Relationship between Maling bamboo (Yushania maling) invasion and decrease of plant species diversity in the Eastern Himalayan temperate forest

Abstract

Temperate forests of the Eastern Himalayan region are undergoing a noticeable transformation due to invasion and over-dominance by indigenous Yushania maling, Maling bamboo. In the present study, the impact of invasion of Maling bamboo on forest species composition in the Senchal Wildlife Sanctuary located in Darjeeling district of West Bengal, India was investigated, using a comparative approach. Ten plots each from Maling and non-Maling habitats at 10 sites were sampled using the nested quadrat method. Maling-infested plots showed lower species richness and diversity compared to non-Maling plots. The Maling-infested plots harboured 119 species compared to 165 species in non‑Maling plots. Across habitat and vegetation strata, diversity indices such as Shannon-Weiner, Menhinick, Simpson, and evenness consistently indicated lower diversity in Maling-dominated habitats accompanied by higher dominance scores. Significantly lower shrub and herb species diversity were observed in Maling plots, along with elevated shrub density and moderately lower tree density as compared to non‑Maling plots. The sapling species diversity and density were significantly lower in Maling plots, along with moderately reduced seedling density. The average Maling culm density was 1232.8 per 0.04 ha. These results underscore the adverse impact of Maling bamboo over-dominance on species composition of shrub, herbs, sapling and seedlings, and the density of trees, shrubs, saplings and seedlings within the temperate forests. Potential management strategies for the native species are discussed.