坐果期不同灌溉条件下枣树光合特性研究

通过测定井式灌溉(T1)、地表滴灌(T2)和对照漫灌(CK)条件下中龄灰枣光合生理指标的日变化,探索不同灌溉方式下枣树的光合特性。使用Li-6400便携式光合测定仪测定3种灌溉方式下中龄灰枣的光合特性日变化并进行分析比较。结果表明:(1)3种灌溉方式下中龄灰枣的净光合速率(Pn)、气孔导度(Cond)和蒸腾速率(Tr)的日变化均呈"双峰型"曲线,有明显的光合"午休"现象;(2)3种灌溉条件下中龄灰枣的水分利用效率(WUE)在上午8:00之后逐渐下降;(3)3种灌溉条件下中龄灰枣光能利用率(LUE)8:00后逐渐下降,18:00后又逐渐升高;(4)T1条件下中龄灰枣的Pn、WUE较T2条件下有显著性差异,与CK条件下有极显著差异。LUE表现为在T1较T2和CK条件下均存在极显著差异。而各灌溉条件下其他光合参数则无显著性差异。与其他灌溉方式相比,井式灌溉有较高的Pn、WUE、LUE、Ci、胞间CO2浓度(Cond)和较低的Tr、气孔限制值(Ls)。     

思茅松干季光合生理日动态及光响应特征分析

采用Licor-6400型便携式光合测定仪测定了思茅松干季的光合作用日变化及光响应特征,分析了光合生理与生态因子之间的相互关系.结果表明:思茅松净光合速率(Pn)、蒸腾速率(Tr)和水分利用效率(WUE)的日变化均呈三峰曲线,Pn峰值分别出现在12:00、14:00和17:00,最高峰出现在光强最强、温度最高的时刻(14:00),胞间CO2浓度(Ci)变化方向则相反.Pn、Tr和气孔导度(cond)与主要环境指标光合有效辐射(PAR)、空气温度(Ta)和大气相对湿度(RH)之间的关系符合二次曲线的变化规律.Pn、Tr与PAR、Ta和RH的相关程度都达到了极显著水平(P<0.01),Coind与Ta相关程度达到显著水平(P<0.05).PAR是影响干季思茅松Pn和Cond最主要的环境因子,而Tr是受Ta影响最强烈的生理因子.非直角双曲线拟合的思茅松光饱和点(LSP)为1800μmol·m-2·s-2左右,表现为典型的阳性树种.     

淹水胁迫下美洲黑杨新无性系光合特征的变化

以美洲黑杨I-69、XL-75、XL-77、XL-90及苏柳J172为研究对象,采用盆栽育苗并实行人工淹水胁迫处理,测定不同淹水胁迫条件下各无性系光合特征,分析各光合生理指标的变化规律、相互关系及其与环境因子的关系。结果表明:淹水胁迫下各无性系Pn、Tr、Cond、Ci均表现出先随淹水胁迫快速下降,至30 d或45 d时略有回升的趋势,其中4个美洲黑杨无性系淹水胁迫时Pn、Tr、Cond在不同无性系之间、淹水与不淹水对照之间均存在显著差异(a=0.01),4个杨树无性系中,以I-69杨下降幅度最大,其Pn下降89.91%~91.98%、Tr下降91.78%~95.27%、Cond下降96.30%~97.41%。Ci在淹水胁迫时下降幅度明显不及Pn,表明淹水胁迫下Pn降低是气孔限制与非气孔限制因素共同作用的结果。水分利用效率WUE随淹水胁迫的进行先上升、后下降,但均高于不淹水对照。叶片蒸汽压亏缺值Vpdl随淹水胁迫程度加深明显上升。对净光合速率与其他光合生理指标及环境因子关系进行了分析。     

施氮水平对4个景观树种光合特性及抗旱性影响

为探讨施氮水平对景观树种光合特性的影响及其抗旱性提升方面的应用潜力,以深山含笑、秋枫、美丽异木棉、紫薇为研究对象,采用盆栽法,测定并分析了0、0.4、0.8、1.2、1.6 g/L硝酸铵处理下4个树种幼苗的光合参数及其对干旱胁迫下施用0、0.4、0.8、1.2 g/L硝酸铵的生长、生理响应差异。结果显示：(1)各施氮水平对各树种幼苗叶片净光合速率(Pn)日变化趋势无明显影响,其中深山含笑、紫薇存在光抑制现象;施氮显著影响了4个树种幼苗叶片Pn、蒸腾速率(Tr)、气孔导度(Gs)、胞间二氧化碳浓度(Ci)、叶绿素含量(Cc),且存在“低促高抑”的现象。(2)Pn与Tr呈极显著正相关线性关系,Pn、Tr分别与Gs呈显著正相关线性关系,Pn与Ci、Cc均无明显相关性(P>0.05),但Ci与Cc显著线性正相关。(3)在40%土壤含水率条件下,供试4个树种幼苗均遭受到了干旱胁迫,幼苗存活率下降,生物量增量降低,叶片水分亏缺率增大,Pn、Tr、Gs、Ci、Cc减小,超氧化物歧化酶活性减弱,丙二醛含量升高。(4)采用11个指标进行评价,干旱胁迫下深山含笑、紫薇以0.8 g/L硝酸铵处理的生长...     

5个苦楝无性系光合特性的初步研究

为深入了解苦楝无性系光合生理特性,比较不同无性系叶片光合参数的差异。本文以5个苦楝优良无性系为参试对象,用Li-6400便携式光合作用测定仪测定叶片净光合速率(Pn)、气孔导度(Gs)、叶片蒸腾速率(Tr)和胞间CO2浓度(Ci),并进行分析比较。结果表明:参试苦楝无性系胞间CO2浓度(Ci)和生理水分利用率(WUE)存在极显著差异;叶片净光合速率(Pn)和叶片蒸腾速率(Tr)存在显著差异;气孔导度(Gs)差异不显著。苏楝J104、苏楝J7和苏楝J61净光合速率(Pn)较大,其中苏楝J61生理水分利用率(WUE)较高。     

NaCl胁迫对5个树种幼苗光合作用特性的影响

以厚叶榆、木栓榆、黄连木、醉翁榆和榉树等1年生盆栽苗为研究对象,测定其在不同浓度NaCl胁迫下的光合作用指标,结果表明:(1)NaCl胁迫初、中期,随着浓度的增大和胁迫时间的延长,各种幼苗的净光合速率(Pn)、气孔导度(Cond)、胞间CO2浓度(Ci)和蒸腾速率(Tr)均呈下降趋势。叶面水气压亏缺(Vpdl)均有增加趋势,但增幅不明显。(2)NaCl胁迫后期,随盐分浓度的增加和时间的延长,Pn、Cond和Tr呈逐渐降低的的趋势,且降幅明显高于初期和中期。(3)5个树种树幼苗Pn的下降在盐胁迫初、中期是气孔限制的结果,后期为非气孔限制和气孔限制共同作用的结果。(4)不同的NaCl浓度与Pn、Cond、Ci和Tr呈负相关,与Vpdl呈正相关。在盐胁迫不同时期,醉翁榆Vpdl与NaCl浓度均呈显著或极显著的相关性;厚叶榆和木栓榆在初期和中期与NaCl浓度的相关性不显著,但后期相关性达到显著或极显著的水平;黄连木在初期与NaCl浓度的相关性不显著,中后期相关程度达到显著,而榉树在整个盐分胁迫期间Vpdl与不同的NaCl浓度均不显著相关。     

不同林龄山桃光合参数特征及光响应研究

山桃作为干旱半干旱地区的主要造林树种,为了促进其发展利用,利用LI-6400XT光合仪测定不同林龄山桃叶片光合速率(Pn)、气孔导度(Gs)、胞间CO_2浓度(Ci)、蒸腾速率(Tr)、水分利用效率(WUE)等光合参数,并通过直角双曲线修正模型对光响应曲线进行拟合。结果显示:2年生山桃的Pn、Tr较高,而WUE较低,说明其生长速度快,蒸腾耗水较多但抗旱性较差,生长期间需要更多的水分补充。通过对最大光合速率(Pm)、暗呼吸速率(R_d)、光补偿点(L_c)和光饱和点(L_m)的比较分析,可以看出2年生山桃对弱光适应能力较好,但要满足山桃的正常生长需求,光照强度应大于1 300.0μmol·m~(-2)·s~(-1)。     

金森女贞光合生理特性的研究

研究了金森女贞光合生理日变化及其光补偿点和饱和点.结果表明:金森女贞的单日净光合速率(Pn)呈双峰曲线,出现"午休"现象,造成Pn下降的主要原因是非气孔因素.蒸腾速率(Tr)和气孔导度(Gs)的变化趋势与Pn相似,胞间CO2浓度(Ci)与之相反.Pn与Ci和PAR的相关性达到极显著水平,Tr与PAR、RH和VPD均达到极显著水平.金森女贞的光补偿点(LCP)为16.67 μmol/(m2·s),饱和点(ISP)约为1 000 μmol/(m2·s),属于阳性植物.     

晚实清香核桃光合特性及其影响因子分析

使用Li-6400光合仪,以晚实清香核桃为研究对象,在自然条件下测定了其光合参数变化规律。结果表明:清香核桃Pn日变化为典型双峰曲线,在12:00左右出现明显的光合"午休"现象,且中午Pn的下降是由非气孔限制引起,光合参数与环境因子间表现出显著或极显著相关性,其中,Pn与PAR呈极显著正相关,与Tr、Gs显著正相关,与Ci、Ta显著负相关。该试验为‘清香’核桃光合特性的后续研究提供了依据。     

三种豆科树种光合特性比较

以长春地区三种豆科树种为试材探索其光合特性差异,为高产栽培应用提供依据。用便携式光合作用仪测光合指标,分光光度计测叶绿素含量。三种豆科树种的Pn日变化均呈双峰曲线,“午休”现象明显。相关性分析表明,刺槐、香花槐的PAR与Pn、Gs与Pn、PAR与Gs均呈显著正相关（P<0.01）;刺槐的Tr和Ci呈显著正相关（P<0.01）,香花槐的Tr和Ci呈显著正相关（P<0.05）。相同的PAR水平下,Pn表现：刺槐>香花槐>青皮槐,光的利用能力：青皮槐>香花槐>刺槐。     

干旱半干旱地区主要树种叶片水分利用效率研究综述

树种选择是干旱、半干旱地区森林植被恢复与重建的关键环节, 而水分利用效率(WUE)是表征树种抗旱性和水分利用特征的基本生理参数, 是目前树种选择研究中的一个热点和难点问题。文中在介绍树木叶片WUE概念和研究方法的基础上, 从树木叶片WUE在树种和生活型之间的差异和时空变化规律及其对光照、水分、温度、CO₂和O₃浓度等环境因子的响应等方面阐述了干旱、半干旱地区主要树种叶片WUE研究的进展情况, 指出目前树木叶片WUE研究中存在的问题及今后研究展望。     

Review on Leaf Water Use Efficiency of Major Trees Species in Arid and Semi-Arid Area

The tree specie selection is the critical part in the process of vegetation restoration and reconstruction in arid and semi-arid areas.As a reliable indicator of drought resistance and water use characteristics of tree species,water use efficiency（WUE） has become a hotspot in the research on tree specie selection.This paper introduced the concept and correspondingly research method of leaf WUE and summarized the research progress of leaf WUE in terms of the variation in leaf WUE between species,positions in the canopy,and characteristics of temporal and spatial variation,its influence on environmental factors like illumination,moisture,temperature, CO₂ and O₃ concentrations.Furthermore,it put forward the problems currently existing in the research and prospected the trend of future research on leaf WUE.     

Tree species composition influences differences in water use efficiency of upland forested microwatersheds

Water use efficiency (WUE) was compared in three upland South Moravian forested microwatersheds in the light of effects of global climate change on forest ecosystems (GCC). The experimental catchments were characterized as upland headwater forested microwatersheds of similar size and morphology and silvicultural system, but each with different dominant tree species in the stands (over 50% of forest stand composition in living stock): Norway spruce, European beech and mixed forest. WUE was evaluated according to mean daily streamflow reduction, measured at the discharge points of the recipients of the individual catchments in precipitation-free periods lasting more than 5 days. During these times, streamflow dynamics are mainly influenced by evapotranspiration processes occurring in the forest stands. Four precipitation-free periods were observed, two in the middle of the growing season and two at its end. Two of these periods were long (15 days or more), and two were shorter (6 days). The results indicated that WUE of upland forested catchments can be very different, depending upon the dominant tree species and the seasonal phase. Highest WUE at the catchment scale (never decreasing below 80%) was exhibited by beech predominating site. WUE of mixed forest was high as well, never decreasing below 69%. The lowest WUE was exhibited by spruce predominating site, especially during a long precipitation-free period in the summer where it decreased down to 39%. In the context of the landscape, upland microwatersheds with pure spruce stands could cause its accelerated dry out in the summer and pose a significant threat to sustainable water and forest management of these areas. In comparison, mixed forests stands where spruce is not the dominant species or beech stands should still be a viable option even under the effects of GCC.     

木荷等6种阔叶树种光合生理特性比较

在东江中上游,对6年生木荷、红锥、火力楠、藜蒴、灰木莲和枫香的净光合速率（Pn）、蒸腾速率（Tr）、水分利用效率（WUE）等生理生态指标开展观测研究,结果表明：8月,6种树种均表现较强的生活力,保持了较高的净光合速率与蒸腾速率;10月,6树种均通过降低光合、蒸腾和提高水分利用效率来适应逆境。8月平均Pn和Tr要比10月均值分别高71.86%和129.22%,10月WUE却要比8月均值高25.78%。6树种Pn、WUE的平均值高低排序,均表现为木荷〉红锥、藜蒴和火力楠〉枫香和灰木莲,说明木荷有较强的环境适应能力和抗旱能力,其次为红锥、火力楠和藜蒴,而灰木莲和枫香较低。     

哈尔滨市6种绿化树种生理特性比较

为了全面了解各绿化树种的生理生态特性,增加哈尔滨市园林绿化树种及其生态功能的多样性,为绿化树种的选择提供理论依据。对东北乡土树种白桦、蒙古栎、糠椴、紫椴、茶条槭和黄檗二年生幼苗的生理指标进行测定,通过这6种树种生理指标的研究,对各树种的适宜应用作综合的评价分析,结果表明：这6树种最大光合速率分别为：茶条槭9.70μmolCO2/m^2·s,白桦7.67μmolCO2/m^2·s,黄檗5.88μmolCO2/m^2·s,紫椴5.51μmolCO2/m^2·s,糠椴5.20μmolCO2/m^2·s和蒙古栎4.04μmolCO2/m^2·s。6树种之间呼吸速率的差异不显著,平均为1.01μmolCO2/m^2·s。水分利用效率的种间差异较大,茶条槭、糠椴和蒙古栎高于黄檗、紫椴和白桦。所以从生态园林的角度,在水分短缺的地点,选择绿化树时应先考虑水分利用效率高的茶条槭、糠椴和蒙古栎,而在土壤水分条件较好的可适当优先考虑净光合能力强的树种。     

Carbon isotope discrimination and oxygen isotope composition in clones of the F(1) hybrid between slash pine and Caribbean pine in relation to tree growth,water-use efficiency and foliar nutrient concentration

The objectives of this study were: (1) to examine how foliar carbon isotope discrimination (Delta) and oxygen isotope composition (delta(18)O) are related to tree growth, ash mineral nutrient concentration and foliar nutrient concentration in 7-year-old clones of the F(1) hybrid between slash pine (Pinus elliottii Engelm.) and Caribbean pine (P. caribaea var. hondurensis Barr. et Golf.) in subtropical Australia; and (2) to evaluate the potential of using foliar Delta, ash mineral nutrient concentration and delta(18)O measurements for selecting F(1) hybrid pine clones with high water-use efficiency (WUE) and growth potential. There were significant differences in tree growth, foliar Delta, delta(18)O and ash mineral nutrient concentration among the eight clones tested. Significant negative linear relationships existed between tree growth and Delta, extrapolating to zero growth at Delta = 24-30 per thousand. There were strong genetic correlations (r = -0.83 to -0.96) between Delta and tree growth, particularly tree height. Significant non-genetic correlations (r = -0.62 to -0.80) existed between Delta and foliar K concentration. Foliar delta(18)O, ash mineral nutrient concentration and foliar nutrient concentration were unrelated to tree growth. In the F(1) hybrid pine clones, variation in tree WUE, as reflected by Delta, was largely attributed to a genetic effect on leaf photosynthetic capacity rather than on stomatal conductance, as reflected by foliar delta(18)O.     

冀北山地3种典型林分类型物种多样性研究

以围场县木兰林管局3种典型森林植被类型为研究对象,从乔木层、灌木层和草本层分别对其物种数和多样性进行了比较。结果表明:落叶松桦木混交林内植物种类有56种,山杨桦木混交林内有53种,油松蒙古栎混交林有44种,乔木层物种多样性差别不明显,灌木层生物多样性指数总体上油松蒙古栎混交林>山杨桦木混交林>落叶松桦木混交林。草本层生物多样性指数除Simpson指数外,其他3个指数规律一致,即油松蒙古栎混交林>山杨桦木混交林>落叶松桦木混交林。     

Ontogenetic changes in water-use efficiency (δC) and leaf traits differ among tree species growing in a semiarid region of the Loess Plateau,China

On the Loess Plateau, China, several planted tree species such as Populus hopeinsis and Robinia pseudoacacia suffer occasional diebacks in the top shoots, reducing growth rates after maturation. However, this does not usually occur in other species, e.g., Ulmus pumila and Zizyphus jujuba. We compared stable carbon isotope ratios (δ¹³C) as indicators of leaf water-use efficiency (WUE), leaf mass per unit area (LMA), and leaf area- and mass-based nitrogen content (N_area and N_mass) by tree height (1, 5, and 10 m) in P. hopeinsis, R. pseudoacacia, U. pumila, and Z. jujuba. In P. hopeinsis and R. pseudoacacia, leaf δ¹³C and N_area were significantly lower in 10-m trees than in 1-m saplings, indicating that leaf WUE and photosynthetic rates of both species decreased with tree height. In contrast, δ¹³C in Z. jujuba varied little with tree height. The δ¹³C of 10-m-tall U. pumila trees was significantly higher than that of 1-m plants, demonstrating an increase in WUE with tree height. Decreasing WUE, leaf N_area, and N_mass with height increases in P. hopeinsis and R. pseudoacacia may be related to water and nutrient limitations for these species in semiarid regions. In contrast, stable or increasing δ¹³C with tree height in U. pumila and Z. jujuba may account (to some extent) for successful production of these species under identical environmental conditions. Diameter growth rate also decreased with maturity in P. hopeinsis and R. pseudoacacia, but increased or was stable for U. pumila and Z. jujuba. The differences in leaf WUE and LMA among species with tree maturity may be related to species’ growth patterns and susceptibility to drought stress, and are likely to be important new criteria for plantation species selection on the Loess Plateau.     

Comparison of drought resistance among Prunus species from divergent habitats

Root and shoot characteristics related to drought resistance were compared among cultivated peach (Prunus persica (L.) Batsch.), P. andersonii (Nevada Desert almond), P. besseyi (western sand cherry), P. maritima (beach plum), P. subcordata (Sierra or Pacific plum), and P. tomentosa (Nanking cherry). In all species, shoot characteristics were more closely associated with drought adaptation than root characteristics. The most xeric species, P. andersonii, had the lowest specific leaf area, smallest leaves, highest stomatal conductance (before stress), highest rate of carbon assimilation (A), high root length/leaf area and root weight/leaf area ratios, and the highest leaf nitrogen content on an area basis. Root hydraulic conductivity was similar for all species, indicating a lack of importance of this parameter for drought resistance. During a 5-7 day drought, water use efficiency (WUE) increased as shoot water potentials (Psi) declined to -3.0 to -4.0 MPa for the xeric P. andersonii and P. subcordata, whereas after an initial increase, WUE decreased with declining Psi in the -1.5 to -3.0 MPa range for the more mesic P. maritima, P. persica and P. tomentosa as a result of non-stomatal limitations to A. Carbon assimilation rate decreased linearly with Psi during drought in all species, but the Psi at which A reached zero was not associated with drought adaptation. We conclude that the variation in leaf characteristics among Prunus species could be exploited to improve the drought resistance of commercial cultivars.     

不同生境下厦门城市绿化树种光合作用的日变化特性分析

用LI-6400红外气体分析仪对厦门市不同生境条件下城市绿化树种的光合特性进行测定,结果表明:在全光照条件下的树种在不同时间段净光合速率均强于受城市环境影响树种,午休现象不明显,而受光照、水分和温度等城市环境胁迫影响,城市中绿化树种逐渐适应在弱光条件下进行光合作用.树种间的光合特性与能力存在明显差异,在光能利用率水平上...