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991.
Quantitative research on composition, biomass and production rates of zooplankton community is crucial to understand the trophic structure in coral reef pelagic ecosystems. In the present study, micro‐ (35–100 μm) and net‐ (>100 μm) metazooplankton were investigated in a fringing coral reef at Tioman Island of Malaysia. Sampling was done during the day and night in August and October 2004, and February and June 2005. The mean biomass of total metazooplankton (i.e. micro + net) was 3.42 ± 0.64 mg C·m?3, ranging from 2.32 ± 0.75 mg C·m?3 in October to 3.26 ± 1.77 mg C·m?3 in August. The net‐zooplankton biomass exhibited a nocturnal increase from daytime at 131–264% due to the addition of both pelagic and reef‐associated zooplankton into the water column. The estimated daily production rates of the total metazooplankton community were on average 1.80 ± 0.57 mg C·m?3·day?1, but this increased to 2.51 ± 1.06 mg C·m?3·day?1 if house production of larvaceans was taken into account. Of the total production rate, the secondary and tertiary production rates were 2.20 ± 1.03 and 0.30 ± 0.06 mg C·m?3·day?1, respectively. We estimated the food requirements of zooplankton in order to examine the trophic structure of the pelagic ecosystem. The secondary production may not be satisfied by phytoplankton alone in the study area and the shortfall may be supplied by other organic sources such as detritus.  相似文献   
992.
Marine Protected Areas (MPAs) are a cost-efficient and management-effective tool. Fishery Resource Conservation Zones (FRCZs) are one type of MPA in Taiwan, and they were designated to ensure the sustainability of fishery resources since 1976; however, government appropriations are the only financing source for FRCZs, leading to manpower and equipment shortages for FRCZ management. This study selected the Touching and Suao FRCZs in Yilan County of Taiwan as cases studies. To assess the feasibility of establishing a sustainable financing mechanism for MPAs, the Contingent Valuation Method (CVM) was applied to examine respondents׳ willingness to pay (WTP) to setup a fund for FRCZ management. The empirical results indicated that approximately 90% of respondents would be willing to donate funding for MPAs, and the WTP per respondent is NT$586.51 (US$19.6). Thus, establishing an MPA fund is a feasible way to operate Taiwanese MPAs through a co-management framework involving the central government, local government, local communities and stakeholders. However, based on our empirical results, a co-management financing mechanism for MPAs should be established to ensure stable and diverse financing sources.  相似文献   
993.
The spatial distribution pattern of organisms is a basic issue in understanding the mechanisms of community assembly. Although the spatial distributions of animals and plants have been well studied, those of microorganisms are still being debated. In this study, we used a fish gut microecosystem to detect the spatial pattern of microbes, because it can provide a relatively unified and stable environment. Results suggest that the turnover of intestinal bacterial assemblages showed a weak but highly significant negative correlation between similarity and distances in the microbial community, in respect of both grass carp intestinal loci distances and the geographical distance between fish sampling sites. Our results also suggest that intestinal bacterial assemblages responded to differences within the external environment and within different parts of the fish themselves. These results show that some, or possibly all, microbes are restricted in their distribution and that environmental factors are also important influences on the structure of intestinal bacterial assemblages. The fish gut microecosystem is useful in promoting study of the spatial distribution patterns of microorganisms.  相似文献   
994.
In this study, the relationship between the subsystems of Asian summer monsoon is analyzed using U.S. National Centers for Environmental Protection/National Center for Atmospheric Research reanalysis and Climate Prediction Center Merged Analysis of Precipitation monthly mean precipitation data. The results showed that there is significant correlation between the subsystems of Asian summer monsoon. The changes of intensity over the same period show that weak large-scale Asian monsoon, Southeast Asia monsoon and South Asian monsoon are associated with strong East Asian monsoon and decreasing rainfall in related areas. And when the large-scale Asian monsoon is strong, Southeast Asia and South Asia monsoons will be strong and precipitation will increase. While the Southeast Asia monsoon is strong, the South Asia monsoon is weak and the rainfall of South Asia is decreasing, and vice versa. The various subsystems are significantly correlated for all periods of intensity changes.  相似文献   
995.
文本蕴含大量地理位置描述信息,有效融合地理关联信息以实现文本的精细定位是地理信息服务的难点。本文提出一种融合土地利用/覆被信息的描述地理位置的细粒度定位方法:在文本描述地理关联信息(地理位置实体、土地利用/覆被实体与空间关系)抽取、土地利用/覆被精细分类与地理位置粗粒度匹配定位的基础上,使用自然语言空间关系近似转换模型,确定地理位置的细粒度定位范围;基于土地利用/覆被实体及其周边精细分类信息,在该范围内检索匹配,确定地理位置的细粒度定位坐标。本文以野生亚洲象活动/肇事监测文本为例开展实验,并用匹配率与位置精度评价定位质量,结果表明:本文方法显著提升了地理位置的细粒度定位质量,实验精确匹配率(81.51%)、位置误差距离的均值(65.97 m)及其≤50 m的比例(70.50%)均优于国内主流在线地理编码与地名检索服务结合空间关系或其单独使用结果。该方法有助于完善地理位置定位方法体系、提升地理信息空间化质量,并可服务于野生动物活动/肇事监测预警等精细定位任务。  相似文献   
996.
河南信阳板栗生长的土壤地球化学评价   总被引:1,自引:0,他引:1  
刘超良  杨扬  王爽  张雷 《岩矿测试》2013,32(4):638-643
信阳板栗是河南省名特优农产品之一,但是有关信阳板栗生长环境的土壤地球化学方面研究较少,致使目前板栗的种植、规划等缺乏理论依据.本文对河南信阳板栗种植区土壤样品的地球化学元素进行测试分析,研究了土壤地球化学元素与板栗品质之间的相关关系.分析结果显示,板栗品质与土壤有机质、阳离子交换量、pH值、全氮、氨态氮、有效锌、有效铜、有效锰、有效硼呈正相关关系,并且与氨态氮、有效锌、有效铜、有效锰、有效硼的相关性很强,说明耕作土壤增加这些元素的含量有利于提高板栗品质,土壤pH值越接近5~6的最适宜范围,板栗品质越好;板栗品质与土壤容重、速效磷、速效钾呈负相关关系,认为在施用磷肥和钾肥增加速效磷、速效钾,提高板栗产量的同时,应注意板栗品质下降的问题.值得注意的是,研究区土壤中有效硼含量低于土壤临界值,是限制板栗品质的重要因素.本研究为提高信阳板栗品质、规划板栗园的种植、科学管理和合理施肥提供了依据.  相似文献   
997.
ABSTRACT

The authors make a general survey of the methods of measuring soil permeability in the field, looking at them from the point of view of the hydrologist.

In the first part they describe new equipment built by the ORSTOM Centre in Lome, Togo, to apply the Muntz method of vertical infiltration under constant head, equipment using a double cylinder and semi-automatic regulation of the discharge.

In the second part, the authors make a mathematical analysis of the Porchet method of horizontal infiltration in a borehole full of water: they show that results may be interpreted even with heterogeneous (multi-layered) soils and that the calculations are simplified using a computer programme.

In conclusion they deal with some results of measurements obtained by the two methods, and examine their accuracy and their correlation with the physical and hydrodynamics characteristics of the soils.  相似文献   
998.
新疆地震烈度衰减关系模型参数拟合   总被引:1,自引:0,他引:1  
By using the existing historical earthquake investigation data in Xinjiang,this paper obtained the envelope curves of isoseismal maps of 103 destructive earthquakes occurring from 1716 to 2010 after digitization of the data. The author summarized the seismic intensity attenuation laws in the Xinjiang region with the multiple regression fitting method. The intensity attenuation function of the elliptical model was provided and the fitting results in different periods and areas were compared. Finally, the intensity attenuation relationship in the Xinjiang region was obtained by the method of constraining the start and end of the attenuation curves.  相似文献   
999.
Based on faults surveying and research data in the Tianjin offshore areas, through studying tectonic structure, Quaternary activity, deep structure, stress and strain fields and seismicity in the Tianjin offshore areas, the activity and tectonic features of the faults are determined synthetically. Using seismo-geological data, and the historical and modern seismicity data, the frequency-magnitude relationship model normalized by 500a is established and based on the relationship between the upper limit of maximum magnitude Mu and at/b, the maximum magnitudes of the sea section of the Haihe river fault and the Haiyi fault are calculated. Then Poisson probability model is adopted and the quantitative parameters, such as the maximum magnitude, occurrence probability, recurrence cycle of the faults in the south Tianjin offshore areas in the coming 50 - 200a, are calculated.  相似文献   
1000.
崇明岛"闸控型"河网水体富营养化特征及其影响因素   总被引:3,自引:1,他引:2  
为研究崇明岛"闸控型"河网水体富营养化特征及其与环境因子的相互作用,以2010年各季节崇明岛河网水质数据为基础,探讨了环境因子与藻类的变化规律及其相互作用机制.结果表明:崇明岛河网水环境中营养盐水平较高,氮污染尤为严重.长江引水进入岛内河网水环境后,营养盐(除SiO3-Si)、Chl.a含量和营养状态都出现了明显的升高.与长江引水相比,河网内藻类群落Chl.a贡献比例的变化主要表现为硅藻比例的下降以及蓝藻和绿藻比例的上升.尽管水温、pH、浊度以及营养盐中的TN、TP、NO3--N、DOC的变化均与Chl.a含量显著相关,但藻类群落对环境因子的响应关系存在较大差异.蓝藻的增加主要与水温和TP含量的升高有关;绿藻与TN、NO3--N的关系最为密切;硅藻的变化只与浊度存在明显正相关,营养盐并不是硅藻生长的促进因子.  相似文献   
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