bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationships between geographical range size, body size, local abundance, and habitat breadth in North American suckers and sunfishes
Authors: Pyron Mark 
Published: March 2003

SummaryAimI examine the relationship between geographical range size and three variables (body size, an index of habitat breadth, and an index of local abundance) within a phylogenetic framework in North American species of suckers and sunfishes.LocationNorth AmericaMethodsRegressions after independent contrasts of geographical range size, body size, habitat breadth, and local abundance.ResultsSpecies with large range sizes tend to be larger‐bodied, be more locally abundant, and have higher habitat breadths. Character reconstructions support the prediction that variables associated with rarity (small geographical range size, low local abundance, low niche breadth, and large body size) evolve in unison, although large body size was associated with the opposite traits in these taxa.Gaston & Blackburn (1996a)suggested using visual identification of the lower boundary of the geographical range‐body size relationship to identify extinction‐prone species; this resulted in thirteen species that are potentially extinction‐prone.Main conclusionsSimilar evolutionary mechanisms appear to operate on body size and other variables related to rarity, even in distantly related taxa.
Seals and seascapes: covariation in Hawaiian monk seal subpopulations and the oceanic landscape of the Hawaiian Archipelago
Authors: Schmelzer Isabelle 
Published: March 2003

AbstractAimThe possible linkages between the spatial distribution of primary productivity over the north‐western Hawaiian islands and trends of subpopulations of Hawaiian monk seals in the period 1956–1995 were assessed. This endangered seal is endemic to the north‐western Hawaiian islands (NWHIs), where about 1300–1400 individuals are distributed among six main breeding subpopulations. A striking property in patterns of abundance among subpopulations is their spatial nature, a feature suggesting that these may be related to variation in the biotic marine environment. In examining linkages between trends in abundance at these subpopulations and the marine habitat of the NWHIs, an understanding of the relative importance of intrinsic or extrinsic regulatory processes to the long‐term dynamics of the seal can be gained.LocationThe north‐western Hawaiian islands (Hawaiian Archipelago).MethodsProductivity of the seascape was mapped using both remotely sensed images and data collected during oceanographic cruises. Measurements included sea surface temperature (SST), vertical water column structure, integrated chlorophyll, and their respective levels of variability. The spatial structure and heterogeneity of both mean values and coefficients of variation of these variables were quantified statistically by calculating descriptive statistics for each block of a 20° × 10° grid (with 200 blocks of dimensions 1°) overlain on each map, and computing spatial statistics for each variable (based on the summary statistics calculated for each block). Multivariate techniques were used to identify biogeographical regions within the pelagic landscape of the NWHIs. Monk seal trends among breeding sites within and among biogeographical regions were compared by analysing correlations among mean beach counts for each subpopulation.ResultsPrimary productivity over the marine habitat of the Hawaiian monk seal was found to be non‐uniform. A significant spatial pattern of primary productivity over the NWHIs, most apparent in a gradient along latitudinal lines, was documented. Multivariate groupings of environmental data partitioned the NWHIs into distinct biogeographical regions, and Hawaiian monk seal breeding areas can be differentiated on the basis of these. Regions with similar environments displayed synchronous variation in monk seal abundance.Main conclusionsThese findings suggest the local trends in monk seal abundance have ultimately been shaped by the quality of the surrounding marine environment. In assessing the dynamics of the Hawaiian monk seal as a whole, and notwithstanding the short‐term and local effects of proximate mortality factors, extrinsic, ecosystem‐level mechanisms appear to be important in shaping the long‐term population dynamics of this endangered mammal. If that is the case, then environmental variation may also be an important determinant of the potential for recovery of these subpopulations and therefore for the entire species.
Centrifugal speciation and centres of origin
Authors: Briggs John C. 
Published: March 2003

AbstractAimTo discuss the development and usefulness of the theory of centrifugal speciation and its practical application to the centre of origin hypothesis.LocationThe Indo‐West Pacific Ocean.MethodsUtilization of patterns demonstrating species diversity, generic age, dispersal tracks, phylogenetics, extinction and genetic diversity.ResultsThe centrifugal speciation hypothesis appears to provide a suitable explanation for the way in which centres of origin theoretically operate. Recent information about the centre of origin in the marine East Indies suggests that it is the source of evolutionary radiation for the Indo‐West Pacific. Its mechanism appears to conform to the centrifugal prediction.Main conclusionsThe East Indies Triangle is the origin of a series of dynamic systems that extend across the entire Indo‐West Pacific. These systems are apparently maintained by a continuous outflow from the centre of origin. A series of species replacements from the East Indies over the past 10 million years would create and perpetuate the systems that have been identified.
Acacia species turnover in space and time in an African savanna
Authors: Bond William J. , Smythe Keri‐Ann , Balfour Dave A. 
Published: March 2003

AimPatterns of species turnover along environmental gradients are better studied than their causes. Competitive interactions, or physiological tolerance are most often cited as determinants of turnover. Here we investigate differential tree species response to disturbance by fire and mammal browsing as causes of changing dominance of species within and among sites along an altitudinal gradient.MethodsWe documented the distribution of two Acacia species using maps and sample transects. We explored possible causes of species turnover by studying differences between the species in tolerance to grass competition using pot experiments, to browsers by observing patterns of shoot damage, and to fire by comparing the size structure of populations burnt at different frequencies and intensities.Results Acacia karroo woodlands were rare and occur at higher elevations than the much more common A. nilotica woodlands. Woodland composition seems set to change in future since the pattern of dominance was reversed in juvenile stages. A. karroo juveniles were very widespread and far more abundant than A. nilotica juveniles. A. karroo juveniles were most abundant in tall fire‐prone grasslands and were rare on grazing lawns whereas A. nilotica showed the reverse pattern. In the pot experiments, growth of both species was suppressed by grasses but there were no significant differences in response between the two species. Juveniles of A. karroo were more heavily browsed than those of A. nilotica. However juveniles of A. nilotica were less tolerant of frequent intense burns than juvenile A. karroo.Main conclusionsDisturbance gradients, from high fire frequency and low herbivore density at high altitudes, to lower fire frequency and higher herbivore density at low altitudes, are responsible for the shift in community structure along the spatial gradient. Differential responses to browsing and fire may also explain temporal turnover from A. nilotica in the past to A. karroo in the present. Changes in the area burnt annually, and in faunal composition, suggest a landscape‐scale shift from grazing‐dominated short‐grass landscapes in the 1960s, favouring A. nilotica, to fire‐dominated tall grasslands in the 1990s favouring A. karroo. We suggest that species turnover due to differential responses along disturbance gradients may be much more widespread than the current paucity of studies suggests.
Geographical abundance distributions of coastal invertebrates: using one‐dimensional ranges to test biogeographic hypotheses
Authors: Sagarin Raphael D. , Gaines Steven D. 
Published: March 2003

AimIt is often assumed that species generally reach their highest densities in the centre of their range and decline in abundance towards the range edges. A number of mechanisms have been proposed that could theoretically support this pattern, and several ecological theories have been developed based on the assumption that this pattern occurs in nature. However, few studies have quantified geographical patterns of species abundance throughout species ranges. This is largely because of the logistical challenges of sampling throughout the large spatial areas of most species ranges. We use intertidal invertebrates, which have relatively well defined linear ranges, to test the hypothesis that species are most abundant in the centres of their ranges.LocationOur sampling programme covered all or most of the ranges of twelve intertidal invertebrate species along the Pacific coast of North America, from Cabo San Lucas (Baja California, Mexico) to Shelikof Island (AK, USA).MethodWe sampled invertebrate density at forty‐two field sites using quadrat and transect methods. We used a shape fitting procedure to find idealized range shapes that best fit the sampled distributions of abundance. The idealized range shapes represented both a distribution where abundance was highest at the range centre and distributions where abundance was highest at one or both of the range edges.ResultsOverall, this suite of species did not show the expected pattern of high abundance near the range centre. Six of the species showed patterns indicative of high densities near one of their range edges, whereas only two showed patterns with high densities near their range centres. Furthermore, nine of the twelve species had sites near the range edges in which density ranked in the top 20% of all sites.Main conclusionsThe hypothesis that species are most abundant in the centre of their ranges cannot be generalized to this diverse suite of intertidal organisms. The diversity of distribution shapes that we found suggest that evolutionary and ecological theories that assume high abundance at range centres should be re‐examined with consideration of alternative abundance distributions. We suggest that sampled geographical distributions of abundance can be combined with demographic and physical factor data taken at the same scale to test hypotheses related to the causes of range boundaries and the responses of species ranges to climatic change.
Humans, fire and landscape pattern: understanding a maquis‐forest complex, Mont Do, New Caledonia, using a spatial ‘state‐and‐transition’ model
Authors: Perry George L. W. , Enright N. J. 
Published: March 2003

Abstract Aim  The research explores how changes in disturbance regime resulting from human settlement may affect landscape structure. A spatially explicit grid‐based simulation model is used to explore the interplay between humans, fire regime and landscape composition.Location  The study site for this research is the botanical reserve at Mont Do, New Caledonia. The endemic conifer Araucaria laubenfelsii (Araucariaceae) forms a key component of the landscape at Mont Do. This species is unusual in that it is found scattered as an emergent in maquis and as a canopy species in adjacent rain forest patches. Although now dominated by a low maquis, prior to human settlement of New Caledonia, montane landscapes such as Mont Do are likely to have been heavily forested.Methods  A spatially explicit simulation model, based on field data and palaeoecological information, was used to explore interactions between disturbance regime and the landscape. The model is described briefly here and more fully in Perry & Enright (2002) Ecological Modelling, 152, 279.Results  The model suggests that human‐influenced changes to the fire regime at Mont Do have been important in generating the current landscape structure. The origin and maintenance of forest landscapes and maquis‐forest mosaic landscapes are considered in the context of alternative stable states. Strong feedback loops between fire size and landscape composition, mediated at the smaller scale by other similar mechanisms, are capable of driving landscape change. The utility of a spatial state and transition modelling approach is demonstrated.Main conclusions  The current landscape pattern on Mont Do is likely the result of changes to the fire regime occurring since human settlement. The specific mechanisms for this change outlined here may occur in a number of other similar systems. Understanding the origin and persistence of these ‘fire landscapes’ in New Caledonia and in the south‐west Pacific in general is crucial for their effective management.
The primary/secondary interface. Cross‐boundary teamwork — missing link for seamless care?
Authors: Hibberd Patricia A. 
Published: March 2003

• Factors for providing a seamless service are given and it is suggested that more collaborative interactions between organizational groups are needed to achieve this.• It is argued that competitive philosophy within the NHS has been prohibitive to seamless care. Elements of the White Paper (DoH, 1997) are discussed in relation to this. Features of a collaborative organization are briefly discussed.• Three current ‘models’ of cross‐boundary interaction at the point of patient transfer are discussed.• A fourth model involving enhanced inter‐sector teamwork with multidisciplinary membership and shared professional, management and patient/carer responsibility is proposed.
Manual handling: what patient factors do nurses assess?
Authors: COOK GLENDA , NENDICK CHRIS 
Published: March 2003

• Since 1990, the philosophy of `safe lifting' has become unacceptable in clinical practice and it is now recommended that nurses do not manually lift patients at all.• A comprehensive moving/handling assessment should be undertaken and should include assessment of the handler's capability as well as the load (patient), task and environment.• This exploratory study focuses on assessment of the load, aiming to identify the patient variables nurses assess when planning moving/handling requirements of adult patients.• Patient variables were identified from a literature review and provided the base for a semistructured postal questionnaire.• Questionnaire responses were subjected to a Principal Component Factor analysis resulting in extrapolation of 5 factors accounting for the majority of variability in the data.• In addition, a further 33 new patient variables were reported to be important in this type of assessment.• Issues for further investigation are highlighted and implications for teaching moving/handling risk assessment are drawn from the findings.
Implementation of risk assessment and classification of pressure ulcers as quality indicators for patients with hip fractures
Authors: GUNNINGBERG LENA , LINDHOLM CHRISTINA , CARLSSON MARIANNE , SJÖdÉn PER‐OLOW 
Published: March 2003

• The aims of the study were (i) to investigate the prevalence of pressure ulcers in patients with hip fracture, on arrival at a Swedish hospital, at discharge, and two weeks post‐surgery; (ii) to test whether clinical use of the Modified Norton Scale (MNS) could identify patients at risk for development of pressure ulcers; and (iii) to compare the reported prevalence of pressure ulcer in the experimental group, where risk assessment and classification of pressure ulcers was performed on a daily basis, with that of the control group, where it was not.• The study design was prospective, with an experimental and a control group. The intervention in the experimental group consisted of risk assessment, risk alarm and skin observation performed by the nurse on duty, in the A & E Department, and daily throughout the hospital stay.• To facilitate the nurse's assessment, a `Pressure Ulcer Card' was developed, consisting of the MNS and descriptions of the four stages of pressure ulcers.• On arrival at the hospital, ≈20% of patients in both groups had pressure ulcers. At discharge, the rate had increased to 40% (experimental) and 36% (control).• Clinical use of the MNS made it possible to identify the majority of patients at risk for development of pressure ulcers. Patients who were confused on arrival developed significantly more pressure ulcers than patients who were orientated to time and place.• No significant difference was found in the reported prevalence of pressure ulcers between the experimental and control groups.
Developments in nursing practice in primary health care in Hong Kong: opportunities and challenges
Authors: Twinn Sheila 
Published: March 2003

• The significance of primary health care to the health of individuals and communities has been well established but the development of primary health care and nursing practice within the context of primary health care remains varied in different countries and settings.• This paper focuses on developments in nursing practice in primary health care in Hong Kong, using three community‐based research projects to identify the opportunities and challenges created for nurses working in these settings. The projects were established in response to identified health needs and to target cancer education, HIV/AIDS and chronic health problems.• Opportunities include the development of professional autonomy, innovative approaches to clinical practice, and developing skills in working with a diverse range of professionals and communities. Challenges include managing uncertainty and the development of evaluation systems to demonstrate health gains from nursing interventions.
Documenting diabetes care: the diabetes nurse specialists' perspective
Authors: Thompson Kathryn A. , Coates Vivien E. , Mcconnell Cassandra J. , Moles Kenneth 
Published: March 2003

Summary•  Diabetes Nurse Specialists (DNSs) are often the hub of the communications network for the entire diabetes multiprofessional health care team, patients and their families. Frequently they liaise between primary and secondary care and have a key role in the provision of a ‘seamless service’. To work effectively and efficiently they need a foolproof system of documentation and communication.•  The aim of the study was to investigate the means by which DNSs document patient care in order to provide baseline information about ongoing record‐keeping practices.•  The study comprised a cross‐sectional survey in which data were obtained by questionnaire. All DNSs in the UK registered with the British Diabetic Association were invited to participate in the study. A 70.3% response rate was achieved (n = 545).•  The results indicated that manual profession‐specific records were used by 65.3% of DNSs, 21.1% used shared/integrated records, 12.8% used computerized records and only 0.7% made use of patient‐held records. Whilst almost all DNSs felt that a good record‐keeping system was essential in providing ‘seamless care’ to patients, not all felt their system was efficient. Of those using a computerized system 65.7% rated it as efficient, compared with only 28.1% of those using a profession‐specific system and 26.1% of those using a manual shared system.•  A high percentage of DNSs (65.9%) felt that the provision of ‘seamless care’ was hindered by communication problems with members of other professional groups.•  The findings from this study indicate that computers alone cannot bridge the gap between primary and secondary care, but ‘seamless care’ may become more of a reality with computerized record‐keeping systems and participation by all members of the multidisciplinary team.
Factors influencing size inequality in peatland black spruce and tamarack: evidence from post‐drainage release growth
Authors: Macdonald S. Ellen , Yin Fengyou 
Published: March 2003

1 We used tree ring analysis to determine stem radius and thus examine size variation over time in two even‐aged (approximately 40‐year‐old) mixed populations of black spruce and tamarack established on peatlands in a boreal forest. We also followed the response of one of these populations to improved edaphic conditions over 8 years following drainage. 2 Populations of trees in undrained areas showed a decline in size variability over time until age 20–25 years, after which size heterogeneity was relatively stable. 3 For trees in undrained areas there was a relationship between age and size for the first 20–25 years, but this relationship then broke down due to a period where relative growth rate and size were inversely related. 4 For the population of trees in the drained area, smaller trees (i.e. those that had been growing more slowly prior to drainage) showed significantly greater drainage‐induced release growth, while larger trees (those growing faster prior to drainage) showed an initial reduction in growth following drainage and, overall, less release growth. 5 The response of tamarack to drainage was more dramatic than for black spruce. 6 Despite extensive variation in tree size, drainage dramatically reduced variability in growth rate among trees of each species, such that size variability in the populations declined. 7 We postulate that the heterogeneity of microsites with respect to edaphic conditions, perhaps associated with the hummock to hollow microtopographic gradient, has a major influence on growth variation, and hence size inequality, in peatland populations of black spruce and tamarack.
The combined effects of scale and productivity on species richness
Authors: Weiher Evan 
Published: March 2003

Summary 1 Although species–area curves are well documented, we know little about how they vary along productivity gradients, nor do we have a firm understanding of whether the richness–productivity relationship is independent of scale. In order to investigate these relationships, 10 species–area curves were constructed for 10 sets of nested quadrats (from 0.25 m2 to 150 m2) in herbaceous marshes where biomass ranged from 128 g m–2 to 1050 g m–2. 2 Slopes (z) of the species–area curves (logS = logc + zlogA) were positively correlated with production (whether measured as biomass or soil organic content). A possible cause of increased slope was larger potential species pools at high biomass. The constants (c) were negatively associated with production, which concurs with the general richness–productivity relationship. 4 Linear models were used to predict both c and z using biomass and soil organic content. Biomass explained about 38% of the variation in both z and logc. Soil organic content was a better predictor. It explained 60% of the variation in z and 41% of the variation in c. 5 The slopes (z) and constants (c) of the species–area curves were negatively correlated. Because c is the expected species richness at 1 m2 and z strongly affects larger‐scale richness, the results suggest that small‐scale richness is not a good indicator of larger‐scale richness. There was no significant relationship between species richness in small‐scale (0.25 m2) quadrats and large‐scale quadrats (150 m2). 6 These results suggest that the conflicting data that have led to recent debate over the richness–productivity relationship may reflect both the effects of scale and the natural history peculiarities of the systems studied.