Elephant <i>Elephas maximus</i> Linnaeus (Proboscidea: Elephantidae) migration paths in the Nilgiri Hills, India in the late 1970s

The study presented was carried out in 1978 with the support of the Asian Elephant Specialist Group (AsESG) of the International Union for the Conservation of Nature (IUCN) Species Survival Commission (SSC). Its objective was to investigate the impediments to elephant movement in the Nilgiri Hills, in the Western Ghats of India, in an attempt to suggest positive steps to encourage movement through the provision of corridors. The report was left unpublished, but given its importance as a reference document for the conservation of the Asian elephant in the Nilgiris, in 2011 the last two authors decided to publish it. The process of habitat fragmentation has been going on ever since man started agriculture. But this problem has, of late, become much more acute due to mounting pressure on land. The corridor concept applied to wildlife is the provision of a free and, as far as possible, unimpeded way for the passage of wild animals between two wildlife zones. A corridor’s more important function is to prevent wild animals from getting isolated in small pocket-like islands. Maintaining elephant habitat connectivity in and around the Nilgiris rests upon the understanding that elephant populations of the several protected areas of the now Nilgiri Biosphere Reserve must remain active. The first author surveyed the Nilgiris on foot and on elephant back for several months in 1978. It was concluded that four areas (the Nilgiri north slopes and Deccan Plateau, the south and southeastern slopes, the Gudalur Plateau, and the upper plateau) harboured together 10 corridors that needed to be maintained, or restored, or even partially restored

Edge transition impacts on swamp plant communities in the Nilgiri mountains, southern India

Swamps represent a relatively understudied ecosystem in many regions, which contrasts markedly with the research attention which other wetlands and Mangrove ecosystems have received. In the upper Nilgiris of southern India, montane swamps are restricted to geographic areas with flat surfaces and bounded by different edge transition vegetation types including grasslands and shola forests. Our study examined whether species richness, endemism, edge and the composition of swamp interior communities have a significant relationship with swamp area. Using species-area curves we continued sampling for species in each swamp until species richness reached the asympote within that swamp. Our results suggest that species richness (log n), log endemism, and edge and swamp interior species composition do not increase significantly with increasing area due to edge effect. Moreover, swamp area and vegetation parameters showed no significant relationships. However our results did indicate that swamps species richness and endemism were affected by abiotic and biotic edge effects, particularly physical topographic environment and the structure of adjoining matrix vegetation. Therefore swamp protection and restoration, in addition to the preservation and management of buffer regions may be important conservation criteria to preserve these fragile ecosystems

Stem anatomy and relative growth rate in seedlings of a wide range of woody plant species and types

Stem traits were analysed in laboratory-grown seedlings of 80 European woody and semiwoody species of known potential relative growth rate (RGR) and of similar ontogenetic phase. The objectives were, firstly, to assess the relation between stem structure and plant growth potential and, secondly, to explore how stem structure varies among species differing in life form and leaf habit. Hydraulic conductance was represented by the mean diameter of the widest xylem conduits (Dmax), and structural strength by the percentage of xylem tissue occupied by cell wall material (CWx) or stem tissue density (SD). Across all species RGR showed a weak positive correlation with Dmax and weak negative ones with CWx and SD, with slow-growers showing great dispersion of stem trait values. In the RGR-Dmax relationship this dispersion disappeared when trees were removed from the analysis. None of the relationships were significant among tree species alone. It was suggested that fast-growers require a xylem with wide conduits (high Dmax) to achieve high hydraulic conductivity, and 'cheaply' constructed stems (low CWx and SD) to maximise allocation to leaves. However, the possession of such traits does not guarantee fast growth, as other factors may constrain RGR elsewhere in the plant. Deciduous seedlings showed higher Dmax and lower CWx than evergreens. Higher Dmax could reflect an innate higher tolerance of conductivity loss by freeze-induced embolism in deciduous plants, which are not burdened by the maintenance of foliage in winter. In contrast, life forms were differentiated most clearly by SD. For instance, shrub seedlings had less dense stem tissues than tree seedlings, possibly because they need less investment in long-term strength and stature