为了解双斑蟳栖息分布规律,实验根据2011—2016年多个季度航次在海州湾进行的渔业资源和环境调查数据,采用广义线性模型(GLM)、广义可加模型(GAM)以及随机森林3种物种分布模型(SDMs)方法,结合AIC(akaike information criterion)准则、...为了解双斑蟳栖息分布规律,实验根据2011—2016年多个季度航次在海州湾进行的渔业资源和环境调查数据,采用广义线性模型(GLM)、广义可加模型(GAM)以及随机森林3种物种分布模型(SDMs)方法,结合AIC(akaike information criterion)准则、累积偏差解释率和交叉检验等评判指标筛选和构建了双斑蟳栖息分布模型,并分析了环境因子对双斑蟳分布的影响。结果显示,3种模型在解释因子与响应变量间的关系上基本一致;其中GAM在模型拟合上具有优势,而随机森林的预测性能明显高于传统的GLM和GAM。双斑蟳相对渔获量在年份和月份间的变异性最为显著,两个因子的解释率分别在18%和3.8%以上。水深和表层盐度对双斑蟳资源分布的影响较大,均与双斑蟳相对丰度呈正相关关系;双斑蟳分布总体呈现冬季相对较高,夏季东北部海域高、西南部低的特点,与海州湾水深分布特点基本一致。本研究还根据FVCOM(finite-volume coasta ocean model)模拟环境数据,利用随机森林分布模型估计了双斑蟳在海州湾海域2011年各个季节的空间分布,为渔业资源的开发和保护提供依据。展开更多
Spatial and temporal distribution of vegetation net primary production(NPP)in China was studied us-ing three light-use efficiency models(CASA,GLOPEM and GEOLUE)and two mechanistic ecological process models(CEVSA,GEOPR...Spatial and temporal distribution of vegetation net primary production(NPP)in China was studied us-ing three light-use efficiency models(CASA,GLOPEM and GEOLUE)and two mechanistic ecological process models(CEVSA,GEOPRO).Based on spatial and temporal analysis(e.g.monthly,seasonally and annually)of simulated results from ecological process mechanism models of CASA,GLOPEM and CEVSA,the following conclusions could be made:(1)during the last 20 years,NPP change in China followed closely the seasonal change of climate affected by monsoon with an overall trend of increas-ing;(2)simulated average seasonal NPP was:0.571±0.2 GtC in spring,1.573±0.4 GtC in summer,0.6±0.2 GtC in autumn,and 0.12±0.1 GtC in winter.Average annual NPP in China was 2.864±1 GtC.All the five models were able to simulate seasonal and spatial features of biomass for different ecological types in China.This paper provides a baseline for China's total biomass production.It also offers a means of estimating the NPP change due to afforestation,reforestation,conservation and other human activities and could aid people in using for-mentioned carbon sinks to fulfill China's commitment of reducing greenhouse gases.展开更多
基金the National Natural Science Foundation of China(Grant No.40471097)National Basic Research Program of China(Grant No.2002CB412507)Knowledge Innovation Program of the Chinese Academy of Sciences
文摘Spatial and temporal distribution of vegetation net primary production(NPP)in China was studied us-ing three light-use efficiency models(CASA,GLOPEM and GEOLUE)and two mechanistic ecological process models(CEVSA,GEOPRO).Based on spatial and temporal analysis(e.g.monthly,seasonally and annually)of simulated results from ecological process mechanism models of CASA,GLOPEM and CEVSA,the following conclusions could be made:(1)during the last 20 years,NPP change in China followed closely the seasonal change of climate affected by monsoon with an overall trend of increas-ing;(2)simulated average seasonal NPP was:0.571±0.2 GtC in spring,1.573±0.4 GtC in summer,0.6±0.2 GtC in autumn,and 0.12±0.1 GtC in winter.Average annual NPP in China was 2.864±1 GtC.All the five models were able to simulate seasonal and spatial features of biomass for different ecological types in China.This paper provides a baseline for China's total biomass production.It also offers a means of estimating the NPP change due to afforestation,reforestation,conservation and other human activities and could aid people in using for-mentioned carbon sinks to fulfill China's commitment of reducing greenhouse gases.
