Distributional patterns of endemic, native and alien species along a roadside elevation gradient in Tenerife, Canary Islands
Distributional patterns of endemic, native and alien species along a roadside elevation gradient in Tenerife, Canary Islands
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DOI：
10.1556/168.2015.16.2.10
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发表时间：
2015-12-01
影响因子：
1.7
通讯作者：
Arevalo, J. R.
中科院分区：
文献类型：
--
作者：
Bacaro, G.;Maccherini, S.;Arevalo, J. R.
外来植物物种的入侵可能是迅速和侵略性的，造成当地生物多样性的侵蚀。岛屿尤其如此，自然和人为走廊促进了入侵植物的快速传播。虽然有证据表明，走廊可能会促进植物入侵，但它们在外来物种传播中的重要性如何沿着环境梯度而变化的问题值得更多的关注。在这里，我们解决了这个问题，通过检查多样性模式（特有的，本地和外来物种的物种丰富度）沿着和跨道路，沿着海拔梯度从海平面到2050米a.s.l.在特内里费岛（加那利群岛，西班牙），在多个空间尺度。物种丰富度进行了评估，采用多尺度抽样设计，包括59个T型断面的150米× 2米，沿着三条主要道路，每一个放置在整个海拔梯度。每个样带由三个部分组成，每个5个地块：第1节位于道路边缘，第2节在中间距离，第3节远离道路边缘，后者代表“本地社区”受道路特定干扰的影响较小。海拔和距离路边的影响进行了评估的三组物种（特有的，本地和外来物种），使用参数和非参数回归分析，以及添加剂多样性分区。道路之间的差异解释了外来物种丰富度和组成的大部分变化。外来物种丰富度的模式也受到海拔的影响，丰富度随着海拔的增加而下降，在高海拔地区没有外来物种的记录。海拔是决定特有种和本地种格局的最重要因素。这些研究结果证实，气候过滤反映在不同的模式沿着海拔梯度是一个重要的决定因素丰富的外来物种（不适应高海拔地区），而人为的压力可以解释丰富的外来物种在低海拔地区。
Invasion by alien plant species may be rapid and aggressive, causing erosion of local biodiversity. This is particularly true for islands, where natural and anthropogenic corridors promote the rapid spread of invasive plants. Although evidence shows that corridors may facilitate plant invasions, the question of how their importance in the spread of alien species varies along environmental gradients deserves more attention. Here, we addressed this issue by examining diversity patterns (species richness of endemic, native and alien species) along and across roads, along an elevation gradient from sea-level up to 2050 m a.s.l. in Tenerife (Canary Islands, Spain), at multiple spatial scales. Species richness was assessed using a multi-scale sampling design consisting of 59 T-transects of 150 m x 2 m, along three major roads each placed over the whole elevation gradient. Each transect was composed of three sections of five plots each: Section 1 was located on the road edges, Section 2 at intermediate distance, and Section 3 far from the road edge, the latter representing the "native community" less affected by road-specific disturbance. The effect of elevation and distance from roadsides was evaluated for the three groups of species (endemic, native and alien species), using parametric and non-parametric regression analyses as well as additive diversity partitioning. Differences among roads explained the majority of the variation in alien species richness and composition. Patterns in alien species richness were also affected by elevation, with a decline in richness with increasing elevation and no alien species recorded at high elevations. Elevation was the most important factor determining patterns in endemic and native species. These findings confirm that climate filtering reflected in varying patterns along elevational gradients is an important determinant of the richness of alien species (which are not adapted to high elevations), while anthropogenic pressures may explain the richness of alien species at low elevation.