Woodcock Stephen, Curtis Thomas P, Head Ian M, Lunn Mary, Sloan William T
Ecol Lett. 2006 Jul;9(7):805-12. doi: 10.1111/j.1461-0248.2006.00929.x.
The recent observation of a power-law relationship, S proportional A(z), between number of taxa, S, and area, A, for microbial eukaryotes and bacteria suggests that this is one of the few generic relationships in ecology, applicable to plants, animals and microbes. However, the rate of increase in the number of species with area varies from approximately the fourth (z = 0.26) to as little as the 50th root (z = 0.0019) in microbes. This is an enormous range for which no quantitative explanation has been proffered. We show by sampling from synthetic populations that the disparity between sample and community sizes in microbial community surveys means z can be considerably underestimated and accrual of rare taxa with increasing area will not be detectable. Significant microbial taxa-area relationships will only be observed when changes in community structure within samples correlate with area. Thus, the very low z values observed recently cannot be used as the sole evidence in support of any particular community theory of community assembly. More generally, this suggests that our search for patterns and laws in the microbial world will be profoundly influenced and, potentially distorted by the sample sizes that are typical of microbial community surveys.
最近观察到，对于微生物真核生物和细菌而言，分类单元数量S与面积A之间存在幂律关系，即S与A(z)成正比，这表明这是生态学中为数不多的通用关系之一，适用于植物、动物和微生物。然而，微生物中物种数量随面积的增加速率变化很大，从大约四分之一次幂（z = 0.26）到低至五十分之一次幂（z = 0.0019）。对于如此大的范围，尚未给出定量解释。我们通过对合成种群进行抽样表明，微生物群落调查中样本大小与群落大小之间的差异意味着z可能会被大大低估，并且随着面积增加稀有分类单元的积累将无法被检测到。只有当样本内群落结构的变化与面积相关时，才会观察到显著的微生物分类单元-面积关系。因此，最近观察到的极低z值不能作为支持任何特定群落组装群落理论的唯一证据。更普遍地说，这表明我们在微生物世界中寻找模式和规律的过程将受到微生物群落调查中典型样本大小的深刻影响，并可能被扭曲。
