Short-term impact of blue mussel dredging (Mytilus edulis L.) on a benthic community

The short-term effect of mussel dredging in a brackish Danish sound was studied. A commercial dredging track was identified and an analysis of the species composition inside the track and at an adjacent control area showed that dredging changed the community structure by reducing the density of polychaetes. In order to investigate the extent and the duration of the dredging impact experimental dredging was conducted. The experimental dredging removed 50% of the mussels in two dredged areas. Immediately after dredging, a significantly lower number of species was measured inside the mussel beds in dredged areas compared to control and boundary areas. This effect lasted for at least 40 days. The analysis of the species composition showed that the dredged area had a significantly lower density, particularly of polychaetes compared to the boundary area. An increased number of species was recorded outside the mussel beds just after dredging, but this effect lasted for less than 7 days. After dredging, brown shrimps, C. crangon invaded the dredged areas. This species is an important predator of smaller invertebrates, and it is suspected that it was feeding on small vulnerable polychaetes exposed at the sediment surface after dredging. The dredging process was observed to form 2–5-cm deep furrows in the seabed, but the sediment texture and the organic content of the sediment was not affected. The biomass accumulation of individual blue mussels was significantly lower in the dredged area compared to the boundary area. This indicates that the disturbance of the mussel bed structure reduced growth and that the lowering of intraspecific food competition caused by a reduced density of mussels did not increase the accumulation of biomass in the mussels which remained in the dredged area.     

福建晋江深沪湾潮间带旧石器遗址

晋江深沪湾海滨潮间带近期发现一处旧石器时代晚期遗址,这种类型的遗址在福建省境内尚属首次。出土的石制品共87件, 分属四种类型, 从器型和加工技术判断, 与我国南方常见的砾石工业不甚相同; 伴生的哺乳动物化石有亚洲象和水牛等。根据遗址周边古牡蛎礁和古森林遗迹测年及与第四纪地层对比, 文化层年代距今25—10ka BP。坐落在潮间带的遗址, 对早期人类生存环境、生产活动和行为方面的研究具有重要意义, 也为深沪湾环境变迁和海平面升降的研究提供新的资料。     

江西官山自然保护区蝶类区系分析

对江西官山自然保护区172种蝶类进行区系分析,结果显示该区蝶类以东洋界为主体,计106种,占总数的61．63％：古北界11种,占总数的6．40％;东洋、古北二界共有种36种,占总数的20．93％。本文记述了官山产39种蝶类分布区的南北限。     

种植黄连和重楼对小型土壤节肢动物群落的影响

为了掌握中药材种植对土壤动物群落的影响,于2020年7月对成都市彭州境内种植期为3年和5年的黄连和重楼样地的小型土壤节肢动物进行了调查.共分离到小型土壤节肢动物526只,隶属于4纲17目69科98类或属,优势类群为等节跳属、平懒甲螨属、符跳属和副跳属.小型土壤节肢动物群落组成结构在不同中药材样地间差异明显,影响群落组成...     

茅口期相对海平面变化对类动物群的影响——以贵州盘县火铺镇茅口组剖面为例

分析贵州盘县火铺镇茅口期海平面变化的过程和Ｔｉｎｇ类动物群的变化规律,研究相对海平面变化对Ｔｉｎｇ类动物群构及演替的影响。相对海平面的升降变化可引起水深及相关生态条件的改变,并对Ｔｉｎｇ类动物群产生影响,相对海平面变化的幅度和速率是造成Ｔｉｎｇ类动物群面貌变化的重要因素,三级相对海平面上升末期和下降未期,海平面的大幅度抬升或下降是造成Ｔｉｎｇ类物种丰度下降,新种增加量减少的重要原因,海平面的持续缓     

Small-scale biogeographical patterns in some groundwater Crustacea, the syncarid, Parabathynellidae

An analysis was made of the micro-distribution patterns of five phylogenetically closely related species belonging to the genus Iberobathynella, a group of subterranean aquatic crustaceans (Syncarida, Parabathynellidae). The two-step model of colonization and speciation seems to provide a valid explanation for the current distribution of a large number of stygobiontic taxa of marine origin (thalassoid). However, with respect to the Iberobathynella, only the colonization of the subterranean environment at the mesoscale level can be explained. The second phase of the model, marine regression, can only explain the colonization of the region by the ancestor; the subsequent evolution and speciation at a smaller scale remain to be explained. Local geological constraints – Upper Triassic gypsiferous mudstone deposits plus faults and thrusting linked to the Alpine Orogeny – are responsible for the appearance of local palaeogeographic phenomena. These may have been the vicariant processes responsible for the geographical and genetic isolation of the ancestral populations of this group, which eventually led to clade divergence. Together with small-scale passive dispersion (11 dispersal events) and local extinction, these processes could be responsible for the current distribution of the five sister taxa inhabiting the caves of the Sierra de la Collada, Spain. A plausible palaeogeographical scenario is offered to explain their present distribution, that clearly came about through chance events.     

Sea and colonial-nesting birds of islands in the southern part of Amurskii Liman

The quantity of the nesting couples of sea birds on the islands of the southern part of Amurskii Liman was determined: common heron Ardea cinerea, slaty-backed gull Larus schistisagus, black-tailed gull L. crassirostris, and sooty guillemot Cepphus carbo.     

A thalloid organism with possible lichen affinity from the Jurassic of northeastern China

Documentation of fossil lichens is rare, despite the fact that lichenization in fungi is believed to be ancient and many paleoecosystems should have provided ample suitable habitats for these organisms. Impression fossils of a cm-sized thalloid organism, Daohugouthallus ciliiferus nov. gen. et spec., are described from a Middle Jurassic deposit nearby Daohugou village, Inner Mongolia, China. The thallus comprises elongate primary axes from which extend lateral and terminal branches that fork once to repeatedly. Extending from all branches (mostly from the lateral margins and tips) are filiform appendages that closely resemble the cilia of certain extant lichens. Some branch tips appear ruptured and covered by minute irregularities, and appear similar to lichen soralia. One specimen is associated with a small seed cone and suggestive of epiphytic growth. The structural similarities with extant lichens, close association with land plants, and the environment in which the organism lived, suggest that the affinity of D. ciliiferus is with the lichens.     

生物表面活性剂修复HOCs污染土壤的研究进展

简要介绍了疏水性有机污染物(HOCs)在土壤环境中积累产生的危害及应用生物表面活性剂(BS)修复HOCs污染土壤的优势.阐明了BS修复HOCs污染土壤的主要机理:BS对HOCs的增溶作用、BS促进土壤中HOCs的解吸、BS促进土壤中HOCs的生物降解.分析了BS的种类及含量、污染土壤对BS的吸附、土壤本身的理化性质等因素对土壤生物修复的影响.探讨了HOCs污染土壤生物修复的发展方向及应用前景.     

内蒙古阿拉善左旗早石炭世有孔虫动物群的发现

笔者首次发现内蒙古阿拉善左旗地区井下早石炭世晚期有孔虫动物群,经研究计有１４属１８种,其中小有孔虫１２属１６种（１新属,新种）Ｔｉｎｇ２属２种,这一孔虫动物群的发现,除证明该地区存在早石炭世地层外,对当时岩相古地理面貌的分析,也具有重要意义。