Grassland Communities, Graminoid Composition, and their Diversity Pattern on the Eastern Mountain Slope of Dochula, Bhutan

Abstract

The composition of grassland communities in Bhutan is poorly understood. This study was conducted to determine the grassland communities and graminoid diversity pattern among different vegetation types on the east slope of Dochula. We laid twenty-four Modified Whittaker (MWP) nested plots in six different vegetation types through stratified random sampling. A total of 268 plant species were recorded, of which 110 were graminoids. Mean alpha richness ranged from 16–38 species between MWPs. Species richness and Shannon index were the highest in agriculture land, while meadow had the lowest. One-way ANOVA showed significantly higher species diversity and richness in agriculture land. Three grassland communities were identified through cluster analysis: Dry Chirpine grassland, Agriculture meadows, and Cool temperate grassland. This study explored the possibility to classify grassland communities in Bhutan and suggests that the current method can be upscaled to classify grassland communities at a national level. However, additional environmental factors such as soil moisture, soil temperature, and nutrient content are required to better explain species distribution and their interactions.