Role of Eucalyptus sp. plantation on regeneration of native tree species in the Upper Palani hills, Tamil Nadu, India
Student name: Ms Anjana Srimathi
Guide: Dr Joachim Schmerbeck
Year of completion: 2012
Host Organisation: TERI University, New Delhi and University of Freiburg, Germany
Supervisor (Host Organisation): Dr Stephanie Gartner
Abstract: The hypothesis that forest plantations can harbour native woody species regeneration was tested
through analysing understory species composition, height class distribution of the regenerating
species, stem density of the plantations, topographic (slope, elevation, distance of native forest
and exposition); disturbance (grazing, fire and trampling) factors and canopy cover or crown
density influence on regeneration in Eucalyptus plantations in Upper Palani Hills, Tamil Nadu,
South India. A total of 60 plots having 7 x 7 m each (49 m²) were sampled across 12 plantations.
The plantations were stratified into four groups based on exposition, elevation and average
height. The species composition and tree diversity was assessed by analysis of species richness,
evenness and diversity between the groups. A total of 19 tree species was found to be
regenerating under the plantations compared to only three exotic tree species regenerating. The
seedling population was the most abundant regenerating level (63.66%). The density of
regeneration ranged from zero stems ha−1 to 3680 stems ha−1 across the 12 Eucalyptus
plantations. The stem density of the Eucalyptus (r=−0.149 and p=0.644), topographic factors
such as slope (r=−0.194 and p=0.3), distance of the native forest (r=−0.163 and p=0.6) seemed
to play no role in regeneration whereas the canopy cover or crown density (r=−0.273 and
p=0.39) and elevation (r=−0.410 and p=0.5) plays a weak role. The species regenerating were
mainly light demanding species (Daphniphyllum neilgherrense, Symplocos cochinchinenesis and
Vaccinium leschenaultii). The heavy grazing intensity category had the highest density of
regeneration (3457 stems ha−1
). The trampling percentage (9 % to 33.3%) showed that low
trampling sites had more regeneration (35%) compared to heavily trampled site (17%
regeneration). The presence of grazing and trampling indicated that disturbance had a crucial
role in regeneration occurrence. These results supported the hypothesis that Eucalyptus
plantations can harbour native species regeneration.
Keywords: Eucalyptus, disturbance, native tree species, topography and Palani Hills
