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31.
32.
我国淡水水域光合产物的气候生产力探讨 总被引:1,自引:0,他引:1
根据太阳辐射在水体中的有效分布、生长季水温和浮游植物光合生态特性等因子,模拟计算了我国大陆东部淡水水域的光合生产力、气候生产力及其季节变化的地理规律。从中得知,这些水域初级产物的年气候生产力主要呈纬向分布,由南向北递减,各地范围在 1.6-24.4gC/m2·a之间,长江以南是>15.0gC/m2·a的高值区,长城以北和四川盆地为<10.0gC/m2·a的低值区,因此,在气候生产力高值区有可能充分利用气候资源优势,开发低成本的自然淡水水域渔业;而在低生产力区,受自然资源的局限其自然捕鱼量需适量控制,因地制宜。 相似文献
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WANG Xiao-long~ 《环境科学学报(英文版)》2007,(8)
Understanding the process of the changing phytoplankton patterns can be particularly useful in water quality improvement and management decisions.However,it is generally not easy to illustrate the interactions between phytoplankton biomass and related environmental variables given their high spatial and temporal heterogeneity.To elucidate relationships between them,in a eutrophic shallow lake,Taihu Lake,relative long-term data set of biotic and abiotic parameters of water quality in the lake were conducted using multivariate statistical analysis within seasonal periodicity.The results indicate that water temperature and total phosphorus(TP)played governing roles in phytoplankton dynamics in most seasons(i.e.temperature in winter,spring and summer; TP in spring,summer and autumn); COD(chemical oxygen demand)and BOD(biological oxygen demand)presented significant positive relationships with phytoplankton biomass in spring,summer and autumn.However,a complex interplay was found between phytoplankton biomass and nitrogen considering significant positive relationships occurring between them in spring and autumn,and conversely negative ones in summer.As the predatory factor,zooplankton presented significant grazing-pressure on phytoplankton biomass during summer in view of negative relationship between them in the season.Significant feedback effects of phytoplankton development were identified in summer and autumn in view that significant relationships were observed between phytoplankton biomass and pH,Trans(transparency of water)and DO.The results indicate that interactions between phytoplankton biomass and related environmental variables are highly sensitive to seasonal periodicity,which improves understanding of different roles of biotic and abiotic variables upon phytoplankton variability,and hence,advances management methods for eutrophic lakes. 相似文献
35.
At a rice-wheat rotational free-air CO2 enrichment(FACE) platform, the effect of elevated atmospheric CO2 on soil nematode communities in a farmland ecosystem was studied. Wheat plots were exposed to elevated atmospheric CO2 (ambient 370 μl/L 200 μl/L).32 families and 40 genera of nematode were observed in soil suspensions during the study period. Under FACE treatment, the numbers of total nematodes, bacterivores and fungivores exhibited an increasing trend. Because of the seasonal variation of soil temperature and moisture, the effect of elevated atmospheric CO2 on soil nematodes was only observed under favorable conditions. The response of nematode communities to elevated atmospheric CO2 may indicate the change of soil food web. 相似文献
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略论中国绿色社区建设 总被引:4,自引:0,他引:4
绿色社区建设在中国刚刚起步 ,这是一种全新的发展理念、发展目标和发展模式 ,是实施可持续发展战略的现实要求 ,是加快中国城市化进程的必然选择 ,是全面建设小康社会的重要内涵 ,是创造绿色文明的热切呼唤。建设绿色社区具有重要的理论指导意义和实践示范作用。 相似文献
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Linda?Anderson-BerryEmail author David?King 《Mitigation and Adaptation Strategies for Global Change》2005,10(3):367-392
Community mitigation of hazard impact requires hazard knowledge and preparedness on the part of the members of diverse and
complex communities. Longitudinal research in the tropical cyclone prone north of Australia has gathered extensive datasets
on community awareness, preparedness and knowledge, in order to contribute to education campaigns and mitigation strategies.
Data have been used to identify issues of vulnerability to cyclones and capacity to deal with the hazard. This has been developed
as a community vulnerability and capacity model that may be applied to diverse communities in order to assess levels of capability
to mitigate and deal with the cyclone hazard. The model is presented here in a simplified form as its development is evolving
and ongoing. 相似文献
40.
珠江口浮游藻类生态及与关键水质因子分析 总被引:10,自引:1,他引:10
从宏观上和特殊性两方面对其进行浮游藻类生态发生与关键水质因子 (盐度、DO、PO4 P、NO3 N)关联的研究与总结。得出二者间确有关联 ,在 12个测点站位中 ,C12 站位具有水域特殊性 ,即在C12 测点具有溶解氧超饱和现象 ,溶氧饱和率为 115 % ,中肋骨条藻高达 8.6 9× 10 5L 1,个体百分组成高达 87.4 % ,藻类优势度为92 .3% ,该测点水域处于赤潮状态 ,并导致C12 测点活性磷浓度为最低测值。由于硝酸盐含量很高 ,藻类生长和硝酸盐的特殊对应关系不明显。相关分析显示 ,在整个水域盐度与藻类生长为正相关 ,藻类丰度与最高溶氧也为正相关 ,藻类生长与活性磷和硝酸盐之间乃为负相关 相似文献