首页|Effects of stand age and inter-annual precipitation variability on fine root biomass in poplar plantations in the eastern coastal China

Effects of stand age and inter-annual precipitation variability on fine root biomass in poplar plantations in the eastern coastal China

扫码查看
原文链接
  • NSTL
  • Elsevier
Although we know that fine roots play an important role in carbon and nutrient cycling in forest ecosystems, knowledge on how fine root biomass (FRB) and its vertical distribution change with stand age and inter-annual precipitation variability is limited. In this study, we conducted a field experiment to explore the effects of stand age and inter-annual precipitation variability on FRB and its vertical distribution along the soil profile (0-100 cm) in poplar plantations on the eastern coast of China. We found that both poplar and understory vegetation FRB increased with increasing stand age. While the vertical distribution of fine roots in understory vegetation was not significantly affected by stand age, the distribution of FRB of poplar trees in deep soil layers was highest at the intermediate stand age (9-year-old). Poplar and understory vegetation FRB varied among sampling years and importantly, variation differed among stand ages. Compared with normal years, FRB of young poplar trees increased in the drought year (2019), while that in old stands decreased. In the subsequent drought recovery year, poplar FRB decreased in all stand ages; especially old stands. We found that poplar trees also optimize water absorption by changing the vertical distribution pattern of fine roots in the drought year. Moreover, unlike poplar trees, FRB of understory vegetation in all stand ages increased significantly in the drought year, but with little difference between the drought recovery and normal years. Structural equation models showed that variation in FRB of both poplar trees and understory vegetation were predominantly determined by soil total nitrogen while the vertical distribution of fine roots was regulated by soil water content. Our findings not only provide a scientific basis for sustainable management of poplar plantations, but also improve the ability to predict carbon dynamics of plantation ecosystems in confronting global climate change.

Stand agePrecipitationFine root biomassVertical distributionPoplar treesUnderstory vegetationSOIL-WATER UPTAKESCOTS PINEUNDERSTORY VEGETATIONVERTICAL-DISTRIBUTIONROBINIA-PSEUDOACACIASUBTROPICAL FORESTHYDRAULIC LIFTTURNOVER RATESUSE EFFICIENCYNORWAY SPRUCE

Geng, Qinghong、Ma, Xiaocui、Fu, Xiaofeng、Yan, Zhengming、Liu, Xiao、Xu, Xia

展开 >

Nanjing Forestry Univ

Ludong Univ

2022

10.1016/j.foreco.2021.119883

Forest Ecology and Management

Forest Ecology and Management

EISCI
ISSN：0378-1127
年,卷(期)：2022.505
  • 8
  • 101