A study on coupling of the grassland pattern and the flood process in Poyang Lake based on the island biogeography theory

Abstract

As a typical type of landscape in Poyang Lake, the largest freshwater lake in China, grassland has been deeply disturbed by the flooding process. However, how the vegetation landscape diversity respond to the flooding process of Poyang Lake remains unclear. In this paper, we randomly selected 10 grasslands in the period of a normal water level from 2010 to 2019 to study the coupling relationship between the vegetation landscape diversity and flooding process, and established the related models based on the island biogeography theory. The results are as follows. (1) There is a positive correlation between the grassland vegetation landscape diversity and grassland area, the best fitting model is the logarithmic function. (2) Using the general dynamic model of island biogeography as a reference, the model of diversity–area–flooding established by using the area of grassland and duration as predictor variables has the highest goodness-of-fit. (3) If grassland was flooded for 120–130 days and the maximum depth of flooding is not more than 2.5 m every year, the vegetation landscape diversity in grasslands will be the highest. The findings have provided an extension to the study of the response of vegetation to flooding processes, and provide a certain theoretical basis for the protection and management of the Poyang Lake ecosystem.

Dynamic simulation of the grassland connectivity and the effects of landscape pattern in China's Poyang Lake from the integrated perspective of habitat and biology

“…It is an unique habitat for wintering migratory birds and many specific species and plays important role in biodiversity conservation. In recent years, studies on grassland mainly focus on the distribution characteristics of grassland (Zhang et al, 2014), the distribution of grassland vegetation and its response to water level changes (Yao et al, 2021) and the impact of hydrology on grassland landscape pattern (Luo et al, 2022). Most current studies focus on the changes of spatial structure of grassland and vegetation community distribution from the perspective of hydrological disturbance.…”