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921.
This study has demonstrated an interaction between the effect of increased ocean acidity and temperature (40 days exposure)
on a number of key physiological parameters in the ophiuroid brittlestar, Ophiura ophiura. Metabolic upregulation is seen in the low pH treatments when combined with low temperature. However, this is far outweighed
by the response to elevated temperature (+4.5°C). In the high temperature/low pH treatments treatments (where calcite is undersaturated)
there appears to be an energetic trade-off likely in order to maintain net calcification where dissolution of calcium carbonate
may occur. This energy deficit results in a ~30% reduction in the rate of arm regeneration at pH 7.3 which is predicted to
be reached by the year 2300. This understanding of how O. ophiura responds to ocean acidification, taking into account an interactive effect of temperature, suggests that fitness and survival
may indirectly be reduced through slower recovery from arm damage. 相似文献
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Environmental conditions causing stress have a significant effect on the generative organs of Scotch pine. The parameters characterizing pine pollen are subject to significant interannual variations and are closely connected with weather and climatic conditions in the period of pollen formation. Airborne pollutants affect the quality of pine pollen, which is especially apparent in the years favorable for the formation of microspores. The ability of Scotch pine pollen to germinate and form pollen tubes in the regions with different technogenic loads proved to be significantly lower than in tree stands of the background areas. 相似文献
927.
T. B. Kalinnikova I. A. Krasnoperova T. M. Gainutdinov S. V. Sadykova M. Kh. Gainutdinov 《Russian Journal of Ecology》2005,36(2):109-114
The thermal resistance of Daphnia magna Straus is a trait depending on the interaction between individuals. The group effect is expressed in D. magna as both a decrease in thermal resistance and a marked individual differentiation with respect to thermal resistance. Two types of interactions between individual D. magna have been found: (1) the release of an unidentified factor decreasing thermal resistance (without noticeably changing the phenotypic variability of this trait) into the medium and (2) a decrease in the thermal resistance of individuals poorly adapted to heat stress, with the thermal resistance of well-adapted individuals (determined by the dependence of thermal resistance on interactions between individuals) remaining the same or even slightly increasing.Translated from Ekologiya, No. 2, 2005, pp. 126–131.Original Russian Text Copyright © 2005 by Kalinnikova, Krasnoperova, T. Gainutdinov, Sadykova, M. Gainutdinov. 相似文献
928.
Combining a computational fluid dynamics (CFD) model and a multi-zonal model, a study was carried out on radon entry through the complex substructure of a house with a cellar. The uniqueness of the radon entry problem in this type of house was due to the involvement of two radon entry routes to two chambers: the cellar and the living area of the house. Soil gas carrying radon was driven through the two routes by two coupled disturbance pressures in the chambers. The effects of temperature differences were considered as another driving force for the radon entry. Examined in this study were the effects of the geometry of the substructure, air permeability of the soil, air-tightness of the cellar shell, and cellar ventilation on radon entry to both the cellar and the living area. The ground floor covering on top of the soil outside a cellar wall increased radon entry through this wall by about 68%, as radon built up to a very high level under the covering. The effect of cellar ventilation was found as follows: the cellar ventilation created a layer of airflow in the soil under the ground floor; the flow passed over a crack in the ground floor, the entry route to the living area, diluting the radon in the area. Hence, the soil gas entering the living area carried less radon. Cellar ventilation seems more effective in reducing radon entry to the living area in a more permeable soil and leaky cellar shell; a moderate cellar ventilation condition achieved 77% reduction in radon entry to the area. When permeability of these two materials was lower and soil radon content remained the same, the chances of radon entry was also lower; hence, the indoor radon level was lower and no radon control was needed. When such soil contains high radon concentration, other mitigation measures must be sought. 相似文献
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Free de Koning Roland Olschewski EdzoVeldkamp Pablo Benítez Magdalena López-Ulloa TomásSchlichter Mercedes de Urquiza 王胜 《Ambio-人类环境杂志》2005,34(3):220-225
复林项目的成本决定了它们与其它减轻大气中日益增加的CO2浓度的方法的竞争力.我们量化了南美两国--厄瓜多尔和阿根廷--人工林和次生林地上生物量和土壤中的碳获取量,并计算了短期碳获取成本.每短期认证减排单位成本为0.1~2.7美元/Mg
CO2,主要取决于机会成本、立地适宜性、贴现率和认证成本.在厄瓜多尔,次生林是一种可行并合算的方法;在阿根延,在适宜性高的土地上进行复林相对便宜一些.我们的研究结果可用于设计有成本效益的CO2汇项目和为土地所有者协商公平的碳价格. 相似文献