Responses of arid plant species diversity and composition to environmental factors

Abstract

An oasis is a unique natural landscape in arid and semi-arid areas, significant for regulating regional microclimates and hydrological processes in deserts. However, little is known regarding the response of natural oasis plants communities to various environmental factors. Nineteen sample plots (50 m × 50 m) were selected in the Daliyabuyi Oasis in the Taklimakan Desert hinterland based on the location of groundwater monitoring wells and 76 vegetation quadrats (25 m × 25 m) were established. A two-way indicator species analysis, Mantel test, detrended correspondence analysis, canonical correspondence analysis (CCA), and hierarchical partitioning were used to provide an in-depth analysis of community classification, species composition, and environmental interpretation of the oasis. A generalized linear model was used to verify the results which showed that the current oasis community could be divided into four types according to the dominant species, which is controlled by soil moisture. Measurement of species composition and distribution of communities showed significant differences between species diversity of individual community types. Variations in groundwater depth affects patterns of species diversity which is sensitive to richness, while the degree of surface water disturbance affects the pattern of species evenness. Moreover, the CCA ordination map showed that community distribution and diversity characteristics have their own preferences in habitat gradients. The study concluded that the species dominance of the community and the composition and distribution are not dominated by a single factor. There are differences in the scale and effect of different water resource types in maintaining community characteristics.

The Impact of Groundwater Burial Depth on the Vegetation of the Dariyabui Oasis in the Central Desert

“…The multi-mean temperature is 12.1 • C, potential annual evaporation is 2480 mm, and an extreme temperature difference exists between day and night. Reeds of the Gramineae family, tamarisk shrub, and poplar tree were the dominant species (Figure 2), and minor vegetation types included camel thorn and bitter pea [38,44]. and groundwater burial depth was analysed using cubic curve regression.…”

“…The multi-mean temperature is 12.1 °C, potential annual evaporation is 2480 mm, and an extreme temperature difference exists between day and night. Reeds of the Gramineae family, tamarisk shrub, and poplar tree were the dominant species (Figure 2), and minor vegetation types included camel thorn and bitter pea [38,44]. [45,46] (https://step.esa.int/main/snap-supported-plugins/sen2cor/sen2cor-v2-11/ (accessed on 15 December 2023)) in the SNAP Toolbox version 2.11.0 was used for atmospheric corrections, radiometric calibrations, and to obtain the Sentinel-2L2A image data.…”

“…Reeds and tamarisks dominate the vegetation in locations with shallow groundwater, poplars and tamarisks dominate in areas with deep groundwater, and poplars and a few tamarisks dominate the northern part of the oasis, where groundwater is the deepest. Vegetation in the northern part of the oasis has been degraded to varying degrees, and studies have been conducted on plant communities affected by the groundwater depth [38], the spatial distribution pattern of poplar [39], and the estimation of vegetation cover in the oasis based on visible and multispectral indices from UAV remote sensing [40].…”

Distinct Impact of Drought on Radial Growth at Different Heights and Parts of Populus euphratica in the Oasis at the Hinterland of the Taklimakan Desert

“…The growth of P. euphratica is influenced by various environmental factors, including groundwater, surface water, and temperature. Groundwater is pivotal in the growth of P. euphratica [30,31]. Previous studies have primarily focused on reconstructing past groundwater depth data or examining the relationship between groundwater and radial growth using tree chronology.…”

“…The Daliyaboyi Oasis is situated in the Tarim Basin of China and is an alluvial oasis formed by the deep penetration of the Keriya River into the hinterland of the Taklamakan Desert [31]. The oases remain in a 'pristine' state with minimal anthropogenic disturbance in this region, which distinguishes them from most of the extant modern oases in Central Asia [32].…”