The alteration and loss of habitats are two of the main threats that biodiversity conservation is currently facing up to. The present study describes the effects of a perturbation and restoration in a reedbed habitat on a bird assemblage. We studied the bird community of a wetland of central Spain between 1995 and 2009, during which time an anthropic perturbation altered the original structure of the habitat; subsequently, as a result of restoration works, the habitat returned to its original state. We evaluated the effects on six population and physical parameters of the birds at three different phases of their life cycles (breeding, wintering and post-breeding migration seasons) before, during and after the habitat alteration. GLM was used to analyze the influence of three independent variables (year, perturbation phase and temperature). The relative abundance and the species richness values decreased when habitat was altered, but then recovered as a result of the regeneration works. This pattern was the clearest amongst specialist species. Breeding success also declined during the perturbation phase and then increased; likewise, the sex ratio changed given that the proportion of male birds increased when habitat was altered. These results are discussed in relation to changes on availability of resources in altered habitats, to the adaptive mechanisms in the exploitation of ecological requirements and to the selection of optimum and sub-optimum habitats by generalist and specialist species. Ecosystem restoration can favour the recovery of population indexes of specialist passerines, although it depends on the efficiency of the type of restoration activity performed and on the complexity of the habitat.

中文翻译：

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沼泽鸟类群对栖息地丧失和随后恢复的个体和人口响应

生境的改变和丧失是生物多样性保护目前面临的两个主要威胁。本研究描述了芦苇栖息地的扰动和恢复对鸟类组合的影响。我们研究了1995年至2009年西班牙中部湿地的鸟类群落，在此期间，人类的扰动改变了栖息地的原始结构。随后，由于进行了修复工作，栖息地恢复了原始状态。我们评估了栖息地改变之前，之中和之后，在鸟类生命周期的三个不同阶段（繁殖，越冬和繁殖后的迁徙季节）对鸟类的六个种群和身体参数的影响。GLM用于分析三个独立变量（年份，摄动阶段和温度）的影响。当栖息地改变时，相对丰度和物种丰富度值降低，但由于再生工作而恢复。在专业物种中，这种模式最为明显。在干扰阶段，繁殖成功率也有所下降，然后又有所增加。同样，性别比也发生了变化，因为生境改变后雄鸟的比例增加。将讨论这些结果，涉及改变的生境中资源的可用性，利用生态需求的适应机制以及通才和专业物种选择最佳和次佳栖息地的情况。生态系统的恢复可以促进专业雀形目种群指数的恢复，