Biogeographical disparity in the functional diversity and redundancy of corals
Biogeographical disparity in the functional diversity and redundancy of corals
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DOI：
10.1073/pnas.1716643115
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发表时间：
2018-03-20
影响因子：
11.1
通讯作者：
Hughes, Terry P.
中科院分区：
文献类型：
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作者：
McWilliam, Mike;Hoogenboom, Mia O.;Hughes, Terry P.
珊瑚是热带珊瑚礁一系列关键生态系统功能的主要贡献者，包括钙化，光合作用，营养循环和提供栖息地结构。珊瑚的丰度在多个尺度上都在下降，珊瑚群落的物种组成正在对人类不断增加的压力，包括人为的全球变暖作出反应。一个紧迫的挑战是了解这些变化的功能后果的丰富和组成在不同的地理环境。虽然珊瑚物种丰富度的全球模式是众所周知的，但人们对珊瑚功能在冗余度高和低的省份和地区的地理分布知之甚少。在这里，我们量化的所有目前公认的虫黄藻珊瑚物种（n = 821）在印度洋-太平洋和大西洋域的功能性状，研究物种丰富度和多样性和冗余的功能性状空间之间的关系。我们发现，性状多样性在物种丰富度的纬度和经度梯度上是非常保守的（超过全球总数的75%），只有在物种贫乏的省份（n <200），如波斯湾（占全球总数的52%），夏威夷（37%），加勒比海（26%）和东太平洋（20%），冗余也减少了。在物种贫乏的省份，大面积的、生态上重要的特征空间是空的，或者只被少数高度独特的物种占据。这些惊人的冗余地理差异可能会影响关键的珊瑚礁功能的恢复力，并突出相对落后的脆弱性，周边地区，这往往是一个低优先级的有针对性的保护工作。
Corals are major contributors to a range of key ecosystem functions on tropical reefs, including calcification, photosynthesis, nutrient cycling, and the provision of habitat structure. The abundance of corals is declining at multiple scales, and the species composition of assemblages is responding to escalating human pressures, including anthropogenic global warming. An urgent challenge is to understand the functional consequences of these shifts in abundance and composition in different biogeographical contexts. While global patterns of coral species richness are well known, the biogeography of coral functions in provinces and domains with high and low redundancy is poorly understood. Here, we quantify the functional traits of all currently recognized zooxanthellate coral species (n = 821) in both the Indo-Pacific and Atlantic domains to examine the relationships between species richness and the diversity and redundancy of functional trait space. We find that trait diversity is remarkably conserved (>75% of the global total) along latitudinal and longitudinal gradients in species richness, falling away only in species-poor provinces (n < 200), such as the Persian Gulf (52% of the global total), Hawaii (37%), the Caribbean (26%), and the EastPacific (20%), where redundancy is also diminished. In the more species-poor provinces, large and ecologically important areas of trait space are empty, or occupied by just a few, highly distinctive species. These striking biogeographical differences in redundancy could affect the resilience of critical reef functions and highlight the vulnerability of relatively depauperate, peripheral locations, which are often a low priority for targeted conservation efforts.