Long‐term trends and drivers of larval phenology and abundance of dominant brachyuran crabs in the Gulf of St. Lawrence (Canada)

Climate change has led to major shifts in the timing of biological events, with many studies demonstrating earlier phenology in response to warming. However, few of these studies have investigated the effects of climate change on the phenology of larvae in marine species. Phenological shifts can result in mismatches between consumers and prey and hence affect growth and survival of individuals, and ultimately population demography. We investigated the temporal changes in phenology and abundance of the larvae of dominant brachyuran crabs in the southern Gulf of St. Lawrence (eastern Canada) based on plankton collections spanning 1982–2012. The Gulf of St. Lawrence has warmed since the early 1990s, and our analyses revealed that larvae of snow crab (Chionoecetes opilio) and toad crabs (Hyas spp.) exhibited a significant trend towards earlier phenology over the 30‐year study period. This shift in phenology appeared to be a consequence of the effect of climate warming on both the timing of hatching and larval development rate. Larval abundance responded differently by crab taxon to climate warming, likely due to differences in thermal tolerance. The warming trend was unfavourable to snow crab, which is the most cold‐adapted and stenothermic of the taxa examined in this study. The abundance of snow crab larvae was lower when sea ice retreat occurred earlier than day 110 of the year and sea surface temperature was higher than 8.5°C. On the other hand, larval abundance of rock crab (Cancer irroratus), which prefers higher temperatures, was positively related to surface temperature.     

气候变化背景下云南松林火灾害的响应规律研究

基于1990—2018年云南省云南松分布区气象数据和森林火灾数据,采用Mann-Kendall趋势检验法、对比分析法以及相关性分析研究气象指标与森林火灾的动态变化趋势和响应规律.结果表明:(1)防火期平均气温在1998—2018年达显著上升水平,年均与防火期的平均相对湿度均在1995—2018年达显著下降水平;年均及防...     

西北地区气候异常与前期环流场异常的关系

利用奇异值分解法(SVD)分析了西北地区季节(春、夏、秋)降水、冬季气温异常与前期高空环流异常的关系,结果表明:前期的高空环流异常对西北地区季节降水、冬季气温异常有重要影响,且与各季节降水和冬季气温异常相对应的前期高空环流异常在前期不同阶段各有其特点.前期的高空环流异常对季节降水和冬季气温异常有一定的预测意义.     

河北省近50年0℃界限温度积温变化特征分析

本文利用京、津、冀区域内建站至2000年70个气象观测站点系统的气象观测资料,通过对河北省日平均气温稳定通过0℃的初日、终日、初终间日数、积温的空间变化、年际变化、年代际变化进行了分析。结果发现,全省及各区域日平均气温稳定通过0℃的积温变化均呈增加的趋势,全省范围内积温平均每10年增加了45℃。其中,增加最多的是太行山区,平均每十年增加了93.0℃;各区域的初终间日数变化都呈增加的趋势。初日呈提前的趋势,初日在全省范围每十年提前了2.2天,终日呈推迟的趋势。     

甘肃省雨养农业区气候变暖背景下秋粮生产脆弱性研究

利用甘肃省雨养农业区4个地(市)31个县近40 a的秋粮产量和气候资料,分析了这几个区域40 a来的气候变化特征、产量演变规律,并对秋粮生产的脆弱性进行了评价。结果表明,近40 a来甘肃雨养农业区的气候表现为暖干化演变趋势;气候的暖干趋势对秋粮的增产不利,气候的暖干化减缓了粮食的增产速度;气候波动剧烈的地区秋粮生产的脆弱度大。强脆弱区主要集中在陇东东部及天水北部地区。     

Ecological impacts of global change on drylands and their implications for desertification

Potential impacts of global change on dryland ecosystems are reviewed from four perspectives. First, results are reviewed from recent research on vegetation change, land degradation and desertification. The role of disturbances and low recurrence events in triggering non-linear changes by driving ecosystems beyond their resilience thresholds is outlined. Particular attention is paid to the development of spatial structures as feedbacks that tend to buffer degradation. Secondly, the synergetic operation of climatic and anthropogenic forcing factors of dryland degradation is discussed in the light of some case histories. Changes in one group of those factors often render the ecosystems particularly sensitive to changes of those in the second group. Thirdly, off-site effects of dryland degradation are summarized, including feedbacks to the atmosphere, changes in biological diversity and downstream impacts in river catchments. Finally, the implications of global change for land degradation control policies are outlined. The importance of prevention is emphasized, as well as the need to carefully consider where to apply rehabilitation and restoration. Prevention includes soft and cheap measures based on management practices, while restoration calls for massive and expensive interventions on soil or vegetation. © 1998 John Wiley & Sons, Ltd.     

黄土高原庆阳地区春玉米生育期对气候变化的响应

旨在研究黄土高原庆阳地区春玉米的生育期气候变化特征及物候变化规律,给粮食生产安全及情报服务提供理论依据。通过以黄土高原庆阳地区有代表性的物候观测站的春玉米生育期内的气温、降水、≥10℃的活动积温作为研究对象,来分析气候变化背景下春玉米生育期的气候资源及物候变化特征。结果表明:春玉米全生育期内平均气温呈上升趋势,上升速率为0.6℃/10a;平均降水量呈减少趋势,减少速率为8.7 mm/10a,但绝大多年份雨水能满足玉米生长发育需要;积温呈增加态势,变化速率为58.0℃/10a,热量资源充足;稳定通过10℃的日期为偏早出现趋势,变化速率为6.3 d/10a。春玉米全生育期日数呈现为缩短的响应特征,减少量为1.7 d/10a。因此,气候变化对春玉米种植较为有利,尤其热量资源增加,有利于拓展种植界限及提高产量。要充分利用气候资源,因地制宜,选择适合的品种及播期进行生产,同时要加强田间管理,充分挖掘气候增产潜力,提高玉米种植的经济效益,为精准脱贫提供决策依据。     

中国农田减缓气候变化的潜力与技术途径

以全球变暖为主要特征的气候变化是当前人类面临的主要环境问题之一,并且对农业生产和粮食安全产生了重大影响。增强作物对气候变化的响应与适应能力,提升农田系统固碳减排潜力,是中国农业生产上亟待解决的重要问题。笔者简要分析了国内农业固碳现状,总结了农业生产上应对气候变化的相关技术体系。通过分析国内农业生产适应和减缓气候变化的潜力和技术途径,对未来增加农业固碳潜力的研究做出了展望,为气候变化背景下实现中国农业的可持续发展提供了新的参考和借鉴。     

吉林省地表温度时空变化及影响因素研究

为了掌握吉林省地表温度的时空变化规律及其影响因素,利用吉林省46个气象站的气象数据,采用气候统计和诊断方法,分析了1961—2015年吉林省地表温度的时空变化及其影响因素。结果表明：1961—2015年吉林省地表温度平均值空间分布呈由西向东逐渐降低的趋势,气候倾向率由西向东先升高后降低。地表温度高的站点升温幅度小于地表温度低的站点。地表温度多年平均值的季节排序为夏季>春季>秋季>冬季。地表温度在1月最低,7月最高。1961—2015年吉林省地表温度以0.70℃/10 a的气候倾向率显著上升,春季、夏季、秋季和冬季气候倾向率分别为0.44、0.36、0.51、1.50℃/10 a。冬季和年平均地表温度分别在2001年和1993年发生突变。地表温度绝大多数异常气候年份为异常偏暖年,多在2010年之后。未来季节和年地表温度均呈上升趋势。海拔是影响地表温度的主要地理因子,气温是主要的气候因子。夏季降水量对地表温度为负效应,冬季降水量以正效应为主。     

气候变化对柴达木盆地主要农作物产量的影响

为合理利用气候资源,提高农作物生产潜力提供科学依据,利用柴达木盆地1991—2017年气温、降水量和主要农作物（小麦、油菜）产量等资料,应用数理统计方法,分析了该区近27年来主要的气候因子（气温和降水）、作物产量的变化特征以及气候因子对农作物产量的影响。结果表明：（1）1991—2017年柴达木盆地年平均气温升高显著,升温率为0.5℃/10 a,降水呈略增加趋势,增幅为16.5 mm/10 a,气候趋于暖湿化。（2）农作物产量增加趋势明显,小麦平均每年增加73.0 kg/hm ²,油菜平均每年增加37.9 kg/hm ²;相对气象产量小麦年际正负变化较明显,油菜年际正负变化较频繁。（3）农作物产量与年平均气温、年降水量存在着显著的相关性,气温每升高1.0℃,小麦产量增加845.8 kg/hm ²,油菜产量增加454.5 kg/hm ²;降水量每增加10 mm,小麦产量增加140.0 kg/hm ²,油菜产量增加74.0 kg/hm ²,气温对农作物产量影响较降水大。