生物地理模型研究进展及在干旱半干旱区的应用     

程国栋  赵传燕  许仲林  彭守璋 《地球科学进展》2013,28(1):17-23

生物地理模型是实现生态保护计划的重要工具.从生物地理模型研究的背景出发,论述了它的发展是科学和实践的需求,分析了基于生态位理论的生物地理模型发展所面临的挑战,特别是数据的获取和关键变量的选择,展望了生物地理模型的发展前景,并对其在干旱半干旱区的应用进行了综述,旨在理解生物地理模型在陆面过程研究和生态恢复中的重要性,以期推动生物地理过程与之相关过程的耦合模拟研究.  相似文献   

Predicting potential distributions of geographic events using one-class data: concepts and methods     

Q. Guo  W. Li  Y. Liu  D. Tong 《International journal of geographical information science》2013,27(10):1697-1715

One common problem with geographic data is that, for a specific geographic event, only occurrence information is available; information about the absence of the event is not available. We refer to these specific types of geospatial data as geographic one-class data (GOCD). Predicting the potential spatial distributions that a particular geographic event may occur from GOCD is difficult because traditional binary classification methods that require availability of both positive and negative training samples cannot be used. The objective of this research is to define GOCD and propose novel approaches for modelling potential spatial distributions of geographic events using GOCD. We investigate the effectiveness of one-class support vector machine (OCSVM), maximum entropy (MAXENT) and the newly proposed positive and unlabelled learning (PUL) algorithm for solving GOCD problems using a case study: species distribution modelling from synthetic data. Our experimental results indicate that generally OCSVM, MAXENT and PUL are effective in modelling the GOCD. Each method has advantages and disadvantages, but PUL seems to be the most promising method.  相似文献   

台湾海峡及邻近海域6种对虾食性特征及其营养级研究   总被引：3，自引：0，他引：3  

黄美珍 《台湾海峡》2004,23(4):481-488

本文主要研究台湾海峡及邻近海域6种对虾的食性特征与营养级.研究结果表明,它们皆为混合食性型的甲壳动物.哈氏仿对虾、鹰爪虾和周氏新对虾的主要饵料生物属底栖生物和浮游动物生态类群,中华管鞭虾和须赤虾的主要饵料生物属浮游动物和底栖生物生态类群;它们的营养级范围在1.64～2.14之间.周氏新对虾、角突仿对虾、须赤虾和鹰爪虾属第二营养层次的杂食性动物,哈氏仿对虾和中华管鞭虾属第三营养层次的低级肉食性动物;它们的食物生境宽度范围为6.48～1.24,其大小范围依次为:哈氏仿对虾、中华管鞭虾、鹰爪虾、周氏新对虾、须赤虾、角突仿对虾;6种虾类之间的食物的重叠指数0.008～0.716.除了周氏新对虾与其它虾类之间食物的重叠指数<0.15外,其它5种虾类之间(食物的重叠指数0.387～0.716)都存在竞争饵料资源的问题.挠足类、长尾类、稚幼鱼、多毛类、硅藻类和肉足鞭毛虫是虾类共同争食的饵料生物.  相似文献   

基于生态位理论的山东省城市旅游竞争力评价及空间格局研究     

李淑娟  王肖  隋玉正 《地域研究与开发》2017,36(5)

基于生态位理论,通过构建市场维、资源维、社会经济维、生态环境维的指标体系,评价2004—2009,2009—2014年山东省城市旅游竞争力,根据聚类分析结果和核心边缘理论,建立山东省城市旅游竞争力空间格局。研究发现:青岛市城市旅游综合竞争力排名稳居第一,烟台市、济南市紧随其后,其余城市的排名变化不大;山东省城市旅游竞争力呈现核心城市—次级城市—边缘城市的空间格局。核心城市可采取协同发展策略,带动和辐射周边城市的发展;次级城市重在加强市场营销,提升市场竞争力;边缘城市以特色策略为主,生态位扩充策略为辅,扩大生态位,提高城市旅游竞争力。  相似文献   

Resource Use by a Mediterranean Rocky Slope Fish Assemblage   总被引：1，自引：0，他引：1  

M. Fasola    L. Canova    F. Foschi    O. Novelli  M. Bressan 《Marine Ecology》1997,18(1):51-66

Abstract. Resource partitioning has been intensely studied in fish assemblages of tropical reefs, whereas surprisingly little research has been conducted on the benthic Mediterranean. Here we describe the composition of a fish assemblage of the rocky slopes at Tremiti Islands, southern Adriatic Sea, the vertical distribution at depths from 0 to 42 m, habitat choice and food use of the different species, and we identify the resources along which species are ecologically segregated. Species composition and fish density showed high similarities with the few other assemblages that have been censused on the rocky coasts of the Mediterranean. We observed a wide overdispersion among species in their use of food and habitat, while very little segregation occurred at the level of depth distribution. No coincident use of food, habitat or active periods occurred among fish species, and no trophic guilds exist in the three-dimensional niche.  相似文献   

Trophic ecology of the Patagonian skate, Bathyraja macloviana, on the Argentine continental shelf     

Scenna  L.B.; Garcia de la Rosa  S.B.; Diaz de Astarloa  J.M. 《ICES Journal of Marine Science》2006,63(5):867-874

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Ecological patterns and sustainability of freshwater swamp forest ecosystems: assessing climate and disturbance interactions     

《Singapore journal of tropical geography》2018,39(1):62-74

Species composition and factors that control the distribution of freshwater swamp forests in West Africa are largely unknown. To achieve this, 24, one‐hectare forest plots were established to assess the tree species (DBH ≥ 10 cm) distribution across the ecosystem. A total of 138 species within 100 genera and 41 families were distributed across the forest plots and 47 species were identified as indicator species. These indicator species were used to constrain the species‐environmental categories across three broad habitat types: the disturbed freshwater zone, the mangrove‐freshwater transition zone and the intact freshwater zone. While 40 species are associated with one of the three forest categories, seven of them coexisted in disturbed and mangrove‐freshwater zones. Disturbance (local factors) was identified as the most important determinant of the species distribution followed by the climatic factors. Future climate predictions for the locations are quite variable and suggest that some species may be non‐viable as the ecosystem's composition may alter. While the indicator species provides insights on the species‐environment relationships, and is useful for informing forest conservation and planning, their tendency to continually co‐exist with others and provide vital functions is dependent on how sustainably the people use them.  相似文献   

1999～2009年岷江上游干旱河谷聚落区林地变化特征     

刘影  郭亚琳  王青 《测绘与空间地理信息》2016,(11):90-93

岷江上游干旱河谷聚落区林地变化情况是检测长江上游生态环境建设好坏的重要指标.本文基于SPOT遥感数据和GIS技术,以聚落生态位为研究单元,分析1999～2009年岷江上游干旱河谷聚落区林地变化特征.结果显示:1)1999 ～2009年,岷江上游聚落生态位内林地面积增加22.58 km2,理县和汶川县增长率较高,分别为87.5％和89.75％;2)岷江上游干旱河谷聚落区林地以2401 ～2600 m为中心呈准正态分布,林地面积增加集中于海拔1 801～2800m地带;3)林地主要分布于15° ～25°之间,不同坡段林地面积均增加,增幅介于36.31％～73.68％之间;4)林地分布呈现北坡与西坡高于南坡与东南坡的特征,受水分与湿度条件影响,北坡和西坡方向上林地增加最多,分别为64.02％和62.78％.因此,由于退耕还林等生态工程的实施,岷江上游干旱河谷聚落区生态环境得到改善.  相似文献   

西部干旱区省会城市生态经济位比较研究     

徐厚琴  方一平 《干旱区地理》2007,30(3):26-430

从生态经济位理论出发,提出了城市生态经济位概念及度量方法,并根据生态经济位计算模型,从社会、经济和环境因子三个层面归结了30个指标,建立了定量评价指标体系,依此测算了2002年、2003年西部干旱区6个省会城市的生态经济位,得出2002年和2003年在西部干旱区省会城市中,乌鲁木齐的生态经济位最大,西宁的生态经济位最小的结论。文章最后分析、解释了西部干旱区6省会城市生态经济位动态变化及其原因。  相似文献   

土地利用可持续发展位理论构建与应用     

陈英  张仁陟  张军 《中国沙漠》2012,32(2):574-579

结合土地利用生态位理论和可持续发展理论,构建了土地利用可持续发展位理论,其核心内容包括土地利用可持续发展基本位、理想位、优势位、关键位和土地利用可持续发展位空间概念及模型。以甘肃省为例,测算确定了甘肃各地州市建设用地与新增建设用地可持续发展位空间。甘肃各地州市建设用地除了嘉峪关、金昌市指标值超出可持续发展位空间外,其余各地州市建设用地控制指标均处于可持续发展位空间内。白银、武威、张掖、酒泉、庆阳、甘南的指标值接近于理想目标;天水、平凉、定西、陇南、临夏的指标值趋近于适度目标。新增建设用地可持续发展位空间结果除平凉市和甘南州外,其余各地州市的控制指标均处于新增建设用地控制指标与其可持续发展位空间之间。表明《甘肃省土地利用总体规划（2006-2020）》确定的各地建设用地与新增建设用地控制规模基本均处于可持续发展位空间范围。甘肃省的实践证明,土地利用可持续发展位理论可用于系统研究土地生态系统变化规律,指导土地资源的可持续利用。  相似文献