高温和低湿对干热河谷7个植被恢复树种光合参数的影响

采用人工气候室控制环境条件,研究了高温（30℃和40℃）对印楝（Azadirachta indica A．Juss．）、木豆[Cajanus cajan（Linn．）Huth]、赤桉（Eucalyptus camaldulensis Dehn．）、蓝桉（E．globulus Labillardiere）、柠檬桉（E．citriodoraHook．）、大叶相思（Acacia auriculiformis A．Cunn．）和麻风树（Jatropha curcas Linn．）7个干热河谷植被恢复树种幼苗叶片光合参数的影响,以及低湿条件对麻风树幼苗叶片光合参数的影响,并对高温及低湿条件下各树种叶片光合参数与叶片含水量的关系进行了探讨。结果表明：在高温条件下,供试树种叶片的净光合速率（Pn）和Fv／Fm值均随叶片含水量的提高逐渐增加,但在40℃条件下各树种的Pn以及刚nn值均明显降低,表明叶片含水量高有利于各树种叶片Pn和n／Fm的提高,而40℃高温则对其Pn和Fv／Frn有明显抑制作用。在非干旱条件下,高温对各树种幼苗的Pn、气孔导度（Gs）、胞间c0：浓度（ci）和蒸腾速率（Tr）均有不同程度影响。在40℃条件下,供试树种中印楝和赤桉幼苗的Pn降幅最小;大叶相思、蓝桉和木豆幼苗的Gs明显增加;各树种幼苗的ci均明显提高;除印楝外,其他6个树种幼苗的Tr明显加剧且叶片水分利用效率降低。在叶片含水量较高的状况下,供试7个树种中印楝和赤桉幼苗的FV／Fm值受高温的影响较小。在空气相对湿度20％的条件下,麻风树幼苗的Pn、Cs、ci及Tr均明显降低,且均随叶片含水量的提高而增加,表明叶片含水量下降是麻风树幼苗光合作用减弱的重要影响因素。研究结果表明：干热河谷地区的高温引起的植物光合限制以非气孔因素为主导;在供试的7个树种中,印楝和赤桉对干热河谷高温干旱生境的适应或忍耐能力较强。     

苹果果面日最高温与主要气象因子的关系

一天中 ,苹果果实表面最高温度与气温、日照、相对湿度和风速有着密切的关系。通过生长季自动监测果实表面温度的变化 ,并与设置在监测树旁边气象记录仪数据对比 ,揭示出树冠西南部果实表面温度与气温、日照、相对湿度和风速呈高度相关。结果还表明 :日照和气温是导致果实表面高温 (>45℃ )的两个主要因子。在大多数情况下 ,这两个因子相互作用决定果实高温是否发生 ,但气温的作用更为重要。一般在晴天 ,树冠西南部果实表面高温通常出现在 1 3 :3 0～ 1 5 :5 0。果实达到临界日烧高温 (>45℃ )的综合气象条件是 (1 0 :0 0～ 1 6 :0 0平均值 ) :日照 >5 80 W/m2 ;气温 >3 1 .8℃ ;风速 <1 .0 m/s;相对湿度 <3 0 %。气温、日照、风速和相对湿度与果实表面温度都呈高度相关 ,其多元回归方程为 :果实表面温度 (℃ ) =1 9.7 0 .842×气温 (℃ ) 0 .0 0 989×日照 (W/m2 ) - 2 .0 8×风速 (m/s) - 0 .1 48×相对湿度 (% ) ,r2 =0 .6 97     

温湿度对稻纵卷叶螟卵的联合作用

为了探讨温湿度在稻纵卷叶螟Cnaphalocrocis medinalis （Guenée）种群发展中的作用, 通过室内实验调查了不同温度和湿度组合下该蛾卵的发育历期、 胚胎发育情况、 孵化率和卵粒重量的变化。结果表明： 在相同温度下卵历期随相对湿度的增大而缩短, 孵化率随相对湿度的加大而提高。在22℃下低于46%的相对湿度显著降低了卵的孵化率, 而在25～34℃下低于66%的相对湿度会引起孵化率的显著降低, 37℃下卵无论在何种湿度中均不能孵化。在50%左右的低湿条件下, 温度高于28℃后卵也不能孵化。温度在22～31℃和相对湿度在77%～100%范围内, 卵的孵化率无显著差异, 这属于稻纵卷叶螟卵的适宜温湿度范围。稻纵卷叶螟卵的发育起点温度和有效积温分别为10.1±0.6℃和63.7±3.5日度。卵的孵化率（Y）与温湿系数（RH/T）间呈显著的逻辑斯蒂曲线关系Y=0.8662/[1+exp(17.4084-7.5714×RH/T)]。温湿系数在2.34以下时卵孵化率将低于50%, 而达到3.0左右时孵化率接近最高值。结论认为, 低湿造成的稻纵卷叶螟卵重量显著降低、 卵粒干瘪、 胚胎发育受阻是致死卵的主要原因。     

The influence of humidity on the attachment ability of the spider Philodromus dispar (Araneae, Philodromidae)

Hairy attachment devices that are not supplemented with fluid secretion have evolved independently in lizards and spiders. van der Waals forces have previously been shown to be responsible for excellent adhesive properties of these structures, but it has recently been reported that wetting phenomena also play an important role in such 'dry adhesives'. To investigate the effect of ambient humidity on the attachment of the living spider Philodromus dispar, traction force was measured on a smooth epoxy resin surface at relative humidities (RHs) of 15, 50, 70, 80 and 99 per cent. The results show that attachment ability is significantly higher at an intermediate humidity compared with that in a dry atmosphere and at high humidity. Water condensation on the substrate surface almost completely abolishes adhesion. Experimental results obtained may be explained by an increase in capillarity or changes in mechanical properties of setae and spatulae owing to water absorption by the cuticle at an intermediate RH. The results obtained show dry adhesion limits under different environmental conditions and are important for understanding spider biology.     

亚高温下不同空气湿度对番茄光合作用和物质积累的影响

为了研究亚高温下不同空气湿度对番茄植株光合作用及物质积累的影响,本试验利用人工气候室,在11:00—15:00平均温度为33℃的亚高温条件下,设置3个空气相对湿度处理,分别为70%～80%(高湿)、50%～60%(中湿)和不加湿的30%～40%(低湿)。结果表明:在处理25d时,高湿处理番茄叶片叶绿素含量、净光合速率显著高于低湿处理,而低湿处理果实空洞率比高湿处理高18.4%(P<0.05);在33℃亚高温条件下,70%～80%的相对湿度有利于光合作用的增强和果实品质的提高。     

西双版纳望天树林林窗小气候特征研究

 对西双版纳望天树林林窗小气候要素的季节变化、水平差异进行了观测研究,并对比分析了两个大小不同林窗内温度垂直分布状况、相对湿度差别。结果表明：大林窗内温度、湿度、光照的日变化均比林内大;大林窗中央光照强度为林内的10倍以上,太阳总辐射量、净辐射量为林内的5倍以上,大林窗中央的蒸发耗热量大于林内,且均占各自净辐射的较大比例(70％～80％),干季大林窗内温度、湿度日变化比雨季剧烈,大林窗内具有两个加热层(幼苗冠层、地表),小林窗仅有一个加热层(幼树冠层),且前者的加热强度大于后者,相对湿度日变化则是大林窗内较剧烈。     

光周期和温湿度对烟蚜茧蜂寄生能力和繁殖的影响

【目的】烟蚜茧蜂Aphidius gifuensis对烟蚜Myzus persicae有着极高的寄生率,而被广泛用于烟田防治烟蚜。但在人工扩繁烟蚜茧蜂过程中,环境因素对烟蚜茧蜂的生长发育有一定影响。本研究旨在明确光周期、湿度和温度对烟蚜茧蜂在烟蚜上寄生力的影响。【方法】在室内分别调查温度25℃、相对湿度70%与4个光周期(9L∶15D,12L∶12D, 14L∶10D和19L∶5D)组合条件下,温度25℃、光周期14L∶10D与4个相对湿度(65%, 70%, 75%和80%)条件下, 以及相对湿度70%、光周期14L∶10D与4个温度(10℃, 15℃, 25℃和35℃)组合条件下,烟蚜茧蜂成蜂对烟蚜若蚜的寄生率及成蜂羽化率、寿命、性比(雌性占比)和后足胫节长度。【结果】结果表明光照时间过长或过短均会对烟蚜茧蜂的生长发育造成负面影响。在温度25℃和相对湿度70%时,光周期14L∶10D下烟蚜茧蜂成蜂的体型最大,其成蜂后足胫节最长,为0.439 mm;光周期为12L∶12D下烟蚜茧蜂成蜂的体型最小,后足胫节长度只有0.345 mm;光周期14L∶10D下烟蚜茧蜂成蜂对烟蚜若蚜的寄生率、寿命也最高,分别为42.61%和42.33 h。在温度25℃和光周期14L∶10D时,烟蚜茧蜂成蜂在烟蚜若蚜上的寄生率随着相对湿度的增加出现先升高后减小的变化情况,在相对湿度为75%下寄生率最高,达54.44%;在相对湿度为65%下寄生率最低,只有21.67%;相对湿度70%下烟蚜茧蜂成蜂的寿命和后足胫节最长,分别为42.33 h和0.439 mm;相对湿度75%下烟蚜茧蜂的寿命最短,只有20.42 h;相对湿度65%下烟蚜茧蜂成蜂的后足胫节最短,仅有0.373 mm。在相对湿度70%和光周期14L∶10D时,温度为25℃比低温为10℃和15℃更有利于烟蚜茧蜂成蜂的生长发育,其寄生率、雌性占比和后足胫节长度分别为4261%, 39.04%和0.439 mm, 均高于10℃和15℃下的值;而高温35℃则不利于烟蚜茧蜂成蜂在烟蚜若蚜上的寄生行为,并无僵蚜产生,甚至会使寄主烟蚜死亡。【结论】在温度25℃和相对湿度70%时,光周期为14L∶10D更有利于提高烟蚜茧蜂成蜂的寄生率、体型和寿命;在温度25℃和光周期14L∶10D时,相对湿度为75%更有利于提高烟蚜茧蜂成蜂的寄生率,相对湿度为70%条件更有利于烟蚜茧蜂寿命、体型的增加;在相对湿度70%和光周期14L∶10D时,温度为25℃更有利于烟蚜茧蜂寄生率、体型以及雌性占比的增加,而低温10℃条件更有利于烟蚜茧蜂的寿命的延长。本研究结果为田间大棚或者室内小棚等烟蚜茧蜂人工扩繁及其复壮提供了科学参考。     

基于冠层温湿度模型的日光温室黄瓜霜霉病预警方法

利用温室环境参数构建室内微环境模拟模型,并结合温室病害模型进行预警,便于开展病害生态防治,以减少农药使用,从而保护温室生态环境和保证农产品质量安全.本文利用温室内能量守恒原理和水分平衡原理,构建了日光温室冠层叶片温度和空气相对湿度模拟模型.叶片温度模拟模型考虑了温室内植物与墙体、土壤、覆盖物之间的辐射热交换,以及室内净辐射、叶片蒸腾作用引起的能量变化;相对湿度模拟模型综合了温室内叶片蒸腾、土壤蒸发、覆盖物与叶面的水汽凝结引起的水分变化.将温湿度估计模型输出值作为参数,输入黄瓜霜霉病初侵染和潜育期预警模型中,估计黄瓜霜霉病发病日期,并与田间观测的实际发病日期比较.试验选取2014年9月和10月的温湿度监测数据进行模型验证,冠层叶片温度实际值与模拟值的均方根偏差（RMSD)分别为0.016和0.024 ℃,空气相对湿度实际值与模拟值的RMSD分别为0.15%和0.13%.结合温湿度估计模型结果表明,黄瓜病害预警系统预测黄瓜霜霉病发病日期与田间调查发病日期相吻合.本研究可为黄瓜日光温室病害预警模型及系统构建提供微环境数据支持.     

十种园林植物叶片导热系数及对流换热系数测定

为研究植物层传热特性,选取校园内十种常见园林植物测定其叶片导热系数、叶片与周边空气对流换热系数,拟合导热系数与叶片含水量的近似关系式,对比实验测定对流换热系数与通过经验公式理论计算所得对流换热系数,比较与叶片接触前后空气的相对湿度。结果表明,叶片存在降温增湿作用,在5～25 ℃下叶片导热系数随温度变化较小;叶温20 ℃时,叶片导热系数随叶片含水量降低而减小;实验测试对流换热系数与理论计算结果吻合度较高。     

开放式空气CO2浓度增高对水稻冠层微气候的影响

利用位于江苏省无锡市安镇的我国唯一的农田开放式空气CO₂浓度增高(FACE)系统平台,于2001年8月26日至10月13日(水稻抽穗至成熟期)进行水稻作物冠层微气候连续观测,以研究FACE对水稻冠层微气候特征的影响.结果表明,FACE降低了水稻叶片的气孔导度,FACE与对照水稻叶片气孔导度的差异上层叶片大于下层叶片,生长前期大于生长后期.FACE使白天水稻冠层和叶片温度升高,这种差异生长前期大于生长后期;但FACE对夜间水稻冠层温度的影响不明显.在水稻旺盛生长的抽穗开花期,晴天正午前后FACE水稻冠层温度比对照高1.2℃;从开花至成熟期,FACE水稻冠层白天平均温度比对照高0.43℃.FACE对冠层空气温度也有影响,白天水稻冠层空气温度FACE高于对照,这种差异随太阳辐射增强而增大且冠层中部大于冠层顶部;冠层中部空气温度FACE与对照的差异(T_face-T_ambient)日最大值在0.47～1.2℃之间,而冠层顶部的T_face-T_ambient日最大值在0.37～0.8℃之间.夜间水稻冠层空气温度FACE与对照差别不大,变化在±0.3℃之内.而FACE对水稻冠层空气湿度无显著影响,表明FACE使水稻叶片气孔导度降低,从而削弱了植株的蒸腾降温作用,导致水稻冠层温度和冠层空气温度升高,改变了整个水稻冠层的温度环     

蚁巢表层土壤温湿度对不同发育阶段红火蚁数量的影响(英文)

红火蚁一种攻击性非常强的外来入侵蚂蚁,可对入侵地的农业生产、生态系统、人体健康和公共安全等产生负面影响,温度和湿度是影响其生长和发育的重要环境因子.本研究评估了红火蚁蚁巢表层土壤温、湿度对红火蚁幼虫、有翅蚁蛹和有翅蚁成虫数量的影响.结果表明,随着土壤温度的升高,幼虫、有翅蚁蛹和有翅蚁成虫的数量都呈先升高后下降的趋势.当温度为26～30℃时,幼虫数量达到最大值,而当温度为20～25℃时,有翅蚁蛹和有翅蚁成虫数量达到最大值.当温度<20℃时,有翅蚁成虫和幼虫的数量均与土壤相对湿度呈负相关,但是有翅蚁雌雄蛹的数量都与相对湿度呈正相关.当温度<20℃时,在相对湿度为41％ ～50％时,雄性有翅蚁的数量达到最大值,在相对湿度为71％ ～80％时,有翅蚁蛹的数量达到最大值.本研究将对防治这种危险的入侵害虫提供理论依据.     

Selective oviposition by a leaf miner in response to temporal variation in abscission

Summary Responses to humidity of net photosynthesis and leaf conductance of single attached leaves were examined in populations of herbs from wet soil sites in Beltsville, Maryland and Davis, California, USA. Plants were grown in controlled environments under three conditions which differed in the magnitude of the day-night temperature difference and in daytime air saturation deficit. No population differences in response were found in Abutilon theophrasti. In Amaranthus hybridus stomatal conductance and net photosynthesis were more reduced by increasing leaf to air water vapor pressure difference (VPD) in the population from Beltsville, but only for the growth condition with a constant 25°C temperature. In Chenopodium album, stomatal conductance was more sensitive to VPD in the population from Davis, but only for the growth condition with 28/22°C day/night temperatures. Population differences in the sensitivity to VPD of leaf conductance were associated with differences in leaf area to root weight ratio. The relative reduction of net photosynthesis as VPD increased was greater than, equal to, or less than the relative decrease in substomatal carbon dioxide partial pressure. The pattern depended on species, and on growth condition. From these results one can not conclude that environmental humidity has been a strong selective force in determining sensitivity to humidity of stomatal conductance.     

In vivo spetrometric analysis of the electrical impedance of the first leaf of maize (Zea mays L.) as a function of soil and atmosphere hydrous conditions

In vivo spectrometric analysis of the electrical impedance of the first leaf of maize (Zea mays L.) as a function of soil and atmosphere hydrous conditions. We have measured the electrical resistance and capacitance of the first leaf of maize aged 14 days. The plants were cultivated at different levels of soil and atmospheric humidity and submitted to quiet or agitated air. In 'control' plants cultivated in quiet air under moderate relative humidity (HRA) (50 to 60%), the amplitude of the spectrometric bioimpedance spectrum (CSB) increased with the quantity of water available to the roots. Agitated air or elevated HRA increased the magnitude of the CSB in plants cultivated at 40% of the maximal retention capacity (CRM) of the soil. On the other hand, the CSB decreased in plants cultivated at 60% of the CRM or in hydroponics. This was accompanied by a dramatic decrease in the electrical resistance. The action of the atmospheric factors studied depends on the quantity of water where the roots are bathing.     

低温胁迫下丛枝菌根真菌对玉米光合特性的影响

利用盆栽试验,在15 ℃和5 ℃低温胁迫下研究了丛枝菌根（AM）真菌对玉米生长、叶绿素含量、叶绿素荧光和光合作用的影响.结果表明：低温胁迫抑制了AM真菌的侵染;接种AM真菌的玉米地上部和地下部干物质量、相对叶绿素含量高于不接种植株.与非菌根玉米相比,菌根玉米具有较高的最大荧光（F_m）、可变荧光（F_v）、最大光化学效率（F_v/F_m）和潜在光化学效率（F_v/F_o）及较低的初始荧光（F_o）,并且在5 ℃处理中差异显著.接种AM真菌使玉米叶片的净光合速率（P_n）和蒸腾速率（T_r）显著增强;低温胁迫下,菌根植株的气孔导度（G_s）显著高于非菌根植株;而胞间CO₂浓度（C_i）显著低于非菌根植株.表明AM真菌可通过提高叶绿素含量及改善叶片叶绿素荧光和光合作用来减轻低温胁迫对玉米植株造成的伤害,提高玉米耐受低温的能力,进而提高玉米的生物量,促进玉米生长.     

全球气候变化对沈阳地区春玉米生长的可能影响

Physiological ecology simulation modelling of maize growth (MPESM) was used to simulate the variation of soil moisture, maize development and maize growth under twelve prescribed climate scenarios, which include doubling CO2, raising mean temperature by 1.5 ℃, 3.0 ℃ and 4.5 ℃, and changing precipitation by 0, +20%, -20%, and -40%. The simulated results were compared with that of the present climate, to assess the sensitivity of maize to climatic change. The analysis indicated that soil moisture is sensitive to reduced precipitation, maize development is sensitive to the rise of temperature, and maize growth is affected greatly by temperature elevation and precipitation variation, which cancel out the positive effects of CO2 elevation. It was found that with the severe change of climate, the leaf biomass, the female fringe biomass, and the leaf area index would decline greatly, and the biomass of stem and root would increase greatly. The average yield of maize will decline between 5% and 30%.     

Response of Tomato Sugar and Acid Metabolism and Fruit Quality under Different High Temperature and Relative Humidity Conditions

The combined stress of high temperature and high relative air humidity is one of the most serious agrometeorological disasters that restricts the production capacity of protected agriculture. However, there is little information about the precise interaction between them on tomato fruit quality. The objectives of this study were to explore the effects of the combined stress of high temperature and relative humidity on the sugar and acid metabolism and fruit quality of tomato fruits, and to determine the best relative air humidity for fruit quality under high temperature environments. Four temperature treatments (32°C, 35°C, 38°C, 41°C), three relative air humidity (50%, 70%, 90%) and four duration (3, 6, 9, 12 d) orthogonal experiments were conducted, with 28°C, 50% as control. The results showed that under high temperature and relative air humidity, the activity of sucrose metabolizing enzymes in young tomato fruits changed, which reduced fruits soluble sugar content; in addition, enzyme activities involved phosphopyruvate carboxylase (PEPC), mitochondria aconitase (MDH) and citrate synthetase (CS) increased which increased the content of organic acids (especially malic acid). Eventually, vitamin C, total sugar and sugar-acid ratio decreased significantly, while the titratable acid increased, resulting in a decrease in fruit flavor quality and nutritional quality in ripe fruit. Specifically, a temperature of 32°C and a relative air humidity of 70% were the best cultivation conditions for tomato reproductive growth period under high temperature. Our results indicating that fruit quality reduced under high temperature at the flowering stage, while increasing the relative air humidity to 70% could alleviate this negative effect. Our results are benefit to better understand the interaction between microclimate parameters under specific climatic conditions in the greenhouse environment and their impact on tomato flavor quality.     

长白山温带阔叶红松林对温湿环境的调节效应

森林具有改善气候、调节微环境的作用,森林小气候的研究对于揭示森林生态系统功能、评估森林生态环境效益具有重要意义.本研究以长白山阔叶红松林为例,基于2003—2014年林内通量塔气象资料及其附近气象站空旷地的同时段气象资料,对其最高、最低和平均气温、相对湿度和表层土壤温度的日变化和季节变化进行对比分析.结果表明: 林内气温和相对湿度分别呈现单峰型和U型日变化规律,日较差较林外低2.31 ℃和8.3%,表层土壤温度日变化趋于恒定,阔叶红松林减缓了温湿度的日变化.夏季主要为降温效应,冬季表现出显著的增温效应.夏季林内气温和土温比林外低1.30和3.91 ℃;冬季林内气温和土温比林外高2.06和5.44 ℃.森林对最高温和最低温的调节效应显著.在季节尺度上,夏季森林降低最高气温和土温1.80和5.45 ℃,冬季提高最低气温和土温3.69和7.92 ℃.在年尺度上,林内年最高气温和土温分别较林外低1.60和4.99 ℃,年最低气温和土温分别较林外高1.12和8.82 ℃.森林对土温的调节效应强于对气温的调节效应.气温和土温均以对低温的保温作用为主.     

Ammonia Flux between Oilseed Rape Plants and the Atmosphere in Response to Changes in Leaf Temperature,Light Intensity,and Air Humidity (Interactions with Leaf Conductance and Apoplastic NH4+ and H+ Concentrations)

NH3 exchange between oilseed rape (Brassica napus) plants and the atmosphere was examined at realistic ambient NH3 levels under controlled environmental conditions. Different leaf conductances to NH3 diffusion were obtained by changing leaf temperature (10 to 40[deg]C), light intensity (0 to 600 [mu]mol m-2 s-1), and air humidity (20 to 80%), respectively. NH3 adsorption to the cuticle with subsequent NH3 transport through the epidermis had no significant effect on the uptake of atmospheric NH3, even at 80% relative air humidity. NH3 fluxes increased linearly with leaf conductance when light intensities were increased from 0 to 600 [mu]mol m-2 s-1. Increasing leaf temperatures from 10 to 35[deg]C caused an exponential increase in NH3 emission from plants exposed to low ambient NH3 concentrations, indicating that leaf conductance was not the only factor responding to the temperature increase. The exponential relationship between NH3 emission and temperature was closely matched by the temperature dependence of the mole fraction of gaseous NH3 above the leaf apoplast (NH3 compensation point), as calculated on the basis of NH4+ and H+ concentrations in the leaf apoplast at the different leaf temperatures. NH3 fumigation experiments showed that an increase in leaf temperature may cause a plant to switch from being a strong sink for atmospheric NH3 to being a significant NH3 source. In addition to leaf temperature, the size of the NH3 compensation point depended on plant N status and was related to plant ontogeny.     

盘锦湿地芦苇(Phragmites communis)群落蒸发散主导影响因子

利用2005年全年盘锦芦苇湿地梯度观测和涡动相关系统的监测数据,对芦苇群落的蒸发散变化规律及其主导影响因子分析表明,不同月份芦苇群落蒸发散日变化呈现出相同的变化趋势,即早晚低、中午高的单峰型曲线;芦苇群落蒸发散主要受当地气象因素、植被生长状况和生理生态特征的影响.相关分析表明,芦苇湿地蒸发散与净辐射、气温、地表温度、相对湿度、风速、土壤含水量等环境因素的变化都有很好的响应.回归分析表明影响生长季主要因素有:净辐射、土壤含水量、相对湿度、气温和地表温度;影响非生长季主要有:净辐射、地表温度和风速.同时,植被生长状况和生理生态特征对蒸发散也有显著影响,其中叶面积指数与气孔导度是芦苇群落蒸发散的主导影响因子.