桉树人工林3种生态系统服务的权衡关系对营林模式的响应

Response of Trade-off Relationships among Three Ecosystem Services in Eucalyptus spp.Plantations to Silvicultural Models

关键词:  机械营林  桉树人工林  土壤有机碳  土壤全氮  物种多样性  权衡与协同

Key words:  mechanical silvicultural  Eucalyptus spp.plantation  soil organic carbon  soil total nitrogen  species diversity  trade-off and synergy

摘要:

探究不同营林模式下桉树(Eucalyptus spp.)人工林生态系统服务(Ecosystem services)间的协同演变，可为桉树人工林的经营管理提供理论依据。本研究根据两种营林模式(传统营林和机械营林)和4个林龄(1年生、2年生、3年生和4年生)设置40个样地，对所选林分的土壤有机碳(SOC)调节、全氮(TN)调节及物种多样性进行测算，利用均方根偏差(Root Mean Square Deviation，RMSD)和广义线性混合模型(Generalized Linear Mixed Model，GLMM)分析不同生态系统服务权衡与协同关系及其影响因素。结果表明：(1)随着林龄的增长，机械营林模式下土壤SOC含量逐渐降低且趋于稳定,而TN含量先降低后增加，与传统营林模式相比无显著差异。机械营林初期物种多样性较低，但随着林龄的增长物种多样性逐渐恢复。(2)土壤SOC调节、TN调节与物种多样性之间具有明显的权衡关系，其中，机械营林模式中物种多样性具有相对较高的收益。随着林龄的增长，传统营林趋于土壤SOC收益，机械营林趋于土壤TN收益。(3)林分平均胸径和林龄是影响生态系统服务权衡的关键因素。综上，在实施机械化经营和管理时，应充分考虑生态系统服务权衡关系的空间异质性特征及其驱动机制差异，通过精准化的局部人工调控措施，有效缓解服务功能间的权衡冲突，实现生态系统服务功能的协同优化。

Abstract:

To explore the co-evolution of ecosystem services of Eucalyptus spp.plantations under different silvicultural models can provide a theoretical basis for the management of Eucalyptus spp.plantations.In this study,40 sample plots were set up according to two silvicultural models (traditional silvicultural and mechanical silvicultural) and four forest ages (1 a,2 a,3 a,4 a).The Soil Organic Carbon (SOC) regulation,Total Nitrogen (TN) regulation and species diversity of the selected stands were measured.The Root Mean Square Deviation (RMSD) and Generalized Linear Mixed Model (GLMM) were used to analyze the trade-off and synergy relationship of different ecosystem services and their influencing factors.The results showed that: (1) With the increase of forest age,the soil SOC content under the mechanical silvicultural model gradually decreased and tended to be stable.However the TN content decreased first and then increased,which was not significantly different from the traditional silvicultural model.The species diversity was low in the early stage of mechanical silvicultural,but the species diversity gradually recovered with the increase of forest age.(2) There was a clear trade-off relationship between soil SOC regulation,TN regulation and species diversity.Among them,species diversity in mechanical silvicultural model had a relatively high benefit.With the increase of forest age,the traditional silvicultural tends to soil SOC benefit,and the mechanical silvicultural tends to soil TN benefit.(3) The average diameter at breast height and stand age were the key factors affecting the trade-off relationship of ecosystem services.In summary,when implementing mechanized operation and management,we should fully consider the spatial heterogeneity characteristics of ecosystem service trade-off relationship and the differences in their driving mechanisms.Through precise localized artificial regulation measures,the trade-off conflict between service functions can be effectively alleviated,and the synergy optimization of ecosystem service functions can be realized.