增强陆地生态系统碳汇(简称陆地碳汇)是减缓大气二氧化碳(CO_(2))浓度上升和全球变暖的重要手段,也是实现我国“碳中和”目标的有效途径.为全面理解陆地碳汇特征及其对实现“碳中和”目标的贡献,本文系统梳理了近40年来陆地碳源汇研究...增强陆地生态系统碳汇(简称陆地碳汇)是减缓大气二氧化碳(CO_(2))浓度上升和全球变暖的重要手段,也是实现我国“碳中和”目标的有效途径.为全面理解陆地碳汇特征及其对实现“碳中和”目标的贡献,本文系统梳理了近40年来陆地碳源汇研究的主要进展,阐述了全球和我国陆地碳汇的时空格局及其驱动因素,分析了陆地碳汇对实现“碳中和”目标的作用.根据全球碳收支评估报告,过去60年全球陆地碳汇从1960年代的(-0.2±0.9)Pg C yr^(-1)(弱碳源;1 Pg=10^(15)g=10亿吨碳)增加至2010年代的(1.9±1.1)Pg C yr^(-1)(碳汇).目前,陆地碳汇主要分布在北半球中高纬度地区,而热带地区表现为微弱的碳汇或碳源.不同类型生态系统的碳汇大小存在差异:森林是陆地碳汇的主体,灌丛、湿地生态系统和农田土壤整体表现出碳汇功能,但草地的碳源汇功能尚不明确.此外,荒漠生态系统可能起着碳汇功能,但其大小和形成机制尚存在争议.大气CO_(2)浓度上升、氮沉降、气候变化和土地覆盖变化等是影响陆地碳汇强度的主要因素,火灾、气溶胶等因素也影响其大小.不同区域陆地碳汇的驱动因素存在差异:北美和欧洲陆地碳汇主要是大气CO_(2)浓度上升和气候变化等因素所致;而在中国,除了上述全球变化要素外,植树造林、生态修复也是驱动其碳汇的重要因素.综合以往研究结果评估,目前我国陆地碳汇强度为0.20~0.25 Pg C yr^(-1),预计2060年可能处于0.15~0.52 Pg C yr^(-1)之间.未来研究需通过扩大生态系统调查与监测的范围、完善陆地生物圈模型等途径提升陆地碳汇的评估精度,量化各类措施对生态系统碳汇潜力的影响,精准评估我国陆地碳汇对实现“碳中和”目标的贡献.展开更多
The secondary forests on northern slope of Mt. Changbai were sampled to investigate the effect of human disturbance on their tree species diversity and community structure. Compared with broad-leaved Korean Pine (Pinu...The secondary forests on northern slope of Mt. Changbai were sampled to investigate the effect of human disturbance on their tree species diversity and community structure. Compared with broad-leaved Korean Pine (Pinus koraiensis) forests, secondary forests were much lower in tree species diversity, community structure indices and stand volume. Secondary forests were dominated by pioneer species, and nearly no natural regeneration of Korean Pine was observed in most of our plots. Stepwise regression revealed that, stand volume was the most powerful predictor for tree species diversity. Tree species diversity decreased with the decrease of volume in secondary forests, while increased in broad_leaved Korean Pine forests. Community structure indexes also dropped significantly with decreasing stand volume in secondary forests under different human disturbances. However, broad_leaved Korean Pine forests did not show significant change in community structure under natural disturbance. These results indicated that, broad_leaved Korean Pine forests were strongly resistant to natural disturbance, while secondary forests were sensitive to human disturbance. The analysis of variance showed that the tree species diversity declined significantly under intensive disturbance (volume was below 100 m3·hm -2),the community structure was influenced significantly under moderate disturbance (volume was below 150 m3·hm -2). Our results suggested that the secondary forests were poor in stand quality, and the tree species diversity and community structure index were sensitive to human disturbance. More effort should be make to protect secondary forests, together with human regeneration of Korean Pine under canopy, in order to promote the recovery of the secondary forests to the broad_leaved Korean Pine forests.展开更多
解释群落的物种多样性大小是生态学研究的一个重要的理论和实践问题。人们提出了群落物种多样性的多种假说,Zobel等人提出的种库假说(species pool hypothesis)是生物多样性理论研究的重要发展。该假说认为,一个群落的物种多样性不仅与...解释群落的物种多样性大小是生态学研究的一个重要的理论和实践问题。人们提出了群落物种多样性的多种假说,Zobel等人提出的种库假说(species pool hypothesis)是生物多样性理论研究的重要发展。该假说认为,一个群落的物种多样性不仅与环境条件和生态过程(ecological process)(如竞争、捕食)有关,也受区域种库(regional species pool)的限制。区域种库是指一个地区可进入某一群落的潜在物种数量,它由地史过程(如冰期、地质年代)和区域过程(物种形成、迁移扩散以及消亡)所决定。按照种库假说,某一生境类型的面积越大,地质年代越古老,物种形成的机会也就越多,因而能适应和分布于该生境的物种也就越多,实际群落中的物种丰富度也就越高。种库在空间上主要有两个层次:区域种库和实际种库,前者指某一生境所拥有的潜在物种数量,主要由生物地理过程(biogeographic processes)所决定;后者则为调查的群落中实际出现的物种数量,主要由竞争等生态过程和区域种库共同决定。本文对种库假说的基本概念、主要内容、种库确定方法等作了介绍,并阐述了作者对这些问题的理解和认识。展开更多
文摘增强陆地生态系统碳汇(简称陆地碳汇)是减缓大气二氧化碳(CO_(2))浓度上升和全球变暖的重要手段,也是实现我国“碳中和”目标的有效途径.为全面理解陆地碳汇特征及其对实现“碳中和”目标的贡献,本文系统梳理了近40年来陆地碳源汇研究的主要进展,阐述了全球和我国陆地碳汇的时空格局及其驱动因素,分析了陆地碳汇对实现“碳中和”目标的作用.根据全球碳收支评估报告,过去60年全球陆地碳汇从1960年代的(-0.2±0.9)Pg C yr^(-1)(弱碳源;1 Pg=10^(15)g=10亿吨碳)增加至2010年代的(1.9±1.1)Pg C yr^(-1)(碳汇).目前,陆地碳汇主要分布在北半球中高纬度地区,而热带地区表现为微弱的碳汇或碳源.不同类型生态系统的碳汇大小存在差异:森林是陆地碳汇的主体,灌丛、湿地生态系统和农田土壤整体表现出碳汇功能,但草地的碳源汇功能尚不明确.此外,荒漠生态系统可能起着碳汇功能,但其大小和形成机制尚存在争议.大气CO_(2)浓度上升、氮沉降、气候变化和土地覆盖变化等是影响陆地碳汇强度的主要因素,火灾、气溶胶等因素也影响其大小.不同区域陆地碳汇的驱动因素存在差异:北美和欧洲陆地碳汇主要是大气CO_(2)浓度上升和气候变化等因素所致;而在中国,除了上述全球变化要素外,植树造林、生态修复也是驱动其碳汇的重要因素.综合以往研究结果评估,目前我国陆地碳汇强度为0.20~0.25 Pg C yr^(-1),预计2060年可能处于0.15~0.52 Pg C yr^(-1)之间.未来研究需通过扩大生态系统调查与监测的范围、完善陆地生物圈模型等途径提升陆地碳汇的评估精度,量化各类措施对生态系统碳汇潜力的影响,精准评估我国陆地碳汇对实现“碳中和”目标的贡献.
文摘The secondary forests on northern slope of Mt. Changbai were sampled to investigate the effect of human disturbance on their tree species diversity and community structure. Compared with broad-leaved Korean Pine (Pinus koraiensis) forests, secondary forests were much lower in tree species diversity, community structure indices and stand volume. Secondary forests were dominated by pioneer species, and nearly no natural regeneration of Korean Pine was observed in most of our plots. Stepwise regression revealed that, stand volume was the most powerful predictor for tree species diversity. Tree species diversity decreased with the decrease of volume in secondary forests, while increased in broad_leaved Korean Pine forests. Community structure indexes also dropped significantly with decreasing stand volume in secondary forests under different human disturbances. However, broad_leaved Korean Pine forests did not show significant change in community structure under natural disturbance. These results indicated that, broad_leaved Korean Pine forests were strongly resistant to natural disturbance, while secondary forests were sensitive to human disturbance. The analysis of variance showed that the tree species diversity declined significantly under intensive disturbance (volume was below 100 m3·hm -2),the community structure was influenced significantly under moderate disturbance (volume was below 150 m3·hm -2). Our results suggested that the secondary forests were poor in stand quality, and the tree species diversity and community structure index were sensitive to human disturbance. More effort should be make to protect secondary forests, together with human regeneration of Korean Pine under canopy, in order to promote the recovery of the secondary forests to the broad_leaved Korean Pine forests.
文摘解释群落的物种多样性大小是生态学研究的一个重要的理论和实践问题。人们提出了群落物种多样性的多种假说,Zobel等人提出的种库假说(species pool hypothesis)是生物多样性理论研究的重要发展。该假说认为,一个群落的物种多样性不仅与环境条件和生态过程(ecological process)(如竞争、捕食)有关,也受区域种库(regional species pool)的限制。区域种库是指一个地区可进入某一群落的潜在物种数量,它由地史过程(如冰期、地质年代)和区域过程(物种形成、迁移扩散以及消亡)所决定。按照种库假说,某一生境类型的面积越大,地质年代越古老,物种形成的机会也就越多,因而能适应和分布于该生境的物种也就越多,实际群落中的物种丰富度也就越高。种库在空间上主要有两个层次:区域种库和实际种库,前者指某一生境所拥有的潜在物种数量,主要由生物地理过程(biogeographic processes)所决定;后者则为调查的群落中实际出现的物种数量,主要由竞争等生态过程和区域种库共同决定。本文对种库假说的基本概念、主要内容、种库确定方法等作了介绍,并阐述了作者对这些问题的理解和认识。
