Forest stand structure and composition in 96 sites along environmental gradients in the central Western Ghats of India

Abstract

This data set reports woody plant species abundances in a network of 96 sampling sites spread across 22 000 km2 in the central Western Ghats region, Karnataka, India (74°15′–75°40′ E; 15°15′–13°30′ N). Due to its varied climate and diverse topography, the study area, which is part of the Western Ghats–Sri Lanka biodiversity hotspot, supports a wide array of non‐equatorial tropical habitats including wet evergreen, moist and dry deciduous, and intact as well as degraded forests and scrublands. These formations, floristically moderately rich and diversified, are characterized by a lower rate of endemism than in the southern part of the Western Ghats. This data paper provides abundance and girth data for 76 813 trees and lianas of 446 species collected in 96 sampling sites during 1996–1997. A total of 61 965 individuals ≥10‐cm girth at breast height (gbh) were recorded in 96 1‐ha macroplots, while 14 848 individuals <10 cm gbh, but >1 m height, were sampled in three 0.1‐ha microplots located within each macroplot. Additional data regarding the stand structure (average canopy height, percent canopy cover, number of strata) and the level of degradation are available for the macroplots, along with environmental data derived from other sources and analyses, such as soil types, rainfall, length of the dry season, and altitude. These data have been used to produce ecological research papers, as well as to elaborate conservation value maps and recommendations toward sustainable management of the forests of the central Western Ghats region.

Functional trait and community phylogenetic analyses reveal environmental filtering as the major determinant of assembly of tropical forest tree communities in the Western Ghats biodiversity hotspot in India

“…We used tree species abundance and stand structure data from a network of 96 plots, one hectare each in size, distributed across wet and dry environmental gradients in the central Western Ghats, India (Ramesh et al 2010b). The study area (13°30′-15°50′ N, 74°15′-75°40′ E) is located within the administrative boundaries of Uttara Kannada, Shimoga and Chikmagalur districts of the State of Karnataka in south-western India (Fig.…”

“…The study region covers 21,970 km 2 area of the central Western Ghats region and extends from the coastal plain of the Arabian Sea to the humid hill zone of the Western Ghats 'great escarpment' , and to the Karnataka plateau, that recedes toward the eastern upland region. These plots were established by the Karnataka Forest Department (KFD) in 1996-1997 (Ramesh et al 2009), and the detailed description of the study area is given in (Ramesh et al 2010a(Ramesh et al , 2010b. We recorded the diameter at breast height (dbh) of all living trees ≥10 cm in each plot along with the phenological classification of each tree as evergreen or deciduous based on existing literature (Pascal 1986) and botanists' expertise.…”

“…In particular, the distribution and abundance patterns of tropical trees with different leaf phenology such as deciduous and evergreen have attracted considerable attention from ecologists, biogeographers, and mathematical modelers for decades (Monk 1966;Givnish 2002;Lavorel and Garnier 2002;Bowman and Prior 2005;Kikuzawa et al 2013). The co-occurrence and different distribution and abundance pattern of evergreen and deciduous tree species across a variety of landscapes showed to be strongly influenced by environmental factors, mainly by climatic variables such as precipitation, temperature, and length of the dry season (Ramesh et al 2010a(Ramesh et al , 2010bGe and Xie 2017). Thus, the climate is considered as the first-order predictor of the shift in relative composition and abundance of tree communities between evergreen and deciduous forests at both small and large spatial scales (Chabot and Hicks 1982;Reich et al 1992;Ramesh et al 2010aRamesh et al , 2010b.…”

“…The co-occurrence and different distribution and abundance pattern of evergreen and deciduous tree species across a variety of landscapes showed to be strongly influenced by environmental factors, mainly by climatic variables such as precipitation, temperature, and length of the dry season (Ramesh et al 2010a(Ramesh et al , 2010bGe and Xie 2017). Thus, the climate is considered as the first-order predictor of the shift in relative composition and abundance of tree communities between evergreen and deciduous forests at both small and large spatial scales (Chabot and Hicks 1982;Reich et al 1992;Ramesh et al 2010aRamesh et al , 2010b. Also, the external factors such as anthropogenic disturbance may also lead to changes in the relative composition of evergreen and deciduous tree species.…”

“…Also, the external factors such as anthropogenic disturbance may also lead to changes in the relative composition of evergreen and deciduous tree species. As anthropogenic disturbances modify the habitat through creating gaps in the canopy and open up areas providing opportunities to light demanding and desiccation tolerant deciduous plant species to colonize the habitat (Ramesh et al 2010a(Ramesh et al , 2010bGonzález-caro et al 2014;Ramachandra et al 2016).…”