No abstract

Changes in tree, liana, and understory plant diversity and community composition in five tropical rain forest fragments varying in area (18–2600 ha) and disturbance levels were studied on the Valparai plateau, Western Ghats. Systematic sampling using small quadrats (totaling 4 ha for trees and lianas, 0.16 ha for understory plants) enumerated 312 species in 103 families: 1968 trees (144 species), 2250 lianas (60 species), and 6123 understory plants (108 species). Tree species density, stem density, and basal area were higher in the three larger (> 100 ha) rain forest fragments but were negatively correlated with disturbance scores rather than area per se. Liana species density, stem density, and basal area were higher in moderately disturbed and lower in heavily disturbed fragments than in the three larger fragments. Understory species density was highest in the highly disturbed 18‐ha fragment, due to weedy invasive species occurring with rain forest plants. Nonmetric multidimensional scaling and Mantel tests revealed significant and similar patterns of floristic variation suggesting similar effects of disturbance on community compositional change for the three life‐forms. The five fragments encompassed substantial plant diversity in the regional landscape, harbored at least 70 endemic species (3.21% of the endemic flora of the Western Ghats–Sri Lanka biodiversity hotspot), and supported many endemic and threatened animals. The study indicates the significant conservation value of rain forest fragments in the Western Ghats, signals the need to protect them from further disturbances, and provides useful benchmarks for restoration and monitoring efforts.

The persistence of wide-ranging mammals such as Asian elephants in fragmented landscapes requires extending conservation efforts into human-dominated landscapes around protected areas. Understanding how elephants use such landscapes may help facilitate their movements and reduce conflict incidence. We studied elephants' use of fragmented habitats and ranging patterns of focal herds in a landscape of rainforest fragments embedded in tea, coffee, and Eucalyptus plantations in the Anamalai Hills. Elephant herds entering this landscape were tracked daily between April 2002 and March 2006, resulting in 985 GPS locations of herds obtained across six major habitats. Natural vegetation in rainforest fragments and riparian habitats, despite low coverage in the landscape, was preferred by elephants during the day. At night, elephants preferred riparian vegetation, avoided other habitats such as swamps and settlements, while the remaining habitats were used proportional to availability. Use of rainforest fragments and riparian vegetation increased over three years of study with a corresponding decline in the use of tea monoculture. Among plantation habitats, coffee, and Eucalyptus were used significantly more during wet and dry seasons, respectively. The concentration of elephants along a major riparian system in the center of the landscape emphasized the role of water and food availability in habitat use during the dry season. Protection of rainforest fragments, secondary vegetation along rivers, and regulated and sequential felling (instead of clear-felling) of Eucalyptus along elephant movement routes will help retain forage, cover, and passage routes of elephant herds and may reduce direct human-elephant encounters in such fragmented landscapes.

No abstract

No abstract