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971.
鄂尔多斯盆地苏里格地区奥陶系马家沟组马五段白云岩的地球化学特征 总被引:1,自引:0,他引:1
苏里格地区奥陶系马家沟组马五段白云岩是重要的油气储集层.多年来,马家沟组白云岩的成因一直是地质研究者讨论的热点话题.对苏里格地区马家沟组马五段白云岩的微量元素及C、O、Sr同位素地球化学资料的分析表明,微量元素表现为高铁、低锰、低锶、低钠;白云石、白云质角砾和孔洞充填白云岩的δ13C和δ18O值较为近似,且白云岩的δ1... 相似文献
972.
Two surveys were performed for determining bacteria biomass (BB), temperature, salinity, chlorophyll a (chl-a) and nutrient concentrations at 11 stations with three sampling depths in the high-incidence regions of red tide in the East
China Sea (ECS) in the spring of 2006. Temperature and salinity increased from nearshore to offshore region and from high
latitude to low latitude in the two cruises of 2006. BB were between 0.3–5.2 mgC m−3 (about 2.1 mgC m−3 on average) and 0.2–6.0 mgC m−3 (about 2.7 mgC m−3 on average) respectively in the two cruises. BB in the surface layer decreased from the Changjiang River estuary to high
sea and from low latitude to high latitude. The results showed that bacterial growth was regulated by temperature, primary
production and inorganic nutrient concentrations depending on different hydrographic conditions. In the surface and middle
layers where the primary production can supply enough organic substrate, temperature was the main factor to control bacteria
biomass. BB showed a good correlation between the surface and middle layers in both cruises. The distribution of nutrients
during both cruises showed a similar decreasing trend from nearshore region and high latitude to offshore region and low latitude.
High BB values were mainly recorded from samples in the middle layer where chl-a concentrations were also high, indicating primary production being strongly correlated with temperature over the ECS shelf.
In the offshore area, phosphate and silicate became limiting factors for phytoplankton growth with indirect influence on BB.
Bacteria played an important role in nitrogen regeneration process turning organic nitrogen to inorganic forms such as NH4
+. The increasing ratio of NH4
+/DIN could be a proof of that. 相似文献
973.
Zhen Tao Quanzhou Gao Wenping Guo Zhengang Wang Yongling Zhang Chenji Xie Xiakun Huang Hongwei Zhong 《山地科学学报》2011,8(5):694-703
A whole year analysis of riverine dissolved organic carbon (DOC) concentrations in the Xijiang River (XJR), South China, showed that the mean riverine DOC concentration (1.24 mg L-1) in the XJR was notably lower than the averaged value (5.75 mg L-1) of the global riverine DOC concentration in several major rivers. There is an inconspicuous monthly fluctuation of the DOC signal in the XJR, but on a semi-yearly time scale, however, the riverine DOC concentration had significant difference between hydrological... 相似文献
974.
人工经济林在中国南方种植面积大,并有不断增加的趋势.人工经济林生态系统受人为周期性经营活动影响比较大,是重要的流动性碳库.因此,选择福建省建瓯市万木林自然保护区内本地条件基本一致的毛竹(Phyllostachys heterocycla)、柑橘(Citrus reticulata Blanco)和锥栗(Castanea henryi)作为研究对象,探讨其土壤有机碳含量及其垂直分布特征,结果表明:3种林地土壤剖面有机碳含量的变化范围分别为毛竹林5.91~19.18 g.kg-1、柑橘5.70~13.31g.kg-1、锥栗3.84~10.78 g.kg-1,3种林地土壤有机碳含量随着深度的增加呈现递减趋势;3种林地0~20 cm、20~40 cm层土壤有机碳含量与40~60 cm、60~80 cm、80~100 cm各层均存在显著性差异(P<0.05);3种林地间土壤有机碳储量均存在显著性差异(P<0.05);使用对数方程对3种林地土壤有机碳含量随土壤深度的变化进行拟合均达到显著水平(P<0.05);土壤有机碳含量与土壤全N、C/N比之间存在一定的相关性,特别是3种林地土壤有机碳含量均与土壤全N含量的相关性最好(... 相似文献
975.
从亚高山森林到高山林线,逐渐严酷的生长环境影响了生物量的积累和分配.本研究采用相对生长法和样方收获法估算了藏东南色季拉山急尖长苞冷杉林在禾同海拔(4 190 m,4 270 m和4 326 m)的地上生物量,分析了群落中不同层次地上生物量、各器官生物量及其分配比例随海拔的变化格局.结果表明:1.急尖长苞冷杉群落地上生物量在181~284 t/hm2之间,其中,乔木层在11~-248 t/hm2,灌木层为35~62 t/hm2,草本层为0.9~1.5 t/hm2;2.群落地上生物量随海拔升高急剧降低,降低的平均幅度为73.1 t/(hm2·100 m);3.随海拔升高,群落地上生物量分配到非光合器官(树干和枝条)的比例显著降低,分配到叶的比例呈增加趋势.随海拔的增加,急尖长苞冷杉群落通过增加叶生物量所占比例(高叶寿命)以延长养分在植物体内的存留时间,提高生态系统的养分利用效率,从而适应高海拔地区的低温胁迫环境. 相似文献
976.
基于能源消费的中国不同产业空间的碳足迹分析 总被引:10,自引:2,他引:8
Using energy consumption and land use data of each region of China in 2007,this paper established carbon emission and carbon footprint model based on energy consumption,and estimated the carbon emission amount of fossil energy and rural biomass energy of dif-ferent regions of China in 2007.Through matching the energy consumption items with indus-trial spaces,this paper divided industrial spaces into five types:agricultural space,living & industrial-commercial space,transportation industrial space,fishery and water conservancy space,and other industrial space.Then the author analyzed the carbon emission intensity and carbon footprint of each industrial space.Finally,advices of decreasing industrial carbon footprint and optimizing industrial space pattern were put forward.The main conclusions are as following:(1) Total amount of carbon emission from energy consumption of China in 2007 was about 1.65 GtC,in which the proportion of carbon emission from fossil energy was 89%.(2) Carbon emission intensity of industrial space of China in 2007 was 1.98 t/hm2,in which,carbon emission intensity of living & industrial-commercial space and of transportation in-dustrial space was 55.16 t/hm2 and 49.65 t/hm2 respectively,they were high-carbon-emission industrial spaces among others.(3) Carbon footprint caused by industrial activities of China in 2007 was 522.34 106 hm2,which brought about ecological deficit of 28.69 106 hm2,which means that the productive lands were not sufficient to compensate for carbon footprint of industrial activities,and the compensating rate was 94.5%.As to the regional carbon footprint,several regions have ecological profit while others have not.In general,the present ecologi-cal deficit caused by industrial activities was small in 2007.(4) Per unit area carbon footprint of industrial space in China was about 0.63 hm2/hm2 in 2007,in which that of living & indus-trial-commercial space was the highest (17.5 hm2/hm2).The per unit area carbon footprint of different industrial spaces all presented a declining trend from east to west of China. 相似文献
977.
低碳旅游发展的困境与对策 总被引:2,自引:0,他引:2
低碳旅游尚处于起步阶段,发展中遇到了诸多困境。该文纵览国内外相关理论研究与实践结果,从旅游者碳排放认知、旅游业碳足迹测度和碳补偿措施有效性等方面,梳理与分析了低碳旅游发展的困境。提出理论上应从澄清相关概念、界定旅游业系统、统一碳足迹测度口径、旅游业碳排放影响等方面加强研究,实践上应从政府领导、主体参与、重点领域突破、多重措施并举等方面建立低碳旅游实施机制,以期丰富旅游环境研究视角,为我国低碳旅游发展提供理论指导和实践参考。 相似文献
978.
979.
980.
Dark respiration (non-photorespiratory mitochondrial respiration),which occurs both in the light and in darkness,is vital for growth and survival of algae and plays a critical role in modulating the carbon balance of them.In the present study,we have investigated dark respiration in the light (R L) and in darkness (R D) in three marine macroalgal species,Hizikia fusiformis (phaeophyta),Gracilaria lemaneiformis (Rhodophyta) and Ulva lactuca (Chlorophyta),cultured at 20℃ using aeration with two CO 2 conditions:current ambient (CO 2 concentration about 380 μl/L) and elevated CO 2 (approximately 720 μl/L) air.R L was estimated by using the Kok method,whereas R D was determined as the rate of O 2 influx at zero light.The results showed that both R L and R D were unchanged for the elevated CO 2-grown algae relative to ambient CO 2 concentration for all the algal species tested.However,R L was significantly lower than R D across all the algal species and growth CO 2 treatments,demonstrating that daytime respiration was partly depressed by the light.The percentage of inhibition of respiration by light was similar between ambient and elevated CO 2 grown algae.The ratio of respiration to photosynthesis,which tended to decrease when estimated using R L instead of R D,was not altered for the elevated relative to ambient CO 2 concentration.The results suggest that R L,rather than R D,is a more accurate estimate of nonphotorespiratory carbon loss in marine macroalgae during the daytime.It would not be anticipated that elevated atmospheric CO 2 would exert a substantial influence on respiratory flux either in the light or in darkness in these particular marine macroalgal species. 相似文献