IPCC-AR4以来华南沿海海平面变化研究若干进展

综述自IPCC-AR4(联合国政府间气候变化委员会第四次评估报告)以来,华南沿海海平面变化研究的新进展,结果显示:1)7 100-3 500 cal a BP时期华南沿海的海平面较今高1.5～2.5 m;2)1970-2010年的海平面上升率为2.5 mm/a,高于同时期全球平均上升率2.1 mm/a,原因与西太平洋暖池直接影响有关;3)采用新的全球冰川均衡调整(GIA)模型分析得出,华南沿海各验潮站的GIA效应值为-0.18～-0.30 mm/a;4)实施“海平面观测与影响评价标准”(HY/T134-2     

The causes and processes responsible for rocky desertification in karst areas of southern China

The karst region of southern China is a fragile ecological zone with widespread rocky desertification. This paper describes the rocky desertification occurring in this region in terms of both natural and anthropogenic factors. During geological time periods, the region’s changing environment governed the natural rocky desertification processes, whereas during historical and modern times, anthropogenic processes have been superimposed on these natural processes. Human activities have accelerated and exacerbated rocky desertification. The period from the beginning to the middle of the Qing dynasty was an important transitional period in which human activities began to exert a particularly strong influence on rocky desertification. Since then, the effect of anthropogenic factors has increasingly exceeded the effect of natural factors. The rocky desertification process in southern China’s karst region combines surface ecological processes (including vegetation degradation and loss, soil erosion, surface water loss, and bedrock solution) with a reduction of the land’s biological productivity, leading to degradation that produces rocky desert. Controlling rocky desertification requires comprehensive development of sustainable agriculture and economic development that provides employment alternatives to agriculture and thereby promotes the rehabilitation of rocky desertified land.     

The Effect of Human Exclusion on the Population Structure of Key-Hole Limpets Fissurella crassa and F. limbata on the Coast of Central Chile

Abstract. We describe the basic ecology of two key-hole limpets, Fissurella crassa and Fissurella limbata , which are heavily harvested by coastal shellfishermen (mariscadores) at the rocky intertidal of central Chile. The ecological role of human predation on these species was assessed. Anthropic exclusion from a stretch of the rocky intertidal at Las Cruces (non-harvested area) for about two and a half years resulted in changes of the densities and size distributions of these fissurelid species as compared to populations in control zones (harvested area). Differential human predation generates, on key-hole limpets, responses of different intensities related to the accessibility of man to the mesohabitats (sheltered platforms, exposed platforms and vertical walls) and fringes of the intertidal (mid-low intertidal and Lessonia nigrescens fringe). Thus, size distributions and mean densities of both fissurelids differ widely between the harvested and non-harvested areas on both platform habitats but not on vertical walls. In the mid-low intertidal fringe, differences are greater than in the less accessible L. nigrescens intertidal fringe. Moreover, we discuss the way in which other species, directly harvested by mariscadores (i. e., the mollusc Concholepas concholepas) can affect the keyhole limpet populations of central Chile rocky shores. Finally, we highlight the ecological role of these limpets on the dynamics of intertidal ecosystems and how they can modify community landscape.     

鲁东胶北地区中太古代唐家庄岩群

１０余年来,通过对鲁东胶北地区太古宙地层的研究,原胶东群中剔除出大量的变质变形深成侵入岩,并从其底部分离出一套呈包体状态残存于花岗质岩石中的紫苏磁铁石英岩、二辉斜长角闪麻粒岩等,据此建立了唐家庄岩群。该岩群为一套经受角闪麻粒岩相高级变质的表壳岩组合,同位素测年数据为２７６３～２９３６Ｍａ,与之相伴产出的超基性岩同位素地质年龄值为２６９３～３１５０Ｍａ,其特征与鲁西地区沂水岩群相似,说明太古宙时鲁东和鲁西曾是一个统一的克拉通陆核。     

潮沟成因类型及其影响因素的探讨

潮沟是潮坪上最活跃的微地貌单元。从成因角度分出了滩面水流冲剧型、潮流辐聚侵蚀型、陆源水流侵蚀继承型和泻湖广海间潮流侵蚀型等四种潮沟类型。根据各地潮沟发育程度的明显差异,提出了影响潮沟发育的七个重要因素。     

基于GIS与地理探测器的岩溶槽谷石漠化空间分布及驱动因素分析

岩溶区土地石漠化已成为中国西部继沙漠化和水土流失后的第三大生态问题,近年来岩溶槽谷区石漠化表现出增加趋势。通过获取槽谷区石漠化、岩性、坡度、海拔、降雨量、土地利用、人口密度和第一产业生产总值等数据,利用GIS空间分析功能和地理探测器模型,探讨了岩溶槽谷区石漠化空间分布特征及驱动因子。主要结论为：① 岩溶槽谷区总石漠化面积为21323.7 km ²,占研究区土地面积的8.3%,其中轻度、中度和重度石漠化面积分别是11894.8 km ²、8615.8 km ²和813.1 km ²,分别占石漠化面积的55.8%、40.4%和3.8%;② 从石漠化的空间分布来看,槽谷区石漠化主要发生在连续性灰岩中,轻度、中度和重度石漠化面积分别为占槽谷区相应石漠化类型面积的22.1%、22.4%和1.9%;槽谷区石漠化主要发生在15°~25°的坡度范围,轻度、中度和重度石漠化面积分别为占槽谷区相应石漠化类型面积的27.1%、18.2%和2.3%;从海拔来看,主要分布于400~800 m范围内,轻度、中度和重度石漠化面积分别为占槽谷区相应石漠化类型面积的24.9%、18.4%和0.2%;从土地利用类型来看,主要发生于山地旱地中;从人口密度来看,集中分布于100~200人/km ²中;从第一产业生产总值来看,集中分布于25亿~50亿元中;③ 地理探测器的因子探测器揭示了岩性（q = 0.58）、土地利用（q = 0.48）和坡度（q = 0.42）3个因子是槽谷区石漠化形成的主要驱动因子,交互式探测器进一步揭示了岩性与土地利用类型（q = 0.85）、坡度与土地利用类型的组合（q = 0.75）共同驱动槽谷区石漠化的形成。     

不同石漠化程度岩溶峰丛洼地系统景观格局的比较

利用花江岩溶峡谷区南坡不同石漠化程度的5个独立的岩溶峰丛洼地系统景观要素的实测数据,分析了多样性、优势度、破碎度、分离度等景观格局指标的变化规律及其所指示的生态学意义。结果表明,这些指标在不同峰丛洼地系统都能较好地评价石漠化过程中景观格局的动态变化规律,对分析石漠化土地的发展趋势具有较好的指示意义。但多样性指数、优势度指数、均匀度指数也与各峰丛洼地系统的景观基质有关,在不同石漠化程度的峰丛洼地系统中,反映的景观生态意义是不一样的。景观格局分析不仅强调面积,而且还考虑所研究石漠化土地的空间分布特征(格局)、景观组成特点与石漠化过程的关系和对石漠化的影响,在石漠化程度判定和石漠化指标的研究中景观格局是一个不可忽视的问题。     

Environmental changes on Yugorski Peninsula, Kara Sea, Russia, during the last 12,800 radiocarbon years

New pollen and radiocarbon data from an 8.6-m coastal section, Cape Shpindler (69°43′N; 62°48′E), Yugorski Peninsula, document the latest Pleistocene and Holocene environmental history of this low Arctic region. Twelve AMS ¹⁴C dates indicate that the deposits accumulated since about 13,000 until 2000 radiocarbon years BP. A thermokarst lake formed ca. 13,000–12,800 years BP, when scarce arctic tundra vegetation dominated the area. By 12,500 years BP, a shallow lake existed at the site, and Arctic tundra with Poaceae, Cyperaceae, Salix, Saxifraga, and Artemisia dominated nearby vegetation. Climate was colder than today. Betula nana became dominant during the Early Preboreal period about 9500 years BP, responding to a warm event, which was one of the warmest during the Holocene. Decline in B. nana and Salix after 9500 years BP reflects a brief event of Preboreal cooling. A subsequent increase in Betula and Alnus fruticosa pollen percentages reflects amelioration of environmental conditions at the end of Preboreal period (ca. 9300 years BP). A decline in arboreal taxa later, with a dramatic increase in herb taxa, reflects a short cold event at about 9200 years BP. The pollen data reflect a northward movement of tree birch, peaking at the middle Boreal period, around 8500 years BP. Open Betula forest existed on the Kara Sea coast of the Yugorski Peninsula during the Atlantic period (8000–4500 years BP), indicating that climate was significantly warmer than today. Deteriorating climate around the Atlantic–Subboreal boundary (ca. 4500 years BP) is recorded by a decline in Betula percentages. Sedimentation slowed at the site, and processes of denudation and/or soil formation started at the beginning of the Subatlantic period, when vegetation cover on Yugorski Peninsula shifted to near-modern assemblages.     

CONSIDERATION OF HYDRODYNAMIC CHARACTERISTICS,SEDIMENTS & ENVIRONMENTAL PROBLEMS OF MUDDY COAST IN THE CONSTRUCTION OF LIANYUNGANG HARBOUR

After nearly 20 years of construction,we have successfully solved a series of hydrologic sedimentaryand environment problems encountered during the construction of the big deep water harbour inLianyungang which can now accommodate ships of 50000 tonnage.With the economic development,the channel of 50000 tonnage will be built soon, and of 100000 tonnage is under planning. Theconstruction of the international container shipping hub at the harbour is being accelerated in anticipationof the opening of the second Eurasian land bridge.The future development of the harbour will givegreat impetus to the local economy of Lianyungang City and make it an international city.     

日本Ms9.0地震前的重力高频扰动

选取中国重力台网14台gPhone弹簧重力仪组成2个观测剖面,对日本本州东海岸附近海域Ms9.0特大地震前（3月1日至10日）的观测数据进行了分析。结果表明：沿海各台站统一出现了喇叭口状的“重力异常扰动”现象,且扰动异常随震中距的增加呈衰减趋势。