共查询到18条相似文献，搜索用时 140 毫秒
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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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《西部林业科学》2017,(2)
为了探究斑叶堇菜和大叶铁线莲的耐阴性,分别对这2种野生地被植物进行30%、60%、90%的3个梯度的遮阴处理,同时以全光照处理作为对照,研究其在这4种处理下的形态和生理指标的变化。结果表明,随着遮阴度的增加,斑叶堇菜的株高、叶面积、叶绿素a、叶绿素b、叶绿素总量及类胡萝卜素的值均逐渐增加,叶绿素a/b的值则逐渐降低;而大叶铁线莲的株高、叶面积、叶绿素a、叶绿素b、叶绿素总量及类胡萝卜素的值则呈现出先升高后降低的趋势,在60%遮阴处理时各指标的值最高,叶绿素a/b的值则先降低后升高,在60%遮阴处理时的值最小。综合分析可知,斑叶堇菜在90%遮阴处理下生长状况最好,而大叶铁线莲最适宜在60%遮阴处理条件下生长。 相似文献
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介绍了适合在吕梁市范围推广的油松(侧柏)、刺槐混交,油松(落叶松、侧柏)、柠条(沙棘)混交,刺槐、柠条混交和山杏(山桃)、柠条混交5种混交造林模式,对于提高吕梁市“三北”防护林工程建设成效具有重要的推动作用。 相似文献
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介绍了适合在吕梁市范围推广的油松(侧柏)、刺槐混交,油松(落叶松、侧柏)、柠条(沙棘)混交,刺槐、柠条混交和山杏(山桃)、柠条混交5种混交造林模式,对于提高吕梁市"三北"防护林工程建设成效具有重要的推动作用. 相似文献
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研究了国槐与核桃半年生蛭石盆栽苗在盐 (NaCl溶液处理浓度为 5 0 ,10 0 ,2 0 0mmol·L- 1)胁迫条件下光合作用的变化。结果表明 ,核桃受盐胁迫后净光合速率明显下降 ,并且随盐浓度增大、胁迫时间延长而下降更多。国槐受盐胁迫后净光合速率增加 ,在短时间胁迫下增加多 ,随胁迫时间延长增加幅度变小。国槐与核桃在 2 0 0mmol·L- 1NaCl胁迫 2 4d内叶绿素a和b的含量变化不大 ,但核桃的叶绿素a/b之值下降。并且国槐的类胡萝卜素含量在盐胁迫后先增加后与对照相平 ,而核桃则明显下降。两个树种CO2 响应曲线的主要差别为国槐光呼吸速率下降为对照的4 3 7% ,核桃则比对照增加了 71.6 0 % ;国槐的CO2 补偿点比对照下降了 13.5 8% ,而核桃则比对照上升了 194 .15 %。两个树种在光响应曲线上的差别为国槐的暗呼吸速率比对照增加了 3倍多 ,而核桃则下降为对照的 6 5 .2 8%。核桃发生明显的光抑制 相似文献
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不同遮阴处理对3种茶花生理特性的影响 总被引：1，自引：0，他引：1
以3个品种的茶花(Camellia)为研究对象,经过3个不同的遮阴(全光照,20%,60%)处理后,测定叶绿素含量、可溶性糖、可溶性蛋白以及游离脯氨酸等生理指标。结果表明:遮阴处理后,叶绿素a、叶绿素b以及叶绿素总量含量增加;而可溶性糖则表现为20%遮阴度>60%遮阴度>全光照;可溶性蛋白与游离脯氨酸在3个品系各遮阴处理之间表现不同。综上表现:20%遮阴度下更适合茶花的生长,香茶花的耐阴性强于其他2种茶花。 相似文献
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通过比较分析紫色土侵蚀区马尾松老头林混交杨梅后混交树种的生长状况、叶绿素含量及光合特性的差异,试图揭示混交的营林模式对混交树种生理生态的影响。结果表明：马尾松老头林混交杨梅后,马尾松的胸径和树高分别增加45.55%和35.90%,其叶片叶绿素 a、b 和叶绿素 a+b 表现为略有增加,而叶绿素 a/b 比值从2.246减少到2.181;马尾松老头林混交杨梅后,马尾松的最大净光合速率和量子效率均表现为显著增加,光的补偿点表现为略为减少,而光的饱和点表现为略为增加,表明混交杨梅后增强了马尾松的光合能力。 相似文献
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We studied morphological and physiological leaf and whole-plant features of seedlings of six late-successional woody species common in the Xishuangbanna lowland rain forest in southwest China. Study species differed in adult stature and shade tolerance and included the shrubs Lasianthus attenuatus Jack and Lasianthus hookeri C.B. Clarke ex Hook. f.; the sub-canopy species Barringtonia macrostachya (Jack) Kurz and Linociera insignis C.B. Clarke; the canopy tree Pometia tomentosa (Blume) Teijsm. & Binn.; and the emergent species Shorea chinensis (Wang Hsie) H. Zhu. After 1 year of growth in low light (4.5% full sun), seedlings were transferred to high light (24.5% full sun) to investigate acclimation responses of existing leaves to forest gap opening and to determine whether seedling capacity for acclimation is a limiting factor in its natural regeneration. Leaves of the shrub species are shade-adapted, as indicated by their low photosynthetic capacity, efficiency in using sunflecks, low stomatal density, low Chl a/b ratio and high spongy/palisade mesophyll ratio. The shrub species utilized sunflecks efficiently because they had a short photosynthetic induction time and low induction loss. In all species, transfer of seedlings to high light resulted in a substantial initial reduction in the dark-adapted quantum yield of photosystem II (variable chlorophyll fluorescence/maximum chlorophyll fluorescence; Fv/Fm) at midday. Predawn Fv/Fm of the taller species did not change greatly, but predawn Fv/Fm of the shrub species decreased significantly without complete recovery within 25 days of transfer to high light, indicating chronic photoinhibition and damage to the previously shade-adapted leaves. Maximum net photosynthetic rate and dark respiration of the four taller species increased considerably after transfer to high light, but not in the shrub species. Similar trends were observed for the number of newly formed leaves and relative height growth rate. We conclude that the shrubs L. hookeri and L. attenuatus have limited potential for developmental and physiological acclimation to high light, which explains their absence from forest gaps. Compared with the shrub species, the taller tree species, which are more likely to experience high light during their life span, showed a greater potential for light acclimation. Physiological differences among the four tree species were not consistent with differences in adult stature. 相似文献
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Prunus domestica L. has green leaves, whereas Prunus cerasifera Ehrh. var. atropurpurea has red leaves due to the presence of mesophyll anthocyanins. We compared morphological and photosynthetic characteristics of leaves of these species, which were sampled from shoots grafted in pairs on P. domestica rootstocks, each pair comprising one shoot of each species. Two hypotheses were tested: (1) anthocyanins protect red leaves against photoinhibition; and (2) red leaves display shade characteristics because of light attenuation by anthocyanins. Parameters were measured seasonally, during a period of increasing water stress, which caused a similar drop in shoot water potential in each species. As judged by predawn measurements of maximum PSII yield, chronic photoinhibition did not develop in either species and, despite the anthocyanic screen, the red leaves of P. cerasifera displayed lower light-adapted PSII yields and higher non-photochemical quenching than the green leaves of P. domestica. Thus, it appears that, in this system, anthocyanins afford little photoprotection. As predicted by the shade acclimation hypothesis, red leaves were thinner and had a lower stomatal frequency, area- based CO2 assimilation rate, apparent carboxylation efficiency and chlorophyll a:b ratio than green leaves. However, red leaves were similar to green leaves in conductivity to water vapor diffusion, dry-mass-based chlorophyll concentrations and carotenoid:chlorophyll ratios. The data for red leaves indicate adaptations to a green-depleted, red-enriched shade, rather than a neutral or canopy-like shade. Thus, green light attenuation by anthocyanins may impose a limitation on leaf thickness. Moreover, the selective depletion of light at wavelengths that are preferentially absorbed by PSII and chlorophyll b may lead to adjustments in chlorophyll pigment ratios to compensate for the uneven spectral distribution of internal light. The apparent photosynthetic cost associated with lost photons and reduced leaf thickness, and the absence of a photoprotective advantage, suggest that there are other, yet to be identified, benefits for permanently anthocyanic leaves of P. cerasifera. 相似文献
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目的]探寻不同木荷种源混交林生产力差异的光合机制。[方法]以福建建瓯、江西信丰和浙江龙泉3个木荷代表性种源1年生和2年生幼苗为试验材料,在与杉木混植条件下,设置100%(L0)、50%(L1)和25%(L2)3种光照的光环境,研究3个木荷种源幼苗的生长性状、光合生理及叶绿素荧光特性等对不同光照响应的差异。[结果]1年生和2年生木荷幼苗的苗高、地径和干质量均表现出显著的种源差异,福建建瓯种源幼苗生长优于浙江龙泉种源和江西信丰种源。随着遮阳强度的提高,1年生和2年生2个发育阶段,福建建瓯种源幼苗比叶面积和叶绿素含量等明显增加,叶绿素a/b值、光饱和点、暗呼吸速率和Fo值等均显著降低,表现出较高的形态和生理塑性;相同遮阳处理下福建建瓯种源幼苗总叶面积、叶绿素含量和Fv/Fm值等指标显著高于浙江龙泉种源和江西信丰种源,而叶绿素a/b值、光饱和点、光补偿点和暗呼吸速率则明显低于两种源;长期遮阳和混植状态下福建建瓯种源幼苗可通过较高的生物量分配塑性,增加根系在土壤中分布来响应邻株竞争,进而促进整株干物质的积累;各光环境下,3个木荷种源2年生幼苗Fo、Fm、Fv/Fm和Fv/Fo等叶绿素荧光参数均较1年生幼苗明显升高,但各光环境间差异不显著。[结论]不同木荷种源混交林生产力差异与其对光照的塑性反应能力有关,并随幼苗年龄而变化。 相似文献
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Effects of soil moisture and light intensity on ecophysiological characteristics of Amorpha fruticosa seedlings 总被引：1，自引：0，他引：1
We investigated the combined effects of soil moisture and light intensity on the growth, development and ecophysiological characteristics of one-year old Amorpha fruticosa seedlings. Soil moisture and light intensity influenced the ecophysiological characteristics of Amorpha fruticosa seedlings. Soil moisture resulted in the decreases of growth rate, individual size, net photosynthetic rate, transpiration rate, leaf water loss rate (WLR), and biomass accumulation of plant parts, and led to increased leaf water saturation deficit (WSD). Under water stress, more photosynthetic products were allocated to root growth. With decreasing light intensity, net photosynthetic rate, transpiration rate, chla/b, water saturation deficit, water use efficiency, water loss rate and biomass accumulation declined, while Chla, Chlb, Chla+b and carotenoids (Car) increased and more photosynthetic products were allocated to stem and leaf growth. Maximum growth vigor, net photosynthetic rate and total biomass accumulation in Amorpha fruticosa seedlings was recorded at 75 80% soil water-holding capacity and 100% light density in greenhouse environments. 相似文献
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华北石质山区乔、灌木耗水特征比较 总被引：1，自引：0，他引：1
本研究采用热扩散式液流探针（TDP）法对华北石质山区黄连木、刺槐、酸枣、荆条的树干液流进行了监测。结果表明：（1）4树种的树干液流均呈现＂几＂字形,其中黄连木呈单峰型,刺槐呈宽峰型,酸枣荆条呈波动状;液流启动黄连木的最早,酸枣和荆条的居中,刺槐最晚;液流停滞黄连木和刺槐晚于酸枣和荆条;液流速度大小为：黄连木〉酸枣〉荆条〉刺槐,日均耗水量为：黄连木〉刺槐〉酸枣〉荆条。（2）4树种树干液流变化阴天时要比晴天时平缓,液流启动晴天早于阴天,而停滞则晴天晚于阴天。（3）不同树干直径的各树种树干液流变化波形基本一致;黄连木树干液流直径大的启动晚,而停滞早,而刺槐则相反;酸枣和荆条不同直径的液流启动与停滞时间几乎一致;除刺槐外,各树种树干液流速度均表现为直径大的小于直径小的,而刺槐则相反;各树种日均耗水量均表现树干直径大的耗水量大。 相似文献