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In the past two decades, the Ministry of Agriculture and Rural Affairs of China (MARA) has issued a series of strict cultivated land protection policies to prevent the spread of farmland abandonment and maintain a dynamic balance between the quantity and quality of arable land. However, high-speed economic development, strict arable land protection policies, and ecological security and sustainable development strategies interacting with human activities have brought challenges to quantifying the effectiveness of arable land protection policies. In this study, we proposed a method to quantify the impacts of the arable land protection policies and evaluate the quantitative impacts on farmland abandonment in Guangdong Province after 2014 from the perspective of landscape ecology. The results illustrated that the landscape fragmentation of farmland abandonment in Guangdong Province decreased after the new arable land policies were issued. More annual farmland abandonment (AFA) shifted to seasonal farmland abandonment (SFA), revealing the considerable pronounced effects of farmland abandonment management. The new policies effectively restrained the area increase for AFA in the regions with lower rural population (RPOP) and lower gross domestic product (GDP), and reduced the fragmentation of AFA in the regions with the highest RPOP and lower GDP. Additionally, the new policies effectively restrained the fragmentation increase for SFA in the regions with lower RPOP and lower GDP, and reduced the area increase for SFA in the regions with the highest RPOP and lower GDP. The management effect was not that significant in the regions with higher RPOP and higher GDP. These findings will provide important data references for arable land decision making in southern China. [ABSTRACT FROM AUTHOR]

Lead-zinc (Pb-Zn) tailings pose a significant environmental threat from heavy metals (HMs) contamination. Revegetation is considered as a green path for HM remediation. However, the interplay between HM transport processes and soil microbial community in Pb-Zn tailings (especially those in production) remain unclear. This study investigated the spatial distribution of HMs as well as the crucial roles of the soil microbial community (i.e., structure, richness, and diversity) during a three-year revegetation of production Pb-Zn tailings in northern Guangdong province, China. Prolonged tailings stockpiling exacerbated Pb contamination, elevating concentrations (from 10.11 to 11.53 g/kg) in long-term weathering. However, revegetation effectively alleviated Pb, reducing its concentrations of 9.81 g/kg. Through 16 S rRNA gene amplicon sequencing, the dominant genera shifted from Weissella (44%) to Thiobacillus (17%) and then to Pseudomonas (comprising 44% of the sequences) during the revegetation process. The structural equation model suggested that Pseudomonas , with its potential to transform bioavailable Pb into a more stable form, emerged as a potential Pb remediator. This study provides essential evidence of HMs contamination and microbial community dynamics during Pb-Zn tailings revegetation, contributing to the development of sustainable microbial technologies for tailings management. [Display omitted] • Pb exhibited distinctive spatial distribution characteristics within the tailings. • Soil microbial played a vital role during the revegetation of production tailings. • Key genus shifted from Weissella to Thiobacillus to Pseudomonas during revegetation. • Pseudomonas identified as the potential Pb-remediation bacteria of Pb-Zn tailings. • SEM quantitatively elucidated the responsive attributes of Pseudomonas towards Pb. [ABSTRACT FROM AUTHOR]