Tree diversity as a control of the element cycles of individual trees in experimentally assembled mixtures in Panama

生物多样性对生态系统功能的影响自1990年代以来一直通过沿自然梯度的观测和操纵实验来研究。虽然已经在草原上发现了多样性的影响，但尚不清楚所观察到的多样性与生态系统过程之间的关系是否也存在于结构更复杂、寿命更长的生态系统中，例如森林。研究表明，物种同一性和组成是元素通量的重要驱动因素。将物种特性引入生态系统模型的模型方法很少见，这些模型传统上将生物群视为黑匣子。要将多样性效应纳入生态系统模型，必须了解个体物种对元素循环的影响。因此，我们建议在巴拿马的跨学科和国际撒丁岛项目中研究树木多样性对元素循环的影响。我们的目标是：(1)建立单一栽培的5个树种的元素预算；(2)评估树种多样性(1、3和6个树种的混合体)对每个树种的元素预算的影响；(3)基于相邻树木之间的相互作用，在现有的森林生物地球化学循环模型中引入多样性效应。我们将确定所有相关生态系统区块的元素储量和主要元素通量。

The effect of biodiversity on ecosystem functioning has been studied since the 1990s by observations along natural gradients and in manipulative experiments. Although effects of diversity have been found in grassland, it is not yet clear, if the observed relation between diversity and ecosystem processes also exist in structurally more complex, long-lived ecosystems, e.g. forests. It has been shown that species identity and composition are important drivers of element fluxes. Model approaches introducing species identity into ecosystem models, which traditionally treat biota as a black box, are rare. To include diversity effects into ecosystem models, the influence of individual species on element cycles must be known. Therefore, we propose to study the effect of tree diversity on element cycling in the interdisciplinary and international Sardinilla Project in Panama. Our objectives are: (1) to set up element budgets for five tree species in monoculture, and (2) to assess the effect of tree diversity (1-, 3-, and 6-species mixtures) on the element budget of each tree species, and (3) to introduce diversity effects into an existing model of biogeochemical cycles in forests based on the interaction between neighboring trees. We will determine element storage in all relevant ecosystem compartments and the main element fluxes.