Ecological quality is overestimated in fragmented urban landscapes: Evidence from the Yangtze River Delta urban agglomeration
4 affiliations
- 1College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China
- 2College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China; Corresponding author.
- 3School of Environmental Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
- 4Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, 320 Donggang West Road, Lanzhou 730000, China
Abstract
Ecological indices derived from satellite observations are widely used to monitor environmental quality in rapidly urbanizing regions. However, most existing approaches primarily capture ecosystem state while neglecting landscape configuration, which may introduce systematic bias in fragmented landscapes. Here, we investigate whether landscape fragmentation constrains ecological quality assessment using the Yangtze River Delta Urban Agglomeration as a case study. Using the Landscape Division Index (DIVISION), we demonstrate that fragmentation represents an independent structural dimension of ecological quality, with IRSEI showing substantial divergence from conventional RSEI (ρ = 0.67), while remaining highly consistent with the intermediate nRSEI framework (ρ = 0.93). Our results reveal that traditional remote sensing-based indices tend to overestimate ecological conditions in highly fragmented urban environments, particularly in suburban and intercity transition zones where vegetation greenness does not necessarily reflect ecological integrity under fragmented conditions. To address this limitation, we incorporate landscape fragmentation into an improved assessment framework and show that accounting for spatial configuration reduces overestimation and provides a more spatially consistent representation of ecological quality. Spatiotemporal analysis further revealed pronounced spatial heterogeneity, although the proportion of areas classified as Poor and Fair declined from 37% in 2001 to 28% in 2022 across the region, persistent degradation remained concentrated in highly fragmented urban cores. These findings highlight that landscape fragmentation plays a critical role in shaping ecological assessment outcomes and should be explicitly considered in satellite-based environmental monitoring and regional sustainability evaluation.
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BibTeX
@article{ren2026ecological,
title = {{Ecological quality is overestimated in fragmented urban landscapes: Evidence from the Yangtze River Delta urban agglomeration}},
author = {Xiaoran Ren and Jian Zhang and Asim Biswas and Yaoyuan Fan and Siyi Cheng and Chunhui Zhan and Xufeng Wang},
journal = {Ecological Indicators},
year = {2026},
month = oct,
doi = {10.1016/j.ecolind.2026.115464},
url = {https://doi.org/10.1016/j.ecolind.2026.115464},
note = {CC BY},
}
RIS
TY - JOUR
TI - Ecological quality is overestimated in fragmented urban landscapes: Evidence from the Yangtze River Delta urban agglomeration
AU - Xiaoran Ren
AU - Jian Zhang
AU - Asim Biswas
AU - Yaoyuan Fan
AU - Siyi Cheng
AU - Chunhui Zhan
AU - Xufeng Wang
PY - 2026
DA - 2026/10/23
JO - Ecological Indicators
DO - 10.1016/j.ecolind.2026.115464
UR - https://doi.org/10.1016/j.ecolind.2026.115464
AB - Ecological indices derived from satellite observations are widely used to monitor environmental quality in rapidly urbanizing regions. However, most existing approaches primarily capture ecosystem state while neglecting landscape configuration, which may introduce systematic bias in fragmented landscapes. Here, we investigate whether landscape fragmentation constrains ecological quality assessment using the Yangtze River Delta Urban Agglomeration as a case study. Using the Landscape Division Index (DIVISION), we demonstrate that fragmentation represents an independent structural dimension of ecological quality, with IRSEI showing substantial divergence from conventional RSEI (ρ = 0.67), while remaining highly consistent with the intermediate nRSEI framework (ρ = 0.93). Our results reveal that traditional remote sensing-based indices tend to overestimate ecological conditions in highly fragmented urban environments, particularly in suburban and intercity transition zones where vegetation greenness does not necessarily reflect ecological integrity under fragmented conditions. To address this limitation, we incorporate landscape fragmentation into an improved assessment framework and show that accounting for spatial configuration reduces overestimation and provides a more spatially consistent representation of ecological quality. Spatiotemporal analysis further revealed pronounced spatial heterogeneity, although the proportion of areas classified as Poor and Fair declined from 37% in 2001 to 28% in 2022 across the region, persistent degradation remained concentrated in highly fragmented urban cores. These findings highlight that landscape fragmentation plays a critical role in shaping ecological assessment outcomes and should be explicitly considered in satellite-based environmental monitoring and regional sustainability evaluation.
SN - 1470-160X
SN - 1872-7034
ER -