Fischer Christina, Hanslin Hans Martin, Hovstad Knut Anders, D'Amico Marcello, Kollmann Johannes, Kroeger Svenja B, Bastianelli Giulia, Habel Jan C, Rygne Helena, Lennartsson Tommy
Faunistics and Wildlife Conservation, Department of Agriculture, Ecotrophology, and Landscape Development, Anhalt University of Applied Sciences, Bernburg, Germany; Evolutionary Zoology, Department of Environment and Biodiversity, University of Salzburg, Salzburg, Austria.
Department of Urban Greening and Vegetation Ecology, Norwegian Institute of Bioeconomy Research, Aas, Norway.
J Environ Manage. 2022 Jun 1;311:114846. doi: 10.1016/j.jenvman.2022.114846. Epub 2022 Mar 12.
Roadsides, in particular those being species-rich and of conservation value, are considered to improve landscape permeability by providing corridors among habitat patches and by facilitating species' dispersal. However, little is known about the potential connectivity offered by such high-value roadsides. Using circuit theory, we modelled connectivity provided by high-value roadsides in landscapes with low or high permeability in south-central Sweden, with 'permeability' being measured by the area of semi-natural grasslands. We modelled structural connectivity and, for habitat generalists and specialists, potential functional connectivity focusing on butterflies. We further assessed in which landscapes grassland connectivity is best enhanced through measures for expanding the area of high-value roadsides. Structural connectivity provided by high-value roadsides resulted in similar patterns to those of a functional approach, in which we modelled habitat generalists. In landscapes with low permeability, all target species showed higher movements within compared to between grasslands using high-value roadsides. In landscapes with high permeability, grassland generalists and specialists showed the same patterns, whereas for habitat generalists, connectivity provided by high-value roadsides and grasslands was similar. Increasing the ratio of high-value roadsides can thus enhance structural and functional connectivity in landscapes with low permeability. In contrast, in landscapes with high permeability, roadsides only supported movement of specialised species. Continuous segments of high-value roadsides are most efficient to increase connectivity for specialists, whereas generalists can utilize also short segments of high-value roadsides acting as stepping-stones. Thus, land management should focus on the preservation and restoration of existing semi-natural grasslands. Management for enhancing grassland connectivity through high-value roadsides should aim at maintaining and creating high-value roadside vegetation, preferably in long continuous segments, especially in landscapes with low permeability.
路边，尤其是那些物种丰富且具有保护价值的路边，被认为通过在栖息地斑块之间提供廊道以及促进物种扩散来提高景观通透性。然而，对于此类高价值路边所提供的潜在连通性，我们却知之甚少。利用电路理论，我们对瑞典中南部具有低或高通透性景观中的高价值路边所提供的连通性进行了建模，其中“通透性”通过半自然草地面积来衡量。我们对结构连通性进行了建模，并且针对栖息地泛化种和特化种，重点以蝴蝶为例对潜在功能连通性进行了建模。我们进一步评估了在哪些景观中，通过扩大高价值路边面积的措施能够最好地增强草地连通性。高价值路边所提供的结构连通性与我们对栖息地泛化种进行建模的功能方法所呈现的模式相似。在低通透性景观中，与利用高价值路边的草地之间相比，所有目标物种在草地内部的移动性更高。在高通透性景观中，草地泛化种和特化种呈现出相同的模式，而对于栖息地泛化种来说，高价值路边和草地所提供的连通性相似。因此，增加高价值路边的比例能够增强低通透性景观中的结构和功能连通性。相比之下，在高通透性景观中，路边仅支持特化物种的移动。高价值路边的连续路段对于增加特化种的连通性最为有效，而泛化种也可以利用作为踏脚石的高价值路边的短路段。因此，土地管理应侧重于保护和恢复现有的半自然草地。通过高价值路边增强草地连通性的管理应旨在维护和营造高价值的路边植被，最好是形成长的连续路段，尤其是在低通透性景观中。
