Spatial and temporal patterns of the sensitivity of radial growth response by Picea schrenkiana to regional climate change in the Tianshan Mountains

Climate change significantly impacts forest ecosystems in arid and semi-arid regions.However,spatiotemporal patterns of climate-sensitive changes in individual tree growth under increased climate warming and precipitation in north-west China is unclear.The dendrochronological method was used to study climate response sensitivity of radial growth of Picea schrenkiana from 158 trees at six sites during 1990-2020.The results show that climate warming and increased precipitation significantly promoted the growth of trees.The response to temperature first increased,then decreased.However,the response to increased precipitation and the self-calibrating Palmer Drought Severity Index(scPDSI)increased significantly.In most areas of the Tianshan Mountains,the proportion of trees under increased precipitation and scPDSI positive response was relatively high.Over time,small-diameter trees were strongly affected by drought stress.It is predicted that under continuous warming and increased precipitation,trees in most areas of the Tianshan Mountains,especially those with small diameters,will be more affected by precipitation.

Multi-scale regionalization based mining of spatio-temporal teleconnection patterns between anomalous sea and land climate events

Climate sequences can be applied to defining sensitive climate zones, and then the mining of spatio-temporal teleconnection patterns is useful for learning from the past and preparing for the future. However, scale-dependency in this kind of pattern is still not well handled by existing work. Therefore, in this study, the multi-scale regionalization is embedded into the spatio-temporal teleconnection pattern mining between anomalous sea and land climatic events. A modified scale-space clustering algorithm is first developed to group climate sequences into multi-scale climate zones. Then, scale variance analysis method is employed to identify climate zones at characteristic scales, indicating the main characteristics of geographical phenomena. Finally, by using the climate zones identified at characteristic scales, a time association rule mining algorithm based on sliding time windows is employed to discover spatio-temporal teleconnection patterns. Experiments on sea surface temperature, sea level pressure, land precipitation and land temperature datasets show that many patterns obtained by the multi-scale approach are coincident with prior knowledge, indicating that this method is effective and reasonable. In addition, some unknown teleconnection patterns discovered from the multi-scale approach can be further used to guide the prediction of land climate.

Construction of Efficient Multiple Planting Patterns of Potato for Tridimensional Climate in Subtropical Region of China

[Objective] The aim was to make full use of light-heat resources to expand the potato planting area on the base of ensuring the production of main grain crops and the limited arable land. [Methods] Through catch crops, multiple cropping and intercropping, new multiple planting patterns of potato with efficiency are constructed, for the purpose of increasing yield and benefit of potato. [Result] In irrigated plain and hill area, three new planting patterns such as autumn potato/rope-rice,winter potato-rice-autumn potato, and autumn（winter） potato-rice were constructed.In dry land of plain and hill area, three new planting patterns such as spring（winter）potato/maize/sweet potato, spring（winter） potato/maize-autumn potato, and wheat ＋ winter potato/maize/sweet potato were constructed. In plateau mountainous area, spring potato/maize was constructed. [Conclusion] With use of new planting patterns, the cropping index of new patterns was 200%-300%, while the accumulated temperature utilization was 68.9%-93.4%, light energy utilization was 0.98%-1.59% and straw utilization was 50%-100%. To compared with traditional planting patterns, the yield increased by 2.6%-93%, and benefit increased by 15.8%-284.3%. Furthermore,multiple planting patterns of potato have become main planting patterns in increasing yield and income in Sichuan.

Spatial Pattern and Regional Types of Rural Settlements in Xuzhou City,Jiangsu Province,China

This paper principally focuses on the morphological differences,spatial pattern and regional types of rural settlements in Xuzhou City of Jiangsu Province in China.Using satellite images of Xuzhou City taken in 2007 and 2008 and models of exploratory spatial data analysis(ESDA) and spatial metrics,the paper conducts a quantitative analysis of the morphological pattern of rural settlements,and finds significant characteristics.First,rural settlements in Xuzhou City are significantly agglomerated in terms of their spatial distribution;meanwhile,there is significant variation in the geographical density distribution.Second,the scale of rural settlements in Xuzhou City is larger than the average in Jiangsu Province,and the histogram of the scale data is more even and more like a gamma distribution.There are a significant high-value cluster in the scale distribution,and local negative correlation between the scale and density distribution of rural settlements in Xuzhou City.Third,the morphology of rural settlements in Xuzhou City shows relative regularity with good connection and integrity,but the spatial variation of the morphology is anisotropic.Finally,according to the characteristics of density,scale,and form of rural settlements,the rural settlements of Xuzhou City are divided into three types:A high-density and point-scattered type,a low-density and cluster-like type and a mass-like and sparse type.The research findings could be used as the scientific foundation for rural planning and community rebuilding,particularly in less-developed areas.

Research on Application of Landscape Pattern in Regional Planning

Landscape ecology is a new science and there are few cases about applying landscape pattern analysis in optimizing regional planning.By taking the planning of the special planning area for Boao Forum for Asia as the study object,several important landscape indexes have been selected for static analysis of landscape structural feature and landscape structural stability.By using ArcGIS,landscape structural stability map has been overlaid with land use planning map,and then optimization suggestions have been proposed for unreasonable plots.Landscape type and landscape pattern diversity have been selected for dynamic analysis and then suggestions for landscape security pattern been put forward.Through case studies,it has provided a reference for landscape pattern analysis as a means to optimize regional planning.

Influence of non-stationarity and auto-correlation of climatic records on spatio-temporal trend and seasonality analysis in a region with prevailing arid and semi-arid climate,Iran

Trend and stationarity analysis of climatic variables are essential for understanding climate variability and provide useful information about the vulnerability and future changes,especially in arid and semi-arid regions.In this study,various climatic zones of Iran were investigated to assess the relationship between the trend and the stationarity of the climatic variables.The Mann-Kendall test was considered to identify the trend,while the trend free pre-whitening approach was applied for eliminating serial correlation from the time-series.Meanwhile,time series stationarity was tested by Dickey-Fuller and Kwiatkowski-Phillips-Schmidt-Shin tests.The results indicated an increasing trend for mean air temperature series at most of the stations over various climatic zones,however,after eliminating the serial correlation factor,this increasing trend changes to an insignificant decreasing trend at a 95%confidence level.The seasonal mean air temperature trend suggested a significant increase in the majority of the stations.The mean air temperature increased more in northwest towards central parts of Iran that mostly located in arid and semiarid climatic zones.Precipitation trend reveals an insignificant downward trend in most of the series over various climatic zones;furthermore,most of the stations follow a decreasing trend for seasonal precipitation.Furthermore,spatial patterns of trend and seasonality of precipitation and mean air temperature showed that the northwest parts of Iran and margin areas of the Caspian Sea are more vulnerable to the changing climate with respect to the precipitation shortfalls and warming.Stationarity analysis indicated that the stationarity of climatic series influences on their trend;so that,the series which have significant trends are not static.The findings of this investigation can help planners and policy-makers in various fields related to climatic issues,implementing better management and planning strategies to adapt to climate change and variability over Iran.

Evaluation of six gauge-based gridded climate products for analyzing long-term historical precipitation patterns across the Lancang-Mekong River Basin

Freshwater plays a vital role in global sustainability by improving human lives and protecting nature.In the Lancang-Mekong River Basin(LMRB),sustainable development is principally dependent upon precipitation that predominantly controls freshwater resources availability required for both life and livelihood of~70 million people.Hence,this study comprehensively analyzed long-term historical precipitation patterns(in terms of trends,variability,and links to climate teleconnections)throughout the LMRB as well as its upper(Lancang River Basin,LRB)and lower(Mekong River Basin,MRB)parts employing six gauge-based gridded climate products:Asian Precipitation Highly-Resolved Observational Data Integration Towards Evaluation of Water Resources(APHRODITE),Climate Prediction Center(CPC),Climate Research Unit(CRU),Global Precipitation Climatology Center(GPCC),Precipitation Reconstruction over Land(PRECL),and University of Delaware(UDEL).Accordingly,annual and seasonal(dry and wet)precipitation time series were calculated for three study periods:century-long outlook(1901-2010),mid-past(1951-2010),and recent decades(1981-2010).However,the role of climate teleconnections in precipitation variability over the LMRB was only identified during their available temporal coverages:mid-past and recent decades.The results generally showed that:(i)both annual and seasonal precipitation increased across all three basins in 1981-2010;(ii)wet and dry seasons got drier and wetter,respectively,in all basins in 1951-2010;(iii)all such changes were fundamentally attributed to increases in precipitation variability on both annual and seasonal scales over time;(iv)these variations were most strongly associated with the Pacific Decadal Oscillation(PDO),Atlantic Multi-decadal Oscillation(AMO)and East Pacific/North Pacific(EP/NP)pattern in the LMRB and the MRB during 1951-2010,but with the North Sea-Caspian Pattern(NCP)and the Southern Annular Mode(SAM)in the LRB;(v)such relationships got stronger in 1981-2010,while the Southern Oscillation Index(SOI)became the most influential teleconnection for dry season precipitation variability across all basins;and(vi)GPCC(APHRODITE)provided the most reliable gauge-based gridded precipitation time series over the LMRB for the years before(after)1951.These findings lay a foundation for further studies focusing on water resources and sustainable development in the LMRB.

Study on Eco-climate Type Regionalization of Wheat Growing Areas in Yunnan Province

In order to provide an objective and scientific theoretical basis for rational distribution of wheat growth in Yunnan Province,according to the relationship between Yunnan weather conditions and wheat growth adaptability,a study on eco-climate type regionalization of wheat growing areas in Yunnan was conducted using principal component analysis and GIS technology. The results show that Yunnan Province could be divided into four types,namely southern warm and humid wheat growing area,central semi-arid wheat growing area,central semi-humid wheat growing area and north-central cold wheat growing area.

Climate state of the Three Gorges Region in the Yangtze River basin in 2022–2023

Based on daily observation data of the Three Gorges Region(TGR)of the Yangtze River basin and global reanalysis data,the climate characteristics,climate events,and meteorological disasters of the TGR in 2022 and 2023 were analyzed.For the TGR,the average annual temperature for 2022 and 2023 was 0.8℃ and 0.4℃ higher than normal,respectively,making them the two warmest years in the past decade.In 2022,the TGR experienced its warmest summer on record.The average air temperature was 2.4℃ higher than the average,and there were 24.8 days of above-average high temperature days during summer.Rainfall in the TGR varied significantly between 2022 and 2023.Annual rainfall was 18.4%below normal and drier than normal in most parts of the region.In contrast,the precipitation in 2023 was considerably higher than the long-term average,and above normal for almost the entire year.The average wind speed exhibited minimal variation between the two years.However,the number of foggy days and relative humidity increased in 2023 compared to 2022.In 2022–2023,the TGR mainly experienced meteorological disasters such as extreme high temperatures,regional heavy rain and flooding,overcast rain,and inverted spring chill.Analysis indicates that the abnormal western Pacific subtropical high and the abnormal persistence of the eastward-shifted South Asian high were the two important drivers of the durative enhancement of record-breaking high temperature in the summer of 2022.

Simulation and Projection of Monso on Rainfall and Rain Patterns over Eastern China under Global Warming by RegCM3

The authors investigate possible changes of monsoon rainfall and associated seasonal (June-JulyAugust) anomaly patterns over eastern China in the late 21st century under the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios (SRES) A2 emission scenario as simulated by a high-resolution regional climate model (RegCM3) nested in a general circulation model (FvGCM/CCM3).Two sets of multi-decadal simulations are performed at 20-km grid spacing for present day and future climate conditions.Results show that the RegCM3 reproduces the mean rainfall distribution;however the evolution of the monsoon rain belt from South China to North China is not well simulated.Concerning the rain pattern classifications,RegCM3 overestimates the occurrence of Pattern 1 (excessive rainfall in northern China) and underestimates that of Pattern 2 (increased rainfall over the Huai River basin).Under future climate conditions,RegCM3 projects less occurrence of Pattern 1,more of Pattern 2,and little change of Pattern 3 (rainfall increase along the Yangtze River).These results indicate that there might be increased rainfall over the Huai-Yellow River area and reduced rainfall over North China in the future,while rainfall over the lower reaches of the Yangtze River basin is not modified significantly.Uncertainties exist in the present study are also discussed.

Spatial patterns of ecosystem vulnerability changes during 2001–2011 in the three-river source region of the Qinghai-Tibetan Plateau, China

The three-river source region (TRSR, including Yangtze, Yellow and Lancang rivers), located in the Qinghai-Tibetan Plateau, China, is a typical alpine zone with apparent ecosystem vulnerability and sensitivity. In this paper, we introduced many interdisciplinary factors, such as landscape pattern indices (Shannon diversity index and Shannon evenness index) and extreme climate factors (number of extreme high temperature days, number of extreme low temperature days, and number of extreme precipitation days), to establish a new model for evaluating the spatial patterns of ecosystem vulnerability changes in the TRSR. The change intensity (CI) of ecosystem vulnerability was also analyzed. The results showed that the established evaluation model was effective and the ecosystem vulnerability in the whole study area was intensive. During the study period of 2001–2011, there was a slight degradation in the eco-environmental quality. The Yellow River source region had the best eco-environmental quality, while the Yangtze River source region had the worst one. In addition, the zones dominated by deserts were the most severely deteriorated areas and the eco-environmental quality of the zones occupied by evergreen coniferous forests showed a better change. Furthermore, the larger the change rates of the climate factors (accumulative temperature of ≥10°C and annual average precipitation) are, the more intensive the CI of ecosystem vulnerability is. This study would provide a scientific basis for the eco-environmental protection and restoration in the TRSR.

Impacts of Climate Change on Net Primary Productivity in Arid and Semiarid Regions of China

In recent years, with the constant change in the global climate, the effect of climate factors on net primary productivity(NPP) has become a hot research topic. However, two opposing views have been presented in this research area: global NPP increases with global warming, and global NPP decreases with global warming. The main reasons for these two opposite results are the tremendous differences among seasonal and annual climate variables, and the growth of plants in accordance with these climate variables. Therefore, it will fail to fully clarify the relation between vegetation growth and climate changes by research that relies solely on annual data. With seasonal climate variables, we may clarify the relation between vegetation growth and climate changes more accurately. Our research examined the arid and semiarid areas in China(ASAC), which account for one quarter of the total area of China. The ecological environment of these areas is fragile and easily affected by human activities. We analyzed the influence of climate changes, especially the changes in seasonal climate variables, on NPP, with Climatic Research Unit(CRU) climatic data and Moderate Resolution Imaging Spectroradiometer(MODIS) satellite remote data, for the years 2000–2010. The results indicate that: for annual climatic data, the percentage of the ASAC in which NPP is positively correlated with temperature is 66.11%, and 91.47% of the ASAC demonstrates a positive correlation between NPP and precipitation. Precipitation is more positively correlated with NPP than temperature in the ASAC. For seasonal climatic data, the correlation between NPP and spring temperature shows significant regional differences. Positive correlation areas are concentrated in the eastern portion of the ASAC, while the western section of the ASAC generally shows a negative correlation. However, in summer, most areas in the ASAC show a negative correlation between NPP and temperature. In autumn, precipitation is less important in the west, as opposed to the east, in which it is critically important. Temperatures in winter are a limiting factor for NPP throughout the region. The findings of this research not only underline the importance of seasonal climate variables for vegetation growth, but also suggest that the effects of seasonal climate variables on NPP should be explored further in related research in the future.

Peat record of climate change for the last 3000 years in Yangmu, Mishan region of Sanjiang Plain

Five pollen zones are identified in Yangmu peatland of Mishan region located at 45o34扤, 132o23扙 through sporo-pollen analysis. The changing process of paleovegetation and paleoclimate was obtained. Warm-inclined broad-leaved forest predominated in the environment of warm climate with a little dry 3400 yr BP. Deciduous broad-leaved and coniferous mixed forests predominated, in which Pinus, Picea and Abies were main species, together with wet meadow in the environment of cool and humid climate during 3400-1940 yr BP. Deciduous broad-leaved and coniferous mixed forests predominated in the dry and warm climate environment 1940-1090 yr BP. Broad-leaved forest was predominant, and the climate was warm and humid 1090-545 yr BP. Marsh meadow predominated when the climate changed to cool and dry 545 yr BP. The composition of the upper part of the 143-125 cm of the peat profile presented the cold period in the early Christian era through mutual identification between the records of historical material such as spores and pollens, susceptibility, organic matter and archaeological studies. The composition of the parts of 125-85 cm and 85-38 cm presented the warm climate in the Northern and Southern Dynasty and Sui and Tang dynasties. Since 3400 yr BP because of the frequent human activities in Mishan region, the amount of cultural relics in the Sui and Tang dynasties increased, which indicated that the ancients took much more woods from the forests in the warm climate environment.

Wavelet analysis of quasi-3-year temperature oscillations in China in last 50 years, and predicted changes in the next 20 years

The wavelet analysis method is used to analyze the annual and winter temperature data of 98 observation stations in China in eight climate zones during the last 50 years （1961-2009）. The periodicities of temperature changes are investigated, and the possible temperature change trends in China in the next 20 years （2012-2029） are also predicted. Our results show that in the inter-annual temperature variability there are pervasive quasi-3- to quasi-4-year cycles, and these cycle changes are relatively steady. The periodic characteristics of the annual temperature changes are clearly different between northern and southern China, and our period superimposition extrapolation shows that both annual and winter temperatures in China will continue to increase in the next 20 years, more so in northern China and in the Qinghai-Xizang Plateau （QXP） than in the southern region, except in the southwest. If temperatures follow historic increasing linear trends, the overall temper- ature is expected to increase by 1℃ between 2010 and 2029.

The Homogeneity of Distributional Patterns of the Global Terrestrial Animal,Plant and Microorganism under the Influence of Ecological Conditions

The world animal geographical regionalization scheme and the plant geographical regionalization scheme have been formulated by zoologists and botanists respectively since the biogeography has been established.This research team initially confirmed the homogeneity of Chinese animal and plant geography.To explore the relationship between the distribution pattern of global animals,plants,and microorganisms,global 141,814 genera of terrestrial animals,17,526 genera of plants,21,321 genera of microorganisms,and their major taxa were analyzed using their proposed SGF(Similarity General Formula)and a new multivariate similarity clustering analysis method.Almost identical analytical results were obtained,meeting the requirements of statistics,geography,ecology and biology respectively.The expected consistency of their distribution pattern was achieved for the first time.We prove that the earth’s ecological conditions affect the homogeneity and accumulation of the distribution of animals,plants and microorganisms.Homogeneity determines the distribution pattern of global kinds of biological consistency,accumulation determines the impact of the evolutionary period on the breadth of distribution,microorganisms appear earliest,plants second,animals later,and their average distribution domain decreases in turn,reflecting these differences.Therefore,this study not only provides a theoretical basis and quantitative basis for the establishment of geographical regionalization scheme but also advances the development of biogeography to a new stage and raises the theory of biogeographic analysis to a new height.

THE ANALYSIS OF MECHANISM OF IMPACT OF AEROSOLS ON EAST ASIAN SUMMER MONSOON INDEX AND ONSET

RegCM4.3, a high-resolution regional climate model, which includes five kinds of aerosols(dust, sea salt,sulfate, black carbon and organic carbon), is employed to simulate the East Asian summer monsoon(EASM) from 1995 to 2010 and the simulation data are used to study the possible impact of natural and anthropogenic aerosols on EASM.The results show that the regional climate model can well simulate the EASM and the spatial and temporal distribution of aerosols. The EASM index is reduced by about 5% by the natural and anthropogenic aerosols and the monsoon onset time is also delayed by about a pentad except for Southeast China. The aerosols heat the middle atmosphere through absorbing solar radiation and the air column expands in Southeast China and its offshore areas. As a result, the geopotential height decreases and a cyclonic circulation anomaly is generated in the lower atmosphere. Northerly wind located in the west of cyclonic circulation weakens the low-level southerly wind in the EASM region. Negative surface radiative forcing due to aerosols causes downward motion and an indirect meridional circulation is formed with the low-level northerly wind and high-level southerly wind anomaly in the north of 25° N in the monsoon area, which weakens the vertical circulation of EASM. The summer precipitation of the monsoon region is significantly reduced,especially in North and Southwest China where the value of moisture flux divergence increases.

Temperature Trend Analysis in the North Pacific Watershed in Mexico

Through the monthly data of 71 meteorological stations of the North Pacific Watershed in northwest Mexico, the annual trends of nine temperature variables were estimated using the non-parametric Mann-Kendall test and the Q Sen’s slope estimator. Annual Q Sen’s slopes were analyzed in spatial terms using geographic variables as independent factors and likewise with Moran’s I index. Three major physiographic zones were used to perform a regional analysis using pooled data. The monthly trends were also analyzed. Divergent annual trends were found for the nine proposed variables and warming trends were predominant in almost all of them. Latitude is the most relevant factor in the spatial distribution of the Q Sen’s slopes. Four temperature variables were found statistically clustered, as depicted by the Moran’s I index. The largest regional Q Sen’s slopes values were found in the Coastal Plains. In this area a larger increase in minimum temperatures was observed, in contrast with the Sierra Madre regions, where the largest rate of increasing change was found in maximum temperatures. The monthly analysis indicates warming trends in the first six months of the year with a sudden decrease in July and also a noticeable decrease in the slope values in December.

“里和”与“外应”:气候变化下环湖地区的适应性治理

气候变化给青藏高原带来显著影响,更是对当地农牧民的生计造成冲击,研究当地气候变化影响及牧民应对策略,不仅是提高气候变化适应能力的起点,也是建立适应气候变化区域格局的重要支撑。基于2020和2023年对案例地Z村的两次实地调研,通过牧户问卷调查和深度访谈,按照适应性治理的三层特征,分析当地气候变化适应的成效与挑战。研究发现:面对降水和气温的变化、湖面扩大、植被变化和灾害影响,牧民积极采取多种办法来减少气候变化的影响,呈现较高的适应性与恢复力。这些适应行动的成功经验源于“里和”,包括人与人之间的合作以及人与自然间的和谐律动。但是“外应”不足仍是挑战,即案例地缺少必要的外部支持,不仅包括直接灾害救助,还包括对其适应能力可持续性的保护和应对潜在的草原生态变化。如果“外应”持续低迷,现有的适应能力终会耗尽。提出建立适应气候变化区域格局应遵循多中心治理的思路,将多个利益相关者联合起来,汇总不同地区气候变化应对的成功经验,形成多种知识的融合,才能形成对地方的有效“外应”,提高中国气候变化适应能力。

不同土地利用方式下银北盐碱地土壤的理化性质特征

以银北地区盐碱地为对象,研究了旱地、水田、灌木林和荒草地4种土地利用方式对0~20 cm和20~40 cm土层土壤容重、总孔隙度、有机碳含量、全氮含量、全磷含量、全钾含量、pH以及全盐含量的影响。结果表明,银北地区不同土地利用方式土壤理化性质差异显著(P<0.05)。旱地和水田土壤容重高于灌木林和荒草地,土壤总孔隙度则低于灌木林和荒草地。4种土地利用方式土壤有机碳和全量养分含量在0~20 cm和20~40 cm土层表现较为相似,有机碳和全氮含量表现为灌木林最高,旱地和水田次之,荒草地最低;旱地和水田土壤全磷含量显著高于灌木林和荒草地(P<0.05);全钾含量在旱地土壤中最高,水田最低。除旱地20~40 cm土层外,土壤pH和全盐含量均表现为荒草地显著高于其他3种土地利用方式(P<0.05)。加权灰色关联分析显示,0~20 cm和20~40 cm土层均表现为灌木林土壤理化性质关联度最大,旱地和水田次之,荒草地最小,说明灌木林对改良银北盐碱地土壤理化性质的效果最优。

京津冀地区高质量发展水平综合评价与预警

京津冀协同发展战略提出以来,三地协同发展取得积极进展,但距目标要求还有很大差距。本文选取2010—2019年京津冀地区高质量发展指标数据,利用因子分析法对各地区及整体发展水平进行综合评价,基于综合得分对其预警,并运用灰色预测分析方法,借助MATLAB软件对未来5年京津冀地区高质量发展情况进行预测。研究发现,京津冀地区整体高质量发展综合得分情况较好,但各地区发展综合得分还有一定的提升空间,且地区间存在差异,这种不均衡的发展态势为三地区未来协同发展提出了新的挑战。