Establishment Potential of Seed Balls in Forest Ecosystems in Tamil Nadu, India

Abstract

Background: Forest degradation and limited success of natural regeneration necessitate cost-effective restoration approaches, with direct seeding emerging as a scalable alternative to conventional planting methods. Seed ball technology offers potential to enhance seed germination and establishment under harsh field conditions, yet its effectiveness in tropical forest ecosystems remains inadequately understood. Aims: The study aims to assess establishment potential of seed balls in different forest ecosystems. Study Design: Laboratory standardization and then field experiments. Place and Duration of Study: Laboratory work and field experiments were conducted in Athikadavu, Pethikuttai forests of Karamadai and Sirumugai forest ranges in Western Tamil Nadu for South-West and North-East monsoon seasons respectively. Methodology: Laboratory experiments were done to determine the germination potential of the selected tree and grass species by use of sand tray, roll towel and pot culture. Depending on the laboratory standardization, seed balls were made with optimized medium of red soil and vermicompost (2:1 ratio) that was found to be effective in terms of seed ball size, weight, fragmentation and dissolution behavior. After this, field experiments were conducted with the seven species. Findings: Laboratory findings showed that there was increased germination in grass species which included Apluda mutica (80%), Eriocoma hymenoides (85%) and lower germination in tree species which included Albizia amara (25%). Nevertheless, very low germination in the forest conditions was observed during field observations. In South-West monsoon, germination was restricted to 27 percent, but a small increase (to 89 percent) was seen during North-East monsoon. Moreover, grass species fared better than tree species and only Albizia amara and Acacia chundra established significantly as far as tree species were concerned. Overall, the study revealed that seed balls had maximum germination potential of about 10% under forest ecosystems. Conclusion: Seasonal effects, as well as fungal infection, pest incidence and environmental conditions, had significant impacts on seed ball establishment. More research to enhance seed ball technology to achieve successful mass restoration of forests is needed.