Biodiversity values of abandoned teak, Tectona grandis plantations in southern Western Ghats: Is there a need for management intervention?

• Published in: Basic and applied ecology 2012-03, Vol.13 (2), p.139-148
• Main Authors: Harikrishnan, S., Vasudevan, Karthikeyan, Udhayan, A., Mathur, P.K.
• Format: Article
• Language: English
• Subjects: Biodiversity; conservation areas; correlation; Elephantidae; Elephas maximus; fauna; feces; flora; Forestry; forests; habitats; herbivores; indigenous species; mithuns; plantations; Regeneration; Restoration; Rusa unicolor; seedlings; species diversity; Tectona grandis; trees; Tropical forest; understory; Western Ghats
• ISSN: 1439-1791
• DOI: 10.1016/j.baae.2012.01.001

Abandoned plantations could potentially support a large number of native tree species through succession and restore the original tree community. In order to assess the ability of abandoned teak plantations to recover through regeneration, teak stands from 29 to 80 years old were sampled for seedling and sapling density, species richness and the use by large ungulates in the southern Western Ghats using 10m circular plots. The influence of the forest-plantation edge was also studied. There was regeneration of a species-rich tree community in the understorey of abandoned teak plantations. However, regeneration was arrested, and thereby the large girth-class tree community remained species-poor. There was no significant change in the tree species richness with distance from natural forest, suggesting that the forest-plantation edge had little influence on the penetration of native tree species inside plantations. Asian elephant and Indian gaur dung densities were significantly lower in the plantations than in the forest. Indian gaur and sambar used the younger plantations intensively, and the density of their dung was negatively correlated with age of the plantation. Abandonment of mature teak stands arrested the succession of native trees. We provide evidence that abandoned teak plantations might not serve as suitable habitats for large herbivores during the dry months of the year in the region. The study highlights the need for active management of mature teak plantations inside wildlife reserves, in order to promote succession and improve the habitat for wild flora and fauna in the Western Ghats. Aufgegebene Plantagen könnten möglicherweise eine große Anzahl einheimischer Baumarten durch Sukzession erhalten und die ursprüngliche Baumgesellschaft wieder herstellen. Um die Möglichkeit abzuschätzen, dass aufgegebene Teakholzplantagen sich durch Regeneration erholen, wurden Teakbestände im Alter von 29 bis 80 Jahren beprobt und die Keimlings- und Schösslingsdichte, der Artenreichtum und die Nutzung durch große Wiederkäuer in den südlichen Western Ghats auf kreisrunden 10m-Probeflächen festgestellt. Der Einfluss der Grenzlinie zwischen Wald und Plantage wurde ebenfalls untersucht. Es kam zur Regeneration einer artenreichen Baumgesellschaft im Unterholz der aufgegebenen Teakplantagen. Die Regeneration war jedoch gehemmt, und deshalb war die Gemeinschaft der Bäume mit großen Stammumfängen artenarm. Es gab keinen signifikanten Unterschied im Artenreichtum der Bäu