Habitat fragmentation and isolation are considered important causes of biodiversity loss in cultural landscapes. To counter the negative effects of fragmentation such as reduced connectivity and increased risks of population extinction due to stochastic processes and genetic erosion, it has been proposed to establish linear ecological corridors to facilitate dispersal between isolated habitat patches. We summarise the current knowledge on the potential benefits and limitations of corridors for reducing the negative effects of habitat fragmentation on plant populations. We address the opportunities and problems that are associated with linear corridors and advocate the use of semi-open corridors as an alternative that might overcome some shortcomings of conventional corridors for plants. Observational and experimental studies have found that various types of linear corridors can increase plant dispersal. Other linear structures such as paths, roads, railways and streams may also function to a certain extent as corridors, although mostly for widespread species. Because plants are highly dependent on external agents such as animals or wind to reach new habitats, the effectivity of corridors is strongly influenced by their structural features and suitability for animal dispersers. However, many plant species can only use corridors for long-distance dispersal if they can also use them as stepping stone habitats where they can establish, grow, reproduce and then disperse further. This dispersal critically depends on suitable light conditions and disturbance regimes, and on a sufficient width of a corridor to reduce edge effects. Thus, hedgerows appear to be suitable corridors for some forest species but are too narrow for forest specialists from the interior of woodlands. Corridors do not only have positive effects but may also facilitate the spread of invasive species. Moreover, a potentially underestimated negative effect of linear corridors is that they may actually create new dispersal barriers when they intersect other habitats. For example, linear woodland corridors that intersect grasslands may successfully connect patches of woodland but simultaneously form strong barriers for grassland species and increase the fragmentation of their populations. As an alternative to linear corridors, we recommend “semi-open corridors” that simultaneously connect patches of both open habitats and woodlands and promote the dispersal of species of both types of habitat. This idea is based on the various types of semi-open landscapes in Europe that have been formed by grazing with livestock, resulting in a mosaic of open habitats, groups of trees or shrubs and small woodland patches, and are characterised by a high diversity of environmental conditions on a small scale. Wide corridors of such semi-open habitats may avoid the strong edge and barrier effects associated with linear corridors and provide suitable stepping stone habitats for species with different habitat requirements.

生境的破碎和孤立被认为是文化景观中生物多样性丧失的重要原因。为了应对碎片化的负面影响，如连接性降低和由于随机过程和遗传侵蚀而导致人口灭绝的风险增加，有人建议建立线性生态走廊，以促进隔离的生境斑块之间的分散。我们总结了有关减少走廊的潜在好处和局限性的现有知识，以减少生境破碎化对植物种群的负面影响。我们解决与线性走廊相关的机会和问题，并提倡使用半开放式走廊作为替代方案，以克服传统植物走廊的某些缺点。观察和实验研究发现，各种类型的线性走廊可以增加植物的扩散。其他线性结构（例如路径，道路，铁路和溪流）在某种程度上也可以充当走廊，尽管大多数用于广泛的物种。由于植物高度依赖外部因素（例如动物或风）才能到达新的栖息地，因此走廊的有效性受其结构特征和对动物分散器的适用性的强烈影响。但是，如果许多植物物种也可以将它们用作垫脚石栖息地，可以在其中建立，生长，繁殖然后进一步分散，则只能将其用于长距离分散。这种扩散主要取决于合适的光照条件和干扰状况，并取决于走廊的足够宽度以减少边缘效应。因此，树篱似乎是某些森林物种的合适走廊，但对于林地内部的森林专家来说太窄了。走廊不仅具有积极作用，而且还可以促进入侵物种的扩散。此外，线性走廊的潜在低估负面影响是，当它们与其他栖息地相交时，它们实际上可能会创建新的扩散障碍。例如，与草原相交的线性林地走廊可以成功地连接林地，但同时也为草原物种形成了强大的屏障，并加剧了其种群的分散。作为线性走廊的替代方案，我们建议“半开放式走廊”同时连接开放式生境和林地的各个部分，并促进两种类型的生境物种的扩散。这个想法是基于欧洲通过放牧牲畜而形成的各种半开放式景观，从而形成了开放式栖息地，成群的树木或灌木丛以及小片林地的马赛克，其特征是小规模的环境条件。这种半开放式生境的宽阔走廊可以避免与线性走廊相关的强烈边缘和屏障效应，并为具有不同生境要求的物种提供合适的垫脚石生境。