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元谋干热河谷区9种造林树种的水分生理特性比较 总被引：1，自引：0，他引：1
１９９３～１９９８年对元谋干热河谷区的９个造林树种的水分生理特性进行了观测。经对各观测树种水分状况、保水能力、蒸腾速率的分析对比表明：多数相思类树种主要通过减少叶子蒸腾耗水以提高其抗旱能力,蒸腾强度小有利于这些树种渡过旱季。乡土树种坡柳和桉类树种（除大叶桉）旱季蒸腾作用比较强烈,但离体叶片失水速度不快,它们具有特殊的水分平衡机制和较强的水分吸收能力,以此增强对干热河谷环境的适应性。此项研究为正确选择元谋以至金沙江干热河谷地区的适宜造林树种,以及人工林的水分管理措施提供了理论依据。 相似文献
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在全球变化的背景下,氮沉降现象普遍,降水分布不均,干旱变得更加频繁,植物对环境变化的响应与适应已成为亚热带地区研究的热点生态学课题之一。以亚热带珍贵常绿阔叶树种刨花楠(Machilus pauhoi)为对象,探讨不同氮磷比及水分添加对其光合生理特性各指标的影响。结果表明:(1)水分对刨花楠净光合速率(P_n)、光补偿点(LCP)、蒸腾速率(T_r)有显著影响,干旱胁迫下(田间持水量为40%)的刨花楠的P_n、LCP和T_r会明显下降,与正常水分条件(田间持水量80%)相比,P_n下降了52%,LCP下降了72%,T_r下降了38%;而水分对光饱和点(LSP)、气孔导度(G_s)、胞间CO_2浓度(Ci)、水分利用效率(WUE)无显著影响;(2)不同氮磷添加对P_n、LSP、LCP、G_s、C_i、WUE等光合生理特性指标无显著影响。 相似文献
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对云南乡土树种车桑子(Dodonaea viscosa)在云南干热河谷旱季期间的光合水分生理特性进行了研究,研究结果表明:(1)车桑子在严重的缺水胁迫下,所产生的光合午休现象主要是由非气孔限制因素光抑制引起的,其保护光合机构免受损伤;(2)车桑子在严重的缺水胁迫下,即在PAR仍不低于1 300 umol.m-2.s-1的情况下,其Pn达到很高水平,仍能维持基本的光合生理能力。表明车桑子在干热河谷的干旱季节对缺水胁迫和高光强有很强的适应能力。 相似文献
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１９９３－１９９８年对元谋干热河谷区的９个造林树种的水分生理特性进行了观测。经对各观测树种水分状况、保水能力、蒸腾速率的分析对比表明;多数相思类树种主要通过减少叶子蒸腾耗水以提高其抗旱能力,蒸腾强度小有利于这些树种渡过旱季、乡土树种坡柳和桉类树种旱季蒸腾作用比较强烈,但离体叶片失水速度不快,它们具有特殊的水分平衡机制和较强的水分吸收能力,以此增强对干热河谷环境的适应性,引项研究来正确选择元谋以至金 相似文献
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植物水势是植物水分生理研究最常用的指标之一。作者对植物水势的研究与应用状况进行了综述,提出利用植物水势,结合气孔导度、相对含水量、水分利用效率等生理指标,对我国主要物种,特别是森林树种的等水/变水行为特征进行深入研究,为确定合理灌溉指标、人工林营造及生态系统保护等提供理论依据。 相似文献
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马尾松是我国南方生态恢复与重建的先锋树种,具有耐干旱、耐贫瘠及速生丰产等优点,其人工林在我国森林资源总量中占举足轻重的位置,但纯林的养分循环差,易导致生产力低下;而研究马尾松光合生理特性及资源利用效率可以为马尾松人工林生产力的提高提供坚实的理论基础。文中综述马尾松光合生理特性及资源利用效率的研究进展,分析逆境胁迫对其光合生理特性及资源利用效率的影响,包括水分胁迫、热胁迫、酸雨胁迫、低磷胁迫及铝胁迫等。在全球变化背景下,研究马尾松光合生理特性与资源利用效率及其对逆境胁迫的响应,对于制定马尾松的管理与保护策略、挖掘其抗性潜力具有重要意义,可为马尾松林分生产力的提升及纯林改良策略的制定提供理论参考。 相似文献
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木麻黄栽培生理生态学研究进展 总被引：5，自引：1，他引：4
木麻黄是重要的防风固沙、用材和薪材树种，近年来在栽培生理生态学领域上的研究取得了较大进展。本文对木麻黄光合生理、水分生理、固氮生理以及木麻黄与气候、立地的关系和生态系统研究等方面进行了评述，并分析了木麻黄栽培生理生态学研究的现状、存在问题和发展方向。 相似文献
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短期干旱和复水对麻栎幼苗光合及叶绿素荧光的影响 总被引：2，自引：0，他引：2
麻栎是鲁中山区森林植被恢复的重要阔叶树种之一,本文以1年生麻标幼苗为试验对象,研究短期干旱和复水对其光合及叶绿素荧光等生理生态特征的影响。结果表明：在干旱胁迫初期,干旱组的各项指标均优于对照组,说明过高的土壤含水量并不利于麻栎幼苗的生长;随着土壤干旱程度的进一步加剧,幼苗的气孔导度减少,导致光合和蒸腾作用的下降,水分利用效率升高;胁迫末期各项光合指标均降到最低。从叶绿素荧光参数可以看出,干旱胁迫并未使幼苗的光合机构发生伤害,幼苗在适宜的水分条件时产生光合能力上调,当水分匮缺时,以叶黄素循环为主的非光化学淬灭耗散掉过剩的光能达到保护光合机构的目的。复水后麻栎幼苗的各项生理生态指标恢复正常,但气孔导度的增大存在一定的滞后效应,导致了水分利用效率的反冲,同时叶黄素库仍然维持较高水平,麻栎幼苗通过物理和化学的双重保护来抵御干旱胁迫和进行胁迫后的恢复。 相似文献
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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... 相似文献
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用隶属函数法对大田贵竹林废弃矿区引入的10种植物的生长和生理指标进行分析。结果显示：废弃矿区植物叶片的叶绿素含量及其光合特性在种间亦存在极显著差异（P〈0.01）,表明不同植物对废弃矿区的适应是存在差异的。利用隶属函数法分析表明,邓恩桉、香樟和泡桐是废弃矿区最适宜栽植的树种,可作为废弃矿区恢复的先锋树种予以大力推广。 相似文献
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竹类植物光合特性与叶片功能性状研究 总被引：1，自引：0，他引：1
光合作用指标作为植物重要生理特性指标,受植物自身遗传特性与周围环境因素影响。植物叶片功能性状反映植物遗传特性以及植物适应周围环境变化的响应对策。因此,研究植物叶片功能性状指标与光合特性参数之间的相关性,具有重要的生理意义和应用价值。竹类植物作为地球陆地生态系统重要组成部分,对竹类植物光合特性与叶片功能性状的研究可为竹子经济栽培、经营管理、合理利用提供理论依据。文中总结了竹种光合特性已有研究成果,归纳影响竹子光合作用的影响因子,评述竹类植物叶片功能性状的研究内容及其对周围环境的响应,探讨竹类植物光合特性与叶片功能性状之间的相关性,并在此基础上提出了竹类植物光合特性与叶片功能性状研究展望。 相似文献
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以2 a生金蒲桃(Xanthostemon chrysanthus)幼苗为材料,研究了全光照,50%遮阴,70%遮阴,90%遮阴4种遮阴处理对金蒲桃生长特性、生物量分配、光合生理变化的影响,结果表明:与自然光全处理对比,遮光极显著(P<0.01)地抑制了金蒲桃幼苗生物量的积累,遮光处理组叶片数量减少,叶生物量比下降,茎生物量比增加;光补偿点、光饱和点、暗呼吸速率和最大光合速率降低,光能利用效率低于全光照叶,强光下遮阴叶的净光合速率保持稳定.上述结果说明:遮阴处理后,金蒲桃在生长特性、生物量分配和光合参数上表现出对遮阴弱光的适应,表明金蒲桃是一种能广泛应用于各种光照条件的优良景观树种. 相似文献
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Tree species response to climate change-induced shifts in the hydrological cycle depends on many physiological traits, particularly variation in water relations characteristics. We evaluated differences in shoot water potential, vulnerability of branches to reductions in hydraulic conductivity, and water source use between Pinus contorta Dougl. ex Loud. var. latifolia Engelm. (lodgepole pine) and Pseudotsuga menziesii (Mirb.) Franco (interior Douglas-fir), and determined the consequences for seasonal changes in photosynthetic capacity. The Douglas-fir site had soil with greater depth, finer texture and higher organic matter content than soil at the lodgepole pine site, all factors that increased the storage of soil moisture. While the measured xylem vulnerability curves were quite similar for the two species, Douglas-fir had lower average midday shoot water potentials than did lodgepole pine. This implied that lodgepole pine exhibited stronger stomatal control of transpiration than Douglas-fir, which helped to reduce the magnitude of the water potential gradient required to access water from drying soil. Stable hydrogen isotope measurements indicated that Douglas-fir increased the use of groundwater during mid-summer when precipitation inputs were low, while lodgepole pine did not. There was a greater reduction of photosynthetic carbon gain in lodgepole pine compared with Douglas-fir when the two tree species were exposed to seasonal declines in soil water content. The contrasting patterns of seasonal variation in photosynthetic capacity observed for the two species were a combined result of differences in soil characteristics at the separate sites and the inherent physiological differences between the species. 相似文献
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丘陵山地针阔混交林光合作用-光响应特性研究 总被引：1，自引：0，他引：1
为探讨丘陵山地针阔混交林中杉木、马尾松、红榉、闽楠、南酸枣5个混交树种对光环境的适应及生理响应,对5个混交树种树冠上、下层叶绿素含量、净光合速率、光响应曲线等光合特性进行了研究。结果表明:混交林中各树种净光合速率与树冠部位、叶绿素含量均达到显著相关性。闽楠叶绿素a/b最低,并具有较高的表观量子效率,为耐阴树种;南酸枣与红榉的叶绿素a/b较高,表观量子效率较低,为喜光树种;杉木、马尾松叶绿素a/b和表观量子效率居中,为喜光树种,略耐阴。闽楠、红榉、杉木光适应幅度较大,且兼具不同需光特性,是适宜的针阔混交造林配置树种。 相似文献
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We compared foliar physiology and several measures of tree resistance to insect attack among ponderosa pine (Pinus ponderosa var. scopulorum Engelm.) trees growing in thinned stands. Measurements were made in a second-growth ponderosa pine forest in northern Arizona where the basal area treatments (6.9, 18.4, 27.6, 78.2 m(2) ha(-1)) have been experimentally maintained by frequent thinnings for 32 years before our measurements began in 1994. Most of the physiological characteristics measured were affected by the basal area treatments. As stand basal area increased from 6.9 to 78.2 m(2) ha(-1), predawn water potential, midday water potential, net photosynthetic rate, resin production, phloem thickness, and foliar toughness decreased. Foliar nitrogen concentration was greatest in trees in the intermediate basal area treatments. Our results show that the physiological condition of second-growth ponderosa pine can be manipulated by silvicultural control of stand basal area, and support the hypothesis that high stand basal area increases tree stress and decreases tree resistance to insect attack. 相似文献
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D. Craven D. DentD. Braden M.S. Ashton G.P. BerlynJ.S. Hall 《Forest Ecology and Management》2011,261(10):1643-1653
Relative to closed-canopy tropical forests, tree seedlings planted in open grown areas are exposed to higher light intensity, air temperatures, vapor pressure deficit, and greater seasonal fluxes of plant available water than mature tropical forests. The species-specific adaptive capacity to respond to variable precipitation and seasonality in open grown conditions, therefore, is likely to affect species performance in large-scale reforestation efforts. In the present study, we compared the photosynthetic characteristics of eight tropical tree species within and between seasons at two study sites with contrasting dry season intensities. All species except Pseudosamanea guachapele reduced leaf physiological function between the wet and dry seasons. The contrasting severity of seasonal drought stress at the study sites constrained growth rates and photosynthetic characteristics differently. Variation of photosynthetic characteristics at the species level was high, particularly in the dry season. Faster growing species at the less seasonal site, Terminalia amazonia, Inga punctata, Colubrina glandulosa, and Acacia mangium, exhibited a greater adaptive capacity than the other species to down-regulate leaf photosynthesis between seasons. As the dry season was more severe at the more seasonal site, most species strongly reduced physiological function regardless of relative growth rates, except two species (Tectona grandis and P. guachapele) with widespread distributions and relatively high drought tolerance. Our results underscore the need to consider seasonal drought tolerance when selecting tree species for specific reforestation sites. 相似文献