for detailed floristic studies to determine the Ó Springer Science+Business Media B.V. 2006 breadth of changes between adjacent forest types and details of local species richness in high diversity areas.

Altitudinal Gradient Affects on Trees and Stand Attributes in Mount Ciremai National Park, West Java, Indonesia

“…The decline in species richness due to higher altitudes in Mount Ciremai National Park (Fig. 1.a.) was similar with a pattern observed in Mount Kerinci in Sumatra and Mount Pangrango in Java (Ohsawa, 1991), Mount Kinabalu in Borneo (Kitayama, 1992;Aiba and Kitayama, 1999), Dongling Mountains in China (Ren et al, 2006), Subansiri in Eastern Himalaya (Behera and Kushwaha, 2007), and Lore Lindu National Park in Central Sulawesi (Culmsee and Pitopang, 2009).…”

Drivers of elevational richness peaks, evaluated for trees in the east Himalaya

“…, Manish et al. ), trees specifically (Carpenter , Bhattarai and Vetaas , Behera and Kushwaha , Acharya et al. ), and ferns and bryophytes (Bhattarai et al.…”

Butterfly diversity along the elevation gradient of Eastern Himalaya, India

“…Elevational pattern of mammals, birds, reptiles, amphibians, fishes and plants have been reported from the Himalayan region (Bhattarai and Vetaas 2003;Bhattarai et al 2004;Oommen and Shanker 2005;Behera and Kushwaha 2007;Chettri 2007;Thapa 2008;Chettri 2010a;Chettri et al 2010;Acharya et al 2011a, b;Khuroo et al 2011;Price et al 2011;Bhatt et al 2012;Naithani and Bhatt 2012;Telwala et al 2013). Despite being important part of an ecosystem (often considered as bio indicators) such studies on butterflies are scanty in the Himalayas (Bhardwaj et al 2012) as well as at global level (Fleishman et al 1998;Vu and Yuan 2003;Levanoni et al 2011;Despland et al 2012;Ilian et al 2012).…”