Microbial production of CO2 in red soil in Stone Forest National Park     

LIANG Fuyuan  SONG Linhua  TANG Tao 《地理学报》2003,13(2):250-256

Lunan stone forest is a kind of typical karst in China, which is mainly developed under red soil. In the winter of 1999, three study sites were chosen in stone forest national park according to vegetation cover, geomorphologic location and soil types. CO2 concentration was measured with Gastec pump at different depths of soil (20, 40, 60 cm) and at the same time soil samples were gathered and soil properties such as soil moisture, pH, soil organic content were analyzed and the total number of viable microbes were counted in laboratory. In the study, dependent variable was chosen as the mean soil log (PCO2), and soil properties were chosen as the independent variables. Multiple stepwise regression analysis showed that the total amount of microbes and soil moisture are the best indicators of the CO2 production, with the equation LOG(PCO2) = - 0.039(TNM) - 0.056(Mo) + 1.215 accounting for 86% of the variation of the soil CO2 concentration, where TNM is the total number of microbes in the soil and Mo is the moisture of soil sample.  相似文献   

USING UPLAND FOREST IN SHIMENTAI NATURE RESERVE,CHINA*     

STEVE S. W. XU  C. Y. JIM 《Geographical review》2003,93(3):308-327

ABSTRACT. The Shimentai Nature Reserve in Yingde County, Guangdong Province, China, established recently in a subtropical upland forest area, has served for ages as an essential and customary source of livelihood for local people. Assessment of forest usage indicates heavy reliance by villagers on its diversified biotic resources. This forest dependence, associated with socioeconomic factors such as distance from village, ethnic origin, out‐migration of rural youngsters, and a local tradition of conservation, is unlikely to decline in the near future. The reserve management recognizes the need to address the livelihood issues of local people and to win local support. A pragmatic adherence to provincial and higher‐level policies that exclude forest‐tapping activities could lead to more people‐versus‐park conflicts, which would dilute fundamental conservation objectives. A more enlightened and localized approach that nurtures a synergy between limited forest use and conservation while helping to develop new income sources could furnish workable alternatives.  相似文献   

大兴安岭浅覆盖区生态地质评价方法初探——以1∶25万区调呼中镇幅为例   总被引：1，自引：0，他引：1       下载免费PDF全文

马江水李仰春  任凤和尤福珍 李清伟 《中国地质》2003,30(3):330-336

通过野外调查，在收集统计大量基础地质、经济地质、环境地质、旅游地质、农(林)业地质等数据信息的基础上，在GIS技术指导下，采用定量定性相结合的半定量分析评价方法，对森林浅覆盖区生态地质现状及各类资源的开发利用潜力进行了综合评价。在研究和探讨森林浅覆盖区生态地质综合评价方法的基础上，提出了森林浅覆盖区生态地质评价模型，确定了综合参数，划分了生态地质类型。  相似文献   

Carbon dioxide and radon gas hazard in the Alban Hills area (central Italy)     

S. E. Beaubien  G. Ciotoli  S. Lombardi 《Journal of Volcanology and Geothermal Research》2003,123(1-2):63

The sudden and catastrophic, or slow and continuous, release at surface of naturally occurring toxic gases like CO₂, H₂S and Rn poses a serious health risk to people living in geologically active regions. In general this problem receives little attention from local governments, although public concern is raised periodically when anomalous toxic-gas concentrations suddenly kill humans or livestock. For example, elevated CO₂ concentrations have been linked to the death of at least 10 people in the central Italian region of Lazio over the last 20 years, while it was the CO₂ asphyxiation of 30 cows in a heavily populated area near Rome in 1999 which prompted the present soil-gas study into the distribution of the local health risk. A detailed geochemical survey was carried out in an area of about 4 km² in the Ciampino and Marino districts, whereby a total of 274 soil-gas samples were collected and analysed for more than 10 major and trace gas species. Data were then processed using both statistical and geostatistical methods, and the resulting maps were examined in order to highlight areas of elevated risk. General trends of elevated CO₂ and Rn concentrations imply the presence of preferential pathways (i.e. faults and fractures) along which deep gases are able to migrate towards the surface. The CO₂ and Rn anomalous trends often correspond to and are usually elongated parallel to the Apennine mountain range, the controlling structural feature in central Italy. Because of this fundamental anisotropy in the factors controlling the soil-gas distribution, it was found that a geostatistical approach using variogram analysis allowed for a better interpretation of the data. With regard to the health risk to local inhabitants, it was found that although some high risk areas had been zoned as parkland, others had been heavily developed for residential purposes. For example, many new houses were found to have been built on ground which has soil-gas CO₂ concentrations of more than 70% and radon values of more than 250 kBq m⁻³. It is recommended that land-use planners incorporate soil-gas and/or gas flux measurements in environmental assessments in areas of possible risk (i.e. volcanic or structurally active areas).  相似文献   

玄武岩盖层下石林的岩溶动力学特征     

谢运球  何师意  章程 《吉林大学学报(地球科学版)》2003,33(3):340-343,359

受玄武岩盖层的影响，石林地区的地下水在雨季和旱季对碳酸盐岩都具有侵蚀性，玄武岩盖层空气CO2呈现出低—高—低的双向变化梯度。溶蚀试验表明．地下0～0．6m，水平方向的溶蚀量大于垂直方向的溶蚀量，而随着深度的增加，垂直方向的溶蚀量大于水平方向。富含CO2的水通过具有最大渗透张量和较小主轴倾角的玄武岩裂隙下渗，对碳酸盐岩的溶蚀作用表现为一个脱钙、富铝铁、硅迁移的复杂过程，并在地下0～0．6m形成许多水平凹槽、穿洞等岩溶形态，而地表0．6m以下以垂向溶蚀为主，有利于石柱的形成与发育。  相似文献   

Possible refugia for reefs in times of environmental stress   总被引：2，自引：0，他引：2  

B. Riegl  W. E. Piller 《International Journal of Earth Sciences》2003,92(4):520-531

This paper investigates the refuge potential of (1) upwelling areas, (2) coral areas at medium depth, and (3) offshore bank and island reefs in a scenario of increased global warming, and thus increased sea surface temperature (SST) and increased solar UV radiation. (1) Observations on coral health and water temperature in the subtropical Atlantic (Eleuthera and Cat Island, Bahamas) and Indian Ocean (Sodwana Bay, South Africa) suggest a link between cool water delivered by upwelling and coral health. After the 1998 bleaching event, caused by strong SST anomalies, coral health and recovery from the previous year's bleaching was significantly better on the narrow southern Cat Island shelf (70% of corals healthy) where the presence of cold water was observed, which was attributed to small-scale upwelling, than on the wide northern Eleuthera shelf (44% of corals healthy), where downwelling of hot bank waters was believed to have damaged corals. In South Africa, regular, short-term upwelling events in five summers reduced SST to well below bleaching level. (2) In the northern Red Sea (Safaga Bay) and in South Africa (Sodwana Bay), wide areas with either coral frameworks or non-framework communities exist. Calculations show that if the top 10 m (20 m) of the ocean became inhospitable to corals, still 50.4% (17.5%) of the coral area would remain intact in the Red Sea and 99% (40%) in South Africa. (3) Offshore bank and island reefs investigated in the Turks, Caicos, and Mouchoir Banks and Grand and Little Cayman showed high rates of mortality and coral diseases. The most remote sites (Mouchoir Bank) were not the healthiest. Refuge areas appear to exist in (1) and (2), but in (3) only if vigorous water-circulation is encountered.  相似文献   

The impact of decentralised forest management on charcoal production practices in Eastern Senegal     

Johan Post  Maaike Snel 《Geoforum》2003,34(1):85-98

In accordance with Senegal’s decentralisation policy, important forest management tasks, including the right to allocate charcoal production rights, have been transferred to rural councils. This paper investigates the impact of these institutional reforms on charcoal production practices using the environmental entitlement framework developed by Leach et al. [Environmental entitlements: dynamics and institutions in community-based natural resource management. World Development 27 (2) (1999) 225]. The councils have not been able to turn their new endowments into entitlements because they lack sufficient strength and legitimacy. Informal institutions, notably the coalition between merchants, state agents and village chiefs, continue to run the charcoal business and are hardly affected by decentralisation efforts. Most rural people, especially those relying solely on agriculture for sustenance, do not benefit at all from the charcoal trade. They do suffer from the environmental costs it brings with it, however. Although tensions between pro-exploitation actors and pro-conservation actors are evident, the pro-exploitation actors’ firm grip on the informal institutions will probably lead to a prolonged subversion of the laws that seek to enhance local control and to sustain the forest.  相似文献   

气象卫星遥感预警福建省森林火灾   总被引：3，自引：2，他引：3       下载免费PDF全文

郑海青张春桂  陈家金王加义 《气象科技》2003,31(3):190-192,F003,173

应用NOAA卫星遥感资料，研究森林防火期内森林植被的干燥指数的变化，结合分析相应的森林火灾的资料，做出福建省森林火险等级空间分布，应用福建省地理信息系统，根据高火险等级的地理位置，预警该地可能发生森林火灾。  相似文献   

中国西部退耕还林(草)和沙漠化土地绿化的区域性气候效应   总被引：10，自引：0，他引：10  

SHI Weilai  WANG Hanjie 《大气科学进展》2003,20(1):45-54

中国正在实施的西部大开发必将导致较大规模的土地利用和地表覆盖(LULC)变化,其中最重要的两类LULC变化是退耕还林(草)和沙漠化土地绿化工程。利用最新的全球地表特征资料数据库(GLCCD)识别以上两项生态建设工程的实施规模与范围,并以此更新了目前比较流行的区域气候模式的下边界条件,利用修正了的区域气候模式研究上述大规模LULC变化可能对中国区域性气候造成的影响。使用的卫星资源数据库是由美国地质测绘局(USGS)和Nebraska-Lincoln大学牵头,根据NOAA卫星的AVHRR资料、USGS掌握的高分辨率数字化地图,以及生态区划和植被分布等资料组建的。  相似文献   

热带森林生态系统气象观测铁塔的设计          下载免费PDF全文

刘玉洪  张克映  马友鑫  张建候 《气象》1997,23(5):41-43

讨论了西双版纳地区原始热带雨林和人工林气象观测铁塔的选择与设计，扼要地介绍了气象观测铁塔的塔形，结构及春功能，并提出了在高湿多雷热带雨林地区设计，安装铁塔应注意的事项及解决途径。  相似文献