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1.
樟树幼树光合特性及其对CO2浓度和温度升高的响应   总被引:34,自引:2,他引:34  
用Li COR 6 4 0 0便携式光合作用测定系统对亚热带常绿阔叶树种樟树幼树的光合特性及其对CO2 升高的响应进行了研究。结果表明 :樟树叶片光合速率日变化呈双峰曲线 ,最高峰出现在 10 :0 0 ,次高峰出现在 14 :0 0 ,午间有明显的“午休”现象 ,气孔因素是导致午休的主要原因。中午光照强度大 ,叶片与空气之间的水汽压差达到最大值 ,相对湿度、气孔导度、胞间CO2 浓度达到最小值 ,诱导叶片光合午休。正常大气条件下 ,樟树叶片光饱和点为 12 5 0 μmol·m- 2 s- 1 ,光补偿点 4 0 6 μmol·m- 2 s- 1 ,在 10 0 0 μmol·m- 2 s- 1 光强下CO2 饱和点为 12 0 0 μmol·mol- 1 ,CO2 补偿点为 5 0 μmol·mol- 1 。水分利用效率、气孔导度、蒸腾速率在不同的CO2 浓度梯度下 ,随着光强的增加而增加。在 2 4~ 35℃时 ,随着光合有效辐射的增加 ,温度升高导致樟树光合速率降低。  相似文献   

2.
西藏林芝云杉针叶净光合速率对环境因子的响应   总被引:7,自引:2,他引:7       下载免费PDF全文
使用便携式光合系统仪Li 6200测定了西藏林芝云杉净光合速率的日变化及其对环境因子如量子辐射、相对湿度和CO2浓度的响应。研究结果表明:林芝云杉的净光合速率在11:00点左右达到最大值,然后逐渐下降,到19:00点左右净光合速率降到0以下,转入暗呼吸。林芝云杉树冠上层的针叶由于受光充分,净光合速率较下层针叶大;阴生叶与阳生叶的净光合速率,上层差别不大,下层以阴生叶为大。在气温20℃左右、相对湿度70%±5%、CO2浓度为305mg·kg-1条件下,林芝云杉的光补偿点约为107 5μmol·m-2·s-1,光饱和点约为770μmol·m-2·s-1;在光强800μmol·m-2·s-1、气温20℃左右、相对湿度70%±5%条件下,林芝云杉的CO2补偿点约为157 2mg·kg-1,CO2饱和点约为3811 33mg·kg-1。  相似文献   

3.
本文以Li-6400XT型光合测定仪连续3d分别测定经辐射处理的毛竹实生苗的光合作用日变化、光响应曲线、CO2响应曲线以及在固定光强和固定CO2浓度下的控制测量。结果表明:各处理光合作用日变化规律基本一致,均在上午10时左右达到最高点,表现出明显的单峰曲线。对照和辐射剂量较低的处理光合作用能力强,而辐射剂量较高的光合作用能力弱。毛竹的光饱和点在1400μmo·lm-·2s-1左右,光补偿点为25μmo·lm-·2s-1。当光强为1400μmo·lm-·2s-1时,毛竹的CO2饱和点为1500μmolCO·2mol-1,CO2补偿点约为65μmolCO·2mol-1。  相似文献   

4.
采用Licor-6400型便携式光合作用测定系统测定了人工混交林中云南松、华山松光合作用对光、CO2浓度的响应曲线,阐述了云南松、华山松光合作用对光和CO2浓度的响应特征.结果表明:云南松、华山松光合速率随光强或CO2浓度的提高而增大,均可用非直角双曲线拟合,并得出一些光合响应特征参数,两树种间差异显著(P<0.05);云南松、华山松具有较高的光饱和点(LSP)和补偿点(LCP),表现为典型的喜阳性特点,具有较强的光能利用能力.在CO2饱和下,云南松、华山松最大净光合速率(Pmax)分别可达14.768、10.289 μmol·m-2·s-1,与光饱和下相比,最大净光合速率(Pmax)分别提高了56.9%和62.0%.与华山松及几个北方针叶树相比,云南松具有较高的光饱和点、最大净光合速率、RuBP羧化效率(CE)、光呼吸速率(却)、CO2饱和点(CSP),以及较低的暗呼吸速率(Rd)、光补偿点、CO2补偿点(CCP),云南松具有高光效和高CO2利用率等光合特性,属于高光能生产潜力的针叶树种.  相似文献   

5.
果桑的光合特性   总被引:4,自引:0,他引:4  
叶片是果树光合作用的主要器官.在云南省草坝农场果桑试验示范园对果桑的光合作用进行了测定.结果表明:果桑净光合速率、蒸腾速率、气孔导度的日变化均呈双峰曲线,且在1 d内的变化趋势类似;光合有效辐射以及温度的走势也极为相似;气孔导度随光合有效辐射的增加和随胞间CO2浓度的增加而减少;果桑的光饱和点为1 841.1μmol.m-2.s-1,光补偿点为34.8μmol.m-2.s-1.  相似文献   

6.
城市观赏树种桂花的光合特性初步研究   总被引:7,自引:0,他引:7  
用LI-COR6400 便携式光合作用测定仪系统研究园林观赏树种桂花的光合特性,结果表明:①桂花叶片的光补偿点为21靘ol photons m-2·s-1,最大净光合速率为3.8靘ol·m-2·s-1,光饱和点为1 748靘ol photons m-2·s-1。②桂花叶片的净光合速率(Photo)日变化为单峰曲线,与光合有效辐射(PAR)的日变化走势一致。③相关分析表明:净光合速率与气孔导度(Cond)、蒸腾速率(Trmmol)、光合有效辐射成显著的正相关,而与饱和蒸汽压差(Vpdl)成显著的负相关;主成分分析表明:光照、温度是光合作用的主导因子,胞间CO2浓度(Ci)、叶面的相对湿度(Rhs)对净光合速率影响也较大;逐步线形回归表明:净光合速率主要受到叶片温度(Tleaf)和胞间CO2浓度的影响。  相似文献   

7.
在完全自然生长不离体的情况下,利用Li-6400测定南召宝天曼生境下山茱萸7月份的光合生理生态指标.结果表明;山茱萸净光合速率日变化呈双峰曲线,具有光合"午休"现象且由非气孔限制因素所致;山茱萸净光合速率与叶片气孔导度、胞间C02浓度、气孔限制值呈线性相关,与光合有效辐射呈二次抛物线型相关,与其它生理生态因子之间没有直接的显著相关,但逐步回归多元统计分析显示利用叶片气孔导度和叶片温度二因子预测山茱萸净光合速率精度较高;在叶温28C和空气CO2浓度360μmol·tool-1条件下,山茱萸净光合速率随光合有效辐射的增强而提高,光补偿点和光饱和点分别为25 μmol·m-2·s-1、1000μmol·m-2·s1,在此条件下,净光合速率与蒸腾速率和叶片气孔导度没有显著的相关关系.但与胞间CO2浓度呈二次抛物线璎显著相关;在叶温28C和光合有效辐射900 μmol·m-2·s-1条件下,净光合速率随着CO2浓度的增加而提高,CO2补偿点和CO2饱和点分别为100μmol·mol-1、1400μmol·mol-1此条件下净光合速率与蒸腾速率和胞间CO2浓度均星对数曲线显著正相关.  相似文献   

8.
2001年旱季,用Li 6400便携式光合测定仪对尖峰岭热带山地雨林下层乔木中华厚壳桂主要光合生理生态因子进行了初步测定,结果显示:冠层不同部位叶片的净光合速率无明显差异;中华厚壳桂具有较低的光饱和点(800μmol·m-2·s-1)、光补偿点(15~20μmol·m-2·s-1)和最大光合速率(≤7μmolCO2·m-2·s-1)等耐荫性光合特性,并且缺乏对高光强改变的光合调节能力,但对光斑却有快速的光合响应能力;短期内高CO2浓度会使其光合速率增加,但对气孔导度和蒸腾作用却有抑制作用;在光合最适温度范围内,温度的升高将明显促进光合作用,温度升高4℃能够使其净光合速率平均提高1 6倍,但一旦超过此范围,温度的升高却将抑制光合作用的进行。在自然条件下净光合速率与光照、温度、CO2浓度及气孔导度并无明显的相关关系,而在控制条件下却呈显著的曲线相关。  相似文献   

9.
研究了9个美洲黑杨无性系的光合生理特性,为优良新无性系的选育提供参考。采用LI-6400便携式光合作用测定系统测定美洲黑杨的光合作用日变化及其光响应曲线,利用非直角双曲线Farquhar模型、二次曲线及直线方式拟合光响应曲线,分析比较光响应特征参数及影响净光合速率因子。结果表明:各无性系的净光合速率均具有明显的日变化规律,tn01-78、tn01-38、tn04-n52呈双峰曲线现象,2个峰值出现的时间在11:00和14:00左右,其余呈单峰曲线,净光合速率最大值出现在12:00左右;不同无性系最大净光合速率、暗呼吸速率、表观量子效率、光饱和点和光补偿点的大小范围分别为20.50~31.42μmol·m-2s-1、1.67~3.19μmol·m-2s-1、0.055~0.279μmol·μmol-1、950.83~1 360.83μmol·m-2s-1和29.03~55.20μmol·m-2s-1;净光合速率(Pn)变化与气孔导度Gs、水压亏缺Vpdl、空气温度Tair和光合有效辐射VPAR呈正相关,与胞间CO2浓度Ci和大气相对湿度(HR)呈负相关;净光合速率与影响因子的相关程度依次为气孔导度>光合有效辐射>胞间CO2浓度>大气相对湿度>空气温度>水压亏缺。  相似文献   

10.
田间和盆栽核桃与柿子苗木光合特性的初步研究   总被引:3,自引:0,他引:3  
研究了核桃(Juglans regia L.)、柿子(Diospyros kaki L.f.)两种苗木在田间和盆栽栽培条件下的光合特性。通过室内人工控制光强和CO2浓度,测得盆栽的核桃、柿子的光补偿点分别是62 μmol CO2/m2·s、40μmol CO2/ m2·s;饱和点分别是1 582 μmol CO2/m2·s、1 064 μmol CO2/m2·s;CO2补偿点分别是135 ml/L、230 ml/L。6月的晴天,核桃、柿子盆栽栽培中的净光和速率日变化呈"双峰"型;田问栽培中仅出现1次高峰。两种栽培均出现"午休"现象。  相似文献   

11.
Muehlewbeckia complera was introduced to China in 2002 as indoor-hanging ornamental foliage plant. The experiment of the shade tolerance for this species was carried out in different light intensities (0.14–946.00 μmol·m−2·s−1). After 40 days in experimental areas, leaf photosynthentic characteristics indexes ofM. complera in different photosynthesis active radiation (PAR) were measured with LI-COR6400 apparatus, such as the light compensation point, light saturation point, and maximum net photosynthesis rate, at the same time, the increments of total leaf area and leaf amount were measured. The results showed that the optimum light intensity range forM. complera was from 9.26 μmol·m−2·s−1 to 569.00 μmol·m−2·s−1 (463–28150 lx, relative humidity (RH) for 46–60%, temperature at 16–22°C). Under this condition, leaf photosynthetic efficiency was tiptop. AlthoughM. complera belonged to the moderate sun-adaptation plant species, the plant growth was inhibited when PAR increased to the level of 569.000 μmol·m−2·s−1 or above.M. complera could sprout new leaves in photosynthesis active radiation of 0.16–19.22 μmol·m−2·s−1 (8–961 lx), or 10 μmol·m−2·s−1 for above 6 h. Foundation item: This study was supported by the Research Foundation of Northeast Forestry University. Biography: YUE Hua (1962-), female, Associate professor in Northeast Forestry University, Harbin 150040, P. R. China. Responsible editor: Zhu Hong  相似文献   

12.
本文研究了大叶桃花心木(Swietenia macrophylla King)一年生幼苗在经过夜温处理后的光响应曲线和在饱和光强下的CO2反应曲线.结果表明:在大气CO2浓度下,叶片的最佳光合作用温度在25-31℃之间,而在饱和CO2浓度下为31-35℃.在25℃以下光合速率开始降低,主要是由于羧化效率的降低,而当温度超过31℃时,光合速率下降,是因为羧化效率的降低和呼吸速率的增加.CO2浓度对光合的促进作用在低温下受到抑制,这意味着未来在CO2浓度增高的情况下,高浓度的CO2对热带常绿植物光合的促进在冬天低温情况下表现不十分明显.图4参23.  相似文献   

13.
The impacts of elevated atmospheric CO2 concentrations (500 μmol·mol−1 and 700 μmol·mol−1) on total soil respiration and the contribution of root respiration ofPinus koraiensis seedlings were investigated from May to October in 2003 at the Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences, Jilin Province, China. After four growing seasons in top-open chambers exposed to elevated CO2, the total soil respiration and roots respiration ofPinus koraiensis seedlings were measured by a Li-6400-09 soil CO2 flux chamber. Three PVC cylinders in each chamber were inserted about 30 cm into the soil instantaneously to terminate the supply of current photosynthates from the tree canopy to roots for separating the root respiration from total soil respiration. Soil respirations both inside and outside of the cylinders were measured on June 16, August 20 and October 8, respectively. The results indicated that: there was a marked diurnal change in air temperature and soil temperature at depth of 5 cm on June 16, the maximum of soil temperature at depth of 5 cm lagged behind that of air temperature, no differences in temperature between treatments were found (P>0.05). The total soil respiration and soil respiration with roots severed showed strong diurnal and seasonal patterns. There was marked difference in total soil respiration and soil respiration with roots severed between treatments (P<0.01); Mean total soil respiration and contribution of root under different treatments were 3.26, 4.78 and 1.47 μmol·m−2·s−1, 11.5%, 43.1% and 27.9% on June 16, August 20 and October 8, respectively. Foundation item: This study was supported by the Knowledge Innovation Project of the Chinese Academy of Sciences (KZCX1-SW-01) and the National Natural Science Foundation of China (30070158). Biography: LIU Ying (1976-), female, Ph. D. Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. China. Responsible editor: Song Funan  相似文献   

14.
Two-year-old seedlings ofPinus koraiensis, Pinus sylvestriformis andFraxinus mandshurica were treated in open-top chambers with elevated CO2 concentrations (700 μL·L−1, 500 μL·L−1) and ambient CO2 concentrations (350 μL·L−1) in Changbai Mountain from June to Sept. in 1999 and 2001. The net photosynthetic rate, dark respiration rate, ribulose-1,5-bisphosphate carboxlase (RuBPcase) activity, and chlorophyll content were analyzed. The results indicated the RuBPcase activity of the three species seedlings increased at elevated CO2 concentrations. The elevated CO2 concentrations stimulated the net photosynthetic rates of three tree species exceptP. sylvestriformis grown under 500 μL·L−1 CO2 concentration. The dark respiration rates ofP. koraiensis andP. sylvestriformis increased under concentration of 700 μL·L−1 CO2, out that ofF. mandshurica decreased under both concentrations 700 μL·L−1 and 500 μL·L−1 CO2. The seedlings ofF. mandshurica decreased in chlorophyll contents at elevated CO2 concentrations. Foundation item: This paper was supported by the National Natural Science Foundation of China (No. 30070158). Knowledge Innovation Item of Chinese Academy of Sciences (KZCX2-406) and “Hundred Scientists” Project of Chinese Academy of Sciences. Biography: Zhou Yu-mei (1973-) Ph. Doctor, Assistant Research fellow Institute of Applied Ecology. Chinese Academy of Sciences. Shenyang 110016. P.R. China. Responsible editor: Song Funan  相似文献   

15.
The net CO2 assimilation rate, stomatal conductance, RuBPcase (ribulose 1,5-biphosphate carboxylose) activity, dry weight of aboveground and belowgroud part, plant height, the length and diameter of taproot ofPinus koraiensis seedlings were measured and analyzed after six-week exposure to elevated CO2 in an open-top chamber in Changbai Mountain of China from May to Oct. 1999. Seedlings were planted in four different conditions: on an open site, control chamber, 500 μL·L−1 and 700 μL·L−1 CO2 chambers. The results showed that the total biomass of the seedlings increased whereas stomatal conductance decreased. The physiological responses and growth to 500 μL·L−1 and 700 μL·L−1 CO2 varied greatly. The acclimation of photosynthesis was downward to 700 μL·L−1 CO2 but upward to 500 μL·L−1 CO2. The RuBPcase activity, chlorophyll and soluble sugar contents of the seedlings grown at 500 μL·L−1 CO2 were higher than that at 700 μL·L−1 CO2. The concentration 500 μL·L−1 CO2 enhanced the growth of aboveground part whereas 700 μL·L−1 CO2 allocated more carbon to belowground part. Elevated CO2 changed the carbon distribution pattern. The ecophysiological responses were significantly different between plants grown under 500 μL·L−1 CO2 and 700 μL·L−1 CO2. Foundation Item: This paper was supported by Chinese Academy of Sciences. Biography: HAN Shi-jie (1956-), male, Ph. Doctor, Professor in Laboratory of Ecological Process of Trace Substance in Terrestrial Ecosystem, Institute of Applied Ecology, Chinese Academy of Sciences. Responsible editor: Chai Ruihai  相似文献   

16.
The photosynthetic response of 12-year oldPinus sylvestriformis to elevated CO2 and its influential factors were tested and analyzed in the forest region of Changbai Mountain in 1999. Trees grown at the natural condition were controlled at three levels of CO2 concentration (350 μL·L−1, 500 μL·L−1 and 700 μL·L−1) by CO2 rich settlement designed by us. Net photosynthetic rates (NPR), temperature, relative humidity, stomatal conductance, intercellular CO2 concentration and photosynthetic active radiation (PAR) were measured at 6:00, 8:00, 10:00, 14:00, 16:00 and 18:00 hours a day. Experimental results showed that the NPR ofPinus sylvestriformis increased by 32.6% and 123.0% at 500 μL·L−1 and 700 μL·L−1 CO2 concentration respectively, compared to ambient atmospheric CO2 concentration (350 μL·L−1). The relations between NPR and influential factors, including temperature, relative humidity, intercellular CO2 concentration and photosynthetic active radiation, were analyzed respectively by regression analysis at different CO2 concentrations. Foundation Item: This project was supported by Chinese Academy of Sciences. Biography: WANG Chen-rui (1970-), male, Assistant Research Fellow in Institute of Applied Ecology, Chinese Academy of Sciences. Responsible editor: Chai Ruihai  相似文献   

17.
Eco-physiological responses of seedlings of eight species,Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica andAcer mono from broadleaved/Korean pine forest, to elevated CO2 were studied by using open-top chambers under natural sunlight in Changbai Mountain, China in two growing seasons (1998–1999). Two concentrations of CO2 were designed: elevated CO2 (700 μmol·mol−1) and ambient CO2 (400 μmol·mol−1). The study results showed that the height growth of the tree seedlings grown at elevated CO2 increased by about 10%–40% compared to those grown at ambient CO2. And the water using efficiency of seedlings also followed the same tendency. However, the responses of seedlings in transpiration and chlorophyll content to elevated CO2 varied with tree species. The broad-leaf tree species were more sensitive to the elevated CO2 than conifer tree species. All seedlings showed a photosynthetic acclimation to long-term elevated CO2. Foundation item: The project was supported by National Key Basic Development of China (G1999043400) and the grant KZCX 406-4, KZCX1 SW-01 of the Chinese Academy of Sciences Biography: WANG Miao (1964-), maie, associate professor in Institute of applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. China. Responsible editor: Song Funan  相似文献   

18.
3年生白桦同时接受3种外源糖溶液(蔗糖、果糖、葡萄糖)和3种高浓度CO2(700、1400、2100μL·μL-1CO2)处理.处理1个月后,测定了叶片的总糖、蔗糖、果糖和蛋白质含量.结果表明:在700μL·L-1和1400μL·L-1 CO2下,外源糖溶液增加了叶片的可溶性糖和蛋白质含量,其中外源蔗糖的效果最好:外源糖溶液与2100μL·L-1CO2结合,会抑制叶片积累总糖和蛋白质:在700μL·L-1和1400μL·L-1CO2下,喷施葡萄糖、果糖的叶片在蛋白质含量上没有明显差别:同700、1400μL·L-1CO2相比,除喷施果糖植株外,2100μL·L-1 CO2明显增加了叶片的总糖、蔗糖、果糖和蛋白质含量:在喷施同种外源糖溶液的情况下,叶片的糖含量与CO2浓度呈正相关性.图6参7.  相似文献   

19.
Four-year-oldPinus sylvestriformis were exposed for four growing seasons in open top chambers to ambient CO2 concentration (approx. 350 μmol·mol−1) and high CO2 concentrations (500 and 700 μmol·mol−1) at Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences at Antu Town, Jilin Province, China (42°N, 128°E). Stomatal response to elevated CO2 concentrations was examined by stomatal conductance (g s), ratio of intercellular to ambient CO2 concentration (c i/c a) and stomatal number. Reciprocal transfer experiments of stomatal conductance showed that stomatal conductance in high-[CO2]-grown plants increased in comparison with ambient-[CO2]-grown plants when measured at their respective growth CO2 concentration and at the same measurement CO2 concentration (except a reduction in 700 μmol·mol−1 CO2. grown plants compared with plants on unchambered field when measured at growth CO2 concentration and 350 μmol·mol−1CO2). High-[CO2]-grown plants exhibited lowerc i/c a ratios than ambient-[CO2]-grown plants when measured at their respective growth CO2 concentration. However,c i/c a ratios increased for plants grown in high CO2 concentrations compared with control plants when measured at the same CO2 concentration. There was no significant difference in stomatal number per unit long needle between elevated and ambient CO2. However, elevated CO2 concentrations reduced the total stomatal number of whole needle by the decline of stomatal line and changed the allocation pattern of stomata between upper and lower surface of needle. Foundation Item: This research was supported by National Basic Research Program of China (2002CB412502), Project of Key program of the National Natural Science Foundation of China (90411020) and National Natural Science Foundation of China (30400051). Biography: ZHOU Yu-mei (1973-), female, Ph. Doctor, assistant research fellow, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. China. Responsible editor: Song Funan  相似文献   

20.
刘颖  韩士杰  林鹿 《林业研究》2009,20(4):367-371
2004年5月至9月,研究了长白山白桦林土壤呼吸以及根系呼吸对土壤呼吸的贡献随土壤温度和土壤湿度的季节变化,研究结果表明:土壤总呼吸、断根土壤呼吸和根系呼吸在生长季内有相似的季节变化趋势,夏季潮湿而且温度较高,呼吸速率也较高,春季和秋季温度较低,呼吸速率也较低。2004年5月至9月,土壤总呼吸、断根土壤呼吸和根系呼吸的平均值分别为4.44,2.30和2.14μmol&#183;m^-2s^-1,三者与土壤温度均呈指数相关,与土壤湿度呈线性相关,三者的Q10值分别为2.82,2.59和3.16,这与其他学者的结果相似。根系呼吸是土壤呼吸的一个重要组成部分,2004年5月至9月,根系呼吸对土壤总呼吸的贡献在29.3~58.7%之间。根据Q10模型估算的土壤总呼吸、断根土壤呼吸和根系呼吸的全年平均值分别为1.96、1.08和0.87μmol&#183;m^-2s^-1,即741.73、408.71和329.24gC&#183;m^-2&#183;a^-1,全年根系对土壤总呼吸的贡献为44.4%。土壤呼吸和土壤温度之间的关系模型是了解和预测长白山白桦林生态系统潜在的随森林管理和气候变化而变化的有用工具。  相似文献   

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