Patterns of structural complexity and human disturbance of riparian vegetation in agricultural landscapes of a Mediterranean area
Patterns of structural complexity and human disturbance of riparian vegetation in agricultural landscapes of a Mediterranean area
复制标题
DOI：
10.1016/s0167-8809(02)00218-9
复制
发表时间：
2003-05-01
影响因子：
6.6
通讯作者：
Costillo, E
中科院分区：
文献类型：
--
作者：
Corbacho, C;Sánchez, JM;Costillo, E
在地中海类型的环境中，河岸走廊是宝贵的高度多样性的生境，主要是在农业景观中。按照沿河流景观的“植被综合体”方法，分析了影响西班牙西南部农业区结构复杂性和人为干扰的因素。通过主成分分析和逐步多元回归分析，得到3个主要结果：(1)河流上游(先锋草本群落)到下游(封闭林)之间存在演替的植被梯度，伴随着木本植物盖度和生境多样性的增加；(2)各种农业生产方式的土地利用强度似乎是造成河岸地区人类干扰的主要原因，主要与地形不规则性有关。因此，位于下游平坦景观中的封闭式林冠被移除、高度修改或广泛碎片化；相反，置于上游野生和粗糙景观中的河岸复合体似乎未受干扰或接近自然；(3)研究区近50%的天然河岸植被已被高度修饰或消失，在大多数情况下，被今天已成为主导地位的非自然形成所取代。保护现存少数保存完好的河岸走廊和恢复河流下游高度变化的河岸地区，已成为维持这些地中海农业景观生物多样性的优先事项。为这项研究开发的广泛和具有成本效益的方法很容易适用于其他大范围的地区，以评估人类干扰对河岸走廊的影响。(C)2002 Elsevier Science B.V.保留所有权利。
Riparian corridors are valuable high diversity habitats in Mediterranean-type environments and mainly in agricultural landscapes. Following a 'vegetation complexes' approach along fluvial landscapes, the factors affecting structural complexity and human disturbance through agricultural areas in south-west (SW) Spain were analysed. Using principal component analysis and a stepwise multiple regression analysis three main results were obtained: (1) a successional vegetative gradient was noted from upper (pioneer herbaceous communities) to lower reaches of streams (closed-canopy forests) with a concomitant increase in both woody cover and habitat diversity; (2) land-use intensity associated with each of the agricultural production methods, which was mainly related to topographic irregularity, appeared to be the main cause of human disturbance in riparian areas. Thus, the closed-canopy forests located in flat landscapes of lower streams were removed, highly modified or extensively fragmented; in contrast, riparian complexes placed on wild and rough landscapes of upper streams appeared as undisturbed or near-natural; (3) nearly 50% of the natural riparian vegetation of the study area has been highly modified or has disappeared, in most cases replaced by non-natural formations which have today become dominant. The protection of the few existing well-preserved riparian corridors and the restoration of highly altered riparian areas in the lower reaches of streams has become a priority in maintaining biodiversity in these agricultural Mediterranean landscapes. The extensive and cost-effective method developed for this study would be easily applicable to other large areas to evaluate the effect of human disturbance on riparian corridors. (C) 2002 Elsevier Science B.V. All rights reserved.