京津冀地区森林土壤酚含量及其关键调控因子

Total phenolic contents in the forest soil of the Beijing-Tianjin-Hebei region and its regulatory factors

由于酚的难分解性和对养分循环有抑制效应,土壤酚含量对森林生态系统具有重要调控作用和指示意义;然而,由于高氮沉降下森林土壤酚观测数据缺乏,土壤酚含量变化及其响应氮沉降或气候因子的敏感性和机制并不清楚.因此,选取全球氮沉降热点区域京津冀地区,对27个不同氮沉降和气候条件下的森林土壤酚含量进行取样测试,探究该地区森林土壤酚含量水平及其影响因子.京津冀地区土壤酚含量点位均值范围在0.09-0.67 mg/g,区域平均水平0.32mg/g,显著低于全球其他地区的观测值(点位均值范围为0.79-5.00mg/g).在研究区内,土壤酚含量因土壤和主要植被类型存在明显差异,总体上针叶树种与棕壤发育导致较高土壤酚含量;并且研究区中森林土壤pH是调节土壤酚含量的主要负面因子.总之,氮沉降热点区域京津冀地区土壤酚含量水平较低,且土壤pH是土壤酚含量的主要调控因子.上述结果和发现对于理解氮污染区森林碳氮循环过程及其对全球变化的响应以及森林资源管理具有重要科学意义.

Soil total phenolic content(TPC)has an important regulatory and indicator role in forest ecosystems owing to its refractory nature and inhibitory effect on nutrient cycling.However,because of the lack of observational data on forest soil TPC under high nitrogen deposition,the sensitivity and mechanism of variation and its response to nitrogen deposition or climate factors are unclear.Therefore,in this study,we selected the Beijing-Tianjin-Hebei(BTH)region of China,a global nitrogen deposition hotspot,to investigate the level of forest soil TPC and its influencing factors by sampling 27 forest soil TPCs under different nitrogen deposition and climatic conditions.The mean values of soil TPC in the BTH region were 0.09–0.67 mg/g,with a regional average of 0.32 mg/g,which was substantially lower than that observed in other regions of the world(point mean 0.79–5.00 mg/g).Within the study area,soil TPC varied substantially by soil and major vegetation type;coniferous species with brown soil produced a higher soil TPC;soil pH serves as the primary negative factor modulating soil TPC.In general,the soil phenol content in the nitrogen deposition hotspot,specifically the Beijing-Tianjin-Hebei area,was relatively low,and soil pH is the main regulator of soil TPC.This study has important implications for the carbon and nitrogen cycles in nitrogen-polluted forested areas and their response to global changes,as well as for the management of forest resources.