Carbon dioxide partial pressure in the columbia river

Columbia River water is supersaturated with respect to atmospheric carbon dioxide by 200 to 870 parts per million. An equilibrium exists between the carbon dioxide partial pressure and pH, and Henry's law is obeyed in this natural water. The carbon dioxide pressure can be calculated by a determination of the pH, total carbon dioxide, and temperature.     

典型气候/环境因子变化对九段沙湿地碳固定潜力的影响

利用人工气候室模拟长江口区域几种典型气候/环境因子的变化特征（全球变暖、CO2增加和海水无机氮污染加剧等）,并从植物生长量和土壤呼吸角度综合分析了这些气候/环境因素的变化对九段沙湿地土壤有机碳汇聚能力的影响。初步结果表明,在实验范围内,与对照相比,单方面的温度升高、无机氮污染加剧和CO2浓度升高会提高九段沙土壤的有机碳汇聚能力。无机氮污染加剧协同升温对土壤呼吸有一定的消减作用,从而提高了土壤有机碳汇聚能力;无机氮污染加剧协同CO2浓度升高会促使土壤有机碳的排放,使其碳汇聚能力下降;CO2浓度升高和全球升温的共同作用不会显著降低有机碳汇聚能力;无机氮污染加剧和CO2浓度升高的基础上加入升温的三因素交互作用会促进土壤有机碳的排放,使其碳汇聚能力下降。因此,要尽力避免海水中无机氮污染加剧和CO2浓度升高两个因素,以及在此基础上升温情况的同时发生。     

Mid-depth circulation of the subpolar north atlantic during the last glacial maximum

Holocene and glacial carbon isotope data of benthic foraminifera from shallow to mid-depth cores from the northeastern subpolar Atlantic show that this region was strongly stratified, with carbon-13-enriched glacial North Atlantic intermediate water (GNAIW) overlying carbon-13-depleted Southern Ocean water (SOW). The data suggest that GNAIW originated north of the polar front and define GNAIW end-member carbon isotope values for studies of water-mass mixing in the open Atlantic. Identical carbon isotope values in the core of GNAIW and below the subtropical thermocline are consistent with rapid cycling of GNAIW through the northern Atlantic. The high carbon isotope values below the thermocline indicate that enhanced nutrient leakage in response to increased ventilation may have extended into intermediate waters. Geochemical box models show that the atmospheric carbon dioxide response to nutrient leakage that results from an increase in ventilation rate may be greater than the response to nutrient redistribution by conversion of North Atlantic deep water into GNAIW. These results underscore the potential rule of Atlantic Ocean circulation changes in influencing past atmospheric carbon dioxide values.     

基于Biome-BGC模型的千烟洲森林水分利用效率研究

目的为了探究全球气候变化背景下森林生态系统水分利用效率的影响因子及其对气候变化的响应。方法本文利用经PEST模型参数优化后的Biome-BGC模型,对千烟洲森林生态系统2000—2014（CK）年以及不同气候情景变化模式下的水分利用效率及其影响因子进行了探究。结果（1）千烟洲的年均温和最大叶面积指数同水分利用效率呈显著正相关关系（P < 0.01）,降水同水分利用效率间的相关性不显著（P > 0.05）。（2）千烟洲不同情景模式水分利用效率的取值区间是2.09 ~ 3.71 g/kg、均值2.90 g/kg。（3）同CK（2.18 ~ 2.57 g/kg、均值2.38 g/kg）相比,千烟洲各情景模式下大气CO₂浓度增加情景（2.38 ~ 3.41 g/kg、均值2.90 g/kg）、降水和大气CO₂浓度同时增加情景（2.38 ~ 3.33 g/kg、均值2.86 g/kg）、气温和大气CO₂浓度同时增加情景（2.58 ~ 3.71 g/kg、均值3.15 g/kg）、降水和气温同时增加（2.30 ~ 2.84 g/kg、均值2.57 g/kg）及降水、气温和大气CO₂浓度同时增加情景（2.70 ~ 3.60 g/kg、均值3.15 g/kg）的水分利用效率差异显著。但是,降水增加情景（2.09 ~ 2.68 g/kg、均值2.39 g/kg）和气温增加情景（2.13 ~ 2.81 g/kg、均值2.47 g/kg）对水分利用效率的影响不显著。（4）降水和大气CO₂浓度同时增加情景与大气CO₂浓度增加情景的水分利用效率差异不显著,气温和大气CO₂浓度同时增加情景与大气CO₂浓度增加情景的水分利用效率差异显著。结论（1）千烟洲森林生态系统的水分利用效率受到气温和叶面积指数的影响,情景分析表明水分利用效率能很好的对气候变化做出响应。（2）降水、气温和大气CO₂浓度对水分利用效率的影响存在耦合效应。（3）增温对水分利用效率的影响要大于降水。      

Equilibration of atmospheric carbon dioxide with sea water: possible enzymatic control of the rate

Surface and subsurface ocean water differ in exchange characteristics with atmospheric carbon dioxide. The possibility of control by an enzyme like carbonic anhydrase has been experimentally explored.     

影响甲烷排放量的两种细菌——产甲烷细菌和甲烷氧化菌的研究进展

产甲烷细菌能够利用环境中的甲酸、乙酸、氢和二氧化碳等小分子化合物生成甲烷,对提高沼气池的甲烷产量具有很高的经济价值。甲烷氧化菌以甲烷为其惟一的碳源和能源,在全球大气甲烷平衡中起着重要的作用。环境中的甲烷在厌氧生境中由产甲烷细菌形成后,经土壤和水层,逸散入大气,在途经土壤和水层时可被栖息于其间的甲烷氧化菌所氧化,土壤中甲烷氧化细菌的氧化作用,大约占大气甲烷消耗量的10%,而且甲烷氧化菌能降解卤化碳氢化合物,具有潜在的商业价值。分别对两种细菌的形态、分类、生理特征、代谢途径、研究方法及其潜在应用价值等进行了综述。     

影响甲烷排放量的两种细菌——产甲烷细菌和甲烷氧化菌的研究进展

产甲烷细菌能够利用环境中的甲酸、乙酸、氢和二氧化碳等小分子化合物生成甲烷,对提高沼气池的甲烷产量具有很高的经济价值.甲烷氧化菌以甲烷为其惟一的碳源和能源,在全球大气甲烷平衡中起着重要的作用.环境中的甲烷在厌氧生境中由产甲烷细菌形成后,经土壤和水层,逸散入大气,在途经土壤和水层时可被栖息于其间的甲烷氧化菌所氧化,土壤中甲烷氧化细菌的氧化作用,大约占大气甲烷消耗量的10%,而且甲烷氧化菌能降解卤化碳氢化合物,具有潜在的商业价值.分别对两种细菌的形态、分类、生理特征、代谢途径、研究方法及其潜在应用价值等进行了综述.     

Atmospheric carbon dioxide: its role in maintaining phytoplankton standing crops

The rate of invasion of carbon dioxide into an artificially eutrophic Canadian Shield lake with insufficient internal sources of carbon was determined by two methods: measuring the carbon : nitrogen : phosphorus ratios of seston after weekly additions of nitrogen and phosphorus, and measuring the loss of radon-222 tracer from the epilimnion. Both methods gave an invasion rate of about 0.2 gram of carbon per square meter per day. The results demonstrate that invasion of atmospheric carbon dioxide may be sufficient to permit eutrophication of any body of water receiving an adequate supply of phosphorus and nitrogen.     

Foraminiferal calcification response to glacial-interglacial changes in atmospheric CO2

A record of foraminiferal shell weight across glacial-interglacial Termination I shows a response related to seawater carbonate ion concentration and allows reconstruction of a record of carbon dioxide in surface seawater that matches the atmospheric record. The results support suggestions that higher atmospheric carbon dioxide directly affects marine calcification, an effect that may be of global importance to past and future changes in atmospheric CO2. The process provides negative feedback to the influence of marine calcification on atmospheric carbon dioxide and is of practical importance to the application of paleoceanographic proxies.     

园林绿地固碳能力分析与研究进展

阐述了园林绿地植物的固碳能力,包括固碳能力测定方法,不同植物及不同形式植物配置的固碳能力,以及园林绿地植物固碳能力的影响因素,包括季节、大气污染物、绿地面积。探讨了园林绿地土壤碳汇,包括土壤碳储量测定方法、土壤碳含量分布特征及其影响因素,其中影响因素包括气候、植被类型、绿地类型、人为干扰、绿地建造时间。针对园林绿地碳循环研究的薄弱环节,从园林绿地系统碳循环机制,构建园林绿地碳循环模型,园林绿地碳库的稳定性维持机制,土壤碳循环过程与土壤水环境的耦合关系等方面,展望了今后的研究方向。     

3-PG生长模型及其在橡胶树栽培领域的应用

现代科技的飞速发展，使得计算机模拟林木的生长成为可能，3-PG模型充分考虑了林龄、温度、盐分、空气湿度、土壤肥力和含水量、霜冻天数等因子对光合作用的影响，通过一系列方程模拟碳量平衡、水量平衡、盐分平衡和太阳辐射变化，以此来模拟林分的动态生长过程。3-PG模型应用于橡胶树栽培具备了各种软、硬件方面的条件，期望能在可行性评估、规划、定产、水分、养分、病虫害防治、割胶、绩效等方面，实现精准栽培。     

Variations in the isotopic composition of carbon in urban atmospheric carbon dioxide

Measurement of the abundance of atmospheric carbon dioxide as an indicator of air pollution has been of very limited value because of variations in urban areas in the substantial concentration of natural carbon dioxide produced from combustion and noncombustion (natural) sources. A solution to this problem is the use of precise isotopic assay of ratios of carbon-13 to carbon-12 in atmospheric carbon dioxide. There is very little variation of carbon isotopic composition in samples taken over rural or urban areas where rapid mixing and diffusion of gaseous combustion products is possible. Significant differences in this composition in samples taken at centrally located points at street level in the lower Manhattan business district show an increase in concentration of atmospheric carbon dioxide of roughly 20 percent produced primarily by automobile exhaust.     

Carbon monoxide: residence time in the atmosphere

A lower limit of 0.1 year for the residence time of carbon monIoxide in the atmosphere is derived from radiocarbon measurements. The action of certain microorganisms and atmospheric photochemical reactions are possible mechanisms for the removal of carbon monoxide. This value can be compared with 2.7 years, a value deduced from estimated rates of carbon monoxide production and global measurements of atmospheric concentrations of carbon monoxide.     

CO_2体积分数升高对土壤-植物系统碳过程的影响

从土壤和植物2个方面,综述了大气二氧化碳体积分数升高对生态系统碳过程的影响。大气CO2体积分数升高,提高了植物的光合速率,促进了生物量的累积,改变了植物的碳结构。高CO2体积分数导致植物基质（C／N）的变化将直接影响枯落物的分解速率。大气CO2体积分数升高通过影响植物生长而间接地对土壤生态过程产生影响。由于高CO2体积分数下碳输入和输出的关系还存在很多不确定性,因此还不能推断高CO2体积分数下土壤碳库是增加还是减少。不同的生态系统类型,对高CO2体积分数的响应状况也不一致。今后应定量研究CO2体积分数升高条件下生态系统各分室碳库的动态,明确土壤、植物和大气碳库储量变化及其之间的碳通量,以便定量化生态系统碳收支对高CO2体积分数升高的响应。另外,还应加强CO2体积分数升高与其他全球变化因子的耦合作用研究,探讨其相互作用的机制,将有助于全面了解全球变化条件下生态系统的碳循环过程。     

Global warming and marine carbon cycle feedbacks on future atmospheric CO2

A low-order physical-biogeochemical climate model was used to project atmospheric carbon dioxide and global warming for scenarios developed by the Intergovernmental Panel on Climate Change. The North Atlantic thermohaline circulation weakens in all global warming simulations and collapses at high levels of carbon dioxide. Projected changes in the marine carbon cycle have a modest impact on atmospheric carbon dioxide. Compared with the control, atmospheric carbon dioxide increased by 4 percent at year 2100 and 20 percent at year 2500. The reduction in ocean carbon uptake can be mainly explained by sea surface warming. The projected changes of the marine biological cycle compensate the reduction in downward mixing of anthropogenic carbon, except when the North Atlantic thermohaline circulation collapses.     

铜陵城市森林建设综述

城市森林建设强调的是以人为本、人与自然和谐相处。绿化是基础,美化是补充,生态化是根本。建设铜陵城市森林,有利于强化城市之＂肺＂功能,能有效地保持大气中二氧化碳与氧气的平衡,缓解热岛效应和温室效应,净化水体,且能较好地稀释、分解、吸收和固定大气中的有毒、有害物质,减轻城市噪音和电磁波污染,从而大幅度提高城市空气质量。建设铜陵城市森林,必须走出认识上的误区：绿化的误区、美化的误区、亮化的误区、净化的误区。     

贵州省退耕还林工程生态服务功能价值评估

运用《退耕还林工程生态效益监测评估技术与管理规范》评估方法,对贵州省退耕林分定位监测数据及工程森林资源进行分析,并对贵州省退耕还林工程涵养水源、保育土壤、固碳释氧、积累营养物资、净化大气环境、生物多样性保护功能进行了物质量及价值量评估.结果表明：贵州省退耕还林工程森林生态服务功能总价值为631.1亿元/a,各项生态服务功能价值量从大到小顺序依次为：涵养水源、保护生物多样性、固碳释氧、净化大气环境、保育土壤、积累营养物质.     

Europe's terrestrial biosphere absorbs 7 to 12% of European anthropogenic CO2 emissions

Most inverse atmospheric models report considerable uptake of carbon dioxide in Europe's terrestrial biosphere. In contrast, carbon stocks in terrestrial ecosystems increase at a much smaller rate, with carbon gains in forests and grassland soils almost being offset by carbon losses from cropland and peat soils. Accounting for non-carbon dioxide carbon transfers that are not detected by the atmospheric models and for carbon dioxide fluxes bypassing the ecosystem carbon stocks considerably reduces the gap between the small carbon-stock changes and the larger carbon dioxide uptake estimated by atmospheric models. The remaining difference could be because of missing components in the stock-change approach, as well as the large uncertainty in both methods. With the use of the corrected atmosphere- and land-based estimates as a dual constraint, we estimate a net carbon sink between 135 and 205 teragrams per year in Europe's terrestrial biosphere, the equivalent of 7 to 12% of the 1995 anthropogenic carbon emissions.     

Influence of carbonic anhydrase activity in terrestrial vegetation on the 18O content of atmospheric CO2

The oxygen-18 (18O) content of atmospheric carbon dioxide (CO2) is an important indicator of CO2 uptake on land. It has generally been assumed that during photosynthesis, oxygen in CO2 reaches isotopic equilibrium with oxygen in 18O-enriched water in leaves. We show, however, large differences in the activity of carbonic anhydrase (which catalyzes CO2 hydration and 18O exchange in leaves) among major plant groups that cause variations in the extent of 18O equilibrium (theta(eq)). A clear distinction in theta(eq) between C3 trees and shrubs, and C4 grasses makes atmospheric C18OO a potentially sensitive indicator to changes in C3 and C4 productivity. We estimate a global mean theta(eq) value of approximately 0.8, which reasonably reconciles inconsistencies between 18O budgets of atmospheric O2 (Dole effect) and CO2.     

Atmospheric input of carbon dioxide from burning wood

The atmospheric input of carbon dioxide from burning wood, in particular from forest fires in boreal and temperate regions resulting from both natural and man-made causes and predominantly from forest fires in tropical regions caused by shifting cultivation, is estimated to be 5.7 x 10(15) grams of carbon per year as gross input and 1.5 x 10(15) grams of carbon per year as net input. This is a significant amount as compared to the fossil fuel carbon dioxide produced from the utilization of oil, gas, coal, and limestone, and bears on the hypothesis of the enhanced sedimentation of marine detritus as a removal mechanism of excess atmospheric carbon dioxide.