Palaeoenvironmental research on diatoms in early and middle Holocene deposits in central North Holland (The Netherlands)

In the geological research of the Holocene coastal deposits of The Netherlands, diatoms are used to reconstruct the sedimentary facies, palaeo-tide levels and salinity gradients during the deposition of the sediments. In this paper, the results of diatom research from 4 borings, taken from the early and middle Holocene deposits of central North Holland are presented. The oldest marine influenced sediments in the area are the deposits of the ‘Velsen layer’, a clay layer rich in organic matter and deposited about 8000–7000¹⁴C years before present (BP) at a depth of 20–12 m below present mean sea-level. This clay layer was formed in a shallow, permanently submerged environment with a limited tidal influence (lagoonal or pond-like conditions). The salinity changed from brackish/freshwater to marine/brackish. The younger sandy and clayey sediments, formed about 7000–4500 BP at a depth of 16–3 m below present mean sea-level, are classified as ‘tidal channel’ and ‘interchannel’ deposits. It is argued, on the base of both diatom and non-diatom criteria, that the lower and middle parts of the interchannel deposits in the central area of the palaeo-tidal basin of North Holland were formed in a subtidal environment. The upper part of the interchannel deposits and the deposits at the fringe of the North Holland tidal basin were formed in the intertidal zone or, at the fringe of the basin, even in the supratidal zone. The salinity in the North Holland tidal basin during the sedimentation of the tidal channel and interchannel deposits was marine/brackish to marine. This study indicates that diatoms, besides their palaeoecological applications, have chronostratigraphical significance (on a regional scale). The diatomsCymatosira belgica andActinoptychus splendens appear to be a useful (eco)stratigraphical marker in the Holocene coastal deposits of The Netherlands and Belgium.     

贵州台江下-中寒武统凯里组遗迹化石群落与环境关系的探讨

通过贵州台江凯里组中丰富的、分异度较高的、以原地埋藏为特征的遗迹化石的研究,探讨凯里组遗迹化石群落的沉积环境和埋藏环境。凯里组遗迹化石群落以节肢动物和软体动物的停息迹、爬行迹和游泳迹占优势,浅层内生爬行觅食潜穴和系统觅食潜穴占有一定的地位,也见有浅的居住滤食性潜穴,属Seilacher的Cruziana遗迹相,为正常浪基面和风暴浪基面之间的浅海软质基底陆棚低能环境,那里盐度正常、光照充足、含氧量充分、水体平静、沉积速率较快。在此环境中,浮游、游泳以及底栖爬行和固着生物类型大量地生长、繁殖和活动,表生遗迹和浅层内生遗迹十分丰富。生物死亡后的腐烂和分解,使得食泥生物大量繁盛。随着沉积物的覆盖和被埋藏生物遗体的分解、腐烂,沉积物内部还原能力逐渐增强,导致分解和腐烂过程终止。     

Orangutan use of vertical space in an innovative habitat

This study measured use of vertical space in an innovative habitat for three adolescent orangutans (Pongo pygmaeus). The indoor habitat was innovative in two main ways: a flooded floor and retractable skylights. It included four large molded trees and interwoven vines throughout 1,620 m³ of space. The exhibit was divided into four vertical levels: skylights, upper canopy, lower canopy, and flooded floor. Five trained observers made instantaneous scans of the exhibit every 5 minutes, in 1‐hour blocks of time over a 10‐month period, logging 180 hours of observations. One location (of 55) and one behavior (of 53) were noted at each interval. Behaviors were collapsed to form five categories: solitary inactivity, solitary activity, social inactivity, social activity, and eating/drinking. Results showed the orangutans favored the upper canopy, which contained many tree limbs for sitting and reclining. The orangutans next favored the lower canopy and the skylights, especially those skylights that were out of public view. The habitat’s flooded floor was avoided (they used it just 1% of the time), as planned by the exhibit designers who intended to showcase these arboreal primates in trees, not on the ground. When compared with wild orangutans, we considered few of their behaviors to be atypical: foraging/eating plastic (vines) and stereotyped behaviors. Overall, the unique design of the habitat provided opportunities for a range of species‐typical behaviors, varying by vertical level, demonstrating the importance of providing sufficient vertical space for orangutans. Zoo Biol 19:239–251, 2000. © 2000 Wiley‐Liss, Inc.     

The effect of habitat and human disturbance on the spatiotemporal activity of two urban carnivores: The results of an intensive camera trap study

With rising urbanization, the presence of urban wildlife is becoming more common, increasing the need for wildlife‐friendly spaces in urban planning. Despite this, understanding is limited to how wildlife exploits urban environments and interacts with human populations, and this is vital to our ability to manage and conserve wildlife in urban habitats. Here, we investigate how two urban mammal species, the red fox (Vulpes vulpes) and the European badger (Meles meles), exploit urban environments. Using intensive camera trap surveys, we assessed how habitat and human disturbance influenced the spatiotemporal activity of these species across south‐west London. Firstly, we found elevated activity levels of both species at boundaries and within built‐up areas, suggesting movement paths follow anthropogenic features. However, badgers were most active in woodland, indicating the importance of high cover habitats suitable for setts and foraging. Secondly, we found badger activity levels were negatively affected by human activity, whilst foxes were unaffected. Further investigation suggested foxes may adapt their activity patterns to avoid human disturbance, with badger activity patterns less plastic. Whilst the results of this study are useful for both the conservation and management of urban wildlife populations, these results also show potential factors which either facilitate or limit wildlife from fully exploiting urban environments.     

Coping with salt without salt glands: osmoregulatory plasticity in three species of coastal songbirds (ovenbirds) of the genus<Emphasis Type="Italic"> Cinclodes</Emphasis> (Passeriformes: Furnariidae)

We investigated the phenotypic plasticity of renal function in three South American coastal passerine Cinclodes (ovenbirds) differing in the proportion of marine prey they consume. Individuals were acclimated to two regimes of salinity for 15 days, and then the maximal urine-concentrating ability (U_max), hematological parameters and kidney morphology of each species were determined. The proportion of kidney mass occupied by medullary tissue, the number of medullary cones in the kidneys, plasma osmolality and U_max differed among the three species, supporting the hypothesis of an adaptation for excretion of the high salt load in the strictly marine C. nigrofumosus. Our results indicate that species of Cinclodes are able to modify the proportion of medullary tissue and the U_max. In addition, we found interspecific differences in the magnitude to which these osmoregulatory parameters can be modified. The greater ability to modify the osmoregulatory features in the migrant species C. oustaleti may enable it to cope with seasonal changes in salt load imposed by the winter consumption of hypertonic prey.Abbreviations U_max maximal urine concentration - SW salt water - TW tap waterCommunicated by I.D. Hume     

A branching model for the spread of infectious animal diseases in varying environments

This paper is concerned with a stochastic model, describing outbreaks of infectious diseases that have potentially great animal or human health consequences, and which can result in such severe economic losses that immediate sets of measures need to be taken to curb the spread. During an outbreak of such a disease, the environment that the infectious agent experiences is therefore changing due to the subsequent control measures taken. In our model, we introduce a general branching process in a changing (but not random) environment. With this branching process, we estimate the probability of extinction and the expected number of infected individuals for different control measures. We also use this branching process to calculate the generating function of the number of infected individuals at any given moment. The model and methods are designed using important infections of farmed animals, such as classical swine fever, foot-and-mouth disease and avian influenza as motivating examples, but have a wider application, for example to emerging human infections that lead to strict quarantine of cases and suspected cases (e.g. SARS) and contact and movement restrictions.     

Economic issues in the management of plants invading natural environments: Scotch broom in Barrington Tops National Park

Scotch broom (Cytisus scoparius, L.), is an exotic leguminous shrub, native to Europe, which invades pastoral and woodland ecosystems and adjoining river systems in cool, high rainfall regions of southeastern Australia. Broom has invaded 10,000ha of eucalypt woodland in Barrington Tops National Park in New South Wales, and is having a major impact on the natural ecology of the sub-alpine environment. It is extremely competitive with the native flora, retarding their growth and in many areas blanketing the ground and preventing growth of many understorey species in open forest areas. A number of rare and endangered species are believed to be under threat from this invasion. An active program to manage the threat is being implemented by the New South Wales National Parks and Wildlife Service. The management issues relevant to this threat are addressed through the application of a detailed bio-economic model of broom management. The results show that intervention in the management of broom in this natural ecosystem is clearly economically justified, and increases in the existing budgets appear to be justified. A combination of control measures, rather than any single measure, is almost always justified. Attempts to eradicate the broom invasion appear to be undesirable, so containment is the preferable strategy. Further, funding bodies should give assurances of future budget levels. The method of analysis reported here should be applicable to other types of biological invasions.     

Reintegrating Coastal Development and Public Health in Western Australia

This article presents three case studies that take a socio-ecological perspective to highlight an interconnectedness between the environment, human participation and organization, and public health, in Western Australian marine, coastal, and near-coastal places. We examine the degree to which coastal zone planning and management interact with public health practitioner, and the consequences of this interaction for biophysical surroundings and human health. The case studies demonstrate the limited roles the public health sector has played, and the indispensable expanded role it might play, in what is traditionally seen as the domain of natural resource management. A socio-ecological analysis highlighted the value of decision-making processes for coastal developments that emphasize dialogue, place, public health issues, resource distribution, as well as ecology. These adaptive capabilities offer scope for understanding the consequences of coastal planning and management actions on both the biophysical condition of the environment and human health, break the cycles of reaction, and provide an alternative framework for regulating the developmental expansion of the Western Australian coastline.David Galloway is a sustainability designer and has undertaken work for some of the pastoralists on the Ningaloo coast. The analysis of the third case study is based, in part, on information gained through these consultancies.     

Daily torpor in elephant shrews (Macroscelidea: Elephantulus spp.) in response to food deprivation

Patterns of daily torpor were measured in response to photoperiod and food restriction at a constant temperature (18 °C) in two species of elephant shrew (Macroscelidea), Elephantulus rozeti (from Morocco) and Elephantulus myurus (from southern Africa). Body temperature was monitored continuously for ca. 3 months using temperature-sensitive telemeters. Under short photoperiods (8:16 L:D), both species entered spontaneous torpor on an ad libitum diet, but showed a higher frequency of induced torpor when food was restricted. Under long photoperiods (16:8 L:D), E. myurus could be induced to enter daily `summer' torpor. A total of 378 torpor bouts were measured, none of which were longer in duration than 18 h. Under short photoperiods, arousal from torpor was associated with the onset of the photoperiod, whereas the time of entry was variable throughout the scotophase. However, E. myurus tended to phase shift torpor from the photophase to the scotophase under long photoperiods, despite displaying weak circadian amplitudes of body temperature indicative of a photophase rest phase. Both species lacked well-defined circadian amplitudes of body temperature, a pattern thought to be associated with polyphasic activity cycles characteristic of several Elephantulus species. It was concluded that these and other patterns of torpor shown by Elephantulus show similarities with other small Afrotropical insectivores inhabiting semi-arid habitats or unpredictable environments. Accepted: 26 July 2000     

江苏句容宝华山全新世中晚期的花粉与环境

根据宝华山华山口和官塘头两个剖面的花粉、地层资料,结合植物大化石和＾１４Ｃ年代资料,提示该地区从＞６７００－５６００ａＢＰ为稳定的温暖湿润时期;自５６００－５１００ａＢＰ为全新世中期气候的转型时期,冷暖干湿变化较大,前期转凉,旱涝频繁,中期暖湿,后期转冷;大约从４４００－４０００ａＢＰ又变为稳定的暖湿气候。还根据自然保护区现代植被与花粉的关系和与植物大化石共生的沉积物花粉,阐明长江下游新石器时代以