Gardezi Tariq, Gonzalez Andrew
Department of Biology, McGill University, Montreal, Quebec H3A 1B1, Canada.
Am Nat. 2008 Jun;171(6):800-15. doi: 10.1086/587520.
Variation in the shape of relationships between species richness and different measures of energy may be linked to variation in the spatial scale on which such relationships are measured. We examine scale dependence in the relationship between potential evapotranspiration and the species richness of fishes in 7,885 postglacial lakes. The strength of this relationship is weak across lake communities but strong and positive across groups of lakes or regions. In addition, the strength and slope of this relationship increase significantly as the regional scale of analysis is increased. We interpret the observed patterns in terms of a simple model whereby energy influences the linear character of the species-energy relationship through its influence on spatial turnover in the species composition (beta diversity). Our results suggest that if energy is strongly tied to patterns of site occupancy or abundance, the parameters of species-energy relationships will depend, to a considerable extent, on the scale of measurement. Furthermore, the ability of high-energy regions to accommodate relatively large numbers of rare or infrequent species may underlie any general tendency for the strength or shape of species-energy relationships to change with scale.
物种丰富度与不同能量指标之间关系形状的变化，可能与测量这些关系的空间尺度变化有关。我们研究了7885个冰期后湖泊中潜在蒸散量与鱼类物种丰富度之间关系的尺度依赖性。这种关系在湖泊群落间较弱，但在湖泊群或区域间较强且呈正相关。此外，随着分析的区域尺度增加，这种关系的强度和斜率显著增加。我们用一个简单模型来解释观察到的模式，即能量通过影响物种组成的空间周转率（β多样性）来影响物种 - 能量关系的线性特征。我们的结果表明，如果能量与栖息地占用模式或丰度紧密相关，那么物种 - 能量关系的参数将在很大程度上取决于测量尺度。此外，高能区域容纳相对大量稀有或不常见物种的能力，可能是物种 - 能量关系强度或形状随尺度变化的任何一般趋势的基础。
