Comparison of the spatio-temporal dynamics of vegetation between the Changbai Mountains of eastern Eurasia and the Appalachian Mountains of eastern North America

The Changbai Mountains and the Appalachian Mountains have similar spatial contexts. The elevation, latitude, and moisture gradients of both mountain ranges offer regional insight for investigating the vegetation dynamics in eastern Eurasia and eastern North America. We determined and compared the spatial patterns and temporal trends in the normalized difference vegetation index (NDVI) in the Changbai Mountains and the Appalachian Mountains using time series data from the Global Inventory Modeling and Mapping Studies 3rd generation dataset from 1982 to 2013. The spatial pattern of NDVI in the Changbai Mountains exhibited fragmentation, whereas NDVI in the Appalachian Mountains decreased from south to north. The vegetation dynamics in the Changbai Mountains had an insignificant trend at the regional scale, whereas the dynamics in the Appalachian Mountains had a significant increasing trend. NDVI increased in 55% of the area of the Changbai Mountains and in 95% of the area of the Appalachian Mountains. The peak NDVI occurred one month later in the Changbai Mountains than in the Appalachian Mountains. The results revealed a significant increase in NDVI in autumn in both mountain ranges. The climatic trend in the Changbai Mountains included warming and decreased precipitation, and whereas that in the Appalachian Mountains included significant warming and increased precipitation. Positive and negative correlations existed between NDVI and temperature and precipitation, respectively, in both mountain ranges. Particularly, the spring temperature and NDVI exhibited a significant positive correlation in both mountain ranges. The results of this study suggest that human actives caused the differences in the spatial patterns of NDVI and that various characteristics of climate change and intensity of human actives dominated the differences in the NDVI trends between the Changbai Mountains and the Appalachian Mountains. Additionally, the vegetation dynamics of both mountain ranges were not identical to those in previous broader-scale studies.     

中国西北地区植被NDVI的时空变化及其影响因子分析

利用GIMMS/NDVI数据分析了中国西北地区1982-2006年植被NDVI时空变化特征及其影响因子。近25年来,中国西北地区年均植被NDVI增速为0.5%/10a,并存在明显的空间差异。天山、阿尔泰山、祁连山、青海的中东部等地区植被NDVI显著增加;青海南部地区、陕西和宁夏交界地区、甘肃部分地区,以及新疆部分地区的植被NDVI下降。从不同植被类型看:林地、草地和耕地的年均NDVI都在提高。研究表明:中国西北地区植被NDVI变化是各种自然和人为因素综合作用的结果。植被NDVI与气温、降水的年际变化整体上都呈弱的正相关。但与其年内变化则都呈显著的线性关系,当月均温量超过20℃时,植被NDVI呈下降趋势;当月降水量在0¹00mm期间,植被NDVI随降水线性增长,当月降水量超过100mm之后,不再有明显的增长趋势。农业生产水平提高和植被生态建设等人类活动对西北地区植被NDVI增加有重要影响。     

新疆NDVI时空特征及气候变化影响研究

基于新疆50个气象测站2003-2010年逐日降水、气温资料,结合逐月归一化植被覆盖影像资料,利用趋势分析、R/S分析、模糊C均值聚类、图像处理等方法,系统分析了全疆NDVI时空变化特征及其可持续性,并探究NDVI与气候因子（气温、降水）之间的相关性。研究表明：植被覆盖及气象因子年际间差异不大,呈现出整体稳定的态势,但年内变化明显。北疆/天山北坡水热条件优良、植被长势最好,且植被长势对气候因子的滞后效应并不明显且滞后时间短。天山南坡/天山东段次之,而南疆植被覆盖程度最差,南疆/天山南坡植被长势对气候因子（降水、气温）存在明显的滞后效应,植被生长受气温、降水限制性更大,且气温作为主要因子,对天山南坡植被生长的限制作用表现得更为突出。总体上,新疆植被覆盖呈持续性变化,现有植被覆盖情况基本保持不变,但呈退化趋势的面积大于得到改善的面积,在一定程度上与人类活动有很大关系,探查植被长势的变化趋势并及时做出相应调整,不仅能为新疆地区的植被保护以及植被恢复工作提供一定的科学依据,更能够为合理有效地安排农作物生产提供重要的理论指导。     

不同数据源归一化植被指数在中国北方草原区的应用比较

中国北方草原区生产力在区域碳水循环、农牧业发展中举足轻重。归一化植被指数（Normalized Difference Vegetation Index,NDVI）广泛应用于生产力的计算,然而目前来源众多的NDVI数据反映中国北方草原植被时空动态的一致性仍未可知。本研究利用2000—2015年3个来源NDVI数据集（MODIS NDVI、GIMMS NDVI和SPOT NDVI）并以国际上公认的数据准确性较高的MODIS NDVI为基准对比分析了中国北方草原区NDVI时空动态的一致性,并选取适宜的NDVI产品揭示研究区NDVI长期的时空格局。结果表明：整个中国北方草原区以及部分草原类型（高寒草甸、高寒草原、高寒荒漠、温带荒漠草原）GIMMS NDVI和MODIS NDVI 2套数据集无论是数值范围,还是年际波动和变化趋势具有较高一致性（二者在高寒草甸、高寒草原、高寒荒漠、温带荒漠草原的相关系数分别为0.60、0.47、0.51、0.74）,而SPOT NDVI数值远高于其他2个数据集,尤其是在青藏高原草原区,SPOT NDVI数值每年较另外两套数据集约偏高0.15,表明该区域使用SPOT数据应慎重。部分温带草原类型（典型草原和草甸草原）GIMMS NDVI和SPOT NDVI数据集在年际波动以及变化趋势上具有较高的一致性（相关系数分别为0.85和0.60）,但温带草原区3种数据集NDVI数值范围整体相差不大,小于0.06。基于上述结果,本研究进一步采用时间序列最长且与MODIS NDVI一致性最好的GIMMS NDVI分析了研究区NDVI的时空动态,发现1982—2015年中国北方草原区NDVI整体呈增加趋势,25%的区域达显著水平（p<0.05）,主要集中在温带草原区;高寒草原区NDVI大部分区域变化不显著且有一定比例的区域NDVI呈显著下降趋势。本研究可以为模型数据集选择和预测中国北方草原区植被对未来气候变化的响应提供科学依据。     

CLIMATIC VARIATIONS IN CHINA OVER THE LAST 2000 YEARS

1 INTRODUCTIONIn the last years, evidence for climate changes showed that the timing of the two great climatic events of “Medieval Warm Period” (MWP) and “Little Ice Age” (LIA) differed geographically (HUGHES et al., 1994, JONES and BRADLEY, 1992). In other words, the cold or warm periods in one region were often not coincident with those in other regions. The Northern Hemisphere warmth degree in the Middle Ages was lower than or at most comparable to that in the mid-20…     

Vegetation dynamics and its relationship with climatic factors in the Changbai Mountain Natural Reserve

This study examined the temporal variation of the Normalized Difference Vegetation Index (NDVI) and its relationship with climatic factors in the Changbai Mountain Natural Reserve (CMNR) during 2000-2009.The results showed as follows.The average NDVI values increased at a rate of 0.0024 year-1.The increase rate differed with vegetation types,such as 0.0034 year-1 for forest and 0.0017 year-1 for tundra.Trend analyses revealed a consistent NDVI increase at the start and end of the growing season but little variation or decrease observed in July during the study period.The NDVI in CMNR showed a stronger correlation with temperature than with precipitation,especially in spring and autumn.A stronger correlation was observed between NDVI and temperature in the tundra zone (2,000-2,600m) than in the coniferous forest (1,100-1,700m) and Korean pine-broadleaved mixed forest (700-1,100m) zones.The results indicate that vegetation at higher elevations is more sensitive to temperature change.NDVI variation had a strong correlation with temperature change (r=0.7311,p<0.01) but less significant correlation with precipitation change.The result indicates that temperature can serve as a main indicator of vegetation sensitivity in the CMNR.     

Vegetation NPP Distribution Based on MODIS Data and CASA Model —— A Case Study of Northern Hebei Province

1 Introduction Vegetation is an important component of terrestrial eco- system, it plays an important role in global matter and energy cycle, carbon balance and climate change. CO2 has effects on global warming, photosynthesis function, Net Primary Productivity (NPP) and earth environmental condition. NPP is one of the important biophysical variables of vegetation activity, and is a beginning link of biogeochemical carbon cycle. Vegetation absorbs CO2 from atmosphere through photosynthesi…     

STUDY ON VEGETATION AND CLIMATE CHANGES IN BEIJING REGION SINCE LATE PLEISTOCENE

１　ＩＮＴＲＯＤＵＣＴＩＯＮＳｉｎｃｅｔｈｅ１９８０ｓａｓｅｒｉｅｓｏｆｒｅｓｅａｒｃｈｐｌａｎｉｎｃｌｕｄｉｎｇＩＧＢＰ（ｔｈｅＩｎｔｅｒｎａｔｉｏｎａｌＧｅｏｓｐｈｅｒｅ．ＢｉｏｓｐｈｅｒｅＰｒｏｇｒａｍｍｅ）ｈａｖｅｂｅｅｎｓｅｔｕｐ，ｏｆｔｈｅｍ，ＰＡＧＥＳ（ｔｈｅＰａｓｔＧｌｏｂａｌｃｈａｎｇｅｓ）ｉｓａｎｉｍｐｏｒｔａｎｔｃｏｒｅｐｒｏｊｅｃｔ．Ｔｈｅｎａｔｕｒｅｒｅｃｏｒｄｓｏｆｏｃｅａｎｄｅｐｏｓｉｔ，ｔｅｒｒｅｓｔｒｉａｌ（ｌｏｅｓｓ，ｌａｋｅｓａｎｄｓｗａｍｐ）ｄｅｐｏｓｉ…     

Effect of Temporal Resolution of NDVI on Potential Evapotranspiration Estimation and Hydrological Model Performance

Normalized difference vegetation index (NDVI) data, obtained from remote sensing information, are essential in the Shuttleworth-Wallace (S-W) model for estimation of evapotranspiration. In order to study the effect of temporal resolution of NDVI on potential evapotranspiration (PET) estimation and hydrological model performance, monthly and 10-day NDVI data set were used to estimate potential evapotranspiration from January 1985 to December 1987 in Huangnizhuang catchment, Anhui Province, China. The differences of the two calculation results were analyzed and used to drive the block-wise use of the TOPMODEL with the Muskingum-Cunge routing (BTOPMC) model to test the effect on model performance. The results show that both annual and monthly PETs estimated by 10-day NDVI are lower than those estimated by monthly NDVI. Annual PET from the vegetation root zone (PETr) lowers 9.77%-13.64% and monthly PETr lowers 3.28%-17.44% in the whole basin. PET from the vegetation interception (PETi) shows the same trend as PETr. In addition, temporal resolution of NDVI has more effect on PETr in summer and on PETi in winter. The correlation between PETr as estimated by 10-day NDVI and pan measurement (R2= 0.835) is better than that between monthly NDVI and pan measurement (R2 = 0.775). The two potential evapotranspiration estimates were used to drive the BTOPMC model and calibrate parameters, and model performance was found to be similar. In summary, the effect of temporal resolution of NDVI on potential evapotranspiration estimation is significant, but trivial on hydrological model performance.     

基于“DEM-NDVI-土地覆盖分类”的天山博格达自然遗产地山地垂直带提取与变化分析

本文基于Landsat影像数据获取天山博格达自然遗产地土地覆盖分类,结合归一化植被指数（NDVI）和数字高程模型（DEM）构建“DEM-NDVI-土地覆盖分类”散点图分析研究区植被受海拔和坡向的水热空间变化影响的分布特征,通过概率统计分析提取博格达遗产地山地垂直带,并结合研究区的气温、降水数据和NDVI变化特征分析垂直带变化的原因。研究结果表明：① 本文利用“DEM-NDVI-土地覆盖分类”散点图,揭示了研究区1989年和2016年的NDVI值和分类类别随着海拔上升的变化特征,其中NDVI值随着海拔上升呈现“倒U形”变化,而不同分类类别在一定的海拔区间内呈现出聚集效应,且不同分类类别有明显的高程界限。② 1989年和2016年博格达遗产地山地垂直带分带上限分别为：1278 m和1185 m（温带荒漠草原带）、1784 m和1759 m（山地草原带）、2706 m和2730 m（山地针叶林带）、3272 m和3293 m（高山草甸带）、3636 m和3690 m（高山垫状植被带）。③ 博格达遗产地1989年和2016年山地垂直带受区域气温升高和降雨增加的影响有较为明显的改变,其中温带荒漠草原带最为敏感,其上限变化最大,向下收缩93 m;山地针叶林带的分布范围则向两侧扩张49 m;山地草甸带带宽基本保持不变,但整体上移了约20 m;冰雪带则受到全球气候变暖的影响向上退缩54 m。     

Warming trend in northern East China Sea in recent four decades

Global warming has become a notable trend especially since an abrupt climate change in 1976. Response of the East China Sea (ECS) to the global warming trend, however, is not well understood because of sparse long-term observation. In this paper, hydrographic observation data of 1957–1996 are collected and reviewed to study climatological variability in northern ECS. Significant warming trends are found in both summer and winter. In summer, the average SST is about 0.46°C higher during the period of 1977-19...     

Detecting Global Vegetation Changes Using Mann-Kendal(MK) Trend Test for 1982–2015 Time Period

Vegetation is the main component of the terrestrial ecosystem and plays a key role in global climate change. Remotely sensed vegetation indices are widely used to detect vegetation trends at large scales. To understand the trends of vegetation cover, this research examined the spatial-temporal trends of global vegetation by employing the normalized difference vegetation index(NDVI) from the Advanced Very High Resolution Radiometer(AVHRR) Global Inventory Modeling and Mapping Studies(GIMMS) time series(1982–2015). Ten samples were selected to test the temporal trend of NDVI, and the results show that in arid and semi-arid regions, NDVI showed a deceasing trend, while it showed a growing trend in other regions. Mann-Kendal(MK) trend test results indicate that 83.37% of NDVI pixels exhibited positive trends and that only 16.63% showed negative trends(P 0.05) during the period from 1982 to 2015. The increasing NDVI trends primarily occurred in tree-covered regions because of forest growth and re-growth and also because of vegetation succession after a forest disturbance. The increasing trend of the NDVI in cropland regions was primarily because of the increasing cropland area and the improvement in planting techniques. This research describes the spatial vegetation trends at a global scale over the past 30+ years, especially for different land cover types.     

Comparative Assessment of Tundra Vegetation Changes Between North and Southwest Slopes of Changbai Mountains,China, in Response to Global Warming

Vegetation in high altitude areas normally exhibits the strongest response to global warming. We investigated the tundra vegetation on the Changbai Mountains and revealed the similarities and differences between the north and the southwest slopes of the Changbai Mountains in response to global warming. Our results were as follows: 1) The average temperatures in the growing season have increased from 1981 to 2015, the climate tendency rate was 0.38℃/10 yr, and there was no obvious change in precipitation observed. 2) The tundra vegetation of the Changbai Mountains has changed significantly over the last 30 years. Specifically, herbaceous plants have invaded into the tundra zone, and the proportion of herbaceous plants was larger than that of shrubs. Shrub tundra was transforming into shrub-grass tundra. 3) The tundra vegetation in the north and southwest slopes of the Changbai Mountains responded differently to global warming. The southwest slope showed a significantly higher degree of invasion from herbaceous plants and exhibited greater vegetation change than the north slope. 4) The species diversity of plant communities on the tundra zone of the north slope changed unimodally with altitude, while that on the tundra zone of the southwest slope decreased monotonously with altitude. Differences in the degree of invasion from herbaceous plants resulted in differences in species diversity patterns between the north and southwest slopes. Differences in local microclimate, plant community successional stage and soil fertility resulted in differential responses of tundra vegetation to global warming.     

FRACTAL ANALYSIS APPLIED TO SPATIAL STRUCTURE OF CHINA＇S VEGETATION

Based on the fractal theory, the spatial structure of China＇s vegetation has been analyzed quantitatively in this paper. Some conclusions are drawn as the following. 1） The relationships between size and frequency of patch area and patch shape index exist objectively for China＇s vegetation. 2） The relationships between perimeter and area exist objectively for China＇s vegetation. 3） The fractal dimension of evergreen needleleaf forests on mountains in subtropical and tropical zones is the largest, while the smallest for deciduous broadleafand evergreen needleleaf mixed forests in temperate zone, reflecting the most complex spatial structure for evergreen needleleaf forests on mountains in subtropical and tropical zones and the simplest for deciduous broadleaf and evergreen needleleaf mixed forests in temperate zone. 4） The fractal dimensions of China＇s vegetation types tend to decrease from thc subtropics to both sides. 5） The stability of spatial structure of deciduous broadleaf and evergreen needleleaf mixed forests in temperate zone is the largest, while the smallest for double-cropping rice, or double-cropping rice and temperate-like grain, and tropical evergreen economic tree plantations and orchards, reflecting the steadiest for deciduous broadleaf and evergreen needleleaf mixed forests in temperate zone and the most unstable for double-cropping rice, or double-cropping rice and temperate-like grain, and tropical evergreen economic tree plantations and orchards in spatial structure. 6） The stability of spatial structure of China＇s vegetation tends to decrease from the temperate zone to both sides, it is significantly pertinent to understand the formation, evolution, dynamics and complexity rule of ecosystem of vegetation.     

VEGETATION CHANGES OF THE TAIHANG MOUNTAINS SINCE THE LAST GLACIAL

1 BACKGROUND The Taihang Mountains is located in the western part of Hebei Province. It is bounded by the North China Plain to the east, the Shanxi Plateau to the west and the Yanshan Mountain to the north; the southern boundary is formed by the Huanghe (Yellow) River. It has an area about 30 000 km2, occupies about 17％ of the total area of Hebei Province. The Taihang Mountains has a continental monsoon climate, with the mean annual temperature between － 1.7℃ to 13℃ and mean ann…     

Morphological characteristics and environmental implications of phytoliths in topsoils from different vegetation zones on northern slope of Changbai Mountains,China

The Changbai Mountains,located in the temperate monsoon climate zone of East Asia,is an ideal loca-tion for the research on timberline response to global changes.In this study,the topsoils were collected from different vertical vegetation zones on the northern slope of the Changbai Mountains,Northeast China in August 2009,and phytoliths in the soil samples were extracted by using wet oxidation method and identified with Motic 2.0 microscope in laboratory.The results show that phytoliths are abundant in the ...     

青藏高原月NDVI时空动态变化及其对气候变化的 响应

青藏高原脆弱的高寒植被对外界干扰十分敏感,使其成为研究植被对气候变化响应的理想区域之一。青藏高原气候变化剧烈,在较短的合成时间研究气候变化对植被的影响十分必要。因此,本文利用GIMMS NDVI时间序列数据集,研究了1982-2012年青藏高原生长季月尺度植被生长的时空动态变化,探讨了其与气温、降水量和日照时数等气候因子的响应关系。结果表明：在区域尺度上,除8月外,其他各月份植被均呈增加趋势,显著增加多发生在4-7月和9月;大部分月份的NDVI增加速率随着时段的延长显著减小,表明NDVI增加趋势放缓;在像元尺度上,月NDVI显著变化的区域多呈增加趋势,但显著减少范围的扩张多快于显著增加。4月和7月植被生长主要是受气温和日照时数共同作用,6月和9月受气温的控制,而8月则主要受降水量的影响。长时间序列NDVI数据集的出现为采用嵌套时段研究植被生长变化趋势奠定了前提,而植被活动变化趋势的持续性则有助于形象表征植被活动变化过程、深入理解植被对气候变化的响应和预测植被未来生长变化趋势。由此推测,青藏高原月NDVI未来增加趋势总体上趋于缓和,但在像元尺度显著变化的区域趋于增加。     

Ice surface-elevation change and velocity of Qingbingtan glacier No.72 in the Tomor region, Tianshan Mountains, central Asia

Glaciers in the Tomor region of Tianshan Mountains preserve vital water resources.However,these glaciers suffer from strong mass losses in the recent years because of global warming.From 2008 to 2009,a large-scale scientific expedition has been carried out in this region.As an individual reference glacier,the tongue area of Qingbingtan glacier No.72 was measured by the high precise Real Time Kinematic-Global Position System (RTK-GPS).In this paper,changes of the tongue area of Qingbingtan glacier No.72 has been studied based on topographic map,remote sensing image and the survey during 2008-2009 field campaign.Results indicated that the ice surface-elevation of the tongue area changed-0.22±0.14 m a-1 from 1964 to 2008.The estimated loss in ice volume was 0.014±0.009 km3,which represented a ～20 % decrease from the 1964 volume and was equivalent to average annual mass balance of-0.20±0.12 m water equivalent for the tongue area during 1964-2008.Terminus retreated by 1852 m,approximately 41 m a-1,with the area reduction of 1.533 km2 (0.034 km2 a-1) from 1964 to 2009.Furthermore,the annual velocity reached to ～70 m a-1.Comparing with the other monitored glaciers in the eastern Tianshan Mountains,Qingbingtan glacier No.72 experienced more intensive in shrinkage,which resulted from the combined effects of climate change and glacier dynamic,providing evidence of the response to climatic warming.     

ZOOPLANKTON COMMUNITY STRUCTURE OF THE SEA SURFACE MICROLAYER NEAR NUCLEAR POWER PLANTS AND MARINE FISH CULTURE ZONES IN DAYA BAY

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｓｅａｓｕｒｆａｃｅｍｉｃｒｏｌａｙｅｒ (ＳＭ)ｗｉｔｈｓｐｅｃｉａｌｐｈｙｓｉｃａｌ,ｃｈｅｍｉｃａｌａｎｄｂｉｏｌｏｇｉｃａｌｐｒｏｐｅｒｔｉｅｓ,ｈａｄｂｅｅｎｗｅｌｌｄｅｓｃｒｉｂｅｄａｓａｓｉｔｅｏｆｉｎｔｅｎｓｉｖｅａｃｃｕｍｕｌａｔｉｏｎｏｆｄｉｓｓｏｌｖｅｄａｎｄｐａｒｔｉｃｕｌａｔｅｏｒｇａｎｉｃｍａｔ ｔｅｒｉｎｖｏｌｖｉｎｇｐｈｙｔｏｐｌａｎｋｔｏｎａｎｄｂａｃｔｅｒｉａ (Ｈａｒｄｙ,1 982 ) .Ｔｈｉｓｅｎｖｉｒｏｎｍｅｎｔｈａｓｇｒｅａｔｉｍｐｏｒ…     

THE PRELIMINARY STUDY ON POSSIBLE SCENARIOS OF FLOOD AND DROUGHT IN CHINA IN THE CASE OF GLOBAL WARMING

ＴＨＥ ＰＲＥＬＩＭＩＮＡＲＹ ＳＴＵＤＹ ＯＮ ＰＯＳＳＩＢＬＥ ＳＣＥＮＡＲＩＯＳ ＯＦ ＦＬＯＯＤ ＡＮＤ ＤＲＯＵＧＨＴ ＩＮ ＣＨＩＮＡ ＩＮ ＴＨＥ ＣＡＳＥ ＯＦ ＧＬＯＢＡＬ ＷＡＲＭＩＮＧ ＣｈｅｎＪｉａｑｉ（陈家其）（Ｎａｎｊｉｎ...