开放系统中农作物对空气CO2浓度增加的响应

FACE试验(free-air CO₂ enrichment)开展的10多年中,供试农作物主要有:C₃禾本科作物小麦(Triticum aestivum L.)、多年生黑麦草(Lolium perenne)和水稻(Oryza sativa L.),C₄禾本科类高粱(Sorghum bicolor(L.)Mench),C₃豆科植物白三叶草(Trifolium repens),C₃非禾本科块茎状作物马铃薯(Solanum tuberosum L.),以及多年生C₃类木本作物棉花(Gossypium hirsutumL.)和葡萄(Vitis viniferaL.).本文系统整理和分析了以下各项参数的结果:光合作用、气孔导度、冠层温度、水分利用、水势、叶面积指数、根茎生物量累积、作物产量、辐射利用率、比叶面积、N含量、N收益、碳水化合物含量、物候变化、土壤微生物、土壤呼吸、痕量气体交换以及土壤碳固定.CO₂浓度升高对农作物的影响作用主要表现在以下方面:(1)促进了植物光合作用、增加了其生物量累积;(2)显著提高C₃作物产量,但对C₄作物产量的影响很小;(3)降低了C₃和C₄作物气孔导度,非常显著地提高了所有作物的水分利用率;(4)对植物生长的促进作用在水分不足与水分充足时二者相当或前者大于后者;(5)对非豆科植物生长的促进作用要受到土壤低N水平限制,而对豆科植物则不受氮肥水平限制;(6)对根系生长的促进作用要大于地上部分;(7)对多年     

开放式空气CO2浓度增高对水稻产量形成的影响

在大田栽培条件下 ,研究开放式空气CO2 浓度增加 (FACE) 2 0 0 μmol·mol-1的处理对水稻产量及产量构成因素的影响 .结果表明 ,FACE处理对水稻株高和主茎叶片数没有明显影响 ,但使水稻生育进程加快 ,全生育期显著缩短 ,增加施N量可减缓FACE处理对水稻全生育期缩短的程度 ;FACE处理能显著增加分蘖数 ,极显著增加穗数 ,提高结实率 ,但使每穗颖花数显著减少 ;FACE处理能显著提高水稻产量 ,在高N条件下增产幅度更大 ;提高FACE处理的每穗颖花数和单位面积颖花数能极显著提高水稻产量 ,增加施N量是提高FACE处理每穗颖花数和单位面积颖花数的重要措施 .     

木本植物对CO2浓度和温度升高的相互作用的响应

CO2浓度和温度是影响木本植物生长和发育的两个关键因子,二者在全球变化中的相互作用对木本植物生长和发育具有显著的影响。大多数研究表明：CO2浓度增加和温度升高的相互作用可能影响木本植物的生长发育,促进光合作用;呼吸作用对CO2浓度增加和温度升高的相互作用存在长期和短期响应差异;二者的相互作用促进生物量增加和生产力的增长。木本植物对CO2浓度和温度升高的相互作用的响应程度因植物种类而异。     

开放式空气CO2浓度增高对水稻N素吸收利用的影响

在大田栽培条件下 ,研究空气中CO2 浓度增高 (FACE) 2 0 0 μmol·mol-1对水稻N素吸收及其利用效率的影响 .结果表明 ,FACE处理使水稻不同生育时期的植株含N率显著下降 ;由于干物质生产量显著增大 ,FACE处理使水稻不同生育时期的N素累积量有所提高 ,但无显著影响 ;FACE处理能够显著提高移栽后 2 8d、抽穗期以及成熟期单位N素的干物质生产效率、单位N素的籽粒生产效率和显著提高水稻的N素收获指数 .高N处理的植株含N率、N素累积量均有所增加 ,但使N素生产效率呈现下降趋势 .     

开放式空气CO2浓度增高条件下旱地土壤气体CO2浓度廓线测定

设计了一套适合于FACE(free airCO2 enrichment)平台的旱地土壤气体CO2 浓度廓线测定方法 ,并将其应用于田间实验 .在江苏省无锡市郊区具有太湖地区典型水稻土的稻麦轮作农田 ,对FACE和对照麦田以及裸土 0～ 30cm土层的土壤气体CO2 浓度廓线进行了观测研究 .结果表明 ,所采用的方法满足进行旱地农田土壤气体CO2 浓度廓线研究的要求 ;在 0～ 30cm土层中 ,上层土壤气体中的CO2 向上垂直扩散要比下层土壤快 ;在作物旺盛生长期 ,大气CO2 浓度升高 2 0 0± 4 0 μmol·mol-1使 0～ 30cm土层的土壤气体CO2 浓度显著提高 14 %± 5 % (t 检验P <0 .0 0 1) .     

开放式空气二氧化碳浓度增高对小麦产量形成的影响

利用农田开放式空气CO₂浓度增高(FACE)系统平台,以弱筋小麦宁麦9号为供试品种,研究大气CO₂浓度增高和不同施氮水平对小麦生育期、株高、产量和产量构成因素的影响.结果表明：FACE处理的小麦播种至抽穗期、抽穗至成熟期及全生育期天数分别比对照缩短1.3、1.3和2.6 d,但均未达到显著水平;FACE处理的小麦穗长、穗下第1和第2节间长度显著变长,成熟期株高显著增加,比对照增加4.0%;低、中、高氮条件下,FACE处理小麦的籽粒产量分别比对照提高15.2%、21.4%和35.4%,平均增产24.6%,均达极显著水平;FACE处理小麦的单位面积穗数极显著增加,比对照增加17.8%,使穗粒数和粒重显著增加,分别比对照增加了2.9%和4.8%.FACE处理使小麦显著增产主要是由于单位面积穗数显著增加,而单位面积穗数的增加主要是由于小麦的分蘖能力明显增强所致.     

水稻生长及其体内C、N、P组成对开放式空气CO2浓度增高和N、P施肥的响应

采用FACE（Free Air Carbon-dioxide Enrichment)技术,研究了不同N、P施肥水平下,水稻分蘖期、拔节期、抽穗期和成熟期根、茎、穗生长,C/N比、N、P含量及N、P吸收对大气CO2浓度升高的响应,结果表明,高CO2促进水稻茎、穗和根的生长,增加分蘖期叶干重,对拔节期、抽穗期的成熟期叶干重没有显著增加,降低茎、叶N含量;增加抽穗期穗N含量;降低成熟期穗N含量;对分蘖期根N含量影响不显著,而降低拔节期,抽穗期和成熟期根N含量,增加拔节期、抽穗期和成熟期叶P含量,对茎、穗、根P含量影响不显著,水稻各组织C含量变化不显著,C/N比增加,显著增加水稻地上部分P吸收;增加N吸收,但没有统计显著性,N、P施用对水稻各组织生物量没有显著影响,高N（HN）比低N（LN）增加组织中N含量,而不同P肥水平间未表现出明显差异,高N条件下高CO2增加水稻成熟期地下部分/地上部分比,文中还讨论了高CO2对N、P含量及地下部分/地上部分比的影响机制。     

CO2浓度升高和降水增加协同作用对玉米产量及生长发育的影响

关于[CO₂]升高和降水变化等多因子共同作用对植物的影响报道较少, 制约着人们对植物对全球气候变化响应的认识和预测。玉米(Zea mays)作为重要的C₄植物, 受[CO₂]和降水影响显著, 但鲜有[CO₂]升高和降水增加协同作用对其产量及生长发育影响的报道。该研究利用开顶式生长箱模拟[CO₂]升高(390 (环境)、450和550 μmol·mol^-1), 降水增加量设置为增加自然降水量的15% (以试验地锦州1981-2010年6至8月月平均降水量为基准), 从而形成6个处理: C₅₅₀W_+15%、C₅₅₀W₀、C₄₅₀W_+15%、C₄₅₀W₀、C₃₉₀W_+15%和C₃₉₀W₀。试验材料选用玉米品种‘丹玉39’。结果表明: [CO₂]升高和降水增加的协同作用在玉米的籽粒产量和生物产量上均达到了显著水平(p< 0.05), 二因子均起正作用, 使籽粒产量和生物产量均升高。籽粒产量在[CO₂] 390、450和550 μmol·mol^-1水平下的降水增加处理较自然降水处理分别增加15.94%、9.95%和9.45%, 而生物产量分别增加13.06%、8.13%和6.49%。因为籽粒产量的增幅略大于生物产量的增幅, 所以促进了经济系数的升高。穗部性状变化显著, 其中, 穗粒数、穗粒重、穗长和穗粗等性状值均随[CO₂]升高而升高, 且各[CO₂]水平下均表现为降水增加处理>自然降水处理, 而瘪粒数相反。但是, [CO₂]升高和降水增加的协同作用也促进了轴粗的升高, 对玉米产量的增加起着限制作用。二因子协同作用在净光合速率(P_n)和叶面积上达到了极显著水平(p< 0.01), 而在株高和干物质积累量上达到了显著水平(p< 0.05)。二因子协同作用使玉米叶片的P_n升高, 植株高度升高, 穗位高升高, 茎粗增加, 叶面积变大, 从而促进了干物质积累量的升高, 为玉米增产打下了良好的基础。这表明: 在未来[CO₂]升高条件下, 一定程度的降水增加对玉米的产量具有正向促进作用。     

开放式空气中CO2浓度增高(FACE)对水稻生长和发育的影响

人类活动导致的大气和气候变化将极大地改变作物的生长环境,其中最大的一个变化就是大气二氧化碳(CO2)浓度的迅速上升:从工业革命前的平均270μmol/mol上升到目前的381μmol/mol,到2050年至少超过550μmol/mol。FACE(Free-air CO2 enrichment,开放式空气中CO2浓度增高)试验是目前评估未来高浓度CO2对作物生长和产量实际影响的最佳方法。水稻无疑是人类最重要的食物来源,迄今为止人类利用FACE技术开展水稻响应和适应的研究已有10a(19982008年)的历史。以生长发育为主线,首次系统综述了10a水稻FACE试验在该领域的研究成果,总结了FACE情形下高浓度CO2(模拟本世纪中叶大气CO2浓度)对主要供试水稻品种(小区面积大于4m2)光合作用、生育进程、地上部生长、地下部生长、物质分配、籽粒灌浆、产量构成以及倒伏性状等影响的研究进展,比较了FACE与非FACE研究之间以及中国和日本FACE研究(世界上唯一的两个大型水稻FACE研究)之间的异同点。根据研究进展以及当前的技术水平,文章最后提出了该领域的3个优先课题:(1)FACE情形下杂交稻生产力响应高于预期的生物学机制;(2)FACE情形下CO2与主要栽培措施的互作效应;(3)FACE情形下CO2与主要空气污染物臭氧的互作效应。这些响应的机理性解析将有助于从根本上减少人类预测未来粮食安全的不确定性,进而更加有效地制订出应对全球变化的适应策略。     

28种园林植物对大气CO2浓度增加的生理生态反应

通过对28种园林植物在不同CO2浓度水平下的气体交换参数的观测,分析了净光合速率、气孔导度、蒸腾速率和水分利用效率等生理生态指标的变化趋势与规律.结果表明,所测植物净光合速率和水分利用效率随CO2浓度升高而线性增加,但不同植物种类对高CO2浓度的反应存在较大差异.气孔导度和蒸腾速率与CO2浓度呈线性负相关关系.当CO2浓度倍增(350～700 μmol·mol-1)时,28种园林植物净光合速率平均提高31.2%,气孔导度降低16.5%,蒸腾速率下降11.7%,而水分利用效率则提高了49.2%.不同光合途径的植物净光合速率和水分利用效率受CO2浓度增加的影响程度为C3植物较大,C4植物较小, CAM植物介于两者之间.对不同生活型植物而言,影响程度则为草本C3植物较大,乔木C3植物较小,灌木C3植物居于两者之间.     

开放式空气CO2浓度增高对水稻冠层微气候的影响

利用位于江苏省无锡市安镇的我国唯一的农田开放式空气CO2 浓度增高 (FACE)系统平台 ,于2 0 0 1年 8月 2 6日至 10月 13日 (水稻抽穗至成熟期 )进行水稻作物冠层微气候连续观测 ,以研究FACE对水稻冠层微气候特征的影响 .结果表明 ,FACE降低了水稻叶片的气孔导度 ,FACE与对照水稻叶片气孔导度的差异上层叶片大于下层叶片 ,生长前期大于生长后期 .FACE使白天水稻冠层和叶片温度升高 ,这种差异生长前期大于生长后期 ;但FACE对夜间水稻冠层温度的影响不明显 .在水稻旺盛生长的抽穗开花期 ,晴天正午前后FACE水稻冠层温度比对照高 1.2℃ ;从开花至成熟期 ,FACE水稻冠层白天平均温度比对照高 0 .4 3℃ .FACE对冠层空气温度也有影响 ,白天水稻冠层空气温度FACE高于对照 ,这种差异随太阳辐射增强而增大且冠层中部大于冠层顶部 ;冠层中部空气温度FACE与对照的差异 (Tface-Tambient)日最大值在 0 .4 7～ 1.2℃之间 ,而冠层顶部的Tface-Tambient日最大值在 0 .37～ 0 .8℃之间 .夜间水稻冠层空气温度FACE与对照差别不大 ,变化在± 0 .3℃之内 .而FACE对水稻冠层空气湿度无显著影响 ,表明FACE使水稻叶片气孔导度降低 ,从而削弱了植株的蒸腾降温作用 ,导致水稻冠层温度和冠层空气温度升高 ,改变了整个水稻冠层的温度环     

开放式空气CO2浓度增高(FACE)对稻田土壤微生物的影响

1　引　　言公元 175 0年前 ,大气ＣＯ2 浓度基本保持 2 80 μｍｏｌ·ｍｏｌ-1左右 .工业革命后 ,其浓度逐渐上升 ,上升速度在 196 0年后加快 ,其中 80年代以来上升最快 .从 80年代到 90年代期间 ,ＣＯ2 浓度从 330 μｍｏｌ·ｍｏｌ-1增加到 35 4 μｍｏｌ·ｍｏｌ-1,平均每年递增 1.8μｍｏｌ·ｍｏｌ-1[2 ] .据ＩＰＣＣ(1995 )估计 ,到 2 1世纪末 ,ＣＯ2 浓度将由目前的 35 5 μｍｏｌ·ｍｏｌ-1上升到 70 0 μｍｏｌ·ｍｏｌ-1.这势必对整个生物界和地球生态环境产生深刻的影响 .因此 ,国内外已开展了大量的研究工作 ,获得了许多研究结…     

Warming and free-air CO2 enrichment alter demographics in four co-occurring grassland species

Species differ in their responses to global changes such as rising CO(2) and temperature, meaning that global changes are likely to change the structure of plant communities. Such alterations in community composition must be underlain by changes in the population dynamics of component species. Here, the impact of elevated CO(2) (550 micromol mol(-1)) and warming (+2 degrees C) on the population growth of four plant species important in Australian temperate grasslands is reported. Data collected from the Tasmanian free-air CO(2) enrichment (TasFACE) experiment between 2003 and 2006 were analysed using population matrix models. Population growth of Themeda triandra, a perennial C(4) grass, was largely unaffected by either factor but population growth of Austrodanthonia caespitosa, a perennial C(3) grass, was reduced substantially in elevated CO(2) plots. Warming and elevated CO(2) had antagonistic effects on population growth of two invasive weeds, Hypochaeris radicata and Leontodon taraxacoides, with warming causing population decline. Analysis of life cycle stages showed that seed production, seedling emergence and establishment were important factors in the responses of the species to global changes. These results show that the demographic approach is very useful in understanding the variable responses of plants to global changes and in elucidating the life cycle stages that are most responsive.     

稻米品质性状对开放式空气二氧化碳浓度增高的响应

利用开放式空气CO2浓度增高(FACE)系统平台。研究大田栽培条件下粳稻武香粳14号稻米品质性状对CO2浓度增高200μmol·mol^-1的响应。结果表明．FACE处理稻谷的出糙率平均比CK高1．4个百分点,整精米率平均比CK低12．3个百分点,较低的供N水平有利于提高FACE条件下的出糙率．较高的供N水平有利于提高FACE条件下的整精米率;FACE处理的稻米垩白略有增加。垩白粒率平均比CK高11．9个百分点,垩白度平均比CK平均高2．8个百分点,较高的供N和供P水平有利于降低FACE条件下垩白大小、垩白粒率和垩白度;FACE处理稻米糊化温度平均比CK平均高0．52℃,胶稠度有提高的趋势,但对稻米直链淀粉含量影响较小,较高的供N和供P水平有利于降低FACE条件下稻米的直链淀粉含量,较低的供N和较高的供P水平有利于降低FACE条件下稻米胶稠度,较低的供N水平有利于降低FACE条件下稻米糊化温度;FACE处理使稻米蛋白质含量比CK平均低0．6个百分点,较低的供N和供P水平有利于降低FACE条件下稻米蛋白质含量。     

Crop responses to CO2 enrichment

Carbon dioxide is rising in the global atmosphere, and this increase can be expected to continue into the foreseeable future. This compound is an essential input to plant life. Crop function is affected across all scales from biochemical to agro-ecosystem. An array of methods (leaf cuvettes, field chambers, free-air release systems) are available for experimental studies of CO₂ effects. Carbon dioxide enrichment of the air in which crops grow usually stimulates their growth and yield. Plant structure and physiology are markedly altered. Interactions between CO₂ and environmental factors that influence plants are known to occur. Implications for crop growth and yield are enormous. Strategies designed to assure future global food security must include a consideration of crop responses to elevated atmospheric CO₂. Future research should include these targets: search for new insights, development of new techniques, construction of better simulation models, investigation of belowground processes, study of interactions, and the elimination of major discrepancies in the scientific knowledge base.     

Productivity and water use of wheat under free-air CO2 enrichment

A free-air CO₂ enrichment (FACE) experiment was conducted at Maricopa, Arizona, on wheat from December 1992 through May 1993. The FACE apparatus maintained the CO₂ concentration, [CO₂], at 550 μmol mol^?1 across four replicate 25-m-diameter circular plots under natural conditions in an open field. Four matching Control plots at ambient [CO₂] (about 370 μmol mol^?1) were also installed in the field. In addition to the two levels of [CO₂], there were ample (Wet) and limiting (Dry) levels of water supplied through a subsurface drip irrigation system in a strip, split-plot design. Measurements were made of net radiation, R_n; soil heat flux, G_o; soil temperature; foliage or surface temperature; air dry and wet bulb temperatures; and wind speed. Sensible heat flux, H, was calculated from the wind and temperature measurements. Latent heat flux, λET, and evapotranspiration, ET, were determined as the residual in the energy balance. The FACE treatment reduced daily total R_n by an average 4%. Daily FACE sensible heat flux, H, was higher in the FACE plots. Daily latent heat flux, λET, and evapotranspiration, ET, were consistently lower in the FACE plots than in the Control plots for most of the growing season, about 8% on the average. Net canopy photosynthesis was stimulated by an average 19 and 44% in the Wet and Dry plots, respectively, by elevated [CO₂] for most of the growing season. No significant acclimation or down regulation was observed. There was little above-ground growth response to elevated [CO₂] early in the season when temperatures were cool. Then, as temperatures warmed into spring, the FACE plants grew about 20% more than the Control plants at ambient [CO₂], as shown by above-ground biomass accumulation. Root biomass accumulation was also stimulated about 20%. In May the FACE plants matured and senesced about a week earlier than the Controls in the Wet plots. The FACE plants averaged 0.6 °C warmer than the Controls from February through April in the well-watered plots, and we speculate that this temperature rise contributed to the earlier maturity. Because of the acceleration of senescence, there was a shortening of the duration of grain filling, and consequently, there was a narrowing of the final biomass and yield differences. The 20% mid-season growth advantage of FACE shrunk to about an 8% yield advantage in the Wet plots, while the yield differences between FACE and Control remained at about 20% in the Dry plots.     

开放式空气CO2增高对水稻物质生产与分配的影响

在大田栽培条件下,研究开放式空气CO2增加(FACE)200μmol·mol^-1的处理对水稻物质生产与分配的影响．结果表明,FACE处理使移栽至抽穗后20d的干物质积累量显著增加,使抽穗后20d至成熟期的干物质生产量显著减少,生物产量显著提高．移栽至抽穗期的干物质积累量增加是由于叶面积系数和净同化率共同提高所致;抽穗期至抽穗后20d的干物质积累量增加主要是由于叶面积系数的增加所致;抽穗后20d至成熟期的干物质生产量减少主要是由于净同化率的下降所造成．提高茎鞘占全株干物重的比例,降低叶片占全株干物重的比例,对穗占全株干物重的比例无显著影响,能显著提高水稻抽穗期茎鞘中可溶性糖、淀粉的含有率和含量,提高FACE处理的生物产量能极显著提高水稻产量(r＝0．7825)．     

Responses of Plant Dark Respiration to Doubled CO2 Concentration

Ten species of plants were grown at ambient (350μmol CO2·mol-1 air) and doubled (700 μmol CO2·mol-1 air) CO2 concentrations at ambient temperature and illumination in order to examine changes of dark respiration of whole seedlings or detached leaves. Effects of CO2 on dark respiration were determined by brief exposure ( ≤ 5 min) to corresponding CO2 concentration and temperatures ( 15,20,25,30 and 35 ℃ ) with infrared CO2 analyzer. The reductions in dark respiration on a weight base for leaves of East-Liaoning oak (Quercus liaotungensis Koidz. ) at 15,20 and 25 ℃ and of soybean ( Glycine max L. ) at 20,25,30 and 35 ℃ and for whole seedlings of three- tcoloured amaranth (Amaranthus tricolor L. ) at 15 and 20 ℃ and cucumber ( Cucumis sativus L. ) at 15 cE measured at elevated concentration relative to the ambient CO2 concentration were observed. No significant difference in respiration responded was observed to elevated or ambient CO2 concentrations at 15 ℃ in maize (Zea mays L. ) seedlings and alfalfa (Medicago sativa L. ) leaves, at 35 ℃ in East-Liaoning oak leaves and at 20,25 and 30 ℃ in three-coloured amaranth seedlings. However CO2 efflux in leaves of weeping willow (Salix babylonica L. ), simon poplar (Populus simonii Carr. ) and eucommia (Eucommia ulmoides Oliv. ) at 15,20,25,30 and 35 ℃, alfalfa at 20,25,30 and 35 ℃, East-Liaoning oak at 30 ℃, maize at 15 ℃, seedlings of common buckwheat (Fagotrytum esculentum Moench) at 15,20,25,30 and 35 ℃, cucumber and maize at 20,25,30 and 35 ℃ and three-coloured amaranth at 35 ℃ showed an increase at elevated in contrast to ambient CO2 concentration. In general, at lower temperatures (i. e. 15, 20 ℃ ) there was no significant difference between elevated and ambient CO2 concentration for dark respiration, while at higher temperatures (i. e. 30,35 ℃ ) elevated CO2 concentration positively stimulate clark respiretion. It has not yet been described that double CO2 concentration could enhance plant dark respiration at 30 and 35 ℃. Impacts of the characteristics in dark respiration on the future changes of vegetation and its mechanism were discussed.