江西省森林净初级生产力动态变化特征及其驱动因子分析  

Forest net primary productivity dynamics and driving forces in Jiangxi Province, China

作　　者：李登秋[1,2] 张春华[3] 居为民[2] 刘丽娟[1] 

机构地区：[1]浙江农林大学环境与资源学院浙江省森林生态系统碳循环与固碳减排重点实验室,浙江临安311300 [2]南京大学国际地球系统科学研究所,南京210023 [3]鲁东大学资源与环境工程学院,山东烟台264025

出　　处：《植物生态学报》2016年第7期643-657,共15页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(41271211);浙江省自然科学基金(LQ16D010008)

摘　　要：亚热带森林生态系统具有巨大的固碳潜力。净初级生产力(NPP)在碳循环过程中具有重要的作用,受到气候变化、大气成分、森林扰动的强度和频度、林龄等因子的综合影响,然而目前上述各因子对亚热带森林NPP变化的贡献尚不明确,需要鉴别森林NPP时空变化的主要驱动因子,以准确认识亚热带森林生态系统碳循环。该文综合气象数据、年最大叶面积指数(LAI)、参考年NPP(BEPS模型模拟)、林龄、森林类型、土地覆盖、数字高程模型(DEM)、土壤质地、CO2浓度、氮沉降等多源数据,利用In TEC模型(Integrated Terrestrial Ecosystem Carbon-budget Model)研究亚热带典型地区江西省森林生态系统1901–2010年NPP时空动态变化特征,通过模拟情景设计,着重讨论1970–2010年气候变化、林龄、CO2浓度和氮沉降对森林NPP动态变化的影响。研究结果如下:(1)In TEC模型能较好地模拟研究区NPP的时空变化;(2)江西省森林NPP 1901–2010年为(47.7±4.2)Tg C·a–1(平均值±标准偏差),其中20世纪70年代、80年代、90年代分别为50.7、48.8、45.4 Tg C·a–1,2000–2009年平均为55.2 Tg C·a–1;随着森林干扰后的恢复再生长,江西省森林NPP显著上升,2000–2009年NPP增加的森林面积占森林总面积的60%;(3)1970–2010年,仅考虑森林干扰因子和仅考虑非干扰因子(气候、氮沉降、CO2浓度)情景下NPP分别为43.1和53.9 Tg C·a–1,比综合考虑干扰因子和非干扰因子作用下的NPP分别低估7.3 Tg C·a–1(低估的NPP与综合考虑干扰因子和非干扰因子作用下NPP的比值为14.5%,下同)和高估3.6 Tg C·a–1(7.1%);气候因子导致平均NPP减少2.0 Tg C·a–1(4.7%),氮沉降导致平均NPP增加4.5 Tg C·a–1(10.4%),CO2浓度变化及耦合效应(氮沉降+CO2浓度变化)分别导致平均NPP增加4.4 Tg C·a–1(10.3%)和9.4 Tg C·a–1(21.8%)。Aims Subtropical forest ecosystem has great carbon sequestration capacity. Net primary productivity（NPP） plays a critical role in forest carbon cycle and is affected by a number of factors, including climate change, atmospheric composition, forest disturbance intensity and frequency, and forest age, etc. However, the contribution of these factors to the temporal-spatial dynamics of NPP is still not clear. Quantifying the main driving forces on the temporal-spatial dynamics of NPP for subtropical forest ecosystems is a critical foundation for understanding their carbon cycle. Methods We utilized multi-sources dataset, including observed meteorological data, inversed annual maximum leaf area index（LAI）, referenced NPP（simulated by Boreal Ecosystem Productivity Simulator（BEPS） model）, forest age and forest types, land cover, digital elevation model（DEM）, soil texture, CO2 concentration and nitrogen deposition. We used the In TEC（integrated terrestrial ecosystem carbon-budget） model to simulate the NPP dynamics for forest ecosystems in Jiangxi Province during the period of 1901–2010. The effects of climate change, forest age, CO2 concentration and nitrogen（N） deposition on forest NPP from 1970 to 2010 werediscussed through designed scenarios. Important findings（1） Validations by flux measurements and forest inventory data indicated that the In TEC model was able to capture the interannual and spatial variations of forest NPP.（2） The average forest NPP was 47.7 Tg C·a–1（± 4.2 Tg C·a–1） during 1901–2010. The NPP in the 1970 s, 1980 s, 1990 s and 2000 s was 50.7, 48.8, 45.4, and 55.2 Tg C·a–1, respectively. As forest regrows, NPP significantly increased for forests in Jiangxi Province in the 2000 s, and exceed that in the 1970 s for more than 60% of the forest area.（3） During 1970–2010, under the scenarios of disturbance and non-disturbance, the forest NPP were underestimated by 7.3 Tg C·a–1（14.5%） and overestimated by 3.6 Tg C·a–1（7.1%） compared

关 键 词：气候变化 CO2 林龄 江西省 净初级生产力 氮沉降 

分 类 号：S718.5[农业科学—林学]