水热积指数的估算及其在中国植被与气候关系研究中的应用

试图利用大气年平均气温、年降水量、可能蒸散和土壤水分平衡之间的关系建立一个水热积指数,并应用年平均气温、年土壤水分盈亏值和水热积指数三个气候变量来限定植物群落组合,构成一个圆形的生命-气候图式。根据全国689个标准气象台站的气候资料,计算了中国8个植被地带和26个亚地带的年平均气温、年土壤水分盈亏和水热积指数,绘制了各气候指标在中国的分布图及散点图,较好表现了中国各植被类型与气候指标的关系和格局,包括寒温带针叶林、冷温带针阔叶混交林、暖温带落叶阔叶林、亚热带常绿阔叶林、热带雨林和季雨林、温带草原、温带荒漠、青藏高原高寒植被,并得到了中国各植被地带的气候指标范围及界限。通过分析可以看出,年平均气温的等值线较好地反映了中国大陆的热量梯度,经度和纬度方向的区分均较明显;年土壤水分盈亏曲线的等值线则比较零乱;综合了热量和水分差异的水热积指数等值线与热量梯度和水分梯度均有一定的对应性,与植被类型的对应也较好。这是在宏观尺度上进行的植被与气候关系研究的一种尝试。     

毛乌素沙地天然植物多样性组成及区系特征分析

毛乌素沙地位于干旱、半干旱区向半湿润区过渡地带,该研究通过野外调查及数据统计,对毛乌素沙地天然植物科、属、种的组成及区系特征进行了分析,并与周围的沙地(沙漠)植物区系进行比较,以明确毛乌素沙地的珍稀植物及其植物多样性组成特征。结果表明:(1)毛乌素沙地天然植物共90科360属772种,区内植物类群相对丰富,植被群落类型多样,优势科明显,单种属、寡种属占到的比例达到73.45%。(2)毛乌素沙地天然植物90科划分为10个分布区类型及4个变型,360属划分为15个分布区类型及10个变型。(3)毛乌素沙地科的植物区系组成以世界分布为主,属的植物区系组成以温带分布为主,反映了该区的植物区系与所处的地理位置和气候具有相适应的特性。(4)毛乌素沙地植物区系成分与浑善达克沙地植物区系亲缘关系最近,与库布齐沙漠、乌兰布和沙漠、库姆塔格沙漠植物区系有一定差异,表明毛乌素沙地植物区系存在明显的从温带分布到地中海区、西亚至中亚分布的过渡性质。     

气候变暖对东北玉米低温冷害分布规律的影响

利用东北地区48个农气站1961-2010年气象资料和近20多年玉米生育期资料,建立生育阶段热量指数和冷害指数,分析气候变暖对东北玉米4个生育阶段热量及低温冷害分布格局的影响。结果表明:热量指数总体表现为明显的增加趋势;平均温度、热量指数的年代际变化特征明显,中晚、晚熟区的上升趋势均小于早、中熟区;冷害频率总体表现为明显的减小趋势;气候变暖对两个熟型区域4个生育阶段的冷害影响并不一致,早、中熟区的冷害平均频率最大值均出现在20世纪60年代,中晚、晚熟区的冷害平均频率最大值均出现在70年代,两个熟型区域的最小值均出现在21世纪初。研究结果可为未来东北地区调整玉米种植制度和生产布局,为适应气候变化和趋利避害提供科学依据。     

中国中东部地区暴雨气候及其农业灾情的风险评估

利用中国中东部292个站点1961-2008年的暴雨气候资料和各省的农业灾情资料,采用主成分分析、软直方图估计、灰色关联法、正态信息扩散等方法,分别构建了暴雨气候指数、农业相对灾情指数及其风险估算模型,对中国中东部地区暴雨气候及其农业灾情的风险进行了研究.结果表明:中国中东部地区的暴雨气候风险,由南向北逐渐减少,高值区位于海南和广东、广西的沿海地区,其次是广西和广东的中北部,江淮地区的湖北、安徽、江西以及湘赣地区的湖南,低值区主要位于除辽宁沿海区域外的东北地区以及华北北部的河北和山西;农业相对灾情风险的高值区位于江淮地区的安徽、湖北,湘赣地区的湖南,东南沿海的广东,低值区是华北地区的河北、河南,东北地区的辽宁;除广东省外,各代表省的暴雨气候指数与农业相对灾情指数的相关系数均达到0.6以上(P＜0.Ol).经多年实际农业灾情验证,暴雨气候指数和农业相对灾情指数能较好地评估实际暴雨的强度及其对农业的影响.     

KIRA指标的拓展及其在中国植被与气候关系研究中的应用

根据Kira以月平均气温5℃为界的热量指数和干湿度指数概念,提出了以月平均气温10℃为界的生物热量指数,包括生物温暖指数(BWI)和生物寒冷指数(BCI),并修正其干湿度指数为生物干湿度指数(BK).利用中国689个标准气象台站的资料,分析我国主要植被类型分布与热量因子和干湿度因子的关系,得出两者之间较好的相关性,生物温暖指数、寒冷指数和干湿度指数的散点图较好地表现了中国各植被类型与气候指标的关系和格局.以10℃为界的生物温暖指数不仅对我国森林植被的地理分布和温度气候带的划分具有较好的指示作用,而且对西南部高山、亚高山地区的植被与气候关系指示性较强;生物寒冷指数则对亚热带和热带的指示性很好,能够较好区分亚热带南部及热带地区;由热量指数和降水量综合得出的生物干湿度指数,对中国西北部干旱、半干旱区以至全国的植被分布与水分、热量因子的关系分析有较好的应用价值.     

毛乌素沙化草地景观生态分类与排序的研究

 本文通过对毛乌素沙地景观生态数据的处理与分析,以广泛应用于植被科学的数量分类方法TWINSPAN为工具,对毛乌素沙地景观生态类型进行了自上而下的等级式的数量分类研究,并与实际情况相结合,提出了毛乌素沙化草地景观生态分类系统。然后又利用算法上与TWINSPAN相似的DCA对沙化草地景观生态类型进行了排序分析,并与数量分类结果相结合,辅以逐步回归分析等多元分析方法,对所划分的各景观生态类型之间的关系进行了分析与探讨,指出毛乌素沙化草地具有较为丰富的景观生态类型,地下水位,覆沙厚度,基质类型控制着沙化草地景观生态类型的发生与演化;提出了毛乌素沙化草地景观生态的演化模式。本文还表明,TWINSPAN和DCA是景观生态研究比较有效的数量分析方法。     

毛乌素沙地柠条群体分子生态学 初步研究：RAPD证据

毛乌素沙地柠条群体是一个杂种带。为了进一步阐明分子变异和基因流与生境或生态过渡带的联系,应用ＲＡＰＤ标记开展了柠条群体的分子生态学研究。根据ＲＡＰＤ数据利用Ｓｈａｎｎｏｎ信息指数估计了６个柠条群体的遗传多样性,发现大部分的分子变异存在于柠条群体之内（８２．４％）,只有少部分的分子变异存在于群体之间（１７．６％）。又利用Ｎｅｉ指数统计了ＲＡＰＤ数据,也证实了大部分的遗传变异存在于群体之内。柠条锦鸡儿群体与中间锦鸡儿群体的遗传分化系数和遗传距离都很小。以上结果都肯定了柠条群体间和种间的基因流动。无论是从多态位点比率还是群体的遗传多样性来看,硬梁和硬梁覆沙群体是最小的,滩地覆沙群体则具有较高的水平。某些ＲＡＰＤ扩增片段的频率在柠条群体间有规律的变化也许具有着特殊的生态学意义,更可能是中性突变的随机固定。根据以上研究可以得出下列结论：①通过比较Ｓｈａｎｎｏｎ指数和Ｎｅｉ指数的统计结果,可以认为,对于异交植物来讲,Ｓｈａｎｎｏｎ指数在统计ＲＡＰＤ数据方面有用。②毛乌素沙地柠条群体之间存在着强大的基因流,物种的杂交性与生态过渡性一致     

黄土高原极端气温变化特征及其与平均气温的相关性

近几十年来,黄土高原极端气候频发,研究和预测极端气候的发生显得尤为重要。目前,关于极端气候的研究多关注事件本身的变化特征,而忽略了平均气温与其变化趋势的相关分析。本研究基于1986—2019年黄土高原79个气象站的逐日最高气温、最低气温和平均气温资料,采用线性倾向估计、Mann-Kendall检验、滑动t检验以及Pearson相关分析方法,对黄土高原地区极端气温的变化趋势及其与平均气温的相关性进行研究。结果表明: 研究期间,黄土高原地区极端气温暖指数呈显著上升趋势,冷指数呈显著下降趋势,极端高温事件发生频率增加;大多极端气温指数在20世纪90年代中后期和2012年发生突变,且极端气温在1998—2012年整体呈现下降趋势,较好地响应了全球变暖停滞现象;平均气温在西部黄土高塬沟壑区、土石山区及河谷平原区的上升趋势较其他区域明显,且极端气温指数大幅变化趋势的站点几乎都发生在平均气温大幅上升的区域;平均气温的小幅上升显著增加了极端高温事件发生的频率,其中,极端低温的变化幅度和速率大于极端高温,气候变暖对极端气温指数产生了不同影响,平均气温的微小变化使得黄土高原整体气候分布向着更易发生热浪的方向转移。     

毛乌素沙地不同飞播造林年限土壤真菌群落结构特征

为探究毛乌素沙地不同飞播造林年限对土壤真菌群落结构的影响,以O、6、16、26和36年共5个飞播造林年限的土壤为对象,采用高通量测序技术检测土壤真菌,分析了其群落结构及多样性,并探讨了土壤因子的影响.结果 表明:随着飞播年限的增加土壤真菌群落结构发生变化,除Simpson指数无明显变化外,真菌Alpha多样性指数、菌门...     

福建省马尾松叶面积指数对气候的响应北大核心CSCD

掌握马尾松叶面积指数(LAI)的时空分布规律是实现马尾松毛虫害空间监测与预警的基础要求。以福建省38个气候台站测定的2010年平均气温、平均气温距平、降雨量、降雨量距平、日照时数及日照时数距平等6个气候要素及实地测定的90个马尾松LAI数据为基础,分别从省域、地市两个尺度分析了福建省马尾松LAI对气候的响应规律。结果表明:(1)除日照时数距平外,其他5个气候要素对马尾松LAI均有显著影响,相关系数排序为:平均气温>降雨量>日照时数>平均气温距平>降雨量距平;(2)从省域尺度上看,马尾松LAI对平均气温的响应呈开口向下的抛物线,对平均气温距平的响应可以用三次曲线较好地予以说明;LAI对降雨量的响应是负向的,降雨量距平对LAI的影响与平均温度相似;对日照时数的响应则呈开头向上的抛物线;(3)从地市尺度上看,马尾松主产区南平、三明、龙岩3市的LAI普遍低于沿海非主产区,尤以南平最低,一方面是由于马尾松LAI对气候要素的直接响应,另一方面则是通过气候对松毛虫分布的影响,使LAI呈现沿海高、内陆低的空间特征。     

Impacts of dust on plant health,survivorship and plant communities in semi‐arid environments

There is a general perception that dust accumulation on plant surfaces causes negative impacts to plants. Consequently, it is common for environmental regulatory agencies to apply vegetation monitoring requirements to oil, gas and mining developments. We use two independent, medium‐term monitoring studies in semi‐arid Australia to examine this relationship at two scales: plant health and survivorship of a threatened subspecies (Tetratheca paynterae paynterae: Elaeocarpaceae) at Windarling Range between 2003 and 2014; and changes in plant health and floristic composition on Barrow Island between 2009 and 2014. Accumulation of dust decreased rapidly with distance from source. At Windarling Range, even at the site with the highest dust load, there was no significant impact on Tetratheca paynterae paynterae compared with the less dusty sites for 10 years. Similarly, there was no significant effect between distance from the source of dust and floristic composition on Barrow Island for 5 years. The probability of plants transitioning to a lower health condition between one year and the next did not appear to be related to dust load. This is further supported by comparing the same site before and after paving the road (removal of dust source), which showed no clear trends. Trends in plant health are likely to be driven more by the variability of cumulative rainfall in the preceding 5 months than dust load. The observed temporal variation in the mean dust load may also be related to variation in rainfall. In conclusion, in these case studies from semi‐arid Australia, we find no evidence to support the perception that, under the observed climatic condition and dust deposition rates up to 20 or 77 g m^?2 per month at Windarling Range and Barrow Island, respectively, dust accumulation on plants causes negative impacts.     

Assessing the impact of extreme adverse weather on the biological traits of a European storm petrel colony

Climate change affects the climatic disturbance patterns and regimes and is altering the frequency and intensity of subtropical cyclones. These events can affect population dynamics of seabirds (e.g., survival, reproduction). In this work we tested the effect of adverse weather on a colony of European storm petrels (Hydrobates pelagicus) located in a small islet (Aketx) in northern Spain. Over a long-term monitoring period (1993–2014) we ringed 3728 petrels. From 2003 onwards we also monitored breeding success, the percentage of immature individuals and moult scores. We used Cormack-Jolly-Seber models and Underhill and Zucchini models to analyze the effects of climatic conditions on a number of biological traits (survival, breeding parameters, moulting patterns). Our analyses revealed a constant value of adult survival over the 26-year monitoring period. Recapture probability, however, tended to be positively influenced by NAO conditions in spring, and negatively influenced by NAO conditions in winter (although this would only affect to a fraction of first-captured birds). Moreover, the impact of adverse weather, especially in 2011 and 2014, resulted in an increasing proportion of yearlings in the breeding population, a lower breeding success and a delayed onset of moult. These effects were similar to those observed during the Prestige oil spill catastrophe.     

The effects of the 2009 dust storm on emergency admissions to a hospital in Brisbane, Australia

In September 2009 an enormous dust storm swept across eastern Australia. Dust is potentially hazardous to health as it interferes with breathing, and previous dust storms have been linked to increased risks of asthma and even death. We examined whether the 2009 Australian dust storm changed the volume or characteristics of emergency admissions to hospital. We used an observational study design, using time series analyses to examine changes in the number of admissions, and case-only analyses to examine changes in the characteristics of admissions. The admission data were from the Prince Charles Hospital, Brisbane, between 1 January 2009 and 31 October 2009. There was a 39% increase in emergency admissions associated with the storm (95% confidence interval: 5, 81%), which lasted for just 1 day. The health effects of the storm could not be detected using particulate matter levels. We found no significant change in the characteristics of admissions during the storm; specifically, there was no increase in respiratory admissions. The dust storm had a short-lived impact on emergency hospital admissions. This may be because the public took effective avoidance measures, or because the dust was simply not toxic, being composed mainly of soil. Emergency departments should be prepared for a short-term increase in admissions during dust storms.     

Timing of precipitation in an arid environment: Effects on population performance of a large herbivore

Climate models predict that shifts in temperature and precipitation patterns are likely to occur across the globe. Changing climate will likely have strong effects on arid environments as a result of increased temperatures, increasing frequency and intensity of droughts, and less consistent pulses of rainfall. Therefore, understanding the link between patterns of precipitation, temperature, and population performance of species occupying these environments will continue to increase in importance as climatic shifts occur within these natural ecosystems. We sought to evaluate how individual, maternal, population, and environmental, particularly temperature and precipitation, level factors influence population performance of a large herbivore in an arid environment. We used mule deer (Odocoileus hemionus) as a representative species and quantified juvenile survival to test hypotheses about effects of environmental factors on population performance. Precipitation events occurring in mid‐ to late‐pregnancy (January–April) leading to spring green‐up, as indexed by normalized difference in vegetation index, had the strongest positive effect on juvenile survival and recruitment. In addition, larger neonates had an increased probability of survival. Our findings indicate that timing and amount of precipitation prior to parturition have strong influences on maternal nutritional condition, which was passed on to young. These results have important implications for understanding how animal populations may benefit from timing of precipitation during spring and prior to parturition, especially in arid environments.     

1986—2019年黄土高原干旱变化特征及趋势

干旱作为极端气候事件之一,其频率和强度的变化影响到区域水资源,而干旱半干旱区植物生长的主要限制因素是水分,因此,研究黄土高原干旱时空特征及未来变化趋势对当地的生态环境具有重要意义。本研究基于1986—2019年降水和温度逐月格点数据,计算标准化降水蒸散发指数(SPEI)和干旱发生频率,并运用Mann-Kendall检验和Sen斜率估计方法,探讨了黄土高原的年、季尺度干旱时空分布及变化特征,最后利用NAR神经网络结合Hurst指数对黄土高原未来干旱趋势进行预测。结果表明: 研究期间,黄土高原总体呈现干旱化趋势,且年际和季节尺度的干旱发生频率在空间上差异较大。其中,年际、春季和冬季以黄土高原东南部和西部干旱发生频率最高,夏季和秋季以西北部干旱发生频率最高。夏季以中度干旱发生频率最高,年际及其他季节以轻度干旱发生频率最高。黄土高原春、夏季呈现干旱化趋势,秋、冬季研究区大部分区域干旱趋势减轻。黄土高原年际、春季、夏季的SPEI值在未来一段时间内仍处于下降趋势,即干旱化趋势加重,且夏季的Hurst指数最大,持续性变化最强,未来持续干旱的可能性高于其他季节。     

中国北方干湿气候区C_3草本植物δ~（13）C值及其与湿润指数的关系

通过对中国北方C3草本植物稳定性碳同位素的测定以及有关该区植被碳同位素资料的收集,共获取了47个样点的地理位置、气候因子和325个植物样品的碳同位素数据;计算了中国北方不同气候分区的湿润指数,分析了C3草本植物δ13C值的空间特征以及与湿润指数等环境因子之间的关系。在所调查的范围内,中国北方地区C3草本植物δ13C值的分布区间为-29.9‰--25.4‰,平均值为-27.3‰。C3草本植物δ13C的平均值从半湿润地区到半干旱地区再到干旱地区显著变重;3个气候分区植物δ13C值的变化范围分别是-29.9‰--26.7‰（半湿润区）、-28.4‰--25.6‰（半干旱区）和-28.0‰--25.4‰（干旱区）。一元回归分析表明,各气候分区C3草本植物δ13C值与湿润指数的关系存在差异,在半干旱区、半湿润区和整个北方地区,C3草本植物δ13C值与湿润指数均呈显著线性负相关（P〈0.05）,随着湿润指数的增加,C3植物δ13C平均值均变轻,但下降幅度不同。而在北方干旱气候区内,C3草本植物δ13C与湿润指数呈显著正相关（P〈0.05）,湿润指数每升高0.1,植物δ13C平均值增加1.3‰。年均温度可能是决定该区内各样点湿润指数和C3植物对13C分馏能力差别的主要原因。     

Grazing effects on the species‐area relationship: Variation along a climatic gradient in NE Spain

Questions: Does grazing have the same effect on plant species richness at different spatial scales? Does the effect of spatial scale vary under different climatic conditions and vegetation types? Does the slope of the species‐area curve change with grazing intensity similarly under different climatic conditions and vegetation types? Location: Pastures along a climatic gradient in northeastern Spain. Methods: In zones under different regimes of sheep grazing (high‐, low‐pressure, abandonment), plant species richness was measured in different plot sizes (from 0.01 to 100 m2) and the slope of the species‐area curves was calculated. The study was replicated in five different locations along a climatic gradient from lowland semi‐arid rangelands to upland moist grasslands. Results: Species richness tended to increase with grazing intensity at all spatial scales in the moist upland locations. On the contrary, in the most arid locations, richness tended to decrease, or remain unchanged, with grazing due to increased bare soil. Grazing differentially affected the slope (z) of the species‐area curve (power function S=c A^z) in different climatic conditions: z tended to increase with grazing in arid areas and decrease in moist‐upland ones. ß‐diversity followed similar pattern as z. Conclusions: Results confirm that the impact of grazing on plant species richness are spatial‐scale dependent. However, the effects on the species‐area relationship vary under different climatic conditions. This offers a novel insight on the patterns behind the different effects of grazing on diversity in moist vs. arid conditions reported in the literature. It is argued that the effect of spatial scale varies because of the different interaction between grazing and the intrinsic spatial structure of the vegetation. Variations in species‐area curves with grazing along moisture gradients suggest also a different balance of spatial components of diversity (i.e. a‐ and ß‐diversity).     

Intense storm activity during the Little Ice Age on the French Mediterranean coast

Understanding long-term variability in the frequency of intense storm activity is important for assessing whether changes are controlled by climate evolution. Understanding this variability is also important for predicting present and future community vulnerability and economic loss. Our ability to make these assessments has been limited by the short (less than 50 years) instrument record of storm activity. Storm-induced deposits preserved in the sediments of coastal lagoons offer the opportunity to study the links between climatic conditions and storm activity on longer timescales. In this study, we present a record of these extreme climatic events that have occurred in the French Mediterrannean coast over the past 1500 years. The identification of these extreme events is based on the analysis of sediment cores from Gulf of Aigues-Mortes lagoons that contain a specific sedimentary and geochemical signature associated with intense storms.Overwash deposits do not show any evidence of intense storm landfalls in the region for several hundred years prior to the late 17th century A.D. The apparent increase in intense storms around 250 years ago occurs during the latter half of the Little Ice Age, a time of lower continental surface temperatures. Comparison of the sediment record with palaeoclimate records indicates that this variability was probably modulated by atmospheric dynamics. The apparent increase of the superstorm activity during the latter half of the Little Ice Age was probably due to the thermal gradient increase leading to enhanced lower tropospheric baroclinicity over a large Central Atlantic/European domain and leading to a modification of the occurrence of extreme wind events along the French Mediterranean coast. A complete understanding of the relationship between climate fluctuations, storm activity, and the coastal response will be crucial to predicting the impacts of future climate change.     

石羊河流域气候干湿状况分析及评价

分析了河西走廊石羊河流域用水区降水的年际时空分布和演化规律,用潜在蒸散、气候干旱指数、蒸降差计算了不同流域段的水分平衡收支情况。结果表明,20世纪80~90年代降水呈增加趋势,但量较小;春、夏季降水增加,秋、冬季降水减少;潜在蒸散多年平均值为1 026.1 mm,并由上游向下游逐渐增大。20世纪70~90年代潜在蒸散呈增加趋势,平均增加4.1~43.6 mm;季节潜在蒸散大小顺序为夏>春>秋>冬,平均为403.5~521.6 mm;历年气候干旱指数平均为0.002,极值出现在下游的民勤地区,达0.581。20世纪70~90年代,气候干旱指数呈增大趋势,气候变得越来越干燥;年水分亏缺量平均为810.7 mm,表现为水分严重不足。最后,提出了合理利用水资源的建议,以科学应对气候变化,促进流域经济持续发展。     

Short-term effect of dust storms on the risk of mortality due to respiratory, cardiovascular and all-causes in Kuwait

This study aimed to investigate the impact of dust storms on short-term mortality in Kuwait. We analyzed respiratory and cardiovascular mortality as well as all-cause mortality in relation to dust storm events over a 5-year study period, using data obtained through a population-based retrospective ecological time series study. Dust storm days were identified when the national daily average of PM₁₀ exceeded 200 μg/m³. Generalized additive models with Poisson link were used to estimate the relative risk (RR) of age-stratified daily mortality associated with dust events, after adjusting for potential confounders including weather variables and long-term trends. There was no significant association between dust storm events and same-day respiratory mortality (RR = 0.96; 95 %CI 0.88–1.04), cardiovascular mortality (RR = 0.98; 95 %CI 0.96–1.012) or all-cause mortality (RR = 0.99; 95 %CI 0.97–1.00). Overall our findings suggest that local dust, that most likely originates from crustal materials, has little impact on short-term respiratory, cardiovascular or all-cause mortality.