Ecologically relevant traits of organisms inhabiting an ecosystem determine its functional fingerprint. Quantifying changes in the shape, volume and shifts in the position of functional fingerprints can provide information about the effects of diversity loss or gain through time, and is a promising means to monitor ecological integrity. This, however, is seldom possible owing to limitations in historical surveys and lack of data on organismal traits, particularly in diverse tropical regions. Using detailed bird surveys from four time periods across more than one century and morphological traits of 233 species, we quantified changes in the avian functional fingerprint of a tropical montane forest site in the Andes of Colombia. We found that 79% of the variation in functional space, regardless of time period, was described by three major axes summarizing body size, dispersal ability, and habitat breadth. Changes in species composition caused significant alterations of the functional fingerprint of the assemblage, with 35-60% reductions in functional richness and dispersion. Owing to species extirpations and to novel additions to the assemblage, functional space is currently smaller and at least 11% different to what it was a century ago, with fewer large-sized species, more good dispersers, and fewer habitat specialists. Extirpated species had high values of functional uniqueness and distinctiveness, resulting in large reductions of functional richness and dispersion after their loss, implying potentially important consequences for ecosystem functioning. Conservation efforts aimed at maintaining ecosystem function must move beyond maintaining species numbers to designing strategies for the maintenance of ecological function by identifying and conserving species with traits conferring high vulnerability.

中文翻译：

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100多年的鸟类调查数据揭示了随着时间推移热带热带山地森林生态系统健康的功能指纹变化

居住在生态系统中的生物在生态方面的相关特征决定了其功能指纹。量化功能指纹的形状，体积和位置变化的变化可提供有关随时间推移而丧失或增加多样性的影响的信息，并且是监测生态完整性的一种有前途的手段。但是，由于历史调查的局限性以及缺乏有关生物性状的数据，特别是在热带地区，这种情况很少出现。通过使用一个多世纪以来四个时期的详细鸟类调查以及233种物种的形态特征，我们量化了哥伦比亚安第斯山脉热带山地森林站点鸟类功能指纹的变化。我们发现，功能空间变化的79％与时间段无关，用三个主要坐标轴来描述，它们概括了身体大小，扩散能力和栖息地宽度。物种组成的变化导致组合功能指纹的显着改变，功能丰富度和分散度降低了35-60％。由于物种的灭绝和组合的新颖性，功能空间目前更小，与一个世纪前相比，至少有11％的差异，大型物种更少，分散剂更多，栖息地专家也更少。灭绝的物种在功能独特性和独特性方面具有很高的价值，导致丧失物种后功能丰富性和分散性大大降低，这意味着对生态系统功能的潜在重要后果。