Habitat Connectivity Using Conefor 2.6 For Salt Spring Island, British Columbia

Habitat connectivity is fundamental for animal species dispersal and gene flow. However, habitats are becoming increasingly fragmented due to anthropogenic activities. In this study, I analyzed habitat connectivity on Salt Spring Island, British Columbia, from the perspective of the brown creeper bird, the red squirrel, and the red-legged frog. These umbrella species were selected since their survival is at risk with global warming that is altering their fragile habitat. The research objectives were: assessing network connectivity; identifying the most important habitat patches; and identifying the most important disturbed areas for restoration. The methods included: creating habitat patches and links based on specific habitat requirements using the Landsat landcover classes and Light Detection and Ranging data; assigning a quality to each landuse category to calculate the area-weighted quality of each patch; and performing the connectivity analysis in Conefor 2.6 using the Probability of Connectivity index and its associated metrics (sum dPC and dNC) as they were proven to perform the best for modeling habitat connectivity. A Probability of Connectivity value of 0.0000344 was computed for frog compared to 0.1081950 and 0.1175361 for the bird and the squirrel, respectively. These low values suggest that all habitats may require restoration, but efforts may be focus on the frog since it is significantly less connected. In total, 304 patches covering 6.7 km2 were identified as areas of very high functional connectivity that may require protection. Additionally, 31.3% of this total area was found to be disturbed by agriculture, urban area, high soil erosion, and/or major road(s), which may indicate an important need for rehabilitation. The best way to enhance the species survival and dispersal rate may be to buffer existing patches with woodland, and develop corridors and hub patches that are large and rich in resources to provide both more connectivity and more habitat.

生境连通性对于动物物种的扩散与基因交流至关重要。然而，受人类活动影响，生境正日益破碎化。本研究以不列颠哥伦比亚省盐泉岛为研究区域，选取褐旋木雀、红松鼠与红腿蛙作为研究对象，开展生境连通性分析。上述类群均为伞护种（umbrella species），其生存因全球变暖正面临威胁——全球变暖正在破坏它们本就脆弱的生境。本研究的研究目标包括：评估生境网络连通性；识别核心生境斑块；以及确定亟需开展修复的受干扰区域。研究方法包括：基于特定生境需求，结合陆地卫星（Landsat）土地覆被分类数据与激光雷达（Light Detection and Ranging）数据，生成生境斑块与连通路径；为每一类土地利用类型赋予质量评分，以计算各斑块的面积加权质量；并在Conefor 2.6软件中开展连通性分析，选用连通概率（Probability of Connectivity）指数及其衍生指标（总连通概率贡献度sum dPC与连通节点贡献度dNC）——已有研究证实，该组合在生境连通性建模中表现最优。经计算，红腿蛙的连通概率值为0.0000344，而褐旋木雀与红松鼠的连通概率值分别为0.1081950与0.1175361。上述较低的连通性数值表明，所有研究类群的生境均需开展修复工作，而红腿蛙的连通性显著更差，因此修复工作应优先聚焦于该物种。总计识别出304个斑块，总面积达6.7平方千米，这些斑块具备极高的功能连通性，亟需开展保护。此外，该保护优先区域总面积中有31.3%受到农业活动、城镇建设、严重土壤侵蚀或主要道路的干扰，这表明该区域亟需开展生境修复工作。提升物种生存能力与扩散效率的最优方案，是以林地对现有生境斑块进行缓冲修复，并构建具备充足资源与规模的连通廊道与核心斑块，从而同时提升生境连通性与生境总量。