环境因子对千里香(Murraya paniculata)蒸腾强度的影响

蒸腾作用是植物水分关系中的一个重要部分,它基本上是蒸发的物理过程,因此受环境因子的影响,同时它也是受植物体本身结构特点影响的生理过程。对植物的蒸腾强度测定,有利于了解植物与环境之间的关系。千里香[Murraya paniculata(L.)Jack]是一种主要生长于石灰岩地区的具有重要药理作用的植物。其生长地的土壤浅薄,而基岩本身又易透水,故石灰岩地区蓄水保水能力较差,土壤常较干燥,测定千里香植物的蒸腾强度,有利于了解石灰岩地区植物的某些特点。     

小叶榕气生根气体交换特征及影响因子研究

用LI-6400XT便携式光合仪测定了小叶榕(Ficus microcarpa L. f.)气生根的气体交换特征。结果表明气生根具有呼吸、蒸腾作用和空气吸湿作用。影响气生根呼吸作用的因素为年龄>空气温度>光强>相对湿度;影响蒸腾作用的因素为年龄>相对湿度>空气温度>光照。年龄小的气生根的呼吸和蒸腾作用较强,年龄大的尤其是木质化程度较高的气生根的呼吸作用较小,水分的释放(蒸腾作用)转变为水分的吸收(吸湿作用)。年龄小的气生根的CO2交换率与温度呈线性关系,温度越高,CO2交换率越大,呼吸越强;H2O交换率与相对湿度呈线性关系,相对湿度越大,H2O交换率越小,蒸腾越弱;年龄大的成熟气生根的H2O交换率与空气相对湿度呈线性关系,相对湿度越大,H2O交换率越小,蒸腾越小。     

Diurnal flight behavior of Ichneumonoidea (Insecta: Hymenoptera) related to environmental factors in a tropical dry forest

The biology and behavior of insects are strongly influenced by environmental conditions such as temperature and precipitation. Because some of these factors present a within day variation, they may be causing variations on insect diurnal flight activity, but scant information exists on the issue. The aim of this work was to describe the patterns on diurnal variation of the abundance of Ichneumonoidea and their relation with relative humidity, temperature, light intensity, and wind speed. The study site was a tropical dry forest at Ría Lagartos Biosphere Reserve, Mexico; where correlations between environmental factors (relative humidity, temperature, light, and wind speed) and abundance of Ichneumonidae and Braconidae (Hymenoptera: Ichneumonoidea) were estimated. The best regression model for explaining abundance variation was selected using the second order Akaike Information Criterion. The optimum values of temperature, humidity, and light for flight activity of both families were also estimated. Ichneumonid and braconid abundances were significantly correlated to relative humidity, temperature, and light intensity; ichneumonid also showed significant correlations to wind speed. The second order Akaike Information Criterion suggests that in tropical dry conditions, relative humidity is more important that temperature for Ichneumonoidea diurnal activity. Ichneumonid wasps selected toward intermediate values of relative humidity, temperature and the lowest wind speeds; while Braconidae selected for low values of relative humidity. For light intensity, braconids presented a positive selection for moderately high values.     

香果树实生苗的光合特性及其与环境因子的关系

为确定香果树实生苗的适生环境并为其自然更新提出有针对性策略,研究了不同生境(冠下、冠缘、林窗和林缘)中2年生香果树实生苗的净光合速率、水分利用效率、叶绿素含量、苗高、基径、生物量等的变化及其与生态因子之间的关系.结果表明: 4种生境中的光合有效辐射最大值为50～1380 μmol·m^-2·s^-1,冠下和冠缘中香果树实生苗的净光合速率日变化呈单峰型,而林窗和林缘实生苗的净光合速率日变化呈双峰型;香果树实生苗为耐阴植物,但耐阴能力较弱,其功能叶的光饱和点、补偿点和暗呼吸在4种生境中大小顺序为: 林缘>林窗>冠缘>冠下,表观量子效率的变化规律与之相反;林窗和冠缘2种生境中香果树实生苗的适应能力较强,叶片的蒸腾速率、气孔导度、水分利用效率和净光合速率较高;林窗中香果树实生苗叶片的叶绿素含量较低,但实生苗的生长速度最快,生物量最大;香果树实生苗的净光合速率与光合有效辐射和气孔导度呈显著正相关.对于冠下生境,需降低林冠层密度,增加透光率,以利于香果树实生苗的光合作用;对于林缘生境,则需要增加植被盖度,降低光照强度,以利于其快速生长.     

不同时间尺度下华北落叶松人工林冠层蒸腾与环境因子的关系

在半干旱区连续2年监测华北落叶松(Larix principis-rupprechtii)的树干液流、气象因子和土壤体积含水量,分析不同时间尺度下人工林冠层蒸腾与环境因子的关系。结果表明：不同时间尺度下,华北落叶松人工林冠层蒸腾的季节变化均呈单峰曲线,即先增大后减小的趋势;2016年、2017年日蒸腾量分别为1.58 mm/d和1.71 mm/d,生长季蒸腾总量分别为241.30 mm和260.97 mm。在日尺度下,气温、太阳辐射强度和饱和水汽压差是影响华北落叶松人工林冠层蒸腾主要环境因子;月尺度下,气温、风速、降水和土壤水分是冠层蒸腾的主要影响因子;冠层蒸腾与降水、大气相对湿度的相关关系由日尺度下的负相关到月尺度的正相关,相关性增强。总体来看,随时间尺度由小到大,气温、风速、大气相对湿度、降水、土壤水分对冠层蒸腾的影响作用增大,而太阳辐射强度、饱和水汽压差的作用减弱;在未来增温增雨趋势下,研究区生长季将延长,华北落叶松人工林冠层蒸腾量可能会加大。     

油蒿资源利用效率在生长季的相对变化及对环境因子的响应

为了探明西北半干旱区典型沙生植物油蒿(Artemisia ordosica)叶水平资源利用效率的相对变化及对环境因子的响应机制, 该研究于2018年5-10月, 使用LI-6400XT便携式光合仪测定了毛乌素沙地油蒿叶片的净光合速率(P_n)、蒸腾速率(E)、叶表面光合有效辐射(PAR_l)、叶表面温度(T_l)、叶表面相对湿度(RH_l), 在实验室计算叶片单位面积氮含量(N_area), 分析了叶片氮利用效率(NUE)、水分利用效率(WUE)、光利用效率(LUE)与环境因子之间的关系及NUE、WUE、LUE之间的相对变化。研究结果表明, 在充足且稳定光强下油蒿的P_n主要受温度的影响, NUE、WUE与VPD_l、T_l之间具有显著负相关关系, NUE、WUE与LUE间为正相关关系, NUE、WUE和LUE最大值分别发生在5、7和9月, 分别为9.43 μmol CO₂·g^-1·s^-1、3.86 mmol·mol^-1、0.04 mol·mol^-1, 资源利用效率的变化主要受P_n的影响。温度通过影响植物N分配来改变P_n, 进而影响着资源利用效率, WUE与LUE显著正相关, 对构建荒漠区生态系统能量交换过程模型有重要意义。     

Effects of Shoot Environment on Apparent Root Resistance to Water Flow in Whole Soybean and Cotton Plants

The response of leaf water potential to change in transpirationrate was examined in young soybean and cotton plants. Leaf waterpotential measured 1 h after transpiration became constant followinga change in humidity and was constant over a wide range of transpirationrates in both species. However, leaf water potential was notin equilibrium with flow until 3 h after transpiration becameconstant. At equilibrium an increase in transpiration alwaysresulted in a decrease in leaf water potential. It was alsofound that different responses of equilbrium leaf water potentialto transpiration rate occurred depending on whether transpirationwas altered by changing humidity, light intensity, or leaf area.Low light and decreased leaf area caused lower leaf water potentialsfor a given transpiration rate. These increases in root resistancecorrelated with lower rates of root elongation. The data indicatethat shoot-root interactions are occurring which affect apparentroot resistance to water flow, and complicate interpretationof whole plant data on leaf water potential and transpirationin terms of the flow dependence of root hydraulic characteristics.     

马占相思林冠层气孔导度对环境驱动因子的响应

利用Granier热消散探针在2003年10月测定了广东鹤山丘陵地马占相思林14株样树的树干液流,同时监测林冠上方的光合有效辐射、空气湿度和气温,结合树木的形态和林分的结构特征,计算马占相思的整树蒸腾(E)、林分总蒸腾(E_t)以及冠层平均气孔导度(g_c),分析树形特征与整树水分利用的关系、冠层气孔导度对光合有效辐射(PAR)和空气水汽压亏缺(D)的响应.结果表明,整树蒸腾与胸径(P＜0.0001)、边材面积(P＜0.0001)和冠幅(P=0.0007)以自然对数的形式、与树高(P=0.014)以幂函数的形式呈现显著正相关.冠层气孔导度最大值(g_cmax)随D的上升呈对数函数下降(P＜0.0001),对光合有效辐射的响应则呈双曲线函数增加(P＜0.0001).液流测定系统能提供连续和准确的整树和林分蒸腾速率值,经严格数学推导公式计算,最终可求出冠层气孔导度,是研究森林水分利用与环境因子相互关系的有效方法.     

Microsite and elevation zone effects on seed pilferage,germination, and seedling survival during early whitebark pine recruitment

Tree recruitment is a spatially structured process that may undergo change over time because of variation in postdispersal processes. We examined seed pilferage, seed germination, and seedling survival in whitebark pine to determine whether 1) microsite type alters the initial spatial pattern of seed caches, 2) higher abiotic stress (i.e. higher elevations) exacerbates spatial distribution changes, and 3) these postdispersal processes are spatially clustered. At two study areas, we created a seed distribution pattern by burying seed caches in microsite types frequently used by whitebark pine's avian seed disperser (Clark's nutcracker) in upper subalpine forest and at treeline, the latter characterized by high abiotic environmental stress. We monitored caches for two years for pilferage, germination, and seedling survival. Odds of pilferage (both study areas), germination (northern study area), and survival (southern study area) were higher at treeline relative to subalpine forest. At the southern study area, we found higher odds of 1) pilferage near rocks and trees relative to no object in subalpine forest, 2) germination near rocks relative to trees within both elevation zones, and 3) seedling survival near rocks and trees relative to no object at treeline. No microsite effects were detected at the northern study area. Findings indicated that the microsite distribution of seed caches changes with seed/seedling stage. Higher odds of seedling survival near rocks and trees were observed at treeline, suggesting abiotic stress may limit safe site availability, thereby shifting the spatial distribution toward protective microsites. Higher odds of pilferage at treeline, however, suggest rodents may limit treeline recruitment. Further, odds of pilferage were higher near rocks and trees relative to no object in subalpine forest but did not differ among microsites at treeline, suggesting pilferage can modulate the spatial structure of regeneration, a finding supported by limited clustering of postdispersal processes.     

10个秋菊品种的光合特性及净光合速率与部分生理生态因子的相关性分析

用CIRAS-2便携式光合测定系统测定了9月至10月10个秋菊[Dendranthema morifolium (Ramat.) Tvzel.]品种叶片的光合特征参数;在此基础上,对叶片光响应参数和CO2响应参数以及部分光合特征参数的日变化进行了比较分析;此外,还对净光合速率(Pn)与部分生理生态因子的相关性进行了分析.结果表明:10个秋菊品种的光补偿点(LCP)为92.83～167.37 μmol·m-2·s-1,光饱和点(LSP)为962.51～1 077.53 μmol·m-2·s-1,说明它们均为喜光植物;10个秋菊品种的CO2饱和点为1 060.46 ～1 485.48μmol·mol-1,CO2补偿点为77.62 ～ 133.16μmo1·mol-1,远大于一般的C3植物;各品种Pn的日变化呈典型的双峰型曲线,首峰(11～19μmol·m-2·s-1)出现在10:00左右,次峰出现在16:00左右,有明显的“午休”现象.相关分析结果表明:10个品种的Pn与气孔导度呈极显著正相关,与蒸腾速率呈显著或极显著正相关(品种‘关东新侠’、‘云龙凤舞’和‘日本黄’除外),与胞间CO2浓度呈显著或极显著负相关,与光合有效辐射强度和大气温度呈不显著正相关,与大气相对湿度和大气CO2浓度呈不显著负相关.早花品种‘太平的小鼓’和‘铜雀春深’具有较高的LSP以及较低的LCP和表观量子效率(AQY),对光照强度的适应范围较大,可栽培在光照较强的环境中;品种‘早粉盘’和‘檀香狮子’具有较高的LCP、AQY和LSP,对强光的利用能力较强;晚花品种‘关东新侠’、‘绿牡丹’和‘星光灿烂’具有较高的LCP和AQY以及较低的LSP,具有一定的耐阴能力,可种植在光照较弱的环境中.     

自然群落中柏达木种群光合产量与光强气温关系的初步研究

关于植物种群的光能利用,植物生产力和净同化率等近年来有不少研究,但其中除了研究植物个体的净同化率外,多为农作物等草本植物群落或者用林业采收法的研究。对于自然木本植物种群及其不同层的植物与光、温度分配关系中用测定光合作用方面的研究工作还不多。 光合作用强度的测定,目前多用离体叶片或盆栽植物进行或者用收集落叶量与砍伐林木     

不同遮荫条件下罗布麻光合特性的初步研究

用便携式光合测定仪和叶绿素荧光仪测定了不同遮荫条件下罗布麻叶片的光合参数和叶绿素荧光参数.结果显示:遮荫50%和70%处理较全光照的罗布麻叶片净光合速率(Pn)、蒸腾速率(Tr)和光饱和点(LSP)分别降低47%和65%、45%和68%、20.41%和37.45%,而表观量子效率(AQY)分别提高33%和36%;不同遮荫下罗布麻的叶绿素荧光参数PSⅡ原初光能转化效率(Fv/Fm)和PSⅡ潜在活性(Fv/Fo)均比全光照降低.研究表明,罗布麻虽对弱光有一定适应能力,但遮荫仍产生明显的弱光抑制而显著降低其光合效率,影响其正常生长.     

A Study on the Relationship Between the Net Photosynthetic Rate of Young European Beech and Main Climatic Factors Under Natural Conditions

Young European beech lives under the blank of European beech mature forest. Its photosynthetic rate was significantly affected by climatic factors. This paper deals with the effect of climatic factors on diurnal variations of the net photosynthetic rate,photosynthetic capacity,lightphocosynthesis curve and temperature effect of net photosynthetic rate under different radiations. The results are as follows:the climatic factors have greater influence on diurnal variations of the net photosynthetic rate. The influence coefficient of radiation,temperature and relative humidity on photosynthetic capacity are 0. 51, 0. 22. and 0. 17,respectively. The light-photosynthesis curve is Y= 1. 49273–1. 58993 × 0. 09328(0.01x). The optimum combination of environmental conditions of photosynthetic rate under natural conditions is:the radiation is more than 45 μE · m-2 · s-1 and meantime the temperature is between 10℃ and 20℃.     

内蒙古高原甘蒙锦鸡儿光合作用和水分代谢的生态适应性研究

 对分布于内蒙古高原和林格尔和阿拉善的甘蒙锦鸡儿（Caragana opulens）种群的光合特性和水分代谢特性进行了比较研究。结果发现：和林格尔种群的光补偿点（500 μmol proton·m-2·s-1以下）、光饱和点（1 200 μmol proton·m-2·s-1）、光合最适温度（26 ℃）均低于阿拉善种群（光补偿点为700～800 μmol proton·m-2·s－1之间;光饱和点为1 500 μmol proton·m－2·s－1;光合最适温度为28～29 ℃）,在低温、低光强下表现出更高的光合速率;和林格尔种群比阿拉善种群需要更高的空气湿度来维持其光合速率;和林格尔种群表现高蒸腾、高光合和低水分利用效率的代谢特点,阿拉善种群采取低蒸腾、低光合和高水分利用效率的节水对策。这些生理特性与它们分布区的光、温、湿条件相适应。阿拉善种群的净光合速率、蒸腾速率和光能利用效率远低于和林格尔种群,而水分利用效率和叶水分亏缺明显高于和林格尔种群。这主要是由于两地区水分状况差异引起的。     

海南红豆（Ormosia pinnata)夏季叶片气体交换，气孔导度和水分利用效率的日变化

对野外海南红豆叶片的气体交换、气孔导度和水分利用效率及其相应环境因子的日变化进行测定的结果表明：夏季７月叶片净光光合速率和蒸腾速率的日变化曲线呈双峰型,前者的变化主要受光控制,与气温、叶温和湿度的关系不明显;后者与光、气温和叶温成正相关,与湿度成负相关,气孔导度对湿度的敏感性比对光和温度明显很多。分析结果显示,气孔导度和光合速率受环境因子的响应是相对独立的,海南红豆的水分利用效率最高值出现在上午较     

大兴安岭重度火烧迹地天然次生林土壤温室气体通量及其影响因子

为研究大兴安岭重度火烧迹地自然恢复后的林分土壤温室气体源汇强度及其影响因素,采用静态箱/气相色谱法,对生长季(6—9月)天然次生林土壤温室气体CO₂、CH₄、N₂O通量进行原位观测.结果表明: 1)生长季内天然次生林土壤为大气CO₂、N₂O的源,CH₄的汇,平均通量分别为575.81 mg·m^-2·h^-1、17.81 μg·m^-2·h^-1和-68.69 μg·m^-2·h^-1;CO₂与CH₄通量在生长季内表现出明显的双峰变化规律,N₂O通量则呈单峰变化,且均在8月达到观测期的最大值.2)土壤温度是影响该区天然次生林土壤温室气体通量的主控因子,土壤湿度和大气湿度在昼夜与季节尺度上与土壤温室气体通量的相关性不同.3)该区天然次生林9:00—12:00时段观测获得的土壤气体通量值经矫正后可代表当日气体通量.研究补充了大兴安岭火烧迹地森林生态系统温室气体通量数据,为该区土壤温室气体源汇的相关研究提供了依据.     

The Effect of Light Intensity and Relative Humidity on Growth Rate and Root Respiration of Plantago lanceolata and Zea mays

Plants of Plantago lanceolata L. and Zea mays L., cv. ‘Campo’were grown at two levels of light intensity. Especially in theroots, the rate of dry matter accumulation decreased at lowlight intensity. The carbohydrate content of both roots andshoots of P. lanceolata was not affected by light intensity.The relative contribution of SHAM¹-sensitive respiration, thealternative chain, to total root respiration of both P. lanceolataand Z. mays, was not affected by light intensity during thedaytime. The alternative pathway was somewhat decreased at theend of the dark period, but not in the root tips (0–5mm) where it still contributed 56% in respiration. It was, therefore,concluded that photosynthesis is not a major factor in regulationof root growth in the species investigated. To see whether the effect of light intensity on root growthrate was via transpiration, plants of Z. mays were grown atdifferent air humidities. Both high humidity and low light intensityaffected the root morphology in such a way that the distancebetween the apex and the first laterals on the primary rootaxis increased. It is suggested that this effect on root morphologyis due to transpiration and the subsequent removal of root-producedinhibitors of lateral root growth; although light intensityalso affected the rate of dry matter accumulation of roots andthe rate was not affected by the humidity of the air. It is,therefore, concluded that the effect of light intensity on therate of dry matter accumulation of roots of Z. mays is not viaan effect on transpiration.     

河西地区几种中生植物的蒸腾和传导率与叶内外环境的关系

用LI-1600稳态气孔仪,测定了河西地区分布较广的五种木本植物的蒸腾和传导率及环境因子。只要光照不低于气孔开启所需的强度,植物蒸腾率最高点之前的高低变化与叶温上升的速率无关,而仅与每一时刻叶温高低密切相关。在种内,蒸腾率大致随叶的厚度和单位叶面积的栅栏组织表面积的增大而提高。但种间则无此相关性。同一样本叶的上下表面蒸腾率之比与其气孔数之比相对应,而种间则毫无关系。环境条件大致相同情况下,二白杨(Populus kansuensis)全天蒸腾量为78.2gH2O·dm-2,沙枣(Elaeagnus angustifolia)为40,4gH2O·dm-2。分别是箭杆杨(P.nigra var.thevestina)的2.5和1.3倍。同一灌溉条件下,梨光杏(Prunus armeniaca var.glabra)为26.7gH2O·dm-2,比毛杏(P.armeniaca var.ansu)高0.6倍。     

Influence of NaCl, Cd(NO3)2 and air humidity on transpiration of Tamarix aphylla

Transpiration rates of young Tamarix aphylla (L.) Karst, plants grown in hydroponics were measured under NaCl- and Cd(NO₃)₂-stress. Transpiration rates were negatively correlated with the relative humidity of the ambient air at all NaCl concentrations investigated. Low and intermediate concentrations of Cd²⁺ (45 and 90 μ M , respectively) in the medium caused an increase in transpiration rates. This was particularly pronounced at low levels of relative humidity. At 180 μ M Cd²⁺, transpiration rates dropped, probably as a result of root damage due to Cd²⁺ toxicity. Since the transpiration rates differed by a factor of ca 3 between day and night, it is concluded that the stomata did not lose their ability to regulate transpiration under the influence of NaCl or of Cd(NO₃)₂. The transpiration behaviour of T. aphylla indicates that the effect of water vapour pressure (presented as relative humidity) on the degree of stomatal opening is small. Under conditions of ample water supply transpiration follows the evaporative demand of the ambient air and is influenced by the water uptake capacity of the root system as well as by other environmental factors, e.g. light.     

桂林岩溶区青冈栎光合速率与环境因子关系初步研究

在自然条件下,对桂林岩溶区青冈栎光合速率与环境因子的关系研究表明,初夏季节青冈栎蒸腾速率日变化为"单峰"曲线,光合速率日变化为"双峰"型曲线,午间光合速率明显降低。青冈栎光合"午休"主要由气孔导度降低引起;通径分析表明,环境因子中空气相对湿度和空气温度对青冈栎光合速率直接影响最大;光合有效辐射对青冈栎光合速率直接影响不显著,而主要是通过其它因子间接影响光合速率。