四川省宝兴县具有海拔高差悬殊、气候多样、动植物资源和森林资源丰富等特点,是世界自然遗产大熊猫栖息地和长江上游生态屏障的重要组成部分。基于2001—2020年MODIS遥感反演数据,采用Sen趋势分析、Mann-Kendall趋势显著性分析和重心转...四川省宝兴县具有海拔高差悬殊、气候多样、动植物资源和森林资源丰富等特点,是世界自然遗产大熊猫栖息地和长江上游生态屏障的重要组成部分。基于2001—2020年MODIS遥感反演数据,采用Sen趋势分析、Mann-Kendall趋势显著性分析和重心转移分析等方法,研究宝兴县植被净初级生产力(NPP)的空间分布特征表明:(1)宝兴县森林植被NPP整体呈上升趋势,其中常绿针叶林与落叶针叶林的NPP分别以5.7 g C·m^(2)·a和10.9 g C·m^(2)·a的速度增长。而常绿阔叶林植被NPP下降幅度尤为显著,平均减少19.0 g C·m^(2)·a,说明宝兴县森林生态系统碳汇能力总体增强;(2)宝兴县森林生态系统在过去20年内保持相对稳定,植被NPP高值区主要集中于南部和东南部山区,植被生态功能呈恢复态势,植被NPP空间重心整体稳定,仅在2012年前后出现显著偏移,但部分林型更替与生态干扰对局部区域功能仍具有重要影响宝兴县常绿阔叶林多年平均植被NPP最高;(3)宝兴县植被NPP空间格局演化稳定,具有高植被NPP区向南部山区集中,暖色区域扩展、低值区收缩等生态功能恢复趋势,说明研究期内植被生产力整体向好;植被NPP空间重心具有局部年份偏移,但整体年均位移小、路径波动有限等特点,表明该区域森林生态系统结构稳定性较强。研究结果对宝兴县混交林与优势针叶林的可持续经营、大熊猫栖息地恢复与重建,林分结构调整与功能精准提升,以及森林生态系统碳汇能力持续增强等具有重要意义。展开更多
Detecting change features of climate variables in arid/semi-arid areas is essential for understanding related climate change patterns and the driving and evolution mechanism between climate and arid/semi-arid ecosyste...Detecting change features of climate variables in arid/semi-arid areas is essential for understanding related climate change patterns and the driving and evolution mechanism between climate and arid/semi-arid ecosystems.This paper takes Inner Mongolia of China,a unique arid/semi-arid ecosystem,as the study area.We first detected trend features of climate variables using the linear trend analysis method and then detected their trend-shift features using the breaks for additive seasonal and trend method based on the time-series of monthly precipitation and monthly mean temperature datasets from 1962 to 2016.We analyzed the different change features of precipitation and temperature on a regional scale and in different ecological zones to discover the spatial heterogeneity of change features.The results showed that Inner Mongolia has become warmer-wetter during the past 54 years.The regional annual mean temperature increased 0.4°C per decade with a change rate of 56.2%.The regional annual precipitation increased 0.07 mm per decade with a slightly change rate of about 1.7%,but the trend was not statistically significant.The warmer trend was contributed by the same positive trend in each season,while the wetter trend was contributed by the negative trend of the summer precipitation and the positive trend of the other three seasons.The regional monthly precipitation series had a trend-shift pattern with a structural breakpoint in the year 1999,while the regional monthly mean temperature series showed an increasing trend without a periodical trend-shift.After the year 2000,the warmer-wetter trend of the climate in Inner Mongolia was accelerated.The late 20th century was a key period,because the acceleration of the wetter trend in some local zones(I and II)and the alleviation of the warmer trend in some local zones(Ⅶ,Ⅷand IX)occurred simultaneously.Moreover,the change features had a strong spatial heterogeneity,the southeastern and southwestern of Inner Mongolia went through a warmer-drier trend compared with the other areas.The spatio-temporal heterogeneity of the climate change features is a necessary background for various types of research,such as regional climate change,the evolution of arid/semi-arid ecosystems,and the interaction mechanisms between climate and arid/semi-arid ecosystems based on earth-system models in Inner Mongolia.展开更多
应用STL(Seasonal-Trend Decomposition using LOESS)方法对1998—2010年滇池外海8个监测站点、10个水质指标的时间序列数据进行递归迭代,分解出低频率的趋势项、高频率的周期项及随机残差项.在此基础上计算稳态变化指数(RSI),对水质趋...应用STL(Seasonal-Trend Decomposition using LOESS)方法对1998—2010年滇池外海8个监测站点、10个水质指标的时间序列数据进行递归迭代,分解出低频率的趋势项、高频率的周期项及随机残差项.在此基础上计算稳态变化指数(RSI),对水质趋势的时、空变化特征进行识别和判定.结果表明,在分析的13年间,滇池外海8个监测站点各指标变化趋势总体一致;BOD5总体呈下降趋势,高锰酸盐指数(COD Mn)总体趋势显著上升,说明有机物可生化性下降;富营养化状态加剧,总氮(TN)总体趋势上升,并逐渐成为藻类的限制性营养盐,总磷(TP)浓度为劣V类,氨氮在氮元素形态中的主导地位正逐渐降低.研究结果表明,"十二五"期间滇池应重点控制氮磷、兼顾有机物污染.展开更多
文摘四川省宝兴县具有海拔高差悬殊、气候多样、动植物资源和森林资源丰富等特点,是世界自然遗产大熊猫栖息地和长江上游生态屏障的重要组成部分。基于2001—2020年MODIS遥感反演数据,采用Sen趋势分析、Mann-Kendall趋势显著性分析和重心转移分析等方法,研究宝兴县植被净初级生产力(NPP)的空间分布特征表明:(1)宝兴县森林植被NPP整体呈上升趋势,其中常绿针叶林与落叶针叶林的NPP分别以5.7 g C·m^(2)·a和10.9 g C·m^(2)·a的速度增长。而常绿阔叶林植被NPP下降幅度尤为显著,平均减少19.0 g C·m^(2)·a,说明宝兴县森林生态系统碳汇能力总体增强;(2)宝兴县森林生态系统在过去20年内保持相对稳定,植被NPP高值区主要集中于南部和东南部山区,植被生态功能呈恢复态势,植被NPP空间重心整体稳定,仅在2012年前后出现显著偏移,但部分林型更替与生态干扰对局部区域功能仍具有重要影响宝兴县常绿阔叶林多年平均植被NPP最高;(3)宝兴县植被NPP空间格局演化稳定,具有高植被NPP区向南部山区集中,暖色区域扩展、低值区收缩等生态功能恢复趋势,说明研究期内植被生产力整体向好;植被NPP空间重心具有局部年份偏移,但整体年均位移小、路径波动有限等特点,表明该区域森林生态系统结构稳定性较强。研究结果对宝兴县混交林与优势针叶林的可持续经营、大熊猫栖息地恢复与重建,林分结构调整与功能精准提升,以及森林生态系统碳汇能力持续增强等具有重要意义。
基金supported by the National Natural Science Foundation of China(41701474,41701467)the National Key Research and Development Plan of China(2016YFC0500205)+2 种基金the National Basic Research Program of China(2015CB954103)the Key Laboratory for National Geograophy State Monitoring(National Administration of Surveying,Mapping and Geoinformation2017NGCM09)
文摘Detecting change features of climate variables in arid/semi-arid areas is essential for understanding related climate change patterns and the driving and evolution mechanism between climate and arid/semi-arid ecosystems.This paper takes Inner Mongolia of China,a unique arid/semi-arid ecosystem,as the study area.We first detected trend features of climate variables using the linear trend analysis method and then detected their trend-shift features using the breaks for additive seasonal and trend method based on the time-series of monthly precipitation and monthly mean temperature datasets from 1962 to 2016.We analyzed the different change features of precipitation and temperature on a regional scale and in different ecological zones to discover the spatial heterogeneity of change features.The results showed that Inner Mongolia has become warmer-wetter during the past 54 years.The regional annual mean temperature increased 0.4°C per decade with a change rate of 56.2%.The regional annual precipitation increased 0.07 mm per decade with a slightly change rate of about 1.7%,but the trend was not statistically significant.The warmer trend was contributed by the same positive trend in each season,while the wetter trend was contributed by the negative trend of the summer precipitation and the positive trend of the other three seasons.The regional monthly precipitation series had a trend-shift pattern with a structural breakpoint in the year 1999,while the regional monthly mean temperature series showed an increasing trend without a periodical trend-shift.After the year 2000,the warmer-wetter trend of the climate in Inner Mongolia was accelerated.The late 20th century was a key period,because the acceleration of the wetter trend in some local zones(I and II)and the alleviation of the warmer trend in some local zones(Ⅶ,Ⅷand IX)occurred simultaneously.Moreover,the change features had a strong spatial heterogeneity,the southeastern and southwestern of Inner Mongolia went through a warmer-drier trend compared with the other areas.The spatio-temporal heterogeneity of the climate change features is a necessary background for various types of research,such as regional climate change,the evolution of arid/semi-arid ecosystems,and the interaction mechanisms between climate and arid/semi-arid ecosystems based on earth-system models in Inner Mongolia.
文摘应用STL(Seasonal-Trend Decomposition using LOESS)方法对1998—2010年滇池外海8个监测站点、10个水质指标的时间序列数据进行递归迭代,分解出低频率的趋势项、高频率的周期项及随机残差项.在此基础上计算稳态变化指数(RSI),对水质趋势的时、空变化特征进行识别和判定.结果表明,在分析的13年间,滇池外海8个监测站点各指标变化趋势总体一致;BOD5总体呈下降趋势,高锰酸盐指数(COD Mn)总体趋势显著上升,说明有机物可生化性下降;富营养化状态加剧,总氮(TN)总体趋势上升,并逐渐成为藻类的限制性营养盐,总磷(TP)浓度为劣V类,氨氮在氮元素形态中的主导地位正逐渐降低.研究结果表明,"十二五"期间滇池应重点控制氮磷、兼顾有机物污染.
