Jansen Merel, Anten Niels P R, Bongers Frans, Martínez-Ramos Miguel, Gavito Mayra E, Zuidema Pieter A
Forest Ecology and Forest Management, Wageningen University, Wageningen, The Netherlands.
Centre for Crop Systems Analysis, Wageningen University, Wageningen, The Netherlands.
Oecologia. 2017 Dec;185(4):663-674. doi: 10.1007/s00442-017-3978-1. Epub 2017 Oct 12.
An unanswered question in ecology is whether the environmental factors driving short-term performance also determine the often observed long-term performance differences among individuals. Here, we analyze the extent to which temporal persistence of spatial heterogeneity in environmental factors can contribute to long-term inter-individual variation in stem length growth. For a natural population of a long-lived understorey palm, we first quantified the effect of several environmental factors on stem length growth and survival. We then performed individual-based simulations of growth trajectories, in which we varied, for two environmental factors: (1) the strength of the effect on stem length growth and (2) the temporal persistence. Short-term variation in stem length growth was strongly driven by light availability. Auto-correlation in light availability and soil pH increased simulated variation in stem length growth among 20-year-old palms to levels similar to the observed variation. Analyses in which we varied both the strength of the effect on stem length growth and the temporal persistence of the environmental factors revealed that a large fraction of observed long-term growth differences can be explained, as long as one of these effects is strong. This implies that environmental factors that are relatively unimportant for short-term performance can still drive long-term performance differences when the environmental variation is sufficiently persistent over time.
生态学中一个尚未解决的问题是，驱动短期表现的环境因素是否也决定了个体间经常观察到的长期表现差异。在这里，我们分析了环境因素中空间异质性的时间持续性在多大程度上会导致茎长生长的长期个体间差异。对于一个长寿林下棕榈的自然种群，我们首先量化了几个环境因素对茎长生长和存活的影响。然后，我们进行了基于个体的生长轨迹模拟，其中对于两个环境因素，我们改变了：（1）对茎长生长的影响强度和（2）时间持续性。茎长生长的短期变化强烈受光照可用性驱动。光照可用性和土壤pH值的自相关性将20岁棕榈茎长生长的模拟差异增加到与观察到的差异相似的水平。在我们同时改变对茎长生长的影响强度和环境因素的时间持续性的分析中发现，只要这些影响中的一个很强，很大一部分观察到的长期生长差异就可以得到解释。这意味着，对于短期表现相对不重要的环境因素，当环境变化随时间足够持久时，仍可驱动长期表现差异。
