bluuebunny/crossref_metadata_2025_split huggingface dataset:
Moving to suburbia: ontogenetic and evolutionary consequences of life on predator‐free islands
Authors: Blumstein Daniel T. 
Published: March 2003

AimMany species find themselves isolated from the predators with which they evolved. This situation commonly occurs with island biota, and is similar to moving from the dangerous inner‐city to the suburbs. Economic thinking tells us that we should expect costly antipredator behaviour to be lost if it is no longer beneficial. The loss of antipredator behaviour has important consequences for those seeking to translocate or reintroduce individuals from predator‐free islands back to the predator‐rich mainland, but we have neither a detailed understanding of the mechanisms of loss nor information on the time course of relaxed selection. Some antipredator behaviours are experience‐dependent: experience with predators is required for their proper performance. In these cases, antipredator behaviour is lost after only a single generation of isolation, but it should be able to be regained following exposure to predators. Other behaviours may be more `hard‐wired'. The evolutionary loss of antipredator behaviour may occur over as few as several generations, but behaviours may also persist for many thousands of years of predator‐free living.LocationAustralia and New Zealand.MethodsI discuss the results of a series of studies designed to document the mechanisms and time course of relaxed selection for antipredator behaviour in macropodid marsupials. Controlled studies of visual, acoustic and olfactory predator recognition, as well as field studies of antipredator vigilance focused on several species of kangaroos and wallabies.ResultsVisual predator recognition may be retained following 9500 years of relaxed selection, but olfactory and acoustic predator recognition may have to be learned. Insular populations allow humans to approach closer before fleeing than mainland animals. Insular species may retain `group size effects' – the ability to seek safety in numbers – when they are exposed to any predators.Main conclusionsI suggest that the presence of any predators may be an important factor in maintaining functional antipredator behaviour. Managers should pay particular attention as to the source and evolutionary history of their population when planning translocations or reintroductions.
Boreal tree taxa in the central Scandes during the Late‐Glacial: implications for Late‐Quaternary forest history
Authors: Kullman Leif 
Published: March 2003

AimThis paper seeks to elucidate the first post‐glacial arrival of tree species to high elevations in the Scandes. This enables testing of general theories concerning glacial refugia, immigration routes and palaeoclimate.LocationThe study site, 1360 m a.s.l., was close to the summit of Mt Åreskutan in the alpine region of the southern Swedish Scandes, 400–500 m above modern tree‐limits.MethodsTree megafossils (trunks, roots, cones) were retrieved (and radiocarbon‐dated) from the ground surface in the forefields of receding `perennial' snow‐patches. This approach allows elevational range‐margin reconstructions to be made with an accuracy not possible with any other method.Results and conclusionsMegafossils were recovered substantially higher and earlier than previously recorded or inferred for tree growth in this part of Europe. The species were Betula pubescens Ehrh. ssp. tortuosa (Ledeb.) Nyman, Picea abies (L.) Karst. and Pinus sylvestris (L.). The oldest dates obtained are c. 14,000, 11,000 and 11,700 BP for these species, respectively. For the first time, explicit evidence of tree growth in the Late‐Glacial (including the Younger Dryas stadial) is demonstrated for central/northern Scandinavia. The swift appearance of boreal tree species at high northern latitudes and altitudes on the western fringe of Scandinavia and near the most extended margin of the Weichselian ice sheet hypothetically suggests that the first immigration of the trees considered here was from the west. Glacial refugia for these species (other plants and animals as well) on the exposed continental shelf areas west and southwest of Norway is hypothesized. By extension, the results fit into a more general pattern, suggesting the presence of boreal and temperate trees quite close to the full glacial (Weichselian) ice margins in central Europe. Thus, the Quaternary forest and landscape history of Europe seems more complex than previously believed.
Physiographical and historical effects on forest vegetation in central New England, USA
Authors: Gerhardt Fritz , Foster David R. 
Published: March 2003

AbstractAim  Land‐use history can be an important determinant of ecosystem characteristics, even in landscapes that outwardly appear ‘natural’. In New England, like much of the eastern United States, the natural reforestation of agricultural lands over the past 150 years has created a predominantly forested landscape. Understanding the physiographical and historical factors controlling forest structure and composition is a major challenge to ecologists, conservationists and land managers.Location  We studied the forest structure and composition of Petersham, Massachusetts, which is located in the Central Upland physiographical province of New England. Like much of New England, Petersham was largely cleared for agriculture by the mid‐1800s, but most of the agricultural fields were abandoned and naturally reforested in the late‐1800s and early 1900s. The modern landscape is > 90% forested by a mosaic of primary and secondary woodlands.Methods  At seventy‐four randomly selected 0.04‐ha plots, we measured the abundances of all vascular plants in the overstory and understory and nine physiographical and historical variables.Results  Species richness was primarily related to landform: species‐rich communities occurred in poorly drained basins and species‐poor communities occurred on well‐drained glacial outwash. Distributions of the sixty‐nine most common species were associated with (in order of importance) landform, past land use and elevation. Many species were restricted to specific physiographical conditions, but no species were restricted to specific past land uses. Nine plant associations identified by two‐way indicator species analysis were associated with elevation, landform, soil texture and past land use. Ordination by canonical correspondence analysis indicated that the vegetation reflected two principal gradients: a physiographical gradient, defined by landform and soil texture, and a land‐use gradient.Main conclusions  These analyses suggest the following ranking of factors controlling forest structure and composition in this landscape at this time: landform > agricultural history > elevation > hurricane = fire = logging. Even in this physically heterogenous landscape, land‐use history continues to play an important role in shaping forest vegetation 100–150 years after agricultural abandonment and reforestation.
Chestnut: history and ecology of a transformed species
Authors: Paillet Frederick L. 
Published: March 2003

Abstract Aim  The character and distribution of American chestnut (Castanea dentata) populations in New England are analysed to identify the extent to which the introduced chestnut blight and historic land use practices have affected chestnut distribution and life history.Location  The study focuses on chestnut in Connecticut and Massachusetts but includes analysis of data related to other Castanea species in North America and Europe.Methods  The ecology and palaeoecology of chestnut is investigated using a range of techniques, including examination of the growth form of chestnut trees in plantations located away from blight, mapping of chestnut sprouts and blight‐killed trees at various locations, anatomical examination of chestnut stems, analysis of early forestry practices, identification of changes in the relative abundance of chestnut pollen in Holocene lake sediments and comparison of American chestnut with other Castanea species.Results  Examination of chestnut sprouts surviving in the former range of that species shows that most sprouts originated from suppressed seedlings and that environmental factors severely limited the survival of sprouts from large blight‐killed trees. Palynological data show that chestnut was either present in very low populations or entirely absent from New England and only became abundant after about 2500 years ago. All factors suggest that chestnut abundance is related to the natural disturbance cycle, while human‐induced transformations of the landscape and the introduction of chestnut blight have further transformed the character of chestnut in New England.Main conclusions  Most surviving chestnut sprouts in New England forests represent old seedlings that have continued to re‐sprout since establishment before the introduction of blight nearly 100 years ago. The growth form of these sprouts ensures a minimal substrate of bark tissue for blight establishment so that blight has a relatively minor effect on seedling–sprout survival. The identification of modern chestnut sprouts as old seedlings indicates that the observed distribution of sprouts in New England woodlands is strongly influenced by land use conditions and especially field abandonment at the time when chestnut blight arrived from its point of introduction.
Three hundred years of forest and land‐use change in Massachusetts, USA
Authors: Hall Brian , Motzkin Glenn , Foster David R. , Syfert Mindy , Burk John 
Published: March 2003

Abstract Aim  The aim of this study was to document changes in forest composition, structure and distribution across Massachusetts, USA, from the time of European settlement (seventeenth century) to the present, and to investigate environmental and historical influences on regional patterns of variation.Location  The study area encompasses the State of Massachusetts (69.9–73.5°E, 41.3–42.9°N), a 21,000‐km2 area in the north‐eastern United States.Methods  A wide range of historical sources was used to document changes in land use and land cover for the historical period. Witness trees from early land surveys enabled us to evaluate vegetation patterns prior to widespread European settlement, and to compare historical and modern species composition. Nineteenth century maps of forest cover and contemporary agricultural censuses documented forest patterns during the peak agricultural period. Geographic Information System analyses were used to relate variation in climate, geology and land‐use history to historical and modern forest composition.Results  Massachusetts has a complex east‐to‐west environmental gradient involving changes in physiography, climate, geology and natural disturbance. Until the middle of the twentieth century, agriculture was the most important land‐use across the region; although the percentage of land in agriculture and the timing of major land‐use changes were remarkably consistent across the state, historical forest patch sizes varied locally and regionally in relation to physiography. Forest composition of both early historical and modern forests is most strongly related to environmental conditions, especially variation in climate. Historical land‐use resulted in a state‐wide increase in early successional tree species and a dramatic, although recovering, change in forest structure.Main conclusions  At a regional scale, environmental conditions apparently control broad patterns of variation in vegetation composition. Historical land‐use practices were relatively homogenous across Massachusetts and local variation was reduced through data averaging at broad spatial scales. At finer spatial scales, historical land‐use has strong and persistent impacts on vegetation composition and structure.
Vegetation variation across Cape Cod, Massachusetts: environmental and historical determinants
Authors: Motzkin Glenn , Eberhardt Robert , Hall Brian , Foster David R. , Harrod Jonathan , MacDonald Dana 
Published: March 2003

AbstractAim We evaluate environmental and historical determinants of modern species composition for upland vegetation types across Cape Cod, Massachusetts, a region that supports numerous uncommon species assemblages that are conservation priorities.Location The study area encompasses the entire peninsula of Cape Cod, Massachusetts, USA.Methods Historical changes in land‐use and land‐cover across the study region were determined from historical maps and documentary sources. Modern vegetation and soils were sampled and land‐use and fire history determined for 352 stratified‐random study plots. Ordination and classification were used to assess vegetation variation, andG‐tests of independence and Kruskal–Wallis tests were used to evaluate relationships among individual species distributions, past land‐use, surficial landforms and edaphic conditions.Results At the scale of this investigation, modern species distributions result from individualistic response to a range of environmental and historical factors, including geography, substrate and disturbance history, especially the pattern of past agricultural activity. The structure or composition of all vegetation types in the region have been shaped by past land‐use, fire, or other disturbances, and vegetation patterns will continue to change through time. Conservation efforts aimed at maintaining early successional vegetation types may require intensive management comparable in intensity to the historical disturbances that allowed for their widespread development.
Latitude, seed predation and seed mass
Authors: Moles A. T. , Westoby M. 
Published: March 2003

AbstractAim We set out to test the hypothesis that rates of pre‐ and post‐dispersal seed predation would be higher towards the tropics, across a broad range of species from around the world. We also aimed to quantify the slope and predictive power of the relationship between seed mass and latitude both within and across species.Methods Seed mass, pre‐dispersal seed predation and post‐dispersal seed removal data were compiled from the literature. Wherever possible, these data were combined with information regarding the latitude at which the data were collected. Analyses were performed using both cross‐species and phylogenetic regressions.Results Contrary to expectations, we found no significant relationship between seed predation and latitude (log10proportion of seeds surviving predispersal seed predation vs. latitude,P= 0.63;R2 = 0.02;n= 122 species: log10proportion of seeds remaining after postdispersal seed removal vs. latitude,P= 0.54;R2 = 0.02;n= 205 species). These relationships remained non‐significant after variation because of seed mass was accounted for. We also found a very substantial (R2 = 0.21) relationship between seed mass and latitude across 2706 species, with seed mass being significantly higher towards the tropics. Within‐species seed mass decline with latitude was significant, but only about two‐sevenths, as rapid as the cross‐species decline with latitude. Results of phylogenetic analyses were very similar to cross‐species analyses. We also demonstrated a positive relationship between seed mass and development time across ten species from dry sclerophyll woodland in Sydney (P < 0.001;R2 = 0.77; Standardized Major Axis slope = 0.14). These data lend support to the hypothesis that growing period might affect the maximum attainable seed mass in a given environment.Main conclusions There was no evidence that seed predation is higher towards the tropics. The strong relationship between seed mass and latitude shown here had been observed in previous studies, but had not previously been quantified at a global scale. There was a tenfold reduction in mean seed mass for everyc. 23° moved towards the poles, despite a wide range of seed mass within each latitude.
Primary plant succession on recently deglaciated terrain in the Canadian High Arctic
Authors: Jones Glenda A. , Henry Greg H. R. 
Published: March 2003

AbstractAim  Primary succession in a high arctic environment was examined to determine whether the patterns conform to models based on studies in temperate regions. The location also presented an unique opportunity to examine a well preserved pre‐Little Ice Age plant community and organically enriched palaeosol that are being released from the glacier along with the glacial and glaciofluvial sediments.Locations  The main location was the recently deglaciated terrain of the Twin Glacier foreland at Alexandra Fjord, Ellesmere Island (79° N). The position of the glacier from air photos in 1959 and 1981, and periodic direct monitoring of the position of the terminus since 1980 provided good chronological control. Surveys of succession patterns were also conducted at four other sites in the Alexandra Fiord region of eastern central Ellesmere Island.Methods  Vegetation cover of mosses and vascular plants (lichens were not present) was measured in 1994 and 1995 using a stratified random design. twinspan and canonical correspondence analysis were used together to examine successional vegetation patterns in relation to a set of environmental variables. Species richness, total vegetation cover, and a combined set of soil parameters (pH, organic matter content, moisture and fine substrate) were compared between the two principal soil types, palaeosol and glaciofluvial sediment.Results  Terrain age accounted for most of the variation in species composition over the study area. The succession followed a directional‐replacement series with four main stages of dominance in at least 44 years: (1) mosses → (2) graminoid‐forb → (3) deciduous shrub‐moss → (4) evergreen dwarf‐shrub‐moss. There was little difference in species richness patterns over time on the palaeosol compared with the glaciofluvial sediment. However, total vegetation cover was significantly higher on palaeosol and there was a significant difference in a combined set of soil parameters between the two soil types, which indicates that palaeosol may provide conditions more favourable for establishment and growth.Main conclusions  Directional‐replacement succession is possible in a high arctic oasis environment; however, this mode of succession is probably atypical of much more extensive high arctic environments such as polar deserts. Descriptive results from four other glacier forelands sampled in 1995 on east‐central Ellesmere Island showed directional succession with no species replacement at two sites and non‐directional succession without species replacement at another site. Primary succession in these high arctic sites is strongly controlled by local environmental conditions.
Sign reading: making sense of what is going on in the ward
Authors: WAKEFIELD ANN 
Published: March 2003

• When entering a ward the environment observed can be perceived in one of two ways: either from the perspective of `background', this being the backdrop against which events take place, or as the main focus of attention, thereby alerting the observer to what is going on in the setting.• Whilst undertaking their work nurses emit signs which patients, relatives and other staff interpret and through which they gain an understanding of the type of work about to be undertaken at the clinical interface.• The themes of private work, showdown work and tragic plight work, which were generated from an observational study in a surgical ward, are discussed in this article.• Findings show that, despite nurses attempts to hide the gravity of a message from patients, they in fact give more away than they hide.
Evidence‐based practice: a retrograde step? The importance of pluralism in evidence generation for the practice of health care
Authors: CLARKE JANICE B. 
Published: March 2003

• The origin of evidence‐based medicine is explored and its connection to evidence‐based practice examined.• Widespread acceptance of the dominant scientific paradigm supporting evidence‐based practice is challenged.• Knowledge classifications and their relevance for nursing practice are considered, with the need for a critical balance to be pursued.• Recommendations are made, regarding the future of evidence for practice, and a brief example of emerging evidence concerning values of professional caring is offered in redressing the balance.
Hope in multiple chemical sensitivity: social support and attitude towards healthcare delivery as predictors of hope
Authors: GIBSON PAMELA REED 
Published: March 2003

• This paper examines hope, as measured by the Herth Hope Scale, and its predictors in a sample of 305 people self‐identified with multiple chemical sensitivity.• The sample had relatively low levels of hope with scores unrelated to gender, severity or length of illness, income loss as a result of illness, or reported iatrogenic harm.• Hope scores were positively correlated with perceived social support, having found personal growth through illness, age, reported level of supportiveness from a partner, an improved course of illness and level of reported safety of the home environment in regard to chemical exposures.• Negative correlations were found with attitude toward healthcare delivery, fatigue and reported abuse/ostracism from family members other than partner.• Social support, Healthcare Orientation, growth through illness, fatigue and age predicted hope scores accounted for 55% of the variance. Implications and suggestions for future research are discussed.
Exercise and nursing therapy for patients with intermittent claudication
Authors: BINNIE ALISON , PERKINS JEREMY , HANDS LINDA 
Published: March 2003

• Intermittent claudication is a common manifestation of arterial disease in the second half of life. Invasive treatments may be inappropriate or unsuccessful, leaving patients with a significant handicap. Nursing intervention can improve the functional ability and the general well‐being of many patients.• This paper provides an account of the development of an out‐patient nursing service for patients with intermittent claudication. It focuses on the exercise training and the psychological support given to patients.• A review of the first 102 claudicants referred to the programme shows the outcome for the patients in terms of improved walking ability.• The details of the nursing intervention reported in the paper should help the growing number of nurses starting similar programmes for vascular patients. They may also be of interest to nurses caring for patients with other chronic health problems.
Core competencies for Clinical Nurse Specialists: a usable framework
Authors: Cattini Pat , Knowles Victoria 
Published: March 2003

• This article describes a framework of generic core competencies for assessing the role of the Clinical Nurse Specialist (CNS). It was devised by a group of CNSs at Kingston Hospital NHS Trust, over a two year period.• Currently, there is considerable confusion surrounding the role of the CNS. The UKCC is in the process of clarifying what is meant by specialist practice, with the aim of formally recognizing its status on the register.• There does not seem to be a consensus opinion on the standards of competence required to practise as a CNS.• This article seeks to address this issue by demonstrating a means of competency‐based assessment for the role of the CNS.