Isolation determines patterns of species presence in highly fragmented landscapes
Isolation determines patterns of species presence in highly fragmented landscapes
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DOI：
10.1111/j.1600-0587.2011.06763.x
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发表时间：
2011-12-01
期刊：
影响因子：
5.9
通讯作者：
Metzger, Jean Paul
中科院分区：
文献类型：
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作者：
Boscolo, Danilo;Metzger, Jean Paul
在支离破碎的景观中，生境可获得性、斑块大小、形状和隔离度的变化可能会影响当地种群的生存。为这类物种提出有效的保护战略首先取决于区分这些因素的特殊影响。为了解决这些问题，我们调查了3种鸟类在巴西大西洋森林景观中的出现情况。应用回放技术收集了80个森林斑块内这些物种的存在/缺失数据，并使用关联模型从景观空间结构中推断它们的占据格局。利用基于最大似然估计的模型选择方法，评估了斑块大小、形状以及周围森林覆盖和隔离的相对重要性。所有物种的存在总体上都受到周围栖息地数量的积极影响，而受到斑块间距离的负面影响。斑块大小和周围景观特征的共同作用是决定这两个物种占有率的重要因素。第三种只受森林覆盖和平均斑块隔离的影响。我们的结果表明，当地物种的存在通常更多地受到与周围森林的隔离而不是仅受斑块大小的影响。我们发现有证据表明，在高度碎片化的地貌中，找不到足够大的斑块定居的鸟类，可能能够克服通过母体的短距离，在它们的家园范围内包括几个附近的斑块，以补充它们的资源需求。在这些情况下，斑块必须被定义为功能上相连的栖息地网络，而不仅仅是连续的林段。大西洋森林的鸟类保护战略应侧重于增加斑块密度和连通性，以便实施森林网络，减少大片残骸与剩余核心栖息地之间的功能隔离。
In fragmented landscapes, changes in habitat availability, patch size, shape and isolation may affect survival of local populations. Proposing efficient conservation strategies for such species relies initially on distinguishing the particular effects of those factors. To address these issues, we investigated the occurrence of 3 bird species in fragmented Brazilian Atlantic Forest landscapes. Playback techniques were used to collect presence/absence data of these species inside 80 forest patches, and incidence models were used to infer their occupancy pattern from landscape spatial structure. The relative importance of patch size, shape and surrounding forest cover and isolation was assessed using a model selection approach based on maximum likelihood estimation. The presence of all species was in general positively affected by the amount of surrounding habitat and negatively affected by inter-patch distances. The joint effects of patch size and the surrounding landscape characteristics were important determinants of occupancy for two species. The third species was affected only by forest cover and mean patch isolation. Our results suggest that local species presence is in general more influenced by the isolation from surrounding forests than by patch size alone. We found evidence that, in highly fragmented landscapes, birds that can not find patches large enough to settle may be able to overcome short distances through the matrix and include several nearby patches within their home-ranges to complement their resource needs. In these cases, patches must be defined as functionally connected habitat networks rather than mere continuous forest segments. Bird conservation strategies in the Atlantic forest should focus on increasing patch density and connectivity, in order to implement forest networks that reduce the functional isolation between large remnants with remaining core habitat.