College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, 510642, P. R. China.
Department of Forestry and Natural Resources, Hardwood Tree Improvement and Regeneration Center, Purdue University, West Lafayette, IN, 47907-2061, USA.
Sci Rep. 2018 Jul 12;8(1):10536. doi: 10.1038/s41598-018-28899-5.
Forests act as major sinks for atmospheric CO. An understanding of the relationship between forest biomass allocation and precipitation gradients is needed to estimate the impacts of changes in precipitation on carbon stores. Biomass patterns depend on tree size or age, making it unclear whether biomass allocation is limited by tree age at regional scales. Using a dataset of ten typical forest types spanning a large age scale, we evaluated forest biomass allocation-precipitation correlations with the aim of testing whether biomass allocation patterns vary systematically in response to altered precipitation. With increasing mean annual precipitation, a significant quadratic increase occurred in ≤30 yr and >60 yr groups in stem biomass, >60 yr group in branch biomass, and >60 yr groups in leaf biomass; and a significant cubic increase occurred in 30-60 yr and all age forest groups in stem biomass, ≤30 yr, 30-60 yr and all age forest groups in branch biomass, ≤30 yr and all age forest groups in leaf biomass, and in each group in root biomass, indicating that organ biomass is strongly limited by precipitation. Thus, forest biomass responds predictably to changes in mean annual precipitation. The results suggest that forest organ biomass-precipitation relationships hold across independent datasets that encompass a broad climatic range and forest age.
森林是大气 CO 的主要汇。为了估计降水变化对碳储量的影响，需要了解森林生物量分配与降水梯度之间的关系。生物量模式取决于树木的大小或年龄，因此尚不清楚在区域尺度上生物量分配是否受到树龄的限制。利用跨越大年龄尺度的十种典型森林类型的数据集，我们评估了森林生物量分配与降水的相关性，目的是检验生物量分配模式是否会因降水的改变而系统地变化。随着年平均降水量的增加，在 ≤30 年和 >60 年组的茎生物量、>60 年组的枝生物量和 >60 年组的叶生物量中，出现了显著的二次增加；在 30-60 年和所有年龄组的茎生物量、≤30 年、30-60 年和所有年龄组的枝生物量、≤30 年和所有年龄组的叶生物量以及每个组的根生物量中，出现了显著的三次增加，表明器官生物量受到降水的强烈限制。因此，森林生物量对年平均降水量的变化有可预测的反应。结果表明，森林器官生物量-降水关系在涵盖广泛气候范围和森林年龄的独立数据集上具有一致性。
