Release from Root Competition Promotes Tree Seedling Survival and Growth Following Transplantation into Human-Induced Grasslands in Sri Lanka

background

This study evaluates the growth and survival of four native tree species planted as seedlings in grasslands situated in previously abandoned tea plantations.

Research Goals & Methods

Each seedling underwent one of eight different treatments based the various combinations of: with or without root competition, shoot competition, and vertebrate herbivory. Seedlings that died within the first month were replaced. Growth and survival was evaluated at 18 and 28 months.

Conclusions & Takeaways

The authors found that root competition was a more significant constraint on seedling growth and survival than above-ground competition and herbivory. Three of the species, Macaranga indica, Schygium spathulatum, and Symplocos cohinchinensis showed positive growth responses to reduced root competition while just the fast-growing light demanding species, Macaranga indica, had higher survival upon the removal of root competition. Symplocos cochinchinensis had the highest growth and survival with and without root competition. The authors suggest that intensive site preparation to reduce the root competition might be necessary for restoration of these species in the grassland. Additionally, they recommend that the Macaranga and Sympolocus species would be the most promising for native species reforestation in the grasslands.