基于格网的GCM数据修订分析未来海南岛农业水热资源的变化特征

以海南岛为研究区域，选用5个大气环流模式（GCMs）1970−1999年的逐日输出数据和同期地面气象观测数据，使用空间插值降尺度到0.5°×0.5°格网。以格网单元为基础，应用系统误差修订（修正值法或比值法）和多模式集合平均方法（贝叶斯模型平均法BMA或等权重平均法EW），训练与验证GCMs输出值并进行综合修订。在此基础上，分析RCP2.6、RCP4.5和RCP8.5情景下，未来海南岛近期（2020−2059年）和远期（2060−2099年）农业水热资源，包括年平均气温、1月平均气温、≥10℃积温、≥20℃积温、年降水量、1月降水量和≥20℃界限温度生长期间降水量的变化特征。结果表明：GCMs输出值的系统误差和BMA权重系数在格网间存在较大的空间差异，且GCMs输出值低估逐日最高气温约3.55℃，高估逐日最低气温约1.19℃，逐日降水量仅为观测值的54.35%。基于格网的综合修订，可有效降低GCMs输出值在空间上的不确定性，BMA与EW的修订结果相似，均优于单一GCM模式。通过格网BMA综合修订后，最高气温、最低气温和降水量在验证期的相关系数r分别约提升0.10、0.07和0.06；均方根误差RMSE分别约降低2.38℃、1.01℃和1.01mm；较单一GCM相对观测值的偏差平均约减少3.25℃、1.13℃和25.67mm。未来海南岛农业热量资源在空间上主要表现为从中部向外围逐渐升高，高温主要分布在南部至西部沿海地区，年平均气温的增幅全岛较为接近，1月平均气温、≥10℃积温和≥20℃积温的增幅分别表现为由东向西、由北向南和由中部向外围递减。在时间上，RCP8.5情景下所有农业热量资源均为极显著增加且增温最快，RCP4.5情景为先增加后平缓，RCP2.6情景较为平缓，远期无显著增温。未来海南岛降水资源在空间上转为由东向西逐步递减的格局，南部和北部沿海地区降水变率增加，西部和中部降水变率减少，在时间上无显著变化趋势。随着未来海南岛气候变暖和降水格局的改变，农作物适宜种植面积扩大，会对农业生产带来巨大挑战，应提前布局，做好趋利避害。     

2020年通辽市开鲁县气候影响评价

本文采用统计分析方法，对2020年开鲁县国家基准气候站采集的气温、降水、日照等基本气象要素数据和相应历年值进行对比分析，并对局地大风、暴雪等重大灾害性天气进行综合分析，并根据分析结果，作出气候对生产生活影响的综合评价。结果表明，2020年气候条件对全县农业生产及人们的生活有利有弊。     

气候变化对藏药独一味适生区分布格局的影响

本研究通过实地调查，运用最大熵（MaxEnt）模型和环境气候数据模拟未来气候变化对青藏高原地区藏药独一味（Lamiophlomis rotata（Benth.）Kudo）适生区空间分布格局的影响，探索其适生区变迁规律。通过ArcGIS和SPSS对模拟结果分析显示，当前气候条件下独一味最适宜生长地区主要分布于青藏高原地区的四川与西藏，甘肃与青海交界处，占青藏高原总面积的24.87%，其中西藏自治区适生区面积最大，其次是四川和青海，甘肃和云南占比最小；未来气候变化使适生区几何中心向西南方向迁移97.1 km，且海拔上升267 m；气候变化带来的适生区扩大面积约为退化面积的2倍，各省适生区面积均呈现增加，西藏增加最多，其次是四川，青海略有增加，云南和甘肃变化不大；如果气候变暖持续发生，人工引种驯化应选择海拔相对较高区域，而低海拔地区由于退化风险，应作为物种保护区域重点监测。本研究将为气候敏感地区野生濒危药用植物的引种驯化及资源保护提供参考依据。     

Tree-ring response of Larix chinensis on regional climate and sea-surface temperature variations in alpine timberline in the Qinling Mountains

Tree-ring width chronologies of Larix chinensis were developed from the northern and southern slopes of the Qinling Mountains in Shaanxi Province,and climatic factors affecting the tree-ring widths of L.chinensis were examined.Correlation analysis showed that similar correlations between tree-ring width chronologies and climatic factors demonstrated that radial growth responded to climate change on both slopes.The radial growth of L.chinensis was mainly limited by temperature,especially the growing season.In contrast,both chronologies were negatively correlated with precipitation in May of the previous year and April of the current year.Spatial climate-correlation analyses with gridded land-surface climate data revealed that our tree-ring width chronologies contained a strong regional temperature signal over much of northcentral and eastern China.Spatial correlation with seasurface temperature fields highlights the influence of the Pacific Ocean,Indian Ocean,and North Atlantic Ocean.Wavelet coherence analysis indicated the existence of some decadal and interannual cycles in the two tree-ring width chronologies.This may suggest the influences of El Nin˜o-Southern Oscillation and solar activity on tree growth in the Qinling Mountains.These findings will help us understand the growth response of L.chinensis to climate change in the Qinling region,and they provide critical information for future climate reconstructions based on this species in semi-humid regions.     

Clostridioides difficile in bat guano

Bats are associated with the emergence of several mammalian diseases. Their sessional migration, and tendency to form large colonies in close proximity to human habitats enables effective intra- and inter-species transmission of pathogens. Clostridioides difficile is an important enteric pathogen in humans and animals; however, the source of its dissemination in the population is unknown. The purpose of this study was to determine the prevalence of C. difficile in bats, and to characterize C. difficile isolates.Feces (n = 93) was sampled from bats during their migration across Europe. Eighteen samples (19.4%) were positive for C. difficile; ribotypes 078, 056, and a new ribotype CDB3 were identified.Clostridioides difficile ribotypes 078 and 056 are associated with human and animal diseases. The C. difficile prevalence and ribotypes in this study do not necessarily identify bats as a significant source, but more likely as an indicator of C. difficile perpetuation in the environment.     

气候变化对中国水稻生产的影响研究进展

水稻生产系统是响应气候变化最敏感的农业生态系统之一,本文综述了当前和未来气候变化对我国水稻生产的影响。气候变化背景下,我国水稻生长季的热量资源增多,辐射资源减少,降水不均一性加大。高温热害、干旱、暴雨和洪涝灾害发生更频繁,这可能降低水、热资源的有效性。气候变化使我国单季稻和双季稻潜在种植边界显著北移,导致单季稻、早稻和晚稻的主要生育期缩短。基于统计模型和水稻生长模型的研究结果表明,如果不考虑品种改良和栽培技术的进步,气候变化使单季稻、早稻和晚稻产量下降,但不同稻作区和方法间存在差异。我国水稻生产重心北移、实测生育期延长和产量增加的变化趋势,反映了水稻生产系统通过种植分布调整、品种改良和技术改进来适应气候变化的能力。未来气候变化将进一步导致水稻生育期缩短和产量下降,对我国水稻生产和粮食安全带来严峻挑战。仍需加强气候变化影响机制的研究及其在影响评估中的应用,减小影响评估的不确定性并增加其系统性,为制定有效的应对策略提供可靠的理论支持。     

尕海湿地植被退化过程中土壤有机碳矿化特征

为了揭示植被退化对湿地土壤碳矿化过程的影响,以甘南尕海4种不同植被退化梯度的湿地(未退化(UD)、轻度退化(LD)、中度退化(MD)及重度退化(HD))为研究对象,采用室内恒温培养和碱液吸收法研究不同土层土壤有机碳(SOC)矿化速率和累积矿化量,结合一级动力学方程,分析土壤半矿化分解时间(T1/2)、有机碳矿化潜势(C0)等参数对植被退化的响应。结果表明:(1)不同植被退化梯度湿地SOC矿化速率在培养期内呈现出基本一致的变化趋势,表现为,培养初期(0~4天)矿化速率快速下降,且数值较高,培养中后期缓慢下降(4~41天)并趋于平稳;各培养温度下,不同植被退化梯度湿地土壤在各土层有机碳矿化速率大小均为UD>LD>MD>HD。(2)在整个培养期间,各植被退化梯度湿地土壤有机碳矿化速率均随土层加深而降低,表层0-10 cm的矿化速率(1.14~16.23 mg/(g·d))均显著高于10-20 cm(1.05~2.85mg/(g·d))和20-40 cm土层(0.94~1.26 mg/(g·d))。(3)4种植被退化梯度湿地在不同温度下的土壤有机碳累积矿化量均值排序为5°C(34.54 mg/g)<15°C(46.67 mg/g)<25°C(58.28 mg/g)<35°C(86.46 mg/g)。(4)一级动力学方程的C0值随植被退化程度增加呈递减趋势,而C0/SOC随着温度的升高而降低。因此,植被退化能显著降低高寒湿地土壤有机碳矿化速率,而气候变暖能够显著增加湿地土壤有机碳矿化量。     

气候变暖背景下河南省夏玉米花期高温灾害风险预估

为预估未来气候变暖背景下夏玉米花期高温灾害风险,根据河南省19个农业气象观测站夏玉米抽雄期常年观测资料和未来RCPs(representativeconcentrationpathways)气候变化情景数据,构建夏玉米花期高温风险评价指标,开展河南省夏玉米花期高温灾害时空特征及风险演变分析。其中RCPs气候情景数据包括基准气候条件(1951—2005年, RCP-rf)和未来(2006—2050年)RCP 4.5(中)、RCP 8.5(高)两种浓度路径数据。以抽雄普遍期及之后7d确定为夏玉米花期,并内插匹配气候情景格点数据。以花期最高气温≥32℃和≥35℃作为轻度和重度高温灾害发生阈值,根据轻、重度夏玉米花期高温发生频率和高温积害,建立风险评价指标并分级。结果表明, RCP-rf情景下全省夏玉米花期高温发生频率在20.5%～81.0%(≥32℃)和3.9%～51.9%(≥35℃)。与基准条件相比,≥32℃高温发生频率增加9.1%(RCP4.5)和11.0%(RCP8.5),≥35℃高温发生频率增加8.7%(RCP4.5)和8.3%(RCP8.5)。RCP-rf情景下全省夏玉米花期高温积害在48.5～200.9℃·d(≥32℃)和9.8～138.5℃·d(≥35℃)。与基准条件相比,≥32℃高温积害增加25.4℃·d (RCP 4.5)和25.6℃·d (RCP 8.5),≥35℃高温积害增加25.8℃·d (RCP 4.5)和31.4℃·d (RCP 8.5)。由综合风险分析可知, RCP-rf情景下夏玉米花期高温灾害高值风险区主要分布在新乡、郑州、许昌、漯河、周口及其以东以北的地区(商丘除外),约占夏玉米主栽区面积的30.1%;RCP4.5情景下高值风险区扩大至洛阳和南阳以东的大部分地区,约占夏玉米主栽区面积的63.4%; RCP 8.5情景下高值风险区面积进一步向西扩大,约占夏玉米主栽区面积的占76.3%。     

Variation in glomalin in soil profiles and its association with climatic conditions,shelterbelt characteristics,and soil properties in poplar shelterbelts of Northeast China

Glomalin-related soil protein(GRSP)sequesters large amounts of carbon and plays important roles in maintaining terrestrial soil ecosystem functions and ecological restoration;however,little is known about GRSP variation in 1-m soil profiles and its association with stand characteristics,soil properties,and climatic conditions,hindering GRSP-related degraded soil improvement and GRSP evaluation.In this study,we sampled soils from 1-m profiles from poplar(Populus spp.)shelterbelts in Northeast China.GRSP contents were 1.8–2.0 times higher in the upper 40 cm soil layers than at 40–100 cm.GRSP-related soil organic carbon(SOC)sequestration in deeper soil layers was*1.2 times higher than in surface layers.The amounts of GRSP-related nutrients were similar throughout the soil profile.A redundancy analysis showed that in both surface and deeper layers,soil properties(pH,electrical conductivity,water,SOC,and soil nutrients)explained the majority of the GRSP variation(59.5–84.2%);the second-most-important factor in GRSP regulation was climatic conditions(temperature,precipitation,and altitude),while specific shelterbelt characteristics had negligible effects(<5%).Soil depth and climate indirectly affected GRSP features via soil properties,as manifested by structural equation model analysis.Our findings demonstrate that GRSP is important for carbon storage in deep soils,regardless of shelterbelt characteristics.Future glomalin assessments should consider these vertical patterns and possible regulating mechanisms that are related to soil properties and climatic changes.