Ecology of macrobenthos in the south of Zhejiang coastal waters   总被引：1，自引：0，他引：1  

贾海波  胡颢琰  唐静亮  王益鸣  柴小平 《台湾海峡》2011,30(4):577-582

为了解浙江南部近岸海域海洋生态环境质量的现状及其变化趋势,2009年4月对浙江南部近岸海域的12个站位进行了大型底栖生物的分类、组成、丰度、生物量以及多样性的研究．应用Bray—Curtis相似性系数聚类和多维尺度排序,对浙江南部近岸海域的大型底栖生物进行群落划分;采用丰度生物量比较法分析群落的稳定性;并研究了对大型底栖生物产生影响的主要环境因子．本次调查共鉴定大型底栖生物109种,多毛类、软体动物和甲壳动物构成主要类群．平均生物量为23．38g／m^2,平均丰度为335．5ind／m^2,平均生物多样性指数为2．69．数量组成：生物量以软体动物居首（13．29g／m^2）,鱼类次之（3．68g／m^2）;丰度以多毛类居首（268．0ind／m^2）,软体动物次之（51．7ind／m^2）．浙江南部近岸海域可划分为3个群落．与环境因子进行相关性分析表明,有机污染含量、深度、溶解氧含量、盐度和悬浮物含量是对浙江南部近岸海域大型底栖生物产生影响的主要环境因子．总体上,除了瓯江口和乐清湾海域受到一定扰动,浙江南部近岸海域大型底栖生物环境质量较好,群落结构较为稳定．  相似文献   

Population dynamics of marine ciliate Euplotes vannus (Protozoa, Ciliophora) in different artificial seawaters     

�����  ����׳  ����  ��ɺ 《中国海洋湖沼学报》2011,29(1):109-117

To study population dynamics of marine ciliates in different artificial seawaters (ASW), the population growth dynamics of a common marine ciliate Euplotes vannus were investigated using beef extract media and rice media for five types of ASW and natural seawater (NSW). The results show that: (1) the population growth rate was in the order of NSW>Flack ASW>Nakamula ASW>Schmadz ASW>Oshima ASW>Subow ASW and was considerably higher in rice media than in beef extract media (apart from Subow ASW); (2) the maximum density of E. vannus in stationary phase in each treatment was ranked as Flack ASW>Nakamula ASW>Schmadz ASW>NSW>Oshima ASW>Subow ASW, and was again higher in rice media than in beef extract media (except for Subow ASW); (3) the exponential and stationary phases were longer in rice media than in beef extract media; (4) strains of E. vannus that had been domesticated for >1 year in ASW grew significantly slower, with lower maximum density and longer stationary phase than those isolated and maintained in NSW. It was demonstrated that: (1) E. vannus may grow well in Flack, Nakamula and Schmads ASW compared with NSW (mainly in terms of growth rate); and (2) Oshima ASW is the preferred choice for stock cultures of E. vannus, but the ASWs Flack, Nakamula and Schmadz are preferred for mass culture. These findings suggest that these three ASWs are effective for the cultivation of marine protozoa for experimental studies on ecology, toxicology and molecular biology.  相似文献   

景观生态学教学的短期户外观摩：云南大学的实践   总被引：2，自引：0，他引：2  

吴兆录 《云南地理环境研究》2011,23(1):1-4,17

景观生态学研究的社会认知度在不断提高,教学研讨却相当滞后。介绍云南大学的景观生态学教学实践和经验,以期抛砖引玉。云南大学的景观生态学教学始于1987年,至今在本科、硕士、博士3个层次上开展不同深度的授课。为期1～2天的短期户外观摩,是课堂教学的组成部分,分3个步骤：（1）行前利用Google Earth网络资源演示预设线路和地点的景观结构和生态过程,激发学生的求知欲望;（2）围绕河流-湖泊污染扩散、越冬红嘴鸥觅食-安全日迁移两种生态流实施户外观摩教学,使学生在现实景观里理解和识别景观基底-廊道-斑块、源汇景观转换、景观边界及边缘效应等书本知识;（3）强化总结讨论,促使户外观摩印象的理论升华。  相似文献   

城市地表温度热岛影响因素研究进展   总被引：14，自引：3，他引：11  

谢苗苗  王仰麟  付梅臣 《地理科学进展》2011,30(1):35-41

城市地表温度热岛是城市生态环境效应研究的热点之一,其影响因素研究为缓解城市热岛带来的负效应、促进城市可持续发展提供依据.本文系统回顾了国内外关于城市地表温度热岛影响因素的研究进展.首先结合热岛效应表征的地表能量过程,基于景观生态学格局-过程理论,从地表能量吸收释放、转换及传输3种过程中归纳热岛效应的影响机理,分别对应地...  相似文献   

山地生态学的研究进展、重点领域与趋势   总被引：4，自引：0，他引：4  

王根绪  邓伟  杨燕  程根伟 《山地学报》2011,29(2)

在全球变化背景下,山地生态系统的剧烈变化不仅对陆地生态系统格局与功能产生较大影响,而且也显著制约着人类社会的可持续发展.在明确山地生态学研究的重要性和迫切性的基础上,通过对国际上山地生态学研究进展的全面综述,阐明了现阶段山地生态学研究的重点领域和前沿科学问题.对我国山地生态学研究的重要性进行了系统分析,并讨论了研究现状及其存在的主要问题.认为作为世界第一山地大国,我国山地生态科学研究应得以重视和发展,以应对全球变化对我国生态和环境安全的影响.  相似文献   

Clubmoss, precipitation, and microsite effects on emergence of graminoid and forb seedlings in the semiarid Northern Mixed Prairie of North America     

J.T. Romo 《Journal of Arid Environments》2011,75(2):98-105

Clubmoss (Selaginella densa Rydb.) provides extensive ground cover throughout the Northern Mixed Prairie of North America, but little is known about how this cryptogam affects seedling emergence relative to precipitation. Seedbed treatments including a control, Glyphosate applied to kill clubmoss, and clubmoss removal were factorially combined with ambient precipitation, precipitation reduced, and irrigation. Graminoid and forb emergence in the seedbeds and the microsites of live clubmoss, dead clubmoss, bare soil, litter, and caespitose grasses was determined. Forb emergence was greatest with clubmoss removal and irrigation. About 2.6-3.6-fold more forbs emerged from bare soil microsites, but clubmoss reduced forb emergence by 32-76%. Litter reduced forb emergence in 2 of 3 years. Graminoid emergence did not vary among seedbeds (P ≥ 0.780), but irrigating increased seedling emergence. Graminoid emergence was unaffected or improved in live clubmoss, dead clubmoss, bare soil, and litter microsites. In the semiarid Northern Mixed Prairie, above-average precipitation combined with bare soil will favor emergence of forbs. By contrast, clubmoss does not limit graminoids because seedlings emerge from a range of seedbeds and microsites provided diaspores are present and precipitation is above average. Emergence of graminoids and forbs is constrained primarily by precipitation in the semiarid Northern Mixed Prairie.  相似文献   

Effects of cattle trampling on vegetation, infiltration, and erosion in a tropical rangeland     

T. Dunne  D. Western 《Journal of Arid Environments》2011,75(1):58-69

Cattle trampling without forage consumption at stocking densities of 0.03-1.4 cows ha⁻¹ was simulated on two dry-season rangelands in Kenya. Experiments under artificial rainfall documented the response of plant cover and production, infiltration, and erosion on a Luvisol and a Vertisol. Trampling reduced plant cover, biomass, and, at the highest rate, regeneration in the ensuing wet season. Infiltration was reduced on the Vertisol but not the Luvisol, although increases in runoff due to trampling were slight. Trampling increased soil loss partly by reducing vegetation cover but mainly by disrupting surface layers of sand on the Luvisol and of clay aggregates on the Vertisol. Soil loss normalized by runoff and rainfall energy declined in a sequence of erosive rainstorms as the sandy surface layer became re-established, but before vegetation recovered. Establishment of a sandy armor layer during runoff events and its disruption by dry-season trampling thus strongly affect soil-loss rates. Trampling limits plant recovery in the ensuing wet season only at intensities typical of settlement and watering centers. The experimental results, generalized with a spatial model of stock density, can be used to estimate the contribution of trampling to forage production and erosion as herding patterns change in response to sedenterization and water development.  相似文献   

Modelling climate‐change impacts on stream temperature of Formosan landlocked salmon habitat     

Ching‐Pin Tung  Tsung‐Yu Lee  Yi‐Chen Yang 《水文研究》2006,20(7):1629-1649

A physics‐based model is provided for predicting the impact of climate change on stream temperature and, in turn, on Formosan landlocked salmon (Oncorhynchus masou formosanus) habitat. Because upstream watersheds on Taiwan Island are surrounded with high and steep mountains, the influence of mountain shading on solar radiation and longwave radiation is taken into account by using a digital elevation model. Projections using CGCM2 and HADCM3 models and CCCM and GISS models provided information on future climatic conditions. The results indicate that annual average stream temperatures may rise by 0·5 °C (HADCM3 short term) to 2·9 °C (CGCM2 long term) due to climate change. The simulation results also indicate that the average suitable habitat for the Formosan landlocked salmon may decline by 333 m (HADCM3 short term) to 1633 m (CGCM2 long term) and 166 m (HADCM3 short term) to 1833 m (CGCM2 long term) depending on which thermal criterion (17 °C and 18 °C respectively) is applied. The results of this study draw attention to the tasks of Formosan landlocked salmon conservation agencies, not only with regard to restoration plans of the local environment, but also to the mitigation strategies to global climate change that are necessary and require further research. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Utilisation and Management Changes in South Kyrgyzstan''''s Mountain Forests     

Matthias Schmidt 《山地科学学报》2005,2(2)

IntroductionThe mountain forests of South Kyrgyzstan have a long history of human influence. The political and socio-economic conditions prevailing in the region have changed dramatically several times over the last century and have played animportant role in forest policy, management and use. To highlight the human-environment relationship, I have chosen here to use a political ecology approach as conceptual framework (cf. Bryant & Bailey 1997, Bryant 1998, Blaikie 1999). In this approach,…  相似文献   

Modelling hydrological management for the restoration of acidified floating fens     

Stefan C. Dekker  Aat Barendregt  Margien C. Bootsma  Paul P. Schot 《水文研究》2005,19(20):3973-3984

Wetlands show a large decline in biodiversity. To protect and restore this biodiversity, many restoration projects are carried out. Hydrology in wetlands controls the chemical and biological processes and may be the most important factor regulating wetland function and development. Hydrological models may be used to simulate these processes and to evaluate management scenarios for restoration. HYDRUS2D, a combined saturated–unsaturated groundwater flow and transport model, is presented. This simulates near‐surface hydrological processes in an acidified floating fen, with the aim to evaluate the effect of hydrological restoration in terms of conditions for biodiversity. In the acidified floating fen in the nature reserve Ilperveld (The Netherlands), a trench system was dug for the purpose of creating a runoff channel for acid rainwater in wet periods and to enable circum‐neutral surface water to enter the fen in dry periods. The model is calibrated against measured conductivity values for a 5 year period. From the model simulations, it was found that lateral flow in the floating raft is limited. Furthermore, the model shows that the best management option is a combination of trenches and inundation, which gave the best soil water quality in the root zone. It is concluded that hydrological models can be used for the calculation of management scenarios in restoration projects. The combined saturated–unsaturated model concept used in this paper is able to incorporate the governing hydrological processes in the wetland root zones. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献