The Cauvery river basin of South India has a large phyto-floristic wealth, rightfully enough to constitute a separate phyto-geographic unit. Increase in the anthropogenic pressures within the river basin and surrounding landscapes have persistently stressed the riparian ecosystem structure adversely, besides altering its composition. The objective of this study was to examine the present status of riparian vegetation along the Cauvery river basin, in response to anthropogenic pressures. For vegetation analysis, the riparian forest coming in the middle stretch of Cauvery river was categorized into two zones, viz., forest zone covering ~54 km stretch and agroecosystem zone covering ~80 km stretch. In each zone, tree species were quantified using transects at 8-km interval. Overall tree species accounting for both forest and agroecosystem were recorded and compared. The results indicate that the mean density and basal area of trees per plot were higher in the forest zone than agroecosystem zone. The Shannon-Weiner diversity of forest zone is 4.6, which is higher than agroecosystem. In addition, species composition indicated a relatively low or poor similarity between the two zones. The vegetation density and site disturbance scores for all the study sites reveals that sand mining and grazing areas have exerted negative impact on riparian forest. The results of the present study clearly brought out the need for preparing and implementing site-specific conservation plans for riparian ecosystem.

This article highlights the impact of anthropogenic disturbance on forest structure and plant diversity in the riparian forest in the Cauvery Wildlife Sanctuary, Karnataka, Southern India. We clustered 11 transects into groups with low and high anthropogenic disturbances. In total, 73 tree species were recorded on 11 transects, of which 57 species were found in less-disturbed sites and 39 species in high-disturbed sites. Shannon-Wiener diversity confirmed higher values for less-disturbed sites (3.2 ± 0.7) compared with high-disturbed sites (2.7 ± 0.5). Evenness index suggested no complete evenness in the two sites. Mean species richness and number of individuals in the majority girth classes were found to be higher in less-disturbed sites than in high-disturbed sites. Non-native plants dominated the high-disturbed sites. The occurrence of native and nonnative species was correlated with the level of disturbance. Current disturbance intensities may have led to loss of native species such as Ixora bracheata, Madhuca latifolia, Syzygium cumini and Terminalia arjuna in riparian forests. This study concludes that species-rich areas in the riparian forests are under threat. Protection of these areas should be prioritized in policy, because anthropogenic disturbance has led to decreasing riparian forest species diversity and structure.

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Eriocaulon vandaanamense (Eriocaulaceae), a new species from a marshy coastal area in the Alappuzha District, Kerala, India, is described and illustrated. Th e new species is similar to E. truncatum and resembles it in having vertically elongated seed coat cells, but diff ers mainly in having pale black hoary fl oral bracts, 3-lobed hoary male sepals, linear-falcate, non-conduplicate hoary female sepals, and small, smooth, pale brown seeds without seed coat appendages.

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