山区生态县区域协调发展的机制构建--以粤北始兴县为例   总被引：1，自引：0，他引：1  

税伟  陈烈  唐常春 《山地学报》2006,24(1):70-78

区域协调机制在不同类型地域和一种类型地域的不同的发展阶段是不同的。始兴县作为一个典型的山区生态县,工业进入加速发展时期,在此经济发展阶段的区域协调问题主要表现在:与外部区域经济、社会发展差距拉大,工业化与流域生态环境保护的矛盾已开始凸现,县政府协调区域发展的财政能力较低,区域协调机制不健全等。由此对始兴县的区域协调机制进行建构:建立健全多层次的区域协调机构;加大纵向和横向政府财政转移支付的力度;加强与相邻相关地区的协调;实施区域空间管治协调,保护城乡生态环境;科学合理选择产业,大力发展循环经济;全县推行绿色GDP考核等。  相似文献   

Lichen-dominated soil crusts as arthropod habitat in warm deserts   总被引：2，自引：0，他引：2  

J.S. Lalley  H.A. Viles  J.R. Henschel  V. Lalley 《Journal of Arid Environments》2006,67(4):579-593

Soil crust lichens can be the dominant vegetation in arid lands, yet their importance as habitat to secondary producers is relatively unknown. This study examines the distribution of arthropod communities in the northern Namib Desert to evaluate whether a lichen-rich area is more or less productive than adjacent habitats in terms of the consumers each supports. Arthropods are diverse and highly endemic in the Namib Desert and lichens dominate this desert's extensive gravel plains. We sampled lichen-rich, dwarf shrub, and unvegetated sites and found distinct arthropod assemblages in the lichen-dominated sites, including species unique to lichen sites. Arthropod assemblages in two of the lichen sites were similar to those found in the dwarf shrub site. In a canonical correspondence analysis, crustose lichens and overall lichen cover were key in driving the variance in arthropod assemblages within the lichen sites. Furthermore, lichen morphotypes, overall lichen cover and species richness, were significantly correlated with the representation of arthropod subgroups and arthropod species richness. These findings provide evidence that lichen-dominated soil crusts in the Namib Desert are important supporters of secondary production, warranting more in-depth studies into the ecology and conservation of this lichen-rich habitat in warm deserts.  相似文献   

Integrated Approaches,Multiple Scales: Snag Dynamics in Burned Versus Unburned Landscapes*     

Joy Nystrom Mast  Carol L. Chambers 《The Professional geographer》2006,58(4):397-405

By studying landscape form and patterns, we can study processes at multiple scales and determine how collectively those processes inform us about function(s). Integrating landscape ecology from a biogeographical perspective with geographic information science (GIScience) practices offers new ways to study how landscapes change over time and space, including how they can be measured, analyzed, and modeled for management needs. This article presents methodologies and selected results of analyzing spatial patterns from field data across multiple scales by examining standing dead tree (snag) processes across wildfire‐disturbed landscapes in Arizona. Our primary motivation was to illustrate a particular type of work benefiting from the coalescing of landscape ecology and GIScience, functioning at the methodological and practical overlap of these two contributing fields. Our management goals were to (1) describe spatial patterns and characteristics of snags in pairs of burned and unburned ponderosa pine forests of Arizona in four recent (within the past ten years) wildfires, (2) document bird response to wildfires by combining landscape ecology and GIScience methods, and (3) link these patterns to snag monitoring plots and cavity‐nesting bird use to predict the probability of snag use by birds and cavity nesters based on snag characteristics (snag use model). The methods and results demonstrate how integration of landscape ecology with both GIS and GIScience improves the ways to study landscapes and land management issues, in this case offering guidelines for retention of snags that provide habitat for wildlife.  相似文献   

Kaleidoscoping Landscapes,Shifting Perspectives     

Kenneth R. Young  Richard Aspinall 《The Professional geographer》2006,58(4):436-447

Landscapes change in complex ways, creating surface patterns reminiscent of forms seen through a kaleidoscope. On the Earth's surface, those forms are linked to, and caused by, processes that originate with bedrock‐soil‐vegetation‐atmosphere interactions. Human‐caused alterations to landscapes are additionally tied to socioeconomic processes. Evaluation of landscape‐level processes can benefit from examining (1) the influence of disturbance regimes in altering landscape patterns, (2) the importance of considering surficial processes, (3) the subtle and cryptic spatial relations that may be present, (4) the reciprocal relationships among local processes and regional consequences, (5) the increased likelihood of some land cover transitions compared to others, and (6) the special case of landscapes with long histories of human use. These are all examples of potential fruitful arenas for interactions and represent a path for expansion of landscape ecology through accommodation of a broad range of content covered by the international GIScience community.  相似文献   

Diurnal Variations of Hydrochemistry in a Travertine-depositing Stream at Baishuitai, Yunnan, SW China   总被引：6，自引：0，他引：6  

Zaihua Liu  Qiang Li  Hailong Sun  Changjun Liao  Huaju Li  Jinliang Wang  Kongyun Wu 《Aquatic Geochemistry》2006,12(2):103-121

Diurnal variations of hydrochemistry were monitored at a spring and two pools in a travertine-depositing stream at Baishuitai, Yunnan, SW China. Water temperature, pH and specific conductivity were measured in intervals of 5 and 30 min for periods of 1 to 2 days. From these data the concentrations of Ca²⁺, HCO₃⁻, calcite saturation index, and CO₂ partial pressure were derived. The measurements in the spring of the stream did not show any diurnal variations in the chemical composition of the water. Diurnal variations, however, were observed in the water of the two travertine pools downstream. In one of them, a rise in temperature (thus more CO₂ degassing) during day time and consumption of CO₂ due to photosynthesis of submerged aquatic plants accelerated deposition of calcite, whereas in the other pool, where aquatic plants flourished and grew out of the water (so photosynthesis was taking place in the atmosphere), the authors suggest that temperature-dependent root respiration underwater took place, which dominated until noon. Consequently, due to the release of CO₂ by the root respiration into water, which dominated CO₂ production by degassing induced by temperature increase, the increased dissolution of calcite was observed. This is the first time anywhere at least in China that the effect of root respiration on diurnal hydrochemical variations has been observed. The finding has implications for sampling strategy within travertine-depositing streams and other similar environments with stagnant water bodies such as estuaries, lakes, reservoirs, pools and wetlands, where aquatic plants may flourish and grow out of water.  相似文献   

宁夏自治区生态农业地质研究及其前景     

曾昭华 《西北地质》2005,38(3):111-118

论述了宁夏回族自治区土壤元素含量和农作物优质高产与土壤环境中化学元素N、P、K、S、Fe、Mn、Cu、Zn、B、Mo、V、Sr、Ti、Mg、La、Ce、Pr、Nd、Sm、Eu、Y、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Ca、Co、Ni、F、Tl、Si、Na、Cr、Pb、Cd、Hg、Se、Ba、Te、Ta有密切的关系.提出了生态农业地质研究的目的、内容、方法、管理及其前景。  相似文献   

Implications of the relationship between catchment vegetation type and the variability of annual runoff   总被引：1，自引：0，他引：1  

Murray C. Peel  Thomas A. McMahon  Brian L. Finlayson  Fred G. R. Watson 《水文研究》2002,16(15):2995-3002

The impact of changing catchment vegetation type on mean annual runoff has been known for some time, however, the impact on the variability of annual runoff has been established only recently. Differences in annual actual evapotranspiration between vegetation types and the potential effect of changing vegetation type on mean annual runoff and the variability of annual runoff are briefly reviewed. The magnitude of any change in the variability of annual runoff owing to a change in catchment vegetation type is related to the pre‐ and post‐change vegetation types and the seasonality of precipitation, assuming that the variability of annual precipitation remains constant throughout. Significant implications of the relationship between vegetation type and the variability of annual runoff are presented and discussed for water resource management, stream ecology and fluvial geomorphology. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

灾害生态学——生态学的一个重要发展方向   总被引：4，自引：0，他引：4  

章家恩 《地球科学进展》2002,17(3):452-456

对灾害生态学有关的基本概念与主要研究内容进行了探讨。认为灾害实际上是一种异常的生态学现象与过程，因此需要从生态学的角度加以研究，特别是要对灾害系统的发生成因、类型、时空分布、发展、危害、预测、控制和灾后恢复等的全过程生态学现象和规律以及相关技术进行研究。同时指出，当今，应围绕重大的全球性环境灾害问题，对其发生与发展的生态学机制与生态学后果，以及减轻、防范这些灾害的关键技术开展研究。  相似文献   

新疆宏观生态的空间分异与变化   总被引：11，自引：12，他引：11  

王永兴 《干旱区地理》2002,25(1):4-9

根据新疆环境和生态特点，将新疆划分为14个二级生态区进行了研究。结果表明，新疆荒漠与非荒漠生态景观面积大致相当，但空间分异较大。新疆北部荒漠景观占全区域的约1／3，非荒漠景观占2／3，宏观生态相对稳定；新疆东部荒漠景观占全区域的2／3以上，宏观生态十分严峻；新疆南部荒漠景观占全区域的1／2，宏观生态稳定性差。沙漠、绿洲、水体三种主要景观类型中，北疆阿尔泰山南坡、伊犁盆地及南疆叶尔羌－喀什河三角洲地区沙漠化呈降低趋势；天山北坡各段及准噶尔盆地西部，20世纪90年代以来沙漠化明显减缓；新疆东部及南部其余各地区沙漠化均呈现增强趋势。新疆水体景观的变化表现为天然和人工水体面积的消长。近50年来，新疆修建的水库和坑塘等人工水体总面积与同期天然水体缩小的面积基本相当，表明新疆水体景观再近50年来的变化主要体现为水体的空间位移。绿洲景观的变化表明，北疆地区天然绿洲与人工绿洲面积的比例已经从50年代的5：1以上下降到约1：1，南疆由6：1以上下降到3：1左右。天然绿洲的减少是绿洲生态局部劣变的标志。研究还表明，新疆宏观生态的空间分异主要受自然因素的影响，其中，区域降水量的影响最为重要。  相似文献   

The Spaces of Conservation and Development around Lake Nakuru National Park,Kenya     

Robert Daniels  Thomas J. Bassett 《The Professional geographer》2002,54(4):481-490

Geographically or sociologically defined resource management units, such as buffer zones or community resource management territories, seek to harmonize local land–use practices with protected–area management objectives. The geographically restricted nature of these models often results in simplistic representations of society–nature relations over time and space. Conservation areas are misrepresented as ecologically and socially homogeneous, as well as politically neutral. This study examines the limits of a spatially defined conservation and development project designed around the physical geographical unit of the watershed at Lake Nakuru National Park, Kenya. It argues that politically motivated violence that has plagued the area since the early 1990s has severely undermined the suitability of such narrowly defined conservation territories. Specifically, the case study points to the permeability of the Lake Nakuru watershed to national and regional political forces that ultimately constrain participation in conservation activities. The spaces of conservation and development must be enlarged to include these extralocal arenas and processes if environmental problems are to be effectively addressed.  相似文献