Deforestation and forest fragmentation in South Ecuador since the 1970s - losing a hotspot of biodiversity

Deforestation and fragmentation are major components of global change; both are contributing to the rapid loss of tropical forest area with important implications for ecosystem functioning and biodiversity conservation. The forests of South Ecuador are a biological ‘hotspot’ due to their high diversity and endemism levels. We examined the deforestation and fragmentation patterns in this area of high conservation value using aerial photographs and Aster satellite scenes. The registered annual deforestation rates of 0.75% (1976–1989) and 2.86% (1989–2008) for two consecutive survey periods, the decreasing mean patch size and the increasing isolation of the forest fragments show that the area is under severe threat. Approximately 46% of South Ecuador’s original forest cover had been converted by 2008 into pastures and other anthropogenic land cover types. We found that deforestation is more intense at lower elevations (premontane evergreen forest and shrubland) and that the deforestation f...

森林砍伐与森林片段化是全球环境变化的核心组成部分，二者共同推动热带森林面积快速缩减，对生态系统功能维持与生物多样性保护均具有深远影响。厄瓜多尔南部森林因极高的物种多样性与特有性（endemism）水平，堪称生物多样性热点地区（biological hotspot）。本研究借助航空影像与ASTER卫星遥感数据，针对这片具有极高保护价值区域的森林砍伐与片段化格局开展了系统调查。两次连续监测时段的年森林砍伐率分别为0.75%（1976年—1989年）与2.86%（1989年—2008年），叠加森林斑块平均面积持续缩小、片段化隔离度不断升高的特征，均表明该区域正面临严峻的生存威胁。截至2008年，厄瓜多尔南部原有森林覆盖面积已有约46%被转化为牧场与其他人工土地覆盖类型。研究发现，低海拔区域（前山常绿林与灌丛）的森林砍伐活动更为剧烈，且森林砍伐行为呈现出……