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大气二氧化碳浓度升高对植物-昆虫相互关系的影响 总被引:4,自引:0,他引:4
综述了CO2浓度升高对植物与昆虫相互关系影响的研究结果。大量研究表明,高浓度CO2对植物生理生化活动有显著的影响,植物营养物质的变化对植食性昆虫亦产生不同程度的影响,高浓度CO2条件对咀嚼式口器昆虫的取食、生长发育和生殖有不同程度的不良影响,昆虫为了获得足够的氮素营养而增加取食强度和时间,从而更易于受到天敌的攻击,这些昆虫的生长率、繁殖和生存率有下降的趋势;而对刺吸韧皮部汁液的昆虫来说,多引起种群数量增加或无显著影响。并对研究中存在的问题进行了分析,提出了今后研究的方向。 相似文献
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Influence of plant diversity and elevated atmospheric carbon dioxide levels on belowground bacterial diversity 总被引:1,自引:0,他引:1
Background
Changes in aboveground plant species diversity as well as variations of environmental conditions such as exposure of ecosystems to elevated concentrations of atmospheric carbon dioxide may lead to changes in metabolic activity, composition and diversity of belowground microbial communities, both bacterial and fungal. 相似文献4.
T. Ellis P.W. Hill N. Fenner G.G. Williams D. Godbold C. Freeman 《Ecological Engineering》2009,35(6):978-986
The effects of elevated atmospheric CO2 (eCO2) and water table draw-down on soil carbon sequestration in an ombrotrophic bog ecosystem were examined. Peat monoliths (11 cm diameter, 25 cm deep) with intact bog vegetation were exposed to ambient or elevated (ambient + 200 mg l?1) atmospheric CO2, combined with a natural water table (level with the peat surface) or a water table draw-down (?5 cm). Eight observations per treatment were included in the study, which was conducted over a 12 week period. Concentration of dissolved organic carbon (DOC), phenolic compounds and the fluxes of CO2 and CH4 were measured. The eCO2 treatment caused an increase in the CH4 and CO2 fluxes and a small decrease in both the DOC and phenolic concentrations. The water table draw-down invoked decreases in phenolic and DOC concentrations, a decrease in CH4 flux and a small increase in CO2 flux. The combined (eCO2 + water table draw-down) treatment caused a larger than expected CH4 flux decrease and CO2 flux increase and an increase in DOC concentration. Our results suggest very different effects on the system dependent on the treatment applied. The draw-down treatment principally increased oxidation of the rhizosphere resulting in increased decomposition and as such a removal of material from the dissolved carbon pool. The data also suggest labile carbon availability may be limiting the rate of decomposition and so slowing inorganic nutrient and carbon pool turn-over. The elevated CO2 addressed the labile-carbon limitation. Under the environment of the combined treatment, these limitations were effectively removed, culminating in a destabilisation of the carbon-sequestering environment to a weaker sink (or even a source) of atmospheric carbon. 相似文献
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Effects of elevated carbon dioxide, ozone and water availability on spring wheat growth and yield 总被引:2,自引:0,他引:2
Håkan Pleijel Johanna Gelang Ebe Sild Helena Danielsson Suhaila Younis Per-Erik Karlsson Göran Wallin Lena Skärby Gun Selldén 《Physiologia plantarum》2000,108(1):61-70
Spring wheat (Triticum aestivum L. cv. Dragon) was exposed to elevated carbon dioxide (CO2), alone (1995) or in combination with two levels of increased ozone (O3) (1994) or increased irrigation (1996) during three successive growing seasons as part of the EU ESPACE‐wheat programme and conducted in open‐top chambers (OTCs) and ambient air (AA) plots at Östad, 50 km north‐east of Göteborg, Sweden. Doubling the CO2 concentration had a positive effect on grain yield in all 3 years (+21, +7 and +11%, respectively), although only statistically significant in 1994. That year was characterised by a warm and dry summer in comparison with 1995 and 1996, in which the summers were more humid and typical for south‐west Sweden. In 1994, the CO2‐induced increase in grain yield was associated with an increase in the duration of the green leaf area, a positive effect on straw yield and on the number of ears per square metre and a negative effect (?13%) on grain protein concentration. Harvest index was unaffected by the elevated CO2 concentration. The only statistically significant effect of elevated CO2 in 1995 was a decrease in the grain protein concentration (?11% in both CO2 concentrations), and in 1996 an increase (+21%) in the straw yield. In 1996 the soil water potential was less negative in elevated CO2, which is likely to reflect a lower water consumption of these plants. Addition of extra O3 significantly affected the grain yield (?6 and ?10%, respectively) and the 1 000‐grain weight negatively (?3 and ?6%). Statistically significant interactions between CO2 and O3 were obtained for the number of ears per unit area and for the 1 000‐grain weight. The 1 000‐grain weight was negatively affected by O3 in low CO2, but remained unaffected in the high CO2 treatment. There was a significant decrease (?6%) in the grain protein concentration induced by elevated irrigation. The chambers, compared with AA plots, had a positive effect on plant development and on grain yield in all 3 years. 相似文献
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大气中CO2浓度升高对植物的影响 总被引:6,自引:0,他引:6
大气中CO_2浓度升高以及由此所引起的温室效应已成为人们普遍关注的议题。在未来的世界里,CO_2浓度将持续上升。预计到21世纪中叶,CO_2浓度可能达到700ppm。一些试验结果表明;CO_2浓度升高对多数植物的个体生长发育有促进作用,其中包括种子的发芽率提高,幼苗生长加快,叶面积增大,根系数量增多,气孔数量减少,茎干生长轮加宽,开花期提早,种子产量提高等。但是,CO_2浓度升高对植物也有不利影响。在高CO_2浓度环境中,由于过量产生的碳水化合物在叶片中的积累和矿物质的不平衡,许多植物在生长后期生长缓慢或出现负增长;个体生长发育规律的变化将导致一些增长种群逐渐向衰退种群过渡;C_3类杂草的加速生长将引起农业欠收;群落结构与组成的变化将促使一些植物走向绝灭;植物残渣中碳氮比的改变将引起生态系统生产力的下降等。因此,对于今后大气中CO_2浓度升高的影响还要做大量的研究。 相似文献
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大气二氧化碳浓度升高对植物的影响 总被引:36,自引:0,他引:36
现代人类的活动,特别是矿场燃料的大量使用和植被的破坏,导致大气CO2浓度持续上升。该文阐述了CO2浓度升高对植物的形态、生理、产量和品质,种群消长,群落组成,生态系统结构与功能的影响。 相似文献
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The elevated concentration of atmospheric CO2 may result in a decline of leaf nutritional quality (especially N) and an increase in some kinds of defensive secondary components (such as phenolics). The changes in the phytochemistry of trees, combined with the effect of elevated CO2 per se, have a potential negative influence on insect herbivores. Here, we review the effect of elevated CO2 on the performance of leaf-feeding forest insects at individual-level and commu-nity-level. The elevated CO2 per se have little influence on the metabolism of insects. Over half of the tree-insect experimental systems show that the performance of individual insect become poorer under high-CO2 grown trees; but the others show that the insects have just little or no response to the treatments. The direction and magnitude of the changes in the performance of insects could be mediated by various factors. The effects of treatment are strongly species-dependent. The magni-tude of changes in the phytochemistry, the sensitivity and adaptive capacity of insects to the poorer leaf quality, the differences in plant growth conditions and experimental methods, and the mediated effects of other environmental factors (such as soil nutrient availability, light, temperature, O3) were all closely related to the final performance of insects. However, the larvae's consumption usually increased under enriched CO2 treatment, which was widely thought to be a compensa-tory response to poorer plant quality. The experiments on forest community-level found identically a reduction in herbivory, which was contrary to the results from small-scale experiments. The changes in insect popula-tion and the actual response of consumption by leaf-feeding forest insects under CO2 enrichment remain unclear, and more field-based experiments need to be conducted. 相似文献
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The elevated concentration of atmospheric CO2 may result in a decline of leaf nutritional quality (especially N) and an increase in some kinds of defensive secondary components
(such as phenolics). The changes in the phytochemistry of trees, combined with the effect of elevated CO2
per se, have a potential negative influence on insect herbivores. Here, we review the effect of elevated CO2 on the performance of leaffeeding forest insects at individual-level and community-level. The elevated CO2
per se have little influence on the metabolism of insects. Over half of the tree-insect experimental systems show that the performance
of individual insect become poorer under high-CO2 grown trees; but the others show that the insects have just little or no response to the treatments. The direction and magnitude
of the changes in the performance of insects could be mediated by various factors. The effects of treatment are strongly species-dependent.
The magnitude of changes in the phytochemistry, the sensitivity and adaptive capacity of insects to the poorer leaf quality,
the differences in plant growth conditions and experimental methods, and the mediated effects of other environmental factors
(such as soil nutrient availability, light, temperature, O3) were all closely related to the final performance of insects. However, the larvae’s consumption usually increased under
enriched CO2 treatment, which was widely thought to be a compensatory response to poorer plant quality. The experiments on forest community-level
found identically a reduction in herbivory, which was contrary to the results from small-scale experiments. The changes in
insect population and the actual response of consumption by leaf-feeding forest insects under CO2 enrichment remain unclear, and more field-based experiments need to be conducted.
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Translated from Chinese Journal of Applied Ecology, 2006, 17(4): 720–726 [译自: 应用生态学报] 相似文献
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大气CO2浓度升高对森林食叶昆虫的潜在影响 总被引:2,自引:0,他引:2
评述了大气CO2浓度升高对森林食叶昆虫的影响,昆虫对森林取食为害水平的潜在变化,以及研究中的主要实验方法.大气CO2浓度升高通过引起叶片化学变化进而影响食叶昆虫个体的取食和生长;但物种对环境变化反应的特异性、植物化学对高浓度CO2的反应强度、昆虫对植物生理变化的敏感性和适应性、研究周期的长短、其它环境因子的协同效应以及不同实验中植物生长条件和研究方法的差异均将影响昆虫反应的方向和强度;CO2气体浓度增高本身可能不足以对食叶昆虫个体的新陈代谢构成影响;大气CO2浓度升高也可能影响森林食叶昆虫种群的大小. 相似文献
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Influence of carbon dioxide on pulmonary vasculature 总被引:3,自引:0,他引:3
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Response of plant roots to elevated atmospheric carbon dioxide 总被引:10,自引:0,他引:10
H. H. ROGERS C. M. PETERSON J. N. McCRIMMON J. D. CURE 《Plant, cell & environment》1992,15(6):749-752
Plant root response to atmospheric CO2 enrichment can be great. Results from this controlled environment investigation demonstrate substantial effects on root system architecture, micromorphology and physiology. The most pronounced effects were an increase in root length (110%) and root dry weight (143%). Root diameter, stele diameter, cortex width, root/shoot and root weight ratios all increased; root numbers did not increase. The long-term implications for belowground processes could be enormous. 相似文献
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Responses of soil biota to elevated atmospheric carbon dioxide 总被引:16,自引:2,他引:14
Elizabeth G. O'Neill 《Plant and Soil》1994,165(1):55-65
Increasing concentrations of atmospheric CO2 could have dramatic effects upon terrestrial ecosystems including changes in ecosystem structure, nutrient cycling rates,
net primary production, C source-sink relationships and successional patterns. All of these potential changes will be constrained
to some degree by below ground processes and mediated by responses of soil biota to indirect effects of CO2 enrichment. A review of our current state of knowledge regarding responses of soil biota is presented, covering responses
of mycorrhizae, N-fixing bacteria and actinomycetes, soil microbiota, plant pathogens, and soil fauna. Emphasis will be placed
on consequences to biota of increasing C input through the rhizosphere and resulting feedbacks to above ground systems. Rising
CO2 may also result in altered nutrient concentrations of plant litter, potentially changing decomposition rates through indirect
effects upon decomposer communities. Thus, this review will also cover current information on decomposition of litter produced
at elevated CO2.
Summary Predictably, the responses of soil biota to CO2 enrichment and the degree of experimental emphasis on them increase with proximity to, and intimacy with, roots. Symbiotic
associations are all stimulated to some degree. Total plant mycorrhization increases with elevated CO2. VAM fungi increase proportionately with fine root length/mass increase. ECM fungi, however, exhibit greater colonization
per unit root length/mass at elevated CO2 than at current atmospheric levels. Total N-fixation per plant increases in all species examined, although the mechanisms
of increase, as well as the eventual benefit to the host relative to N uptake may vary. Microbial responses are unclear. The
assumption that changes in root exudation will drive increased mineralization and facilitate nutrient uptake should be examined
experimentally, in light of recent models. Microbial results to date suggest that metabolic activity (measured as changes
in process rates) is stimulated by root C input, rather than population size (measured by cell or colony counts). Insufficient
evidence exists to predict responses of either soil-borne plant pathogens or soil fauna (i.e., food web responses). These
are areas requiring attention, the first for its potential to limit ecosystem production through disease and the second because
of its importance to nutrient cycling processes. Preliminary data on foliar litter decomposition suggests that neither nutrient
ratios nor decomposition rates will be affected by rising CO2. This is another important area that may be better understood as the number of longer term studies with more realistic CO2 exposures increase. Evidence continues to mount that C fixation increases with CO2 enrichment and that the bulk of this C enters the belowground component of ecosystems. The global fate and effects of this
additional C may affect all hierarchical levels, from organisms to ecosystems, and will be largely determined by responses
of soil biota. 相似文献
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Soil carbon dioxide partial pressure and dissolved inorganic carbonate chemistry under elevated carbon dioxide and ozone 总被引:1,自引:0,他引:1
Global emissions of atmospheric CO2 and tropospheric O3 are rising and expected to impact large areas of the Earths forests. While CO2 stimulates net primary production, O3 reduces photosynthesis, altering plant C allocation and reducing ecosystem C storage. The effects of multiple air pollutants can alter belowground C allocation, leading to changes in the partial pressure of CO2 (pCO2) in the soil , chemistry of dissolved inorganic carbonate (DIC) and the rate of mineral weathering. As this system represents a linkage between the long- and short-term C cycles and sequestration of atmospheric CO2, changes in atmospheric chemistry that affect net primary production may alter the fate of C in these ecosystems. To date, little is known about the combined effects of elevated CO2 and O3 on the inorganic C cycle in forest systems. Free air CO2 and O3 enrichment (FACE) technology was used at the Aspen FACE project in Rhinelander, Wisconsin to understand how elevated atmospheric CO2 and O3 interact to alter pCO2 and DIC concentrations in the soil. Ambient and elevated CO2 levels were 360±16 and 542±81 l l–1, respectively; ambient and elevated O3 levels were 33±14 and 49±24 nl l–1, respectively. Measured concentrations of soil CO2 and calculated concentrations of DIC increased over the growing season by 14 and 22%, respectively, under elevated atmospheric CO2 and were unaffected by elevated tropospheric O3. The increased concentration of DIC altered inorganic carbonate chemistry by increasing system total alkalinity by 210%, likely due to enhanced chemical weathering. The study also demonstrated the close coupling between the seasonal 13C of soil pCO2 and DIC, as a mixing model showed that new atmospheric CO2 accounted for approximately 90% of the C leaving the system as DIC. This study illustrates the potential of using stable isotopic techniques and FACE technology to examine long- and short-term ecosystem C sequestration. 相似文献
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Increased mercury in forest soils under elevated carbon dioxide 总被引:1,自引:0,他引:1
Fossil fuel combustion is the primary anthropogenic source of both CO2 and Hg to the atmosphere. On a global scale, most Hg that enters ecosystems is derived from atmospheric Hg that deposits
onto the land surface. Increasing concentrations of atmospheric CO2 may affect Hg deposition to terrestrial systems and storage in soils through CO2-mediated changes in plant and soil properties. We show, using free-air CO2 enrichment (FACE) experiments, that soil Hg concentrations are almost 30% greater under elevated atmospheric CO2 in two temperate forests. There were no direct CO2 effects, however, on litterfall, throughfall or stemflow Hg inputs. Soil Hg was positively correlated with percent soil organic
matter (SOM), suggesting that CO2-mediated changes in SOM have influenced soil Hg concentrations. Through its impacts on SOM, elevated atmospheric CO2 may increase the Hg storage capacity of soils and modulate the movement of Hg through the biosphere. Such effects of rising
CO2, ones that transcend the typically studied effects on C and nutrient cycling, are an important next phase for research on
global environmental change. 相似文献
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Previous work indicated that long-term exposure to elevated carbon dioxide levels can reduce hydraulic conductance in some species, but the basis of the response was not determined. In this study, hydraulic conductance was measured at concentrations of both 350 and 700 cm3 m–3 carbon dioxide for plants grown at both concentrations, to determine the reversibility of the response. In Zea mays and Amaranthus hypochondriacus , exposure to the higher carbon dioxide concentration for several hours reduced whole-plant transpiration rate by 22–40%, without any consistent change in leaf water potential, indicating reversible reductions in hydraulic conductance at elevated carbon dioxide levels. Hydraulic conductance in these species grown at both carbon dioxide concentrations responded similarly to measurement concentration of carbon dioxide, indicating that the response was reversible. In Glycine max , which in earlier work had shown a long-term decrease in hydraulic conductance at elevated carbon dioxide levels, and in Abutilon theophrasti , no short-term changes in hydraulic conductance with measurement concentration of carbon dioxide were found, despite lower transpiration rates at elevated carbon dioxide. In G. max and Medicago sativa , growth at high dew-point temperature reduced transpiration rate and decreased hydraulic conductance. The results indicate that both reversible and irreversible decreases in hydraulic conductance can occur at elevated carbon dioxide concentrations, and that both could be responses to reduced transpiration rate, rather than to carbon dioxide concentration itself. 相似文献