Nitrogen storage and allocation in China’s forest ecosystems

作者：Li XU,Nianpeng HE

摘要：Forests are important parts of terrestrial ecosystems and play a leading role in regional and global nitrogen(N)cycles.Detailed assessment of N storage and allocation in China’s forests is critical to improve the accuracy of regional or global N estimates and to guide policy-makers in the formulation of scientific and effective N management measures.However,the fore stN storage at national scale remains unclear.Based on 4420 forest field-investigated data,we investigated the N storage allocation in China’s forests,explored the spatial patterns and influence factors.The data included vegetation information on various organs(i.e.,leaf,branch,stem,and root)and soil information at different depths(0-30 cm and 0-100 cm).The total N storage in China’s forest ecosystems was 14.45±8.42 tN hm^–2;0.86±0.51 tN hm^–2(5.95%)in vegetation and 13.59±8.40 tN hm^–2(94.05%)in soil(0–100 cm).The storage and allocation of N varied significantly across various regions and forest types.For different ecological regions,N storage varied from 10.34 to 23.11 tN hm^–2,and the allocation ratio of N storage between vegetation and soil(0–100 cm)varied from 0.03 to 0.16.For different forest types,the N storage varied from 12.87 to 18.32 tN hm^–2,and the allocation ratio of N storage between vegetation and soil(0–100 cm)varied from 0.03 to 0.09.The spatial patterns relative to N storage and allocation in forests were different.Climate was the primary factor influencing the spatial variation in forestN storage,while soil texture was the main factor influencing the spatial variation in N allocation.These first estimates of N storage and allocation ratio in China’s forests are keys for improving the fitting accuracy of regional N cycle models and provide a reference for regional management of forestN.

发文机构：Key Laboratory of Ecosystem Network Observation and Modeling College of Resources and Environment

关键词：FORESTNitrogencyclingNitrogenstorageALLOCATIONCLIMATESoilnutrientSoiltexture

分类号： S718.5[农业科学—林学]