Driving Forces of Intra-Annual Variation in Plant Spectral Beta Diversity in Inner Mongolia Grassland

Abstract

The variation trend of plant spectral beta diversity index of different types of grasslands in Inner Mongolia and its key climate drivers were explored by analyzing the changes of monthly and annual climate variables and spectral index of plant diversity during the period from 1982 to 2017.All the study areas are located in nature reserves that provide protection for fragile ecosystems and biodiversity, so grazing and human disturbance can be ignored. The results show that the variation trends in plant spectral diversity of different types of grassland in Inner Mongolia were different. The plant diversity in Anxi nature reserve reached the highest in October, while that in West Ordos, Xilingol and Tumuji nature reserve reached the highest in April. Temperature is a key driving factor for the variation of beta diversity of all types of grassland plants, and is negatively correlated with the plant diversity. Compared with the inter-annual scale, the climatic factors on the inter-monthly scale have a greater impact on the grassland plant diversity. Understanding monthly climate variables help us monitor the dynamic change of grassland plant diversity in a timely and effective manner.