Jinghua Huang

Global biodiversity loss poses critical challenges to achieving the UN Sustainable Development Goals, particularly SDG 15 (Life on Land) and the 30 × 30 target. However, translating broad sustainability targets into regionally optimized conservation strategies remains challenging, as current planning approaches typically treat coverage targets as fixed constraints rather than optimizing ecological outcomes. Here, we propose a dose–effect framework that integrates spatial prioritization with standardized effect-size analysis to identify protection coverage that maximizes gains in ecosystem multifunctionality, supporting sustainable ecosystem management. Using the Loess Plateau of China as a case study, we constructed a composite ecological function index from five ecosystem services, identified conservation priorities using Zonation with existing protected areas locked in as the highest-priority foundation, and quantified the dose–effect relationship between incremental coverage and standardized multifunctionality gains. Results revealed a nonlinear, threshold-dependent curve, with an optimal threshold at 30.79% coverage where the standardized effect reached its maximum. Beyond this threshold, marginal gains declined as the study incorporated lower-quality habitats. This study demonstrates that explicit dose–effect assessment provides a replicable, sustainability-oriented protocol for optimizing protected area expansion, enabling decision-makers to balance conservation effectiveness with sustainable land-use planning across diverse contexts.

Chinese wolfberry (Lycium chinense Miller) is a vital medicinal plant and a key species for ecological restoration. While Species Distribution Models (SDMs) are commonly used to predict habitat suitability, they often rely exclusively on native occurrence data, potentially underestimating a species’ climatic niche breadth under assumptions of niche conservatism. This study aims to evaluate the global climatic tolerance of Chinese wolfberry by integrating occurrence data from both native and introduced ranges. We assess the impact of climate change on its potential range shifts in China and determine whether native-only models underestimate the species’ climatic tolerance. We compiled 984 high-quality global distribution points (536 native, 448 introduced). We compared climatic niche breadth derived from native-only data with that from global data. Using MaxEnt modeling, we projected the global niche model onto China under current conditions and under four future Shared Socioeconomic Pathways (SSP126, SSP245, SSP370, and SSP585) for the year 2070 to analyze changes in habitat suitability and centroid migration. The study confirms that relying solely on native data significantly underestimates the climatic tolerance of Chinese wolfberry, particularly for thermal variables (e.g., mean temperature of the warmest/coldest month). The global model, driven primarily by the coldness index, annual biotemperature, and humidity index, showed excellent performance (AUC = 0.952). Currently, highly suitable habitats cover approximately 44% of China’s land area. However, future projections indicate a severe decline in habitat quality. While the total suitable area remains relatively stable, the proportion of highly suitable habitat within the total habitat is projected to drop from 62.6% to as low as 19% under high-emission scenarios. The centroid of highly suitable habitats is expected to migrate multidirectionally at an annual rate of 0.97–2.42 km·a⁻¹, while the altitudinal centroid shows a drastic upward shift of up to 7.24 m·a⁻¹ under the SSP585 scenario. Integrating global occurrence data provides a more robust estimate of the ecological tolerance of Chinese wolfberry. Future climate change poses a significant threat to the quality of suitable habitats in China, necessitating adaptive management strategies such as assisted migration to northern refugia and the implementation of climate-smart agricultural practices to sustain the economic and ecological value of this species.

While organic amendments are extensively applied to increase soil organic carbon (SOC), the mechanisms by which they restructure soil food web energetics to regulate microbial necromass formation and carbon sequestration remain unclear. We conducted a 105-day incubation experiment to investigate how three organic amendments (straw, biochar, liquid organic fertilizer), differing in C:N ratio and pH, and applied at three rates, affect nematode food web energetics and carbon sequestration in black soils of Northeast China. Results showed that amendment properties and application rates jointly shaped nematode energetic structure, differentially regulating total energy flux (E_t) and flow uniformity (U). Straw (moderate C:N, near-neutral pH) strongly increased both E_t (up to 587% above control) and U (peak at 1.68) by fostering fungivore-dominated energy channels. Despite its high C:N ratio, biochar’s alkaline pH favored bacterial-dominated channels, improving flow uniformity (U up to 1.61) without increasing E_t. Liquid fertilizer (low C:N, high pH) produced rate-dependent outcomes: the low rate increased E_t by 210% above control via enhanced bacterial channels, whereas the high rate suppressed E_t but elevated U by reducing energy allocated to plant parasites. Critically, energy flow uniformity correlated positively with fungal necromass carbon, which drove SOC accumulation, whereas total flux was strongly linked to bacterial necromass carbon, suppressing SOC. All amendments finally enhanced omnivore-predator energy flux, boosting top-down regulation and uniform energy distribution. However, mineral fertilizer truncated the food web and suppressed flow uniformity, failing to increase SOC. Therefore, organic amendments enhance SOC by restructuring nematode-mediated energy flow by reinforcing fungal-dominated channels and/or increasing flow uniformity, thereby promoting fungal necromass accumulation and providing a mechanistic basis for targeted management of degraded black soils.

Applying organic amendments enhances agroecosystem multifunctionality (EMF), yet its mechanisms via soil food-web energetics remain unclear. A field experiment was conducted on China’s Loess Plateau in a winter wheat system, comparing mineral fertilizer with straw, biochar, and liquid organic fertilizer to assess their impacts on nematode communities and EMF (plant performance and carbon, nitrogen, phosphorus cycling). Using high-throughput sequencing and energy flux modeling, we found that straw and biochar enhanced nematode diversity and co-occurrence network complexity, while liquid organic fertilizer reduced network complexity. Straw balanced fungal- and bacterial-driven energy pathways, enhancing energy flow uniformity (1.05) and EMF. However, its high C:N ratio requires mineral fertilizers to alleviate nitrogen limitations, ensuring stable bacterial energy fluxes and preventing functional trade-offs. Biochar elevated total energy flux but prioritized bacterial- and herbivore-driven pathways, reducing energy flow uniformity (0.76) and functional balance. Liquid organic fertilizer favored omnivores-predators, destabilizing lower trophic functions with minimal functional gains. Amendment properties (C:N ratio, pH) shaped nematode-mediated energy distribution, linking biodiversity to multifunctionality. Overall, straw is optimal for supporting EMF when combined with mineral fertilizers, while biochar and liquid fertilizer require tailored management to mitigate functional trade-offs. These findings advance sustainable strategies for dryland agroecosystems in the Loess Plateau region and similar environments.

China has implemented several ecological projects in the Loess Plateau region to address severe land degradation and soil erosion. Accurately assessing ecological restoration and its driving factors remains challenging. Previous studies in this area concentrated on driving factors have mainly focused on natural factors at the regional or watershed scale, with limited consideration of socioeconomic factors at the county scale. In this study conducted in Huanglong County on the Loess Plateau, the focus was to fill the gaps in previous research and provide insights into the socioeconomic driving forces behind vegetation greening. Remote sensing image data (NDVI) from 1999 to 2019 were used to analyze vegetation greenness dynamics in the region. Five socioeconomic variables were considered, including afforestation intensity, deforestation intensity, agricultural intensity, village intensity, and road intensity layers, to characterize the impact of afforestation, agriculture, and urbanization policies. The RESTREND (residual trends) method was employed to assess the relative importance of climate and human activities on vegetation dynamics. This study found that temperature–NDVI relationships are more suitable for building RESTREND models than precipitation–NDVI relationships. Human activity was the main driver of vegetation dynamics, contributing 62% compared to 38% from climate change. Agricultural practices and afforestation were found to have a positive impact on ecological restoration, while deforestation and urbanization had no significant impact. These findings highlight a conceptual framework for understanding the intricate relationship between ecological restoration, climatic factors, and human activity on the Loess Plateau. This study suggests that significant progress has been made in ecological restoration through human efforts in combating land degradation. However, it emphasizes the need to strengthen natural conservation efforts and gradually transition toward restoration processes driven by natural forces for sustainable socioeconomic development. The methodology used in this study can be applied to explore the driving forces of ecological restoration in other regions facing human-driven land degradation.

In order to explore the impact of soil erosion degradation on soil hydraulic properties of slope farmland in a typical black soil region, typical black soils with three degrees of erosion degradation (light, moderate and heavy) were selected as the research objects. The saturated hydraulic conductivity, water holding capacity and water supply capacity of the soils were analyzed, as well as their correlations with soil physicochemical properties. The results showed that the saturated hydraulic conductivity of black soils in slope farmlands decreased with erosion degradation degree, which was higher in 0–10 cm soil layer than in 10–20 cm soil layer. The water holding capacity and water supplying capacity of typical black soils also decreased with the increase of erosion degradation degree, and both of them were stronger in the upper soil than in the lower soil. With the aggravation of erosion degradation of black soils, soil organic matter content decreased while soil bulk density increased, leading to the decline of soil hydraulic conductivity. The increase of soil bulk density and the decrease of contents of organic matter and >0.25 mm water stable aggregates were the main factors leading to the decrease of soil water holding capacity. These findings provide scientific basis and basic data for rational utilization of soil water, improvement of land productivity and prevention of soil erosion.

Soil nematode communities can offer valuable indicators for monitoring the status of soil ecosystems. However, their potential for assessing soil restoration under revegetation has been neglected in temperate arid and semiarid areas. This study examined the characteristics of soil nematode communities and their relationships with soil physicochemical properties under five typical revegetation approaches in the semiarid Loess Plateau of China. The results showed that planting an artificial Caragana korshinskii forest led to the recovery of the soil food web, which significantly increased soil nematode abundance (138.10 ± 11.60 inds./100 g dry soil) and community diversity (Shannon-Wiener diversity: 2.48 ± 0.13; trophic diversity: 3.08 ± 0.02), associated with the high contents of SOC and NH₄⁺-N. However, establishing an artificial Prunus sibirica forest improved neither soil properties nor nematode community characteristics, reflecting poor soil ecosystem restoration. After establishing an artificial Prunus davidiana forest (PD) and an artificial Medicago sativa grassland (MS), substantial increases in herbivorous and fungivorous nematodes were observed, respectively, likely due to the accumulation of particular genera that fed on roots (e.g., Pratylenchus) or their symbiotic fungi (e.g., Tylencholaimus), which might result in the deterioration (in MS) or restoration (in PD) of the soil food webs. Natural grassland restoration greatly improved soil properties (i.e., SOC, NH₄⁺-N, microbial biomass carbon) but did not change the nematode community obviously, probably due to top-down predation in natural habitats. In conclusion, the characteristics of nematode communities can effectively indicate the restoration of soil food webs and identify their possible driving forces under revegetation, which have important implications for vegetation restoration in arid and semiarid regions.

Climate change has a profound impact on the distribution of species on Earth. At present, there are two contrasting views explaining the direction of species range shifts. One is a single poleward (northward in the Northern Hemisphere) view, while the other is a multi-directional view (e.g., westward, southward, and eastward). Exploring the universality of these two views has become a key focus in climate change ecology. Here, we study the habitat range shift velocity of 99 tree species in China under future climate change scenarios using a bioclimatic envelope model (also called species distribution model) and a climate velocity method. A Monte Carlo method is used to test the consistency between the range shift pattern and stochastic process, and confusion matrices and kappa values are calculated to evaluate the consistency between the bioclimatic envelope model and climate velocity method. The results indicate that the tree species in China are generally expected to shift northwards, with northwest and northeast directions accounting for a larger proportion. The northward-shifting species are mainly distributed in the east monsoon region of China, while the multi-directional shifting species are mainly distributed in the alpine and arid regions of China. The shift directions described by the bioclimatic envelope model are inconsistent with those described by the climate velocity method. The results imply that the tree species in China support the view of the northward shift pattern but, more specifically, should be considered in terms of a multi-directional northward shift pattern. The results also emphasize that the inter-species variation in climate tolerance has been largely ignored in physical-based climate velocity methods. The development of a biological and vector operation-based climate velocity indicator may be more useful in characterizing the range shifts of species, compared to existing physical and scalar operation-based climate velocity indicators. This study provides favorable evidence for the pattern of climate change-induced range shifts in China, as well as in Eastern Asia.