Unmasking secondary vegetation dynamics in the Brazilian Amazon
Unmasking secondary vegetation dynamics in the Brazilian Amazon
复制标题
揭示巴西亚马逊次生植被动态
DOI：
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发表时间：
2020
影响因子：
6.7
通讯作者：
Carlos M Souza
中科院分区：
文献类型：
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作者：
Sâmia Nunes;Luis C. Oliveira;João V. Siqueira;D. Morton;Carlos M Souza
次生植被（SV）从土地废弃是一个常见的过渡阶段，农业用途热带森林砍伐后。因此，SV对热带森林边界的碳固存和生境破碎化的影响取决于SV动态和人口统计。在这里，我们使用MapBiomas年度土地覆盖数据的时间序列来生成1985年至2017年巴西亚马逊地区SV范围，年龄和净碳吸收的第一次估计。SV随着时间的推移而增加，2017年总计12 Mha，其中44% ≤5岁。在1988年至2017年期间，19.6 Mha的SV被清除，巴西监测系统（PRODES）检测到的原始森林砍伐面积增加了45.5%。自2011年以来，SV损失率已超过PRODES毁林率。根据年龄和损益的程度，SV在此期间是一个小的净碳汇（8.9 Tg C yr−1）。由于SV没有受到国家环境立法的正式保护，也没有受到PRODES的监测，SV在巴西亚马逊地区的长期效益仍然不确定。
Secondary vegetation (SV) from land abandonment is a common transition phase between agricultural uses following tropical deforestation. The impact of SV on carbon sequestration and habitat fragmentation across tropical forest frontiers therefore depends on SV dynamics and demographics. Here, we used time series of annual MapBiomas land cover data to generate the first estimates of SV extent, age, and net carbon uptake in the Brazilian Amazon between 1985 and 2017. SV increased over time, totaling 12 Mha in 2017, 44% of which was ≤5 years old. Between 1988 and 2017, 19.6 Mha of SV was cleared, adding 45.5% to the area of primary deforestation detected by the Brazilian monitoring system (PRODES). Rates of SV loss have exceeded PRODES deforestation since 2011. Based on the age and extent of gains and losses, SV was a small net carbon sink during this period (8.9 Tg C yr−1). As SV is not formally protected by national environmental legislation or monitored by PRODES, long-term benefits from SV in the Brazilian Amazon remain uncertain.