Centre for Complexity Science, Zeeman Building , University of Warwick , Coventry CV4 7AL, UK.
School of Medical and Applied Sciences , Central Queensland University, North Rockhampton , Queensland, Australia.
R Soc Open Sci. 2016 Mar 30;3(3):150519. doi: 10.1098/rsos.150519. eCollection 2016 Mar.
Measurement of population persistence is a long-standing problem in ecology; in particular, whether it is possible to gain insights into persistence without long time-series. Fractal measurements of spatial patterns, such as the Korcak exponent or boundary dimension, have been proposed as indicators of the persistence of underlying dynamics. Here we explore under what conditions a predictive relationship between fractal measures and persistence exists. We combine theoretical arguments with an aerial snapshot and time series from a long-term study of seagrass. For this form of vegetative growth, we find that the expected relationship between the Korcak exponent and persistence is evident at survey sites where the population return rate can be measured. This highlights a limitation of the use of power-law patch-size distributions and other indicators based on spatial snapshots. Moreover, our numeric simulations show that for a single species and a range of environmental conditions that the Korcak-persistence relationship provides a link between temporal dynamics and spatial pattern; however, this relationship is specific to demographic factors, so we cannot use this methodology to compare between species.
种群持久性的衡量一直是生态学中的一个长期存在的问题；特别是，是否有可能在没有长时间序列的情况下深入了解持久性。空间格局的分形测量，如 Korcak 指数或边界维数，已被提议作为潜在动态持久性的指标。在这里，我们探讨了在什么条件下分形度量与持久性之间存在预测关系。我们结合了理论论证和对长期海草研究的航拍快照和时间序列。对于这种营养生长形式，我们发现，在可以测量种群返回率的调查点，Korcak 指数和持久性之间的预期关系是明显的。这突出了基于空间快照的幂律斑块大小分布和其他指标的使用的局限性。此外，我们的数值模拟表明，对于单一物种和一系列环境条件，Korcak 持久性关系提供了时间动态和空间格局之间的联系；然而，这种关系是特定于人口因素的，因此我们不能使用这种方法来比较物种间的关系。
