PDF(Pubmed)
Abstract：
The Coastal California Gnatcatcher (Polioptila californica californica), a federally threatened species, is a flagship species for regional conservation planning in southern California (USA). An inhabitant of coastal sage scrub vegetation, the gnatcatcher has declined in response to habitat loss and fragmentation, exacerbated by catastrophic wildfires. We documented the status of gnatcatchers throughout their California range and examined post-fire recovery of gnatcatchers and their habitat. We used GIS to develop a habitat suitability model for Coastal California Gnatcatchers using climate and topography covariates and selected over 700 sampling points in a spatially balanced manner. Bird and vegetation data were collected at each point between March and May in 2015 and 2016. Presence/absence of gnatcatchers was determined during three visits to points, using area searches within 150 x 150 m plots. We used an occupancy framework to generate Percent Area Occupied (PAO) by gnatcatchers, and analyzed PAO as a function of time since fire. At the regional scale in 2016, 23% of the points surveyed were occupied by gnatcatchers, reflecting the effect of massive wildfires in the last 15 years. Similarly, PAO in the post-fire subset of points was 24%, with the highest occupancy in unburned (last fire <2002) habitat. Positive predictors of occupancy included percent cover of California sagebrush (Artemisia californica), California buckwheat (Eriogonom fasciculatum), and sunflowers (Encelia spp., Bahiopsis laciniata), while negative predictors included laurel sumac (Malosma laurina) and total herbaceous cover; in particular, non-native grasses. Our findings indicate that recovery from wildfire may take decades, and provide information to speed up recovery through habitat restoration.
摘要：
加州沿海抓捕者（Polioptilacalifornicacalifornica），受到联邦威胁的物种，是南加州（美国）区域保护规划的旗舰物种。沿海鼠尾草灌木丛植被的居民，由于栖息地的丧失和碎片化，gnatcatcher已经下降，灾难性的野火加剧了。我们记录了整个加利福尼亚范围内的gnatcatchers的状况，并检查了gnatcatchers及其栖息地的火灾后恢复情况。我们使用GIS使用气候和地形协变量为加利福尼亚沿海捕集者开发了栖息地适宜性模型，并以空间平衡的方式选择了700多个采样点。在2015年至2016年3月至5月的每个时间点收集鸟类和植被数据。在对地点的三次访问中确定是否存在抓捕者，在150x150m地块内使用面积搜索。我们使用占用框架来生成gnatcatchers占用的百分比面积(PAO)，并分析了火灾以来PAO与时间的关系。在2016年的区域规模上，23%的调查点被gnatcatchers占据，反映了过去15年大规模野火的影响。同样，火灾后子集的PAO为24%，在未燃烧的栖息地（上次火灾<2002年）中占用率最高。入住率的积极预测因素包括加利福尼亚鼠尾草（Artemisiacalifornica）的覆盖率，加州荞麦（Eriogonomfasciculatum），和向日葵（Enceliaspp。,漆树)，而负面预测因素包括月桂树（Malosmalaurina）和总草本覆盖率；特别是，非本地草。我们的研究结果表明，从野火中恢复可能需要几十年，并提供信息，通过栖息地恢复加速恢复。
