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 | | 为了更好的帮助您理解掌握查询词或其译词在地道英语中的实际用法，我们为您准备了出自英文原文的大量英语例句，供您参考。 | |
Fine roots have enormous surface areas, growing and turning over quickly, which plays an important role in terms of substance cycling and energy flow in the forest ecosystem.
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The soil microbial biomass and nutrient status under the native broadleaved forest and Cunninghamia lanceolata plantations at the Huitong National Research Station of Forest Ecosystem (in Hunan Province, midland of China) were examined in this study.
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Chemical contents in precipitation change significantly when different kinds of external chemical materials are added, removed, translocated and transformed to or in the forest ecosystem along with precipitation.
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Based on the data collected from 31 plots and 93 soil samples, the state of health of the forest ecosystem is discussed and the appropriate FHA age has been determined.
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Castanea squinii Dode, an endemic tree widely distributed in China, plays an important role both in chestnut breeding and forest ecosystem function.
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| According to the principles and methods cf landscape geochemistry, the samples of soil, plant and surface water collected at the same time eluvial, super-aqual and aqual landscapes in the different landforms were studied and analysed as a whole ecosystem.The abundance of the eight trace elements in every landscape's component and the geochemical patterns of the landscape were given, and the relationship between the couse of the characteristics and ; the environmental factors was disscussed by analyzing the vertical... According to the principles and methods cf landscape geochemistry, the samples of soil, plant and surface water collected at the same time eluvial, super-aqual and aqual landscapes in the different landforms were studied and analysed as a whole ecosystem.The abundance of the eight trace elements in every landscape's component and the geochemical patterns of the landscape were given, and the relationship between the couse of the characteristics and ; the environmental factors was disscussed by analyzing the vertical redistribution of elements under the conditions of supergenesis geochemistry, especially the distribution of the trace element's speciations in the soils. It can be concluded that. ( 1 ) the geochemical contrast is not strong in the tropical forest ecosystem of Yunnan, but there's a little relative enrichment in the eluvial landscape for the elements Fe, Cr, Ni whose aqual migration is weak yet. ( 2 ) The portion of the trace elements bound to Fe-Mn oxides in soil is always very high, especially the element Mn covering 70%. (3) Living things-forest cover is an important reservoir of the trace elements. The concentration of trace elements bound to organic matter in soil surface, however, is very low. | 本文以我国云南典型热带森林生态系统为研究对象,在物质循环较封闭的地段,按照不同地貌部位、不同的物质淋溶堆积景观类型进行采样,采样时在同一单元景观内同时收集土壤、风化壳、植物和天然水的样品,分析各样品中九种重金属元素的含量分布以及土壤风化壳样品中各元素的六种赋存形态的含量分布,通过对比元素在不同单元景观间、不同景观要素间和景观要素内部的分异特征,从而给出热带森林生态系统中元素的分布形成规律和动态分异特征。 | An investigation on the biogeochemical cycling of nitrogen, phospho-:rus and sulphur in a pinus tabulaeformis forest ecosystem in Haihe river basin revealed that the accumulation of N, P and S in the stand are 310.92, 31.31 and 30.34 kg/ha, respectively. The annual uptake of the three elements were found to be 37.43, 3.59 and 4.59 kg/ha and the return 12.60, 0.48 and 0.39, respectively. The amounts of N, P and S .accumulated in soil of 0-50 cm are 6399.3, 703.24 and 767.67 kg/ha, among which 741.89, 67.18... An investigation on the biogeochemical cycling of nitrogen, phospho-:rus and sulphur in a pinus tabulaeformis forest ecosystem in Haihe river basin revealed that the accumulation of N, P and S in the stand are 310.92, 31.31 and 30.34 kg/ha, respectively. The annual uptake of the three elements were found to be 37.43, 3.59 and 4.59 kg/ha and the return 12.60, 0.48 and 0.39, respectively. The amounts of N, P and S .accumulated in soil of 0-50 cm are 6399.3, 703.24 and 767.67 kg/ha, among which 741.89, 67.18 and 130.86 kg/ha are in available fraction. The annual input from precipitation and the output through leaching are 16.39 and 0.525 for N, 0.087 and 0.041 for P and 20.52 and 2.085 for S, all in kg/ha. The output due to runoff and soil erosion are 16.07, 0.97 and 7.01 kg/ha for three elements. The input-output is balanced for N, positive for S and negative for P. | 海河流域怀柔山地油松林生态系统N,P,S元素生物地球化学循环研究结果表明,生态系统氮素输入输出基本平衡。氮素、磷素在未来一段时间内将在植物凋落层中累积,硫则在凋落物层、土壤中累积。这种情况形成了城市郊区森林生态系统元素循环的独特特性。 | In this paper, a mathematical model of the hydrological cycle of the forest set up on the basis of a man-made forest which originated from a bog land in the suburbs of Edinburgh in southern Scotland is described. The whole process is abstractly recognized as a forest ecosystem with 5 compartments, namely, trees, grasses, ditches, ditch slopes and ditch bottoms. With the aid of some methematical formulas and computer techniques, the hydrological process of the system, which includes flow interception, surface... In this paper, a mathematical model of the hydrological cycle of the forest set up on the basis of a man-made forest which originated from a bog land in the suburbs of Edinburgh in southern Scotland is described. The whole process is abstractly recognized as a forest ecosystem with 5 compartments, namely, trees, grasses, ditches, ditch slopes and ditch bottoms. With the aid of some methematical formulas and computer techniques, the hydrological process of the system, which includes flow interception, surface flow, stared in soil, groundwater and the other hydrological phenomena, can be systematically simulated in a quantitative form. The amounts of rainfall and evaporation are put into the model and the runoff water is drained away from it- It is given here for an example to simulate the hydrological process of the system in 1986 and check the simulation efficiency. Through comparing the computed and observed flows of the forest ecosystem, it is found that the simulation efficiency is 93.5% on the daily basis and 85.1% on the two-hour basis.The model reveals the mechanism of the hydrological cycle of the forest. We can estimate the runoff by using the amounts of input pricipitation and evaporation only. It will be helpful to understanding the hydrological effect of the man-made forest which originates from a bog land. | 本文描述了一个根据起源于南苏格兰爱丁堡郊区沼泽地的人工林建立的数学模型。该模型把群落的整个水分过程抽象地看作有5个分室——乔木、草本、沟、沟坡与沟底组成的生态系统;借助于数学公式和计算机技术,对包括截流、表面流、土壤贮藏水与地下水等现象在内的水文过程以定量的形式进行了模拟;模型中输入降雨和蒸发量,输出径流量。文中以1986年系统的水文过程作为一个例子,并利用模拟值与真值对模拟效果进行了检验:以天为单位的模拟效率为93.5％,以2h为单位的模拟效率为85.1％。该模型揭示了森林水分循环的机理,仅利用降雨和蒸发量就能估计径流量。它将有助于了解起源于沼泽地人工林的水文效应。 | | | | << 更多相关文摘 |
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forest ecosystem
森林生态系统
查询“forest ecosystem”译词为用户自定义的双语例句
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