Zhang Yong, Jia Qiang, Prins Herbert H T, Cao Lei, de Boer Willem Fred
Resource Ecology Group, Wageningen University, Wageningen, The Netherlands; School of Life Science, University of Science and Technology of China, Hefei, Anhui, China.
School of Life Science, University of Science and Technology of China, Hefei, Anhui, China.
PLoS One. 2015 May 21;10(5):e0124972. doi: 10.1371/journal.pone.0124972. eCollection 2015.
Explaining and predicting animal distributions is one of the fundamental objectives in ecology and conservation biology. Animal habitat selection can be regulated by top-down and bottom-up processes, and is mediated by species interactions. Species varying in body size respond differently to top-down and bottom-up determinants, and hence understanding these allometric responses to those determinants is important for conservation. In this study, using two differently sized goose species wintering in the Yangtze floodplain, we tested the predictions derived from three different hypotheses (individual-area relationship, food resource and disturbance hypothesis) to explain the spatial and temporal variation in densities of two goose species. Using Generalized Linear Mixed Models with a Markov Chain Monte Carlo technique, we demonstrated that goose density was positive correlated with patch area size, suggesting that the individual area-relationship best predicts differences in goose densities. Moreover, the other predictions, related to food availability and disturbance, were not significant. Buffalo grazing probably facilitated greater white-fronted geese, as the number of buffalos was positively correlated to the density of this species. We concluded that patch area size is the most important factor determining the density of goose species in our study area. Patch area size is directly determined by water levels in the Yangtze floodplain, and hence modifying the hydrological regimes can enlarge the capacity of these wetlands for migratory birds.
解释和预测动物分布是生态学和保护生物学的基本目标之一。动物栖息地选择可受自上而下和自下而上过程的调控，并由物种间相互作用介导。体型各异的物种对自上而下和自下而上的决定因素反应不同，因此了解这些对这些决定因素的异速生长反应对于保护工作很重要。在本研究中，我们利用在长江洪泛区越冬的两种体型不同的鹅类，检验了源自三种不同假说（个体-面积关系、食物资源和干扰假说）的预测，以解释两种鹅类密度的时空变化。使用带有马尔可夫链蒙特卡罗技术的广义线性混合模型，我们证明鹅类密度与斑块面积大小呈正相关，这表明个体-面积关系最能预测鹅类密度的差异。此外，与食物可利用性和干扰相关的其他预测并不显著。水牛放牧可能有利于更多白额雁栖息，因为水牛数量与该物种的密度呈正相关。我们得出结论，斑块面积大小是决定我们研究区域内鹅类物种密度的最重要因素。斑块面积大小直接由长江洪泛区的水位决定，因此改变水文状况可以扩大这些湿地对候鸟的容纳能力。
