What is groundwater and what does this mean to fauna? - An opinion     

Susanne I. Schmidt  Hans Jürgen Hahn 《Limnologica》2012,42(1):1-6

Many subsurface waters are considered groundwater but are influenced in shallow depths by hyporheic, parafluvial and/or soil interception water to such a degree that groundwater fauna (stygofauna) communities may be significantly altered. Recharge, even if spatially and temporally distinct, delivers input of dissolved oxygen, organic matter (OM), and nutrients that caters sustainably for ubiquists such as stygophiles and hyporheic fauna, but renders the life of uncompetitive stygobites difficult or impossible. The impact of recharge at shallow groundwater thus needs to be taken into account when determining groundwater fauna reference communities and when evaluating monitoring studies.One of the main characteristics of groundwater is low OM concentration. In contrast, high OM concentrations are typical of hyporheic or parafluvial waters, which are enriched by OM from the river, the riparian soils and from interflow, and which contribute significantly to river OM balance. Consequently, for ecological studies on subsurface waters, both the origin of the water and OM, and the intensity of surface water interactions should be considered. Here, we discuss how groundwater spatial and temporal heterogeneity translates into faunal distribution patterns. In terms of the origin of water and OM, and from an ecological point of view, we need to distinguish between (i) shallow groundwater characterized by infiltrating precipitation and soil recharge, (ii) shallow groundwater interacting with surface water bodies such as continuously flowing and ephemeral streams and rivers, and (iii) “old” groundwater which has no recent connections to the surface and is thus largely secluded from input of nutrients and carbon. Water in the first two groups is characterized by high amounts of OM of varying quality, while water in the third group is characterized by low amounts of low quality OM. Consequently, stygophiles dominate in groups 1 and 2, with hyporheic fauna taking up a considerable proportion in group 2, while stygobites only dominate in group 3. Thus, for studies aiming to assess impacts on groundwater, only sampling sites of the third group should be used for reference sites as these are the most likely sites to have little surface impact and a stygofauna representative of the deeper aquifer.  相似文献   

喀斯特高原不同植被演替阶段土壤动物群落特征   总被引：3，自引：0，他引：3  

樊云龙  熊康宁  苏孝良  陈浒  邹细霞 《山地学报》2010,28(2)

选择贵州喀斯特高原三个典型地貌单元作为研究区,于2009-05对不同植被演替阶段的土壤动物群落进行研究.共获土壤动物3 992只,隶属于5门10纲26目,共31个类群,优势类群为弹尾目(Collembola)、甲螨亚目(Oribatida)、中气门亚目(Mesostigmata);常见类群为前气门亚目(Prostigmata)、膜翅目(Hymenoptera)、鞘翅目(Coleoptera)、半翅目(Hemiptera )、近孔寡毛目(Plesiopora)、双翅目(Diptera)、双尾目(Diplura).研究结果表明,随着喀斯特植被的不断退化,土壤动物数量不断减少,表现为林地＞灌丛＞草地＞石漠化地;类群数亦呈减少趋势.各演替阶段土壤动物表聚性明显,但人为干扰(如翻耕等)可导致土壤动物出现逆分布现象.土壤动物多样性分析表明,中小型土壤动物的多样性指数从林地到石漠化地逐渐减小.  相似文献   

论热河生物群   总被引：11，自引：4，他引：7  

季强 《地质论评》2002,48(3):290-296

本文对中生代热河生物群的研究历史作了简要回顾,着重阐述了热河生物 群的定义、组成、地层分布和时代,并讨论了与热河生物群相关的我国北方陆相侏罗系－白垩系界线问题。  相似文献   

南极长城站附近的脊椎动物 Ⅰ鸟类          下载免费PDF全文

张春光  高耀亭 《极地研究》1991,3(1):30-38

本文对在南极长城站区附近活动的6科11种鸟类的数量、分布、繁殖、行为、栖息环境等作了比较详细的报道。作者认为:(1)在长城站区附近分布的鸟类全为肉食性种类;(2)企鹅在整个食物链中占有非常重要的作用;(3)亲鸟的护幼行为较强;(4)所观察到的鸟类全为早成或半早成鸟,但亲鸟育雏期又都较长,这是一种特殊习性。  相似文献   

东江鱼类区系研究     

叶富良  杨萍  宋蓓玲 《广东海洋大学学报》1991,(2)

根据1981—1983年的调查结果,记述东江125种鱼类,分隶干11目25科,其中纯淡水鱼类为111种,鲤科鱼类有63种,占鱼类总数的50.4％,构成东江鱼类的基础;并讨论了东江鱼类的地理分布、来源、区系组成和地理区划。  相似文献   

A statistical test on diversity changes of Early and Middle Permian fusulinacean fauna in South China     

SHI Yukun & YANG Xiangning Department of Earth Sciences  Nanjing University  Nanjing  China 《中国科学D辑(英文版)》2005,48(7)

Regional stratigraphic data of major fossil groups in the critical geologic periods could provide reliable materials not only for the studies of diversity changes in different biogeographic provinces,but also for the comparison of regional patterns in the major biotic events accumulated in a long history of investigation,the paleontologic and stratigraphic data of South China have made indispensable contributions to re-vealing the pattern of end-Permian extinction[1―3],analyzing the differenc…  相似文献   

贵州关岭动物群产出地层的地球化学特征及其对物源和沉积环境的指示意义   总被引：1，自引：0，他引：1       下载免费PDF全文

唐宾  郝维城  孙作玉 《古地理学报》2005,7(2):261-274

对贵州关岭晚三叠统法郎组瓦窑段底部的毛凹剖面系统地采集了105个岩石样品，测定了样品中的36种化学元素含量。作者对它们进行元素富集因子（EF）分析、R型聚类分析、R型因子分析、元素和氧化物的含量与Al2O3的含量比值以及δCe在剖面中垂向变化的分析，讨论了元素含量变化的制约因素、沉积物的来源、古海洋氧化还原条件的变化、关岭动物群的埋藏环境。结果表明：研究的5.2 ~17.7 m段剖面地层以陆源碎屑和生物碎屑混合沉积为主，沉积物来源于陆壳，而不是火山和热液的来源，其沉积的氧化还原条件多次反复变化；元素的含量变化主要受陆源物质、氧化还原条件、生物碎屑以及成岩作用控制；从元素地层学角度将所研究的剖面段从下到上可划分为4层，第1层至第4层元素对比值曲线呈现出平缓波动-频繁波动-平缓波动的周期性变化特征；该段偏还原的环境对海百合及海生爬行动物化石的保存和埋藏起了良好的作用。  相似文献   

Mammal fauna first found in alluvial-speleogenic formations of the late Neopleistocene and Holocene, northern Urals, locality Cheremukhovo-1     

T. V. Strukova  O. P. Bachura  A. V. Borodin  V. V. Stefanovskii 《Stratigraphy and Geological Correlation》2006,14(1):91-101

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The Mesozoic ostracod genus Arculicythere Grékoff: further evidence for the southern Gondwana seaway     

Sara Ballent  Robin Whatley   《Cretaceous Research》2006,27(6):728-734

This paper demonstrates that Arculicythere Grékoff is a widespread taxon in the uppermost Upper Jurassic and Lower Cretaceous of Gondwana. It occurs in Madagascar, India, Israel, South Africa, the Falklands Plateau, Argentina and Australia. The earliest record is from the Upper Tithonian of Madagascar but the most profuse occurrences are in the Albian, when the genus was very widespread around Gondwana. Its distribution seems to be associated with a major southern Gondwana seaway, and the genus provides additional proof of the existence of this corridor. Unlike another endemic gondwanine genus, Majungaella Grékoff, which ranged from earlier in the Jurassic but extended into the Neogene in the Antarctic, or Rostrocytheridea Dingle that survived into the Campanian of the Antarctic, Arculicythere seems to have become extinct in the Albian.  相似文献   

The nature of Mawsonites (Ediacara fauna)     

A.J. van Loon   《Gondwana Research》2008,14(1-2):175

Some representatives of the Ediacara fauna have been later re-interpreted as pseudofossils. This was recently also done for Mawsonites, which was re-interpreted as a sedimentary structure formed due to interaction of a sand volcano (or water-escape structure) and a biomat. This sedimentary genesis appears not to be tenable, as several physical processes should have been involved, none of which is known from modern times or the geological past. It is concluded that Mawsonites must be considered as a fossil, either an imprint or a true fossil. This interpretation may be tested on one or more fragments of the structure.  相似文献