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Landscape Pattern and Plant Diversity in an Arid Inland River Basin: A Structural Equation Modeling Approach Based on Multi-Source Data
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College of Tourism, Xinjiang University of Finance and Economics, Urumqi 830012, China
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College of Economics, Xinjiang University of Finance and Economics, Urumqi 830012, China
3
Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
*
Author to whom correspondence should be addressed.
Biology 2025, 14(8), 1100; https://doi.org/10.3390/biology14081100
Submission received: 29 July 2025
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Revised: 18 August 2025
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Accepted: 19 August 2025
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Published: 21 August 2025
(This article belongs to the Section Conservation Biology and Biodiversity)
Simple Summary
Arid river basins are very sensitive to climate and land-use change, but it is unclear how the environment, landscape structure, and habitat connections together shape plant diversity. We studied the Hotan River Basin in northwest China using satellite images (2000, 2012, and 2023), field plots, terrain, and climate data. Over the past two decades, the bare land shrank and was mainly replaced by shrubland and cropland, while the construction land expanded. The landscape became more fragmented and heterogeneous (more, smaller, less-clumped patches). Plant diversity was highest on gentle-to-moderate slopes and where the annual rainfall was about 32–36 mm. Using a statistical pathway model, we found that the environmental conditions directly increase plant diversity, but the way the land is arranged (its structure) could reduce it when fragmentation is high. The habitat connectivity—how well patches are linked for seed and pollen movement—directly promotes diversity. The strongest pathway is the environment, which first reshapes the landscape structure, and then affects connectivity and ultimately plant diversity. These insights support “connectivity-first” planning in drylands: protect and restore the riparian and shrubland corridors and stepping-stone patches, guide construction away from the key links, and maintain environmental flows and shallow-groundwater belts to keep habitat networks functional under climate stress.
Abstract
Biodiversity in arid river basins is highly climate-sensitive, yet the multi-pathway relations among the environment, landscape structure, connectivity, and plant diversity remain unclear. Framed by a scale–place–space sustainability perspective, we evaluated, in the Hotan River Basin (NW China), how the environmental factors affect plant diversity directly and indirectly via the landscape configuration and functional connectivity. We integrated Landsat images (2000, 2012, and 2023), 57 vegetation plots, topographic and meteorological data; computed the landscape indices and Conefor connectivity metrics (PC, IIC); and fitted a partial least squares structural equation model (PLS-SEM). From 2000 to 2023, the bare land declined, converted mainly into shrubland and cropland; the construction land is projected to expand under SSP1-2.6/SSP2-4.5/SSP5-8.5 by 2035 and 2050. The landscape metrics showed a rising PD, DIVISION, and SHDI/SHEI, and a declining AI and CONTAG, indicating finer, more heterogeneous mosaics. Plant diversity peaked on low–moderate slopes and with ~32–36 mm annual precipitation. The PLS-SEM revealed significant direct effects on diversity from environmental factors (positive), landscape structure (negative), and connectivity (positive). The dominant chained mediation (environment → structure → connectivity → diversity) indicated that environmental constraints first reconfigure the spatial structure and then propagate to community responses via connectivity, highlighting connectivity’s role in buffering climatic stress and stabilizing communities. The findings provide a quantitative framework to inform biodiversity conservation and sustainable landscape planning in arid basins.
