Friedrich Russell, Philpott Stacy M
Department of Environmental Sciences, University of Toledo, Toledo, OH 43606, USA.
Environ Entomol. 2009 Jun;38(3):600-7. doi: 10.1603/022.038.0311.
Urbanization impacts biodiversity, yet few studies examine general impacts of urbanization on insects. Furthermore, few studies examine availability and limitation of potential cavity nesting sites for ants, an important regulating factor in ant communities that may vary in different urban habitats. We compared three urban habitat types (gardens, vacant lots, and forests) in Toledo, OH, to examine availability and ant preferences for different cavity nesting resources (small and large hollow twigs and cavities). We added 72 artificial large hollow twigs (83 by 6 mm), small hollow twigs (140 by 2 mm), and spherical hollow cavities (6.52-31.1 cm(3) in volume, 1-mm opening) to six sites from May to August 2007 to determine whether nest-site limitation impacts ant communities. We collected natural nests to compare natural abundance and occupancy of cavity nests in different urban habitats. We opened artificial and natural nests to calculate the percentage occupied by cavity-nesting ants. Across all habitats, small twigs represented 81.1% of natural nests, spherical nests represented 10.1%, and large twigs 8.2%. Ants occupied 8.1% of natural large twigs, 14.6% of cavities, and 4.1% of small twigs. For artificial nests, 21.5% of large twigs, 1% of small twigs, and 1% of spheres were occupied. The high percentage of occupied artificial large twigs could imply this is a preferred and limiting resource in urban habitats. The results show that certain types of nesting resources may be an important factor mediating ant communities in urban green spaces.
城市化会影响生物多样性，但很少有研究探讨城市化对昆虫的总体影响。此外，很少有研究考察蚂蚁潜在巢穴筑巢地点的可利用性和限制因素，而这是蚂蚁群落中的一个重要调节因素，在不同的城市栖息地可能会有所不同。我们比较了俄亥俄州托莱多市的三种城市栖息地类型（花园、空地和森林），以研究不同巢穴筑巢资源（小空心树枝和大空心树枝以及空洞）的可利用性和蚂蚁偏好。2007年5月至8月，我们在六个地点添加了72个大型人工空心树枝（83×6毫米）、小型空心树枝（140×2毫米）和球形空心洞（体积为6.52 - 31.1立方厘米，开口为1毫米），以确定巢穴筑巢地点的限制是否会影响蚂蚁群落。我们收集自然巢穴以比较不同城市栖息地中空洞巢穴的自然丰度和占用情况。我们打开人工和自然巢穴以计算由筑巢蚂蚁占用的百分比。在所有栖息地中，小树枝占自然巢穴的81.1%，球形巢穴占10.1%，大树枝占8.2%。蚂蚁占据了自然大树枝的8.1%、空洞的14.6%和小树枝的4.1%。对于人工巢穴，21.5%的大树枝、1%的小树枝和1%的球体被占用。人工大树枝的高占用率可能意味着这是城市栖息地中一种首选且有限的资源。结果表明，某些类型的筑巢资源可能是调节城市绿地中蚂蚁群落的一个重要因素。
