Conservation implications of seed rain in mid elevation grasslands of Silent Valley: a case study.
Jawaharlal Nehru Tropical Botanic Garden And Research Institute
Tree species occurring in grasslands accelerate seed rain. This subsequently promotes seedling recruitment. These tree species can be used in similar habitats elsewhere for triggering natural afforestation. Forests developed through this process generate appropriate ecosystems that are capable of meeting the needs of animal communities as such ecosystems evolve along with the animals.
We identified 12 tree species, based on abundance, in five mid elevation grasslands contiguous to evergreen forests of Silent Valley in the Western Ghats, India. Seed rain beneath the canopies of these trees was studied establishing 108 seed traps: 60 in open areas of grasslands and 48 beneath the trees. Seedling demography in open grasslands was studied taking 25, 10x10 quadrates and that beneath the trees was studied taking the entire canopy area beneath the trees.
Seed rain was 32 times greater under the tree canopies than in open grasslands. Seedling diversity and density were also 1.5 times and 33 times higher respectively. The highest seed rain was recorded beneath Glochidion ellipticum. The highest seedling diversity and density was recorded beneath Olea dioica.
Of the 78 tree species found in the forests contiguous to grasslands, only 23 could establish in the grasslands and attract seed dispersers. But only 8 species could harbour seedlings under the canopies with high diversity and density. Such species, if introduced in similar habitats, can trigger natural afforestation, corridor construction and revival of degraded forests. This would be less labour intensive, inexpensive and meet the ecosystem needs of animals.