The functional trait values that constitute a whole-plant phenotype interact with the environment to determine demographic rates. Current approaches often fail to explicitly consider trait-trait and trait-environment interactions, which may lead to missed information that is valuable for understanding and predicting the drivers of demographic rates and functional diversity. Here, we consider these interactions by modeling growth performance landscapes that span multidimensional trait spaces along environmental gradients. We utilize individual-level leaf, stem and root trait data combined with growth data from tree seedlings along soil nutrient and light gradients in a hyper-diverse tropical rainforest. We find that multiple trait combinations in phenotypic space (i.e. alternative designs) lead to multiple growth performance peaks that shift along light and soil axes such that no single or set of interacting traits consistently results in peak growth performance. Evidence from these growth performance peaks also generally indicates frequent independence of above and below ground resource acquisition strategies. These results help explain how functional diversity is maintained in ecological communities and question the practice of utilizing a single trait or environmental variable, in isolation, to predict the growth performance of individual trees.

中文翻译：

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替代设计和热带树苗生长性能景观

构成整株植物表型的功能性状值与环境相互作用以确定人口统计率。当前的方法通常未能明确考虑特质-特质和特质-环境的相互作用，这可能会导致错过对于理解和预测人口比率和功能多样性的驱动因素很有价值的信息。在这里，我们通过对沿着环境梯度跨越多维特征空间的增长绩效景观进行建模来考虑这些相互作用。我们利用个体水平的叶、茎和根性状数据，结合来自高度多样化热带雨林中土壤养分和光梯度的树苗生长数据。我们发现表型空间中的多个性状组合（即 替代设计）导致多个生长性能峰值沿着光轴和土壤轴移动，因此没有一个或一组相互作用的特征始终如一地导致峰值生长性能。来自这些增长绩效峰值的证据通常也表明地上和地下资源获取策略的频繁独立性。这些结果有助于解释如何在生态群落中保持功能多样性，并质疑单独利用单一性状或环境变量来预测单个树木的生长性能的做法。