Lampinen Jussi, Ruokolainen Kalle, Huhta Ari-Pekka
Department of Biology, University of Turku, Turku, Finland.
PLoS One. 2015 Nov 13;10(11):e0142236. doi: 10.1371/journal.pone.0142236. eCollection 2015.
Regularly managed electric power line corridors may provide habitats for both early-successional grassland plant species and disturbance-dependent alien plant species. These habitats are especially important in urban areas, where they can help conserve native grassland species and communities in urban greenspace. However, they can also provide further footholds for potentially invasive alien species that already characterize urban areas. In order to implement power line corridors into urban conservation, it is important to understand which environmental conditions in the corridors favor grassland species and which alien species. Likewise it is important to know whether similar environmental factors in the corridors control the species composition of the two groups. We conducted a vegetation study in a 43 kilometer long urban power line corridor network in south-western Finland, and used generalized linear models and distance-based redundancy analysis to determine which environmental factors best predict the occurrence and composition of grassland and alien plant species in the corridors. The results imply that old corridors on dry soils and steep slopes characterized by a history as open areas and pastures are especially suitable for grassland species. Corridors suitable for alien species, in turn, are characterized by productive soils and abundant light and are surrounded by a dense urban fabric. Factors controlling species composition in the two groups are somewhat correlated, with the most important factors including light abundance, soil moisture, soil calcium concentration and soil productivity. The results have implications for grassland conservation and invasive alien species control in urban areas.
定期管理的电力线路走廊可能为早期演替的草原植物物种和依赖干扰的外来植物物种提供栖息地。这些栖息地在城市地区尤为重要，在那里它们有助于保护城市绿地中的本土草原物种和群落。然而，它们也可能为已经在城市地区占主导地位的潜在入侵外来物种提供更多立足点。为了将电力线路走廊纳入城市保护，了解走廊中的哪些环境条件有利于草原物种和哪些外来物种非常重要。同样重要的是要知道走廊中类似的环境因素是否控制着这两类物种的组成。我们在芬兰西南部一个43公里长的城市电力线路走廊网络中进行了一项植被研究，并使用广义线性模型和基于距离的冗余分析来确定哪些环境因素最能预测走廊中草原和外来植物物种的出现和组成。结果表明，干燥土壤和陡坡上具有开放区域和牧场历史特征的旧走廊特别适合草原物种。适合外来物种的走廊则具有肥沃的土壤、充足的光照，并且被密集的城市结构所环绕。控制这两类物种组成的因素在一定程度上相互关联，最重要的因素包括光照充足、土壤湿度、土壤钙浓度和土壤生产力。这些结果对城市地区的草原保护和入侵外来物种控制具有启示意义。
