Characterization of forest-grassland mosaic in upper Palni Hills: analyzing the vegetation and soil characteristics along the ecotone from grassland to shola
Student name: Mr Sandeep Juyal
Guide: Dr Joachim Michael Schmerbeck
Year of completion: 2013
Host Organisation: University of Freiburg, Germany
Supervisor (Host Organisation): Dr Stefanie Gartner
Abstract: The plant community composition and structure of shola-grassland and their ecotone was
studied in the high hills of Palnis by analyzing the change in plant composition from
ecotone to shola and grassland and what determines this ecotone. Species inventory was
done on lower, middle and upper layer and tree regeneration was recorded according to
different height and dbh parameters. In total 45 plots were laid down in grassland, ecotone
and shola for vegetation assessment. Basic edaphic characteristics and disturbance signs
were taken into consideration. Hemispherical photos were clicked to calculate the canopy
openness. Height and dbh of trees were recorded to calculate the basal area and index
for volume. Sampling was carried out in plots systematically distributed at a regular distance
on a transect starting from ecotone going on both sides in shola forest and grassland. The
species composition, richness and evenness was assessed between grassland, ecotone and
shola.
Tree regeneration was recorded in grassland suggesting the ability of trees to grow in
grassland. A high number of tree regeneration was observed in ecotone and shola shown by
the total index for volumeand biomass of trees. A significant difference was found in depth of
horizons of grassland, ecotone and shola. Sholas were found on slopes equal to grassland
suggesting that the sholas do have potential of growing in steep slopes. Disturbances like
fire and browsing was present in the grassland shown by the disturbance signs found in plots.
The presence of signs of disturbance support the idea that fire frequency and sapling growth
rate can play a major role in establishment of woody and tree species in the grassland
of woody and tree species in the grasslands. Due to the inability of forest to colonize in the
grassland which is under the influence of frequent or moderate fires, a sharp ecotone or
boundary is maintained between the two vegetation. The source of fire and frequency can play
a role in establishment of tree species in grassland and the depth of soil was found to be an
important factor for the presence of these vegetation types in close viscinity.
Key words: Shola, ecotone, disturbance, regeneration
