气候变化对黄山区域生物多样性保护的影响与对策

以黄山区域自然保护区为研究对象,利用黄山50年气象观测数据分析气候变化趋势和主要特征,总结、分析、评估与预测气候变化对生物多样性的影响和潜在威胁。结果表明：①50年来黄山区域年均气温总体呈上升趋势,气候正趋变暖,但局部期间也有震荡现象。特别是20世纪90年代以来,气温升高比较显著;②黄山年降水总趋势呈波动性减少,减少率为-2．28mm／年。上世纪90年代以后,降水偏多,21世纪初降水显著偏少;近20年来极端天气发生频繁,未来有些极端事件的发生频数还可能会更高。③气候变暖会加剧病虫害的流行及黄山森林的脆弱性,改变森林结构与分布,致使多数森林群落生产力趋于下降,使动、植物物候产生了不同程度的响应。气温升高和降水模式的变化可能导致松材线虫等外来物种产生快速扩散与大规模入侵,致使黄山松受到严重威胁。     

播期对川中丘陵区油菜倒伏性状的影响

油菜机械化生产中,植株倒伏是影响机械化收获的重要因素。为探讨不同播种期对川中丘陵区油菜倒伏性状的影响,以川油36和蓉油18为供试材料,分别设置9月22日、9月29日、10月6日、10月13日和10月20日5个播期处理,分析不同播期条件下油菜生育期气象因子、倒伏性状指标的变化情况。结果表明,随播种期推迟,油菜生育期内的降水量、积温、日均最高气温、日均最低气温和日照时长均逐渐下降,生育期逐渐缩短,成熟期植株株高、分枝部位、根颈粗、茎秆粗降低,倒伏系数增加。油菜抗倒伏能力在9月22-29日播期处理之间最强。因此,川中丘陵区油菜的适宜播期为9月下旬。     

Short-term water management at early filling stage improves early-season rice performance under high temperature stress in South China

Asymmetric warming and frequent temperature extremes are the consequences of climate change that are affecting crop growth and productivity over the globe while heat stress at early filling stage is of serious concern for the early-season rice in double cropping rice system of South China. In present study we assessed different short-term water management strategies to cope with the high temperature at early filling stage in rice. Water was applied as flood irrigation at two various depths i.e., 4–5 cm (I1) and 5–10 cm (I2) during 9:00–18:00 and then drained off at 18:00 as well as applied over-head during different time spans i.e., over-head sprinkle irrigation during 11:00–12:00, 13:00–14:00 and 14:00–15:00 at 60–80% relative humidity (RH) at early filling stage and regarded as S1, S2 and S3, respectively. A control was maintained with the maintenance of 1 cm water layer as normal farmer practice of this region. A fragrant rice cultivar, ‘Yuxiangyouzhan’ in early March (regarded as early season rice) in both 2014–15 and the effectiveness of different water management strategies were measured by estimating physio-biochemical responses, photosynthesis, yield and quality of rice exposed to high temperature stress at early filling stage. Our results showed that water treatments lowered lipid peroxidation (in terms of reduced malondialdehyde (MDA) contents) whilst proline and protein contents were affected differently. The water treatments also regulated the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), nevertheless, improved plant photosynthesis and gas exchange, rice yield and quality attributes considerably by lowering severity of canopy temperatures than control (CK). On average, both flood and sprinkler water application were proved effective against high temperature stress, nonetheless, flood irrigated treatments were remained more effective than sprinkler which provided 26.58 and 43.63% higher grain yields in 2014–15, respectively than CK. On average, 5.58 and 11.92% higher grain yields were recorded in flood irrigation than sprinkler irrigation whereas among individual water application treatments, I1 was noted as the most effective regarding grain yield of rice (26.76 and 49.35% higher yield than CK) in both years which suggests that maintenance of 4–5 cm water layer might be helpful for the rice to withstand against high temperature stress at post heading and/or early filling stage in early-season rice production in South China.     

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.     

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.     

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%。     

新疆阿勒泰地区20cm蒸发皿蒸发量的变化特征

利用新疆阿勒泰地区7个气象台站1964-2001年连续38a的20cm口径蒸发皿资料,运用线性趋势法、Mann-Kendall法对该地区蒸发皿蒸发量的年代际变化趋势和突变情况进行了研究。结果表明:整个地区平均而言,20世纪70年代的年平均蒸发皿蒸发量最高,此后逐年代下降,大部分站点的年代际变化趋势与全区一致,东部有两站不同;夏季平均蒸发量最大、春季次之,冬季最少;除冬季外,平均季蒸发量与年变化一致。年平均及春、夏、秋季蒸发皿蒸发量呈波动变化状态,冬季呈显著的上升趋势。空间分析表明,夏秋季大部分站的蒸发皿蒸发量呈显著下降趋势,个别站呈显著上升趋势;冬季大部分站呈显著上升趋势,春季大部站变化不明显。突变检测表明,该地区年及夏秋季蒸发皿蒸发量80年代中期有一次明显的突变,春、冬季突变不明显。各站及不同季节趋势变化和突变时间的不同步,表明气候变化在不同的地区和季节会有不同的体现。     

陇东黄土高原典型站苹果生长对气候变化的响应

利用西峰、崆峒两地连续24a的苹果物候观测资料(1984-2007年)、产量资料(1986-2007年)和1961-2007年的气象观测资料,分析陇东黄土高原苹果生育进程等对气候变化的响应。结果显示,分析期内,随着气候变化,当地苹果的叶芽开放、开花等生育期提前,成熟期推迟,生长周期延长;生育期气象条件呈现出向暖干化发展的趋势,以花期变化最为明显;影响崆峒苹果产量的主要气象因子为4月份最低气温、1月上旬降水、6月上旬日照时数以及7-8月最低气温,在气候变化条件下,这些因子的变化各不相同,对苹果产量的影响有利有弊。未来在苹果生产中,应调整布局、加强田间管理以应对气候变化的影响。     

1981-2009年江苏省气候变化趋势及其对水稻产量的影响

利用江苏省1981-2009年7个农业气象站点的气象和水稻物候、产量资料,从平均气温和降水量对水稻产量影响的基本方程入手,定义了平均气温和降水量变化趋势对水稻产量趋势的贡献率,揭示江苏省近30a气候变化趋势对水稻产量的影响.结果表明,近30a来,江苏省水稻全生育期平均气温和最低气温呈上升趋势,最高气温的变化在苏南和苏北地区差异较大,尤其在开花-成熟阶段,苏南地区呈上升趋势,而苏北地区则呈相反变化趋势.气温(包括平均气温、最低气温和最高气温)与水稻产量呈正相关,1981-2009年平均气温升高对江苏省水稻产量影响的平均值约为1.2％,对产量趋势的贡献率约为30.0％.降水量的变化趋势不明显,降水量与水稻产量的相关性亦不显著,说明在研究区内降水量的变化对水稻产量的影响较小.总体上,江苏省近30a气候变化有利于水稻生产.     

锡林浩特市日照时数的气候变化特征分析

利用锡林浩特市50a(1961-2010)日照时数以及总云量、低云量、降水量和水汽压等资料,采用气候倾向率分析其变化趋势,利用滑动T检验法和累积距平结合的方法进行突变分析,并根据各气象要素的年、季变化趋势及其与日照时数变化趋势的对应关系对日照时数变化原因进行分析。结果表明,锡林浩特市年日照时数呈极显著增加趋势(P<0.01);从年代际变化看,20世纪60-90年代,年均日照时数呈持续增加趋势,90年代达到最大,进入21世纪后,年均日照时数则明显减少;四季中夏季日照时数呈极显著增加趋势(P<0.01)。各季日照时数偏少期为20世纪60-70年代,偏多期为80年代-21世纪初;各月日照时数均呈波动上升趋势,增加最多的为8月;年日照时数在1985年发生了由少到多的突变,季日照时数发生突变是导致年突变的原因,尤以春季和夏季最为显著;云量是决定日照时数增加的重要原因之一,日照时数增加还与夏季、冬季水汽压以及夏季和秋季降水量密切相关。