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1.
测定了不同土壤水分条件下黄栌光合作用的CO2响应过程,采用直角双曲线修正模型对其响应过程进行拟合。结果表明:黄栌的净光合速率(Pn)对土壤水分的变化具有显著的阈值响应。维持黄栌较高光合速率的RWC在42.1%-73.6%(MWC在11.0%-19.2%)之间时,最适宜的RWC为61.7%(MWC为16.1%)左右。黄栌的羧化效率(CE)、光合能力(Pnmax)、光呼吸速率(Rp)表现为对土壤水分具有明显的阈值响应,当RWC为61.7%(MWC为16.1%)时CE、Pnmax达到最大值,当RWC为73.6%(MWC为19.2%)时Rp达到最大值。黄栌的CO2补偿点(Γ)、CO2饱和点CSP随着土壤含水量的增加表现出先下降后上升的规律。  相似文献   

2.
阿尔山地区兴安落叶松林下植物种群生态位   总被引:1,自引:0,他引:1       下载免费PDF全文
将由林龄(AG)、海拔(AL)以及物种数目(IS)组合而成的综合资源位指数(RGI)作为资源轴的划分标准,应用Levins(B(sw)i)和Shannon-Wiener(B(L)i)生态位宽度指数,生态位重叠指数(LihLhi)以及生态位相似性比例指数(Cih)等将阿尔山地区不同起源的兴安落叶松林(天然林、人工林及火烧迹地恢复林)划分为6个资源位,在此基础上进行群落调查,对林下植物种群的生态位进行了定量分析。结果表明:兴安苔草和黑麦草的重要值最大,不同资源位重要值之和达到114.924 8%和70.911 1%。生态位宽度较大的有北方拉拉藤、粗根老鹳草、黑麦草及兴安苔草,这些物种适应能力强,分布范围大,倾向于泛化种。生态位狭小的植物种群则可能成为林区进行植物多样性保护的重点,需要引起特别关注。本研究证实生态位宽度较大种群与其他种群存在较大的生态位重叠和相似性,而这在某些重要值较低且生态位宽度较窄的种群也会出现(如铁杆蒿、黄花委陵菜及巴天酸模),生态位重叠和相似性并非仅仅取决于生态位宽度。生态位重叠既能反映两种群在共享资源时的竞争关系,也能反映两者在利用资源时相互促进的关系。生态位宽度较大的植物种可作为植被恢复阶段的先锋种,而与其生态位重叠较大的物种以及与先锋种生态位相似性比例较小的物种则可作为伴生种,以便于充分利用环境资源,逐步恢复受损地区的植被。  相似文献   

3.
采用水蒸气蒸馏法和气相色谱-质谱联用技术,对新疆圆柏(Sabina vulgaris Ant.)鲜叶和贮存1年的干燥叶中的挥发油化学成分进行检测,鲜叶中的成分鉴定了31种,干叶中的成分鉴定了23种,共有成分15种。与鲜叶比较,干叶中含量减少的成分是:2,7-二甲基-3-辛烯-5-炔(51.88%,15.29%,前者为鲜叶中的量,后者为干叶中的量,下同)、1-柠檬烯(1.65%,1.13%)、α-异松油烯(0.92%,0.58%)、3,7-二甲基-甲基酯-2,6-辛二烯酸(2.88%,0.50%)、α-长叶蒎烯(1.91%,1.46%)、α-雪松醇(12.69%,10.81%),含量增加的成分是:β-侧柏酮(1.01%,1.98%)、4-甲基-1-(1-甲基乙基)-3-环己烯-1-醇(0.22%,2.83%)、β-香茅醇(0.22%,10.83%)、乙酸香桧酯(4.37%,39.83%),新疆圆柏鲜叶和干叶中的挥发性成分及其含量差异甚大,但是特征成分种类基本一致,随着叶的干燥贮存时间的延长,其挥发性成分及其含量在逐渐减少。  相似文献   

4.
Roberntz P 《Tree physiology》2001,21(12-13):931-940
Branches of field-grown Norway spruce (Picea abies (L.) Karst.) trees were exposed to either long-term ambient or to elevated CO2 concentrations ([CO2]) using the branch bag technique. The light-saturated photosynthetic rates (A(max)) of current-year shoots differing in nitrogen (N) status were measured at various temperatures and at either ambient (360 micromol mol(-1), AMB) or elevated (ambient + 350 micromol mol(-1), EL) [CO2]. The value of A(max) was determined at various intercellular [CO2]s (A/Ci curves) and used to normalize photosynthetic rates to the mean treatment C(i) values, which were 200 micromol mol(-1) (AMB) and 450 micromol mol(-1) (EL), respectively. Needle N status and temperature strongly affected A(max). The response to N increased with temperature, and the photosynthetic temperature optimum increased with N status. This was assumed to be a result of reduced mesophyll CO2 conductance. The relative increase of Amax in the EL treatment compared to the AMB treatment varied from 15 to 90%, and increased with temperature, but decreased with N status. Nevertheless, the absolute photosynthetic response to EL increased with shoot N status. The relative increase in the instantaneous response of A(max) to elevated [CO2] was about 20% higher than the long-term response, i.e., there was downward acclimation in Amax in response to elevated [CO2]. The photosynthetic temperature optimum increased 4 degrees C with either a short- or a long-term increase in [CO2]. The bag treatment itself increased A(max) by approximately 16% and the temperature optimum of A(max) by approximately 3 degrees C.  相似文献   

5.
Naturally regenerated 20-25-year-old Scots pine (Pinus sylvestris L.) trees were grown in open-top chambers in the presence of an elevated temperature or CO(2) concentration, or both. The elevated temperature treatment was administered year-round for 3 years. The CO(2) treatment was applied between April 15 and September 15 for 2 years. The photosynthetic responses of 1- and 2-year-old needles to varying photon flux densities (0-1500 micro mol m(-2) s(-1)) and CO(2) concentrations (350, 700 and 1400 micro mol mol(-1)) during measurement were determined. The CO(2) treatment alone increased maximum photosynthetic rate and light-use efficiency, but decreased dark respiration rate, light compensation and light saturation regardless of needle age. In contrast, the temperature treatment decreased maximum photosynthetic rate and photosynthetic efficiency, but increased dark respiration rate, light compensation and light saturation. The aging of needles affected the photosynthetic performance of the shoots; values of all parameters except photosynthetic efficiency were less in 2- than in 1-year-old needles. The CO(2) treatment decreased and the temperature treatment enhanced the reduction in maximum photosynthesis due to needle aging.  相似文献   

6.
以戊二醛为交联剂,壳聚糖为聚合物基质,固化余甘子单宁制备一种固体吸附材料余甘子固定化单宁(PEIT),并采用FT-IR、DSC、TG对PEIT的结构和热性质进行了表征。研究结果表明:余甘子单宁通过戊二醛与壳聚糖基质产生了交联,最佳制备条件为2 g余甘子单宁,m(戊二醛)∶m(余甘子单宁)1∶4,m(壳聚糖)∶m(余甘子单宁)1.5∶1,反应液初始pH值4,55℃反应3 h。将制备的PEIT用于吸附金属离子,结果显示其对Ge(Ⅳ)、Ga(Ⅲ)和In(Ⅲ)有良好的吸附效果,当pH值为4时,In(Ⅲ)吸附量最大;当pH值为3时,Ge(Ⅳ)和Ga(Ⅲ)吸附量最大;对这3种金属离子的吸附符合准二级动力学方程,说明其吸附机理为化学吸附;吸附过程对温度并不敏感,且最佳吸附温度为30℃。吸附等温线符合Langmuir等温线模型,证明其表面存在均匀的吸附位点,且主要是单分子层吸附,Ga(Ⅲ)、In(Ⅲ)和Ge(Ⅳ)的最大吸附量分别为67.65、70.00和54.11 mg/g。  相似文献   

7.
Small birch plants (Betula pendula Roth) were cultivated in a hydroponic spray solution where the relative growth rate (R(G); day(-1)) was controlled by the relative supply rate of zinc (R(Zn); day(-1)). After an adjustment phase to steady-state growth, R(G) equaled R(Zn). The R(Zn) treatments were 0.05, 0.125 and 0.20 day(-1) with free access to all other nutrients. In an additional treatment, there was free access to all nutrients, including zinc (FA treatment). The pH of the nutrient solution was approximately 4.5 and conductivity was 100 &mgr;S cm(-1). The duration of each treatment depended on R(Zn) and ranged from 4 (FA treatment) to 10 weeks (at R(Zn) = 0.05 day(-1)). The plants showed persistent and typical zinc-deficiency symptoms at steady-state growth when R(G) was 0.05 and 0.125 day(-1), whereas there were few symptoms when R(G) was 0.2 day(-1). The Zn concentration of the plants ranged from 8 (at R(Zn) = 0.05 day(-1)) to 21 &mgr;g g(DM) (-1) (DM = dry mass) (at R(Zn) = 0.2 day(-1)) and was approximately 42 &mgr;g g(DM) (-1) in the FA treatment. Uptake rates of Zn, calculated per root growth rate (&mgr;mol g(DM, root) (-1)), were about 2.8 times higher at R(Zn) = 0.20 day(-1) than at R(Zn)= 0.05 day(-1). The root and stem biomass fractions were approximately constant at all supply rates of Zn, whereas the leaf biomass fraction tended to increase with increasing supply rate of Zn. Net assimilation rate was constant from FA to an R(Zn) of 0.125 day(-1) but decreased by a factor of about 2 at R(Zn) = 0.05 day(-1). Leaf area ratio and specific leaf area were smaller at low supply rates of zinc than at high supply rates.  相似文献   

8.
采用水蒸气蒸馏法(SD)提取光叶拟单性木兰叶片中的挥发油,用气相色谱-质谱(GC-MS)联用技术分析挥发油的成分,鉴定出34个化合物。其主要成分为1R-α-蒎烯(7.432%)、香桧烯(13.516%)、β-松节烯(7.615%)、间-甲基异丙基苯(7.21%)、桉油醇(7.139%)、松油-4-醇(5.004%)、β-石竹烯(5.577%)、β-荜澄茄烯(4.435%)。体外抑菌和抗肿瘤实验表明,光叶拟单性木兰挥发物质对大肠杆菌、金黄色葡萄球菌、红酵母有一定的抑制作用;对人非小细胞肺癌(NCI-H460)、胃腺癌(SGC-7901)有较强的抑制作用,当挥发油质量浓度为50μg.mL-1时,抑制率分别达到83.24%、72.26%。  相似文献   

9.
海岸带沙荒风口木麻黄无性系造林效果的综合评价   总被引:2,自引:1,他引:2  
以木麻黄无性系的防护效能和速生丰产性能为基础,运用多目标决策方法,对沿海沙荒风口6种木麻黄无性系造林效果进行综合评价,结果表明:在沙荒风口造林的6种木麻黄无性系中,粤501最抗风,其防护效能最高,平18次之;平18最速生丰产,粤501其次;莆20在6种无性系中无论抗风性还是速生丰产性能均最低。综合评价指标以平18最高,粤501次之,莆20最小。平18和粤501是沿海沙荒风口造林理想的木麻黄无性系。  相似文献   

10.
本文采用正交设计对红松播种苗进行了施肥效应研究,测定了不同施肥组合条件下苗木的形态指标。结果表明:影响苗木生长的各肥料因子的顺序依次为C(追施尿素)、A(施基肥)、B(追施二铵),促进苗木生长的较佳施肥组合为A3(4)B1C3,即基肥用量为有机肥7 500 g/m2 二铵7g/m2或有机肥7 500 g/m2 二铵7 g/m2 硫酸钾12 g/m2;追肥二铵用量为0;追肥尿素的用量为30 g/m2。  相似文献   

11.
泡桐花精油化学成分分析   总被引:12,自引:0,他引:12  
利用水蒸气蒸馏法提取泡桐花中的精油,运用GC-MS技术,对其化学成分进行分析鉴定,用色谱峰面积归一化法计算各组分的相对含量。分离出91个组分,鉴定了其中69个组分,占总精油量的89.33%。泡桐花精油的主要成分为苯甲醇(13.276%)、1,2,4-三甲氧基苯(8.342%)、2-甲氧基-3-(2-丙烯基)-苯酚(6.141%)、3,4-二甲氧基苯酚(3.986%)、二十三烷(3.682%)和二十五烷(3.238%)等。  相似文献   

12.
应用GC-MS技术对福建产的含笑叶、花挥发油成分进行分离鉴定。从含笑叶挥发油中鉴定出35种成分,占色谱峰总面积的90.83%,其主要成分为β-榄香烯(29.82%)、石竹烯(11.87%)、Elixene(8.39%)、γ-榄香烯(7.26%)和(Z)-5,11,14,17-二十碳四烯酸甲酯(5.70%);从含笑花挥发油中鉴定出23种成分,占色谱峰总面积的94.53%,其主要成分为β-榄香烯(41.08%)、(Z)-5,11,14,17-二十碳四烯酸甲酯(14.56%)、石竹烯(9.53%)、Elixene(7.31%)和大根香叶烯D(5.43%)。试验结果表明,含笑叶、花挥发油组分较为相似,且都含有丰富的抗肿瘤活性成分β-榄香烯,具有较高的药用价值,值得进一步研究并开发利用。  相似文献   

13.
A comparative study of Frequency Ratio(FR)and Analytic Hierarchy Process(AHP)models are performed for forest fire risk(FFR)mapping in Melghat Tiger Reserve forest,central India.Identification of FFR depends on various hydrometeorological parameters altitude,slope,aspect,topographic position index,normalized differential vegetation index,rainfall,air temperature,land surface temperature,wind speed,distance to settlements,and distance by road are integrated using a GIS platform.The results from FR and AHP show similar trends.The FR model was significantly higher accurate(overall accuracy of 81.3%,kappa statistic 0.78)than the AHP model(overall accuracy 79.3%,kappa statistic 0.75).The FR model total forest fire risk areas were classified into five classes:very low(7.1%),low(22.2%),moderate(32.3%),high(26.9%),and very high(11.5%).The AHP fire risk classes were very low(6.7%),low(21.7%),moderate(34.0%),high(26.7%),and very high(10.9%).Sensitivity analyses were performed for AHP and FR models.The results of the two different models are compared and justified concerning the forest fire sample points(Forest Survey of India)and burn images(2010-2016).These results help in designing more effective fire management plans to improve the allocation of resources across a landscape framework.  相似文献   

14.
将不同地区采集的6种桑树砧木进行盐(NaCl)胁迫处理,根据不同桑种实生苗的相对生长量、盐害指数的统计分析,对桑树砧木耐盐性比较、评价.结果表明,桑树砧木耐盐性由高到低分别是安徽的华桑、新疆的白桑、河北的鲁桑、安徽的鲁桑、江苏的山桑、广东的广东桑.  相似文献   

15.
The status of the incidence of the bark beetle Scolytus kashmirensis Schedl on elm (Ulmus spp.) trees was determined in four districts of the Kashmir Valley in 2009.The incidence of the borer was higher in the Anantnag (25.93%) and Shopian (22.35%) districts of the Kashmir Valley,followed by the Ganderbal (17.14%) and Baramulla (16.67%) districts.The overall infestation recorded in these districts was 20.52%.The beetle under study chewed the scars on twigs of both the host and tentative non-host plants supplied to them in cages but bored and laid eggs in only one of them (the host plant).Both species of elm,Ulmus wallichiana and U.villosa,were susceptible to borer attacks;however,U.villosa showed low susceptibility and high resistance compared to U.wallichiana.Older,taller elms were preferred for feeding by bark beetles and are therefore much more susceptible to its infestation compared to younger elms.This bark beetle species also preferred to oviposit in branches of the host plants with diameters of 9-12 mm.  相似文献   

16.
An intumescent waterborne amino-resin fire-retardant coating for wood (C) was synthesized and its fire-retardant and smoke-suppressant properties were investigated. The main film-builder of C was urea-formaldehyde resin blended with polyvinyl acetate resin. The intumescent fire-retardant system of C consisted of guanylurea phosphate (GUP), ammonium polyphosphate (APP), pentaerythritol (PER) and melamine (MEL). Specimens of plywood painted, respectively, with a commercial intumescent fire-retardant coating (A), a synthesized coating (C), and the main film-builder of coating C (B), as well as an unpainted plywood (S-JHB), were analyzed by cone calorimetry (CONE). The results show a marked decrease in the heat release rate (HRR) and the total heat release (THR), an increased mass of residual char (Mass), a marked postponement in time to ignition (TTI) and a reduced carbon monoxide production rate (P CO). The smoke production rate (SPR) and total smoke production (TSP) of the plywood painted with coating C were observed with the CONE test. The overall fire-retardant and smoke-suppressant performance of the synthesized coating C was much better than that of the commercial coating A. The thermo-gravimetric analysis (TGA) results of coating C and its film-builder B indicated that the thermal degradation process of B was slowed down by the addition of the intumescent fire-retardant system; the increase in the amount of charring of coating C was considerable. __________ Translated from Scientia Silvae Sinicae, 2007, 43(12): 117–121 [译自: 林业科学]  相似文献   

17.
杨树叶面积与生长指标的关系分析   总被引:5,自引:0,他引:5  
刘奉觉  郑世锴 《林业科学》1989,25(4):370-374
树冠叶面积与树干材积的关系,反映着林木叶部光合产物的供应与干部材积生长需要之间的供需关系,表现为叶面积与林木生长指标、尤其是与材积的关系。对这些关系的分析研究,有助于了解林木材积形成过程及其与环境条件的协调程度,还可用于一定条件  相似文献   

18.
‘CAF8’是运用单株选择和集团选择育种手段,从云南元江县地方栽培品种中选育出的木豆新品种。生育期257~265天,平均株高(231.5±32.7)cm,地径(3.74±0.76)cm,单株荚数(794.8±272.6)个,每荚粒数(4.5±0.4)粒,种子百粒质量(7.85±0.51)g,单株粒质量(81.17±23.40)g。  相似文献   

19.
在内蒙古阿尔山的田间诱捕试验中,落叶松八齿小蠹引诱剂1共诱集到16头落叶松八齿小蠹和1319头天敌红胸郭公虫,而落叶松八齿小蠹引诱剂2诱集到24104头落叶松八齿小蠹和776头红胸郭公虫。室内的触角电位试验结果表明:落叶松八齿小蠹对引诱剂2的触角反应(雌虫2.139mV±0.678mV,雄虫2.169mV±0.473mV)大于引诱剂1(雌虫0.440mV±0.232mV,雄虫0.297mV±0.142mV),对引诱剂1的反应值和对照差不多;而红胸郭公虫对引诱剂1的触角反应(雌虫4.618mV±1.106mV,雄虫4.534mV±1.087mV)明显大于引诱剂2(雌虫2.209mV±0.680mV,雄虫1.953mV±0.601mV),对引诱剂2也有一定的反应值。触角电位试验与田间诱捕试验结果相符合。GC-MS分析结果表明:引诱剂1的主要成分为3.06%的cis-geraniol,1.98%的Ipsenol,80.36%的(S)-cis-verbenol和1.03%的1-verbenone;结合卖方公司提供的数据,引诱剂1的主要成分为4.78%的2-methyl-3-buten-2-ol,63.71%的Ipsenol(纯度为96.9%),1.46%的Cedrene和22.42%的Isocaryophillene。结合以上数据分析得出:不同成分引诱剂对落叶松八齿小蠹及天敌红胸郭公虫引诱能力显著不同,Ipsenol对诱集落叶松八齿小蠹起重要作用,而(S)-cis-verbenol则对诱集天敌红胸郭公虫起重要作用。  相似文献   

20.
4-己基间苯二酚和曲酸对舞毒蛾酚氧化酶的抑制作用   总被引:2,自引:0,他引:2  
以舞毒蛾为材料,分离提取酚氧化酶,研究4-己基间苯二酚(4HR)和曲酸对舞毒蛾酚氧化酶活力的影响.结果表明:4HR对该虫的单酚酶和二酚酶活性均表现很强的抑制作用,其IC_(50)分别为0.000 41和0.000 35mmol·L~(-1).其中,4HR对单酚酶活力表达的迟滞时间有明显的延长效应,浓度为0.000 2 mmol·L~(-1)时可使单酚酶活力表达迟滞时间从181 s延长到253 s;而当浓度为0.000 5 mmol·L~(-1)时,其迟滞时间则延长至372 s.以邻苯二酚为底物时,4HR对二酚酶的抑制作用表现为典型的竞争型抑制类型,抑制常数K_1为0.000 15 mmol·L~(-1).曲酸对舞毒蛾的单酚酶和二酚酶活性均表现较强的抑制作用,其IC_(50)分别为0.06和0.92 mmol·L~(-1).曲酸对单酚酶活力表达的迟滞时间也有明显的延长效应,浓度为0.1 mmol·L~(-1)时可使单酚酶活力表达迟滞时间从306 s延长到732 s;而当浓度为0.15 mmol·L~(-1)时,其迟滞时间则延长至900 s.以邻苯二酚为底物时,曲酸对二酚酶的抑制作用表现为典型的竞争型抑制类型,抑制常数K_i为0.51 mmol·L~(-1).  相似文献   

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