Forest fragmentation and edge effects from deforestation and selective logging in the Brazilian Amazon
Forest fragmentation and edge effects from deforestation and selective logging in the Brazilian Amazon
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DOI：
10.1016/j.biocon.2008.04.024
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发表时间：
2008-07-01
影响因子：
5.9
通讯作者：
Silva, Jose N.
中科院分区：
文献类型：
--
作者：
Broadbent, Eben N.;Asner, Gregory P.;Silva, Jose N.
森林破碎化是由于砍伐森林和干扰造成的，随后的边缘效应深入到剩余的森林地区。没有任何研究量化了砍伐森林和选择性采伐单独和合并对大片地区森林破碎化和边缘效应的影响。这项研究的主要目标是：（1）量化巴西亚马逊地区森林砍伐和伐木造成的森林破碎化的速度和程度，（2）通过对边缘创建的潜在生态影响的文献综述，将森林破碎化的时空动态联系起来。利用地理信息系统和遥感技术，我们对森林破碎化进行了量化，森林破碎化的定义是1999年至2002年在巴西亚马逊河流域110多万公里（2）的森林边缘面积比和森林碎片数量的增加。每年，砍伐森林和伐木产生的新林缘分别为32 000公里和38 000公里，而剩余森林的林缘面积比分别增加了0.14和0.15。在我们的研究期间，森林砍伐和伐木相结合，使剩余森林的边缘面积比增加了65%，同时分别产生了5539和3383个新的森林碎片。虽然我们发现90%的森林碎片小于4 km（2），但我们也发现50%的剩余完整森林位于大于35，000 km（2）的连续森林区域。然后，我们进行了文献回顾，记录了146个边缘效应，发现这些渗透到100米的中位数距离，在我们的研究区域在2002年的距离包括6.4%的所有剩余的森林，而53%的森林位于两公里的边缘。每年砍伐森林和伐木使边缘林的比例分别增加0.8%和3.1%。由于这两项活动，边缘森林的总比例每年增加2.6%，而100米以内的比例增加了0.5%。在我们的研究期间，森林砍伐导致了额外的类似3000 km（2）的边缘森林，而伐木产生了类似20，000 km（2）的森林，因为它深入到完整的森林地区。这些结果显示了整个亚马逊地区以前未量化的软边缘的大范围和快速扩张，并强调了对其生态影响进行更多研究的必要性。(C)2008爱思唯尔有限公司保留所有权利。
Forest fragmentation results from deforestation and disturbance, with subsequent edge effects extending deep into remaining forest areas. No study has quantified the effects of both deforestation and selective logging, separately and combined, on forest fragmentation and edge effects over large regions. The main objectives of this study were to: (1) quantify the rates and extent of forest fragmentation from deforestation and logging within the Brazilian Amazon, and (2) contextualize the spatio-temporal dynamics of this forest fragmentation through a literature review of potential ecological repercussions of edge creation. Using GIS and remote sensing, we quantified forest fragmentation defined as both increases in the forest edge-to-area ratio and number of forest fragments - and edge-effected forest occurring from these activities across more than 1.1 million km(2) of the Brazilian Amazon from 1999 to 2002. Annually, deforestation and logging generated similar to 32,000 and 38,000 km of new forest edge while increasing the edge-to-area ratio of remaining forest by 0.14 and 0.15, respectively. Combined deforestation and logging increased the edge-to-area ratio of remaining forest by 65% over our study period, while generating 5539 and 3383 new forest fragments, respectively. Although we found that 90% of individual forest fragments were smaller than 4 km(2), we also found that 50% of the remaining intact forests were located in contiguous forest areas greater than 35,000 km(2). We then conducted a literature review documenting 146 edge effects and found that these penetrated to a median distance of 100 m, a distance encompassing 6.4% of all remaining forests in our study region in the year 2002, while 53% of forests were located within two km of an edge. Annually deforestation and logging increased the proportion of edge-forest by 0.8% and 3.1%, respectively. As a result of both activities, the total proportion of edge-forest increased by 2.6% per year, while the proportion within 100-m increased by 0.5%. Over our study period, deforestation resulted in an additional similar to 3000 km(2) of edge-forest, whereas logging generated similar to 20,000 km(2), as it extended deep into intact forest areas. These results show the large extent and rapid expansion of previously unquantified soft-edges throughout the Amazon and highlight the need for greater research into their ecological impacts. (C) 2008 Elsevier Ltd. All rights reserved.