The combined effect of surface water and groundwater on environmental heterogeneity reveals the basis of beta diversity pattern in desert oasis communities

Abstract

Beta diversity indicates the species turnover with respect to a particular environmental gradient. It is crucial for understanding biodiversity maintenance mechanisms and for prescribing conservation measures. In this study, we aimed to reveal the drivers of beta diversity patterns in desert hinterland oasis communities by establishing three types of surface water disturbance and groundwater depth gradients. The results indicated that the dominant factor driving the beta diversity pattern within the same gradient shifted from soil organic matter to pH, as groundwater depth became shallower and surface water disturbance increased. Among the different gradients, surface water disturbance can have important effects on communities where original water resource conditions are extremely scarce. Under the premise that all habitats are disturbed by low surface water, differences in groundwater depth dominated the shifts in the community species composition. However, when groundwater depth in each habitat was shallow, surface water disturbance had little effect on the change in species composition. For the two components of beta diversity, the main drivers of species turnover pattern was the unique effects of surface water disturbance and soil environmental differences, and the main driver of species nestedness pattern was the common effect of multiple environmental pressures. The results of this study suggest that increasing the disturbance of surface water in dry areas with the help of river flooding will help in promoting vegetation restoration and alleviating the degradation of oases. They also confirm that surface water and groundwater mutually drive the establishment of desert oasis communities. Equal focus on both factors can contribute to the rational ecological recovery of dryland oases and prevent biodiversity loss.

Influence of surface water and groundwater on functional traits and trade-off strategies of oasis communities at the end of the Keriya River, China

“…However, except for the summer floods, the seasons and timing of flood events are not fixed. During the flood period, some areas experience different degrees of surface water overflow, leading to surface water disturbances on a certain scale (Shi et al, 2022). The plant community of the oasis consists mainly of Populus euphratica, Tamarix chinensis, Phragmites australis, and others.…”

The Great Gobi A Strictly Protected Area: Characterization of Soil Bacterial Communities from Four Oases

“…Moreover, such results are mostly obtained by studies carried out on samples collected from sandy dunes, with high temperatures and soil nutrient limitation [ 20 ]. On the other hand, desert oases represent a research hotspot in ecology and biodiversity, where much endemic plant, animal and microbial biodiversity coexists and responds well to environmental changes and stress conditions occurring in such extreme areas such as drought [ 21 ]. Such unique environments are quite fragile and complex, and are often the product of several isolation, adaptation and integration events through time and space, where cultural and natural factors influenced the development and interconnection among oases [ 22 ].…”