Human activities such as deforestation and urbanization have affected the regional habitat quality of the Poyang Lake area. To evaluate the evolution of habitat quality and its influencing factors in the area, we used Classification and Regression Trees (CART) to interpret the land-use status and used the InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) model to analyze the characteristics of changes in habitat quality in the Poyang Lake Eco-Economic Zone (PLEEZ) from 1988 to 2018. The results show that, from 1988 to 2018, land use in the PLEEZ underwent significant changes. The changes in land use led to a gradual increase in habitat degradation and a gradual decrease in habitat quality in the study area. Rapid urbanization notably decreased the habitat quality in the study area. However, at the same time, the ecological protection projects such as returning farmland to forests slowed the decline in habitat quality. Driven by these two factors, habitat quality in the PLEEZ gradually declined but the rate of its decline was suppressed. The findings of this study are of great significance for the coordinated development of social, economic, and ecological development in the PLEEZ and similar areas.

Cultivated land quality (CLQ) is at the core of the trinity protection of cultivated land in China. Scientific evaluation of CLQ and identification of its obstacle factors are the foundation for the construction and improvement of the quality of cultivated land. The main objective of this study was to evaluate CLQ and identify its obstacle factors, and Quzhou County, an intensive agricultural region in the North China Plain (NCP), was selected as a case study. The evaluation index system of CLQ was constructed based on five dimensions, including climate condition, topographic characteristic, soil property, farming status, and environmental condition, by analyzing the logical evolution of elements, processes, functions, and quality of cultivated land. A methodological system based on the Weighted Summation Method (WSM) and the “1 + X” model was developed to evaluate the CLQ. Then, the obstacle diagnosis model constructed based on the Cask Law and relevant academic studies was used to identify the obstacle factors of CLQ. The results showed that the proportion of high-, medium-, and low-quality cultivated land in Quzhou County was 36.19%, 33.60%, and 30.21%, respectively, and the average grade of CLQ was 2.97, which was considered to be at a medium level. Moran’s I of global spatial autocorrelation in Quzhou County was 0.8782, indicating a significant positive autocorrelation of the cultivated land quality index (CLQI). The main obstacle factors of CLQ in Quzhou County were soil profile constitution, irrigation guarantee rate, groundwater depth, and soil microbial biomass carbon. Therefore, based on the stable and dynamic characteristics of the obstacle factors, suggestions were provided to improve the quality of cultivated land in terms of strengthening the consolidation of cultivated land, transforming the concept of agricultural fertilization, and carrying out cultivated land recuperation. This study provides a new perspective on the cognition, evaluation, and identification of obstacle factors of CLQ, and the findings of this study can provide a reference for the consolidation and improvement of CLQ in the NCP.

【目的】耦合土地利用显性形态和隐性形态开展农村居民点转型研究，为协调农村居民点显性形态与隐性形态冲突提供理论依据和实践参考。【方法】本文借鉴区域土地利用转型“冲突-协调”理论模式，引入耦合协调模型、皮尔逊相关性系数、灰色关联度模型剖析天津市1980—2020年农村居民点显性形态和隐性形态转型的内在关联机制。【结果】①1980—2020年天津市农村居民点显性形态和隐性形态指数呈上升趋势，环城四区农村居民点显性形态和隐性形态发生了转型，其中东丽区、津南区显性形态演变的突变点出现在2000—2005年，西青区出现在2000年前后，北辰区出现在2005—2010年；东丽区、津南区、北辰区隐性形态演变的突变点出现在2005年前后，西青区出现在2000—2005年。②天津市农村居民点显性形态和隐性形态耦合协调关系经历了低度耦合协调、中度耦合协调、基本耦合协调3个阶段，耦合协调程度呈现由环城四区向远郊五区和滨海新区递减的趋势。③1980—2000年农村居民点显性形态中的面积、斑块数量和斑块密度显著影响隐性形态，2000—2010年为斑块数量、人均面积和凝聚度指数，2010—2020年为凝聚度指数、人均面积和景观形状指数。【结论】本文研究结果可为通过调整农村居民点显性形态从而优化隐性形态，协调两者演化冲突，实现农村居民点转型重构提供科学依据。