Institute of General Ecology and Environmental Protection, Technische Universität Dresden, Tharandt, Germany.
German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.
Sci Adv. 2023 Oct 6;9(40):eadi2362. doi: 10.1126/sciadv.adi2362.
Tree species diversity and mycorrhizal associations play a central role for forest productivity, but factors driving positive biodiversity-productivity relationships remain poorly understood. In a biodiversity experiment manipulating tree diversity and mycorrhizal associations, we examined the roles of above- and belowground processes in modulating wood productivity in young temperate tree communities and potential underlying mechanisms. We found that tree species richness, but not mycorrhizal associations, increased forest productivity by enhancing aboveground structural complexity within communities. Structurally complex communities were almost twice as productive as structurally simple stands, particularly when light interception was high. We further demonstrate that overyielding was largely explained by positive net biodiversity effects on structural complexity with functional variation in shade tolerance and taxonomic diversity being key drivers of structural complexity in mixtures. Consideration of stand structural complexity appears to be a crucial element in predicting carbon sequestration in the early successional stages of mixed-species forests.
树种多样性和菌根关系对森林生产力起着核心作用，但驱动生物多样性与生产力正相关关系的因素仍知之甚少。在一项通过操纵树木多样性和菌根关系的生物多样性实验中，我们检验了地上和地下过程在调节年轻温带树木群落木材生产力方面的作用以及潜在的机制。我们发现，树木物种丰富度而非菌根关系通过增强群落内的地上结构复杂性来提高森林生产力。结构复杂的群落比结构简单的林分生产力几乎高出一倍，尤其是在高光照截获时更是如此。我们进一步证明，过度生产主要归因于生物多样性对结构复杂性的净正效应，而耐荫性和分类多样性的功能变化是混交林中结构复杂性的关键驱动因素。考虑林分结构复杂性似乎是预测混交林早期演替阶段碳固存的关键因素。
