Identifying the impact of new cropland expansion: evidence from the framework of element, pattern, and function
摘要
In response to the increasing food demands of a growing global population, vast tracts of natural habitat have been converted into new cropland. However, previous studies of new cropland development have primarily focused on the unidimensional impacts on landscape pattern or system functions and lacked systematic effects evaluation. Taking Zhejiang Province as a case study, we constructed a systematic framework to quantify the changes in element features, landscape pattern, and system functions resulting from new cropland development during the period of 1990–2019. Our findings revealed that 0.49 million ha of new cropland in Zhejiang Province was developed over the past three decades. The new cropland, extending outward around the existing cropland, exhibited a significant uphill trend (0.001 level) with 4.03 m year−1 in elevation and 0.1° year−1 in slope. The new cropland was mainly distributed in Wenzhou, Hangzhou, and Lishui, and the majority (99.90%) was converted from forest land. This development led to an intensification of landscape fragmentation while simultaneously increasing landscape diversity. As the uphill trend progressed, the utilization efficiency and average yields of new cropland gradually decreased, the climate change mitigation of natural vegetation declined, and soil water balance decreased due to the combined effects of increased water yield and reduced soil conservation. Implementing management strategies that balance food production and ecological security in the future is crucial to mitigating the negative impacts of new cropland development.