Yihe Lü

Amidst escalating pressures from anthropogenic disturbances and climate change, understanding the spatiotemporal dynamics of ecosystem structure-function relationships is fundamental for advancing conservation and sustainable development. While existing studies have explored aspects of either ecosystem structure or function, integrated analyses of their overall synergistic coordination remain limited. To address this knowledge gap, we proposed an integrated framework using the coupling coordination degree (CCD) to quantify the interaction and coordinated development of ecosystem structure and function in China’s drylands. Leveraging high-resolution, multi-source remote sensing data, we combined Random Forest modeling with partial correlation analysis to identify key drivers and project future CCD trajectories under four IPCC climate scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5). From 2000 to 2020, CCD exhibited a pronounced northwest-to-southeast gradient, with 66.9% of the regions showing improvement and 23.5% experiencing decline. The aridity index (AI) was identified as the predominant determinant of CCD variability, demonstrating a positive relationship in 96.2% of the study area, a pattern driven by moisture-mediated constraints on ecosystem self-organization. Future projections reveal a concerning divergence: under fossil-fueled development scenarios (SSP5-8.5), 52.42% of regions are anticipated to undergo CCD deterioration by mid-century, compared to 44.56% under sustainable development (SSP1-2.6). Notably, the regulatory influence of AI on CCD is predicted to intensify under moderate-to-high emission scenarios, underscoring the escalating role of drought as a critical force governing ecosystem stability. These findings provide novel mechanistic insights into the complex internal interactions of ecosystems under climate change. For moisture-limited ecosystems, our results underscore the imperative for adaptive management strategies that enhance hydrological regulation and promote drought-resilient species assemblages.

Ecological restoration has been widely regarded as an essential strategy to enhance carbon sequestration in ecologically fragile areas. However, the long-term sustainability and dynamics of carbon sequestration induced by afforestation remain uncertain, particularly in dryland river basins. Clarifying long-term carbon sequestration trends and understanding the impact of planted forests on these trends are crucial for ecological management and achieving carbon neutrality targets. In this study, we evaluated the dynamics of vegetation carbon sequestration and soil carbon storage in the Yellow River Basin (YRB) over the past two decades using annual Net Primary Production (NPP) and Soil Organic Carbon (SOC) datasets. Our results indicated that afforestation significantly enhanced NPP during the initial restoration phase (NPP increased by 34%), but subsequently NPP declined (NPP decreased by 10%), whereas SOC exhibited a modest increase with a gradually decreasing growth rate over time. Increased frequencies of extreme temperature and drought events negatively affected soil moisture availability and the sustained growth of planted forests. Furthermore, land-use transitions contributing to enhanced carbon sequestration and storage approached saturation, constrained by environmental limitations and cultivated-land protection policies. Given water-resource constraints, realizing future carbon sequestration benefits in dryland ecosystems requires more strategic vegetation spatial planning within ecological restoration initiatives. Our findings provide valuable insights for carbon management strategies in the YRB and similar dryland river basins.

Ongoing and widespread permafrost degradation potentially affects terrestrial ecosystems, whereas the changes in its effects on vegetation under climate change remain unclear. Here, we estimated the relative contribution of progressive active layer thickness (ALT) increases to vegetation gross primary productivity (GPP) in the northern permafrost region during the 21st century. Our results revealed that ALT changes accounted for 40% of the GPP increase in the permafrost region during 2000–2021, with amplified effects observed in late growing season (September–October) (43.2%–45.4%) and was especially notable in tundra ecosystems (51%–52.6%). However, projections indicated that this contribution could decrease considerably in the coming decades. Model simulations suggest that once ALT increments (relative to the 2001–2021 baseline) reach approximately 90 cm between 2035 and 2045, the promoting effect of ALT increase on vegetation growth may disappear. These findings provide crucial insights for accurately modelling and predicting ecosystem carbon dynamics in northern high latitudinal regions.

Desert and semi-desert ecosystems cover a large proportion of global land area, but their tree-ring materials had traditionally been studied less intensively than that of forest ecosystems. In this study, we presented the time series of growth rings from eight typical shrub species of the semi-desert region in the northern foot of Yinshan Mountain, Inner Mongolia, China. The results showed that all those shrub species had recognizably demarcated annual rings of main stems, and tree-ring chronologies could been constructed successfully. The climate-growth analysis indicated that the chronologies was positively correlated with precipitation and PDSI but negatively correlated with temperature variables, indicating that drought stress had primary importance in the control of the relative ring width from year to year for those shrub species. Interestingly, the annual growth rate of those shrub species had no noticeable downward trend in recent decades, indicating that shrub growth had not negatively impacted the recently developed warm–dry climate in the sample sites. Our results provide evidence that growth rings in the main stems of shrub species in the northern foot of Yinshan Mountain should be a reliable proxy of annual fluctuation in the semi-desert environment of China.

The ecological conservation and restoration of drylands is a global challenge, which is always under resources constraints and in competition with land developments. Here, we aim to identify ecological conservation and restoration priority areas based on the objectives of maximizing ecological values and minimizing opportunity costs with zonation as a heuristic spatial optimization tool. We take the Inner Mongolia (IM) of China as a typical dryland region. Results reveal that the efficiency of multi-objectives for ecological restoration is often better than a single objective. IM should focus on ecological conservation supplemented by restoration. Conserving 36.9% and restoring 13.1% of IM can provide an average of 72% of ecosystem functions while consuming 20% of opportunity costs. Our framework aligns with the need for nature-based solutions and rationalizes the allocation of resources for ecological conservation and restoration projects in complex dryland regions.