Plasticity in leaf litter traits partly mitigates the impact of thinning on forest floor carbon cycling

1. Reducing stand density by thinning intensification has been emphasized as an efficient strategy of forest adaptation to climate change as it improves stand resistance to drought. Yet, it is still unclear how it could affect litter C cycling processes. Recent evidence indicates that the plasticity of an oak tree species can lead to a decline in its leaf litter quality and decomposability following thinning. The consequences for litter decomposition and forest floor C storage at the ecosystem-scale remain largely unexplored. 2. In this study, we took advantage of a regional-scale, multi-site network of long-term thinning experiments in temperate oak (Quercus petraea) forests to address this issue. We measured ecosystem properties related to forest floor C cycling in 19 plots across eight experimental sites covering a large gradient of stand density and age. Though we expected thinning to affect in situ litter decomposition by altering oak leaf litter quality, we conducted complementary...

1. 通过强化间伐（thinning intensification）降低林分密度（stand density），已被视为森林适应气候变化的高效策略，因其可提升林分的抗旱性。然而，目前尚不清楚该措施会对凋落物碳循环（litter C cycling）过程产生何种影响。近期研究证据表明，某栎树树种的表型可塑性（plasticity）会在间伐后导致其叶凋落物质量（leaf litter quality）与分解性（decomposability）下降。生态系统尺度（ecosystem-scale）下，间伐对凋落物分解及林地地表碳储量的影响仍在很大程度上未被探明。
2. 本研究依托温带无梗花栎（Quercus petraea）林的区域尺度（regional-scale）多站点长期间伐试验网络，旨在解决这一科学问题。研究团队在覆盖林分密度与林龄大范围梯度的8个试验站点的19个样地（plots）中，测定了与林地地表碳循环（forest floor C cycling）相关的生态系统属性。尽管我们曾推测间伐可通过改变栎树叶凋落物质量，进而影响原位凋落物分解（in situ litter decomposition），但本研究还开展了补充性……