bluuebunny/crossref_metadata_2025_split huggingface dataset:
A reconstruction of the history of a Holocene sand dune on Great Barrier Island, northern New Zealand, using pollen and phytolith analyses
Authors: Horrocks M. , Deng Y. , Ogden J. , Sutton D. G. 
Published: March 2003

AbstractAim  To reconstruct the history of a Holocene sand dune using pollen and phytolith analyses, and to identify the strengths, weaknesses and compatibility of these two methods in the interpretation of Quaternary coastal environments.Location  Great Barrier Island, northern New Zealand.Methods  Pollen and phytolith analyses were carried out on a sequence through a Holocene sand dune containing a palaeosol.Results  Phytoliths were present throughout the sequence. Grass phytoliths increased at the expense of tree phytoliths following fire disturbance. Pollen (and spores) was preserved only in the palaeosol part of the profile. Pteridium fern spores increased at the expense of tall tree pollen following the fire disturbance.Main conclusions  Lack of phytolith production by many species and problems of taxonomic specificity in many others restricts the usefulness of phytolith analysis to defining only broad vegetation types. In New Zealand, gymnosperms are invisible in the phytolith record and ferns are extremely under‐represented. In contrast, pollen analysis usually provides a great deal of information regarding the composition of a particular vegetation type. The loss of microscopic charcoal fragments during the phytolith extraction process is a disadvantage in the reconstruction of environments where fires have occurred. The greater durability of phytoliths compared with pollen means that phytoliths may be found in sediments where pollen has not been preserved. The phytolith record may also provide evidence of wetter environments that are not apparent in the pollen record. Unlike grass pollen, which is widely dispersed and therefore blurs the spatial record, the presence of grass phytoliths in sediments indicates a local source. The simultaneous application of both methods potentially provides a powerful tool in ecological interpretation and the reconstruction of Quaternary coastal environments.
Global distribution patterns of non‐halacarid marine intertidal mites: implications for their origins in marine habitats
Authors: Procheş Şerban , Marshall David J. 
Published: March 2003

AimWe investigated the taxonomic, ecological and global biogeographical trends of non‐halacarid marine mites with a view to understanding their origins in the marine environment. While halacarid mites are typically marine, numerous other mite taxa occupy littoral habitats, including rocky‐shores, boulder beaches, salt marshes and mangrove forest floors, and occur in most geographical regions.LocationThis study concerns the extant taxa of non‐halacarid marine mite from intertidal zones, worldwide.MethodsA literature survey was undertaken to compile the records for localities and habitats of all the known species of non‐halacarid intertidal mite. Simple analyses were used to determine their taxonomic and geographical trends. A multivariate analysis was used to compare how closely the biogeography of selected faunas conformed with the generally accepted marine biogeographical zones.ResultsAlthough the species records are incomplete because of variable sampling intensities among regions, there is clear indication that these marine mite faunas are species‐poor (only 162 species were recorded in the literature). The records for some groups (ameronothroid and hyadesiid mites), some habitats (rocky‐shores) and some world regions (Eastern Atlantic‐Boreal, Sub‐Antarctic and Southern New Zealand) are apparently representative of actual faunas, whereas those for the mesostigmatid and non‐halacarid prostigmatid mites, and mangrove and salt marsh habitats, are clearly incomplete. The faunas comprise mites from four suborders, the Mesostigmata, Prostigmata, Oribatida and Astigmata. Structuring of the lower taxonomic levels differs markedly among the suborders; mesostigmatid and prostigmatid mites comprise low species to genus and species to family ratios, relative to oribatid and astigmatid mites. These mite groups also differ with respect to ecological and geographical attributes; ameronothroid (oribatid) and hyadesiid (astigmatid) mites exhibit wider generic geographical distributions and stronger marine trophic links.ConclusionsThe emerging trends suggest different geological time‐scales for the evolutionary incursions into the marine environment by the mesostigmatid and prostigmatid mite group and the oribatid and astigmatid mite group. They suggest that members of the latter have had longer associations with marine intertidal systems. The origins of both groups are also likely to differ from those of the typically marine halacarid mites.
Assessing biogeographic relationships between North American and Chinese macrofungi
Authors: Mueller Gregory M. , Wu Qiu‐Xin , Huang Yong‐Qing , Guo Shou‐Yu , Aldana‐Gomez Ruth , Vilgalys Rytas 
Published: March 2003

AimA close biogeographic relationship between the macrofungi of eastern North America and eastern Asia has been documented based on comparisons of species lists. In addition to having a similar species composition, the two regions are reported to share a number of species with putative disjunct distributions. This close biogeographic relationship, however, has rarely been tested within a phylogenetic context. In this paper we examine relationships within three genera, Armillaria, Xerula and Suillus (Fungi, Basidiomycetes, Agaricales) chosen as exemplars of different ecological guilds occupied by macrofungi (plant pathogens, saprobes, mutualists).LocationFieldwork for this project centered in eastern North America, Central America, China and Australasia. Material from additional localities were obtained from cooperating herbaria and additional sequences were downloaded from GenBank.MethodsITS sequence data were used to construct phylogenies for each genus.ResultsOnly one of four tested putative disjunct species, Xerula hispida Halling and Mueller, was supported. Material referable to X. furfuracea (Peck) Redhead, Ginns and Shoemaker from China and North America do not form a monophyletic group. Disjunct populations of Suillus spraguei (Berkeley & Curtis) Kuntze were shown to be paraphyletic. The morphological similarity of the Chinese material to the North American material is likely due to morphological stasis. Finally, morphologically identical material referable to Suillus americanus (Peck) Snell in Slipp and Snell from eastern North America and S. sibiricus (Singer) Singer from China, along with the morphologically similar western North American S. sibiricus, probably represent a single circumboreal taxon.Main conclusionsThe resulting data, while not refuting the hypothesis that there exists a relatively close biogeographic relationship for macrofungi between eastern North America and eastern Asia, suggest that the relationship may not be as close as indicated by morphological data. These results are similar to emerging data from analyses of flowering plants displaying putative eastern North American/eastern Asian disjunct distribution patterns.
Linking abundance, occupancy and spatial structure: an empirical test of a neutral model in an open‐forest woody plant community in eastern Australia
Authors: Falster Daniel S. , Murray Brad R. , Lepschi Brendan J. 
Published: March 2003

AimsWe implemented a neutral model of a positive relationship between abundance and distribution (occupancy) to examine how spatial structure influences abundance–occupancy relationships. The spatially explicit neutral model distributes individuals of species randomly and independently of one another in space to produce a positive abundance–occupancy relationship. Using empirical data, we tested whether abundance–occupancy relationships diverged significantly from the theoretical neutral model, and determined whether significant divergences emerged through intraspecific aggregation or over‐dispersion of individuals.LocationField work was conducted in open‐forest vegetation of the Black Mountain region in south‐eastern Australia.MethodsAt eight floristically similar sites in open‐forest vegetation, we established a 20 × 20 m census plot and spatially mapped all individuals of each woody species. The abundance and distribution of each species was determined at each site at three spatial scales within the census plot. Observed abundance–occupancy relationships were compared with the spatially explicit neutral model using linear regression techniques. Monte‐Carlo methods using a two dimensional Poisson process were then used to classify the spatial structure of species as random, aggregated or over‐dispersed.ResultsWe found consistent evidence among the eight sites for abundance–occupancy relationships to diverge significantly from the neutral model at the three spatial scales within each community. The direction that the slopes of relationships diverged from the neutral model provided consistent evidence that aggregation of individuals within species was responsible for modifying the form of abundance–occupancy associations in this vegetation, a feature most evident with increasing scale.Main conclusionsAggregation is not a mechanism that causes positive abundance–occupancy relationships. Under the neutral model of a positive abundance–occupancy relationship, aggregation should be viewed as a mechanism which modifies a pre‐existing relationship, rather than causing a relationship which would not have otherwise existed. In other words, in the absence of aggregation a positive abundance–occupancy relationship would still exist.
Climate and animal distribution: a climatic analysis of the Australian marsupial Trichosurus caninus
Authors: Fischer J. , Lindenmayer D. B. , Nix H. A. , Stein J. L. , Stein J. A. 
Published: March 2003

AimA detailed bioclimatic analysis was completed for an Australian arboreal marsupial, the mountain brushtail possum Trichosurus caninus. This was done to explore climatic factors underpinning the distribution of the species.LocationLocation data used for bioclimatic modelling comprised of 879 records, covering the entire known range of T. caninus throughout eastern Australia.MethodsThe computer package BIOCLIM was used to generate a bioclimatic profile of T. caninus. Frequency distributions of climatic attributes in the profile were examined using histograms and a pattern analysis (using the computer package PATN) to determine if there were bioclimatically distinct groups of possums.ResultsInitial analyses of bioclimatic attributes of all records split the location data into two discrete groups based on the frequency distribution of ‘mean temperature of the wettest quarter’ of an average year, as this had a discontinuous, bimodal frequency distribution. Pattern analysis produced groupings congruent with this. When analysed separately, the bioclimatic domains of the two groups were geographically discrete. Although many key bioclimatic attributes were similar (particularly those defining light and moisture regimes that relate to vegetation structure), temperature regimes and seasonality of rainfall regime were very different for each group.Main conclusionsThe two groups identified in this study were congruent with two groups established by an earlier multivariate morphometric analysis of T. caninus. Further targeted field research together with genetic analyses, are needed to further investigate the taxonomic significance of findings on (1) the bioclimatic domain(s) and (2) the morphology of T. caninus.
Ecological biogeography of southern polar encrusting faunas
Authors: Barnes David K. A. , De Grave Sammy 
Published: March 2003

AimTo investigate the affinities and similarities between coastal (marine) encrusting faunas along the Andes–Scotia Arc–Antarctic Peninsula mountain chain with a uniform sampling strategy.LocationTwelve different samples sites were selected on the (southern) South American and (western) Antarctic continents. The sites spanned 25° of latitude along the Andes–Scotia Arc–Antarctic Peninsula mountain chain from Tierra del Fuego to the Ross Sea (Antarctica).MethodsEncrusting faunal colonists were identified on rocky (boulder/cobble) surfaces constituting a total surface area of 2 m2from each of twelve localities at depths from the intertidal zone to 12 m. Faunal suites of sites were subjected to differing but common modern analyses, Detrended Correspondance Analysis (DCA) andTWINSPAN.ResultsTypically the number of encrusting species increased with depth and decreased with isolation (remote islands, such as South Georgia and Bird Island had depauperate faunas). The proportion of the total fauna constituted by bryozoans, sponges and other taxa changed with site latitude and isolation. Ordination (DCA) of the site species data matrix revealed distinct Patagonian, Falkland and Antarctic groupings. Ordination of just the Antarctic grouping revealed a cline from the northerly and shallower sites to those more southerly and deep.TWINSPANanalysis of the same data set largely supported the ordination. Ordination at generic level showed a high degree of similarity with the species ordination pattern.Main conclusionsThe north/south, deep/shallow, cline found shows distinct faunistic patterning within biogeographic zones. The separation of sites within and outside the Polar Frontal Zone (PFZ) support more classically based historic biogeographic studies. The major difference between the findings of this study was the organization of sites into a cline vs. distinct zones. The simplest explanation for why studies yeild such different findings must lie with the considerable differences in the types of data sets used; historical records or (as here) short‐term, uniform, sampling strategies.
Biogeography of tropical reef fishes: the South Atlantic puzzle
Authors: Joyeux J.‐C. , Floeter S. R. , Ferreira C. E. L. , Gasparini J. L. 
Published: March 2003

AimTo reveal underlying distributional mechanisms of tropical reef fishes in the South Atlantic.LocationThe tropical South Atlantic, with emphasis on the Brazilian province.MethodsThe disjunct distributions of thirty‐five reef fish species occurring in the Brazilian Province were analysed to allow a better understanding of present biogeographical patterns. To avoid potential bias because of taxonomic problems or misidentification, we only included families taxonomically well documented, with conspicuous species, and relatively easy to identify.ResultsThe low‐level differentiation between Caribbean and Brazilian species/populations, as well as the presence of restricted populations of a few northern or southern species on the opposite side of the Amazon River, clearly indicate that this barrier to dispersion can be occasionally bridged. Transoceanic dispersal appears to be frequent and to occur along three routes: from the Caribbean to North East Atlantic, from northern Brazil to the Gulf of Guinea, and from Africa to southern Brazil. Intermediate stepping‐stones are apparently not required along transatlantic routes because of the rarity of consecutive colonizations. However, intermediate stopovers are persistently used along short routes. In all cases, the long‐term success of colonists, i.e. the establishment of stable local populations, appears to depend upon ecological factors.Main conclusionsThe puzzling patterns of distribution found in the South Atlantic seem primarily the outcome of allopatric speciation and of the interaction of long distance dispersal abilities and ecological processes. Successfulness of the colonization of remote sites appears to be less dependent from dispersal ability than upon persistence ability or settlement preferences.
Biogeography of the tenebrionid beetles (Coleoptera, Tenebrionidae) on the Aegean Islands (Greece)
Authors: Fattorini Simone 
Published: March 2003

AimThis research aimed to study if a transitional character can be postulated for the tenebrionid beetle (Coleoptera, Tenebrionidae) fauna of the Aegean Islands, and to identify ecological and historical factors responsible for observed patterns.LocationEastern Mediterranean, Aegean Islands.MethodsA total of 32 Aegean Islands and 166 taxa (species and subspecies) were included in this study. In order to assess whether the Aegean tenebrionid fauna is mainly equilibrial or relictual, the importance of different eco‐geographical variables (i.e. area, latitude, longitude, distance to the nearest island, distance to the mainland) in determining species richness and endemicity levels was analysed by using several statistical methods. These included single regressions, multiple regressions, and partial correlations. Cluster analysis, multidimensional scaling (MS) and discriminant function analysis (DFA) were used to quantify the similarities between the islands. Regression lines were used to study variations in the proportion of Balkan and Anatolian species. Parsimony Analysis of Endemicity (PAE) was used to study possible relationships between hierarchical species assemblages and palaeogeographical reconstructions.ResultsIsland area accounted for most variability in species number. Distances to the nearest island and to the mainland were not identified as of any statistical importance in affecting species number. The proportion of Balkan taxa sharply decreases from west to east, whereas the Anatolian taxa follow an opposite trend. The proportion of endemic taxa appears uncorrelated with island present isolation, while the proportion of subendemic taxa appears to be affected by present distance to mainland and interisland distances. Cluster analysis, MS and DFA, as well as PAE, revealed a clear faunal discontinuity between the western and central Aegean Islands on one side, and the islands close to the Anatolian coast on the other side. This discontinuity, consistent with the persistence (from Messinian to Pleistocene) of a sea barrier between these two groups of islands, strongly supports the importance of Pleistocene island configurations in determining present distributional patterns.Main conclusionsThe tenebrionid fauna of the Aegean Islands appears to be relictual. Most of the tenebrionid species have probably colonized the Aegean Islands by means of land‐bridges during Pleistocene falls in the sea level. The palaeogeography of Pleistocene island groupings is identified as responsible for present levels of endemicity and distributional patterns. An overall transitional character can be observed for the tenebrionid fauna in the study area. However, in accordance with the persistence of a deep sea barrier between the western and the eastern islands, these two groups appear to harbour very distinct faunas.
Fluctuating asymmetry as a bio‐indicator in isolated populations of the Taita thrush: a Bayesian perspective
Authors: Lens Luc , Van Dongen Stefan 
Published: March 2003

AimWe examined whether developmental instability can be used as a bio‐monitoring tool in the endangered Taita thrush (Turdus helleriL.) through the measurement of individual levels of fluctuating asymmetry in tarsus length. Because estimates of the association between developmental instability, stress and fitness derived from traditional regression are biased, we compared parameter estimates obtained from likelihood based analysis with those obtained from a Bayesian latent variable model.LocationTaita thrushes were captured and measured in three isolated cloud forest fragments located in the Taita Hills of south‐east Kenya.MethodsWe applied mixed‐effects regression with Restricted Maximum Likelihood parameter estimation (performed with SAS version 8.0) and Bayesian latent variable modelling (performed with WINBUGS version 1.3 and CODA version 0.4) to estimate unbiased levels of developmental instability and to model relationships between developmental instability and body condition in 312 Taita thrushes.ResultsLikelihood and Bayesian analyses yielded highly comparable results. Individual levels of developmental instability were strongly inversely related to body condition in the subpopulation with the lowest average condition. In contrast, both variables were unrelated in two other subpopulations with higher average condition. Such heterogeneity in association was in the direction expected by developmental theory, given that higher condition suggests more benign ambient conditions. The estimated levels of body condition in the three subpopulations did not support their presumed ranking in relation to environmental stress. Developmental instability and body condition are therefore believed to reflect different aspects of individual fitness.Main conclusionsVariation in developmental homeostasis, either modelled as observable variable (fluctuating asymmetry) or latent variable (developmental instability), appears a useful indicator of stress effects in the Taita thrush. Because relationships between environmental stress and developmental instability may depend on the extent to which stress‐mediated changes in other components of phenotypic variation are correlated, the study of trait asymmetry should preferably be combined with that of other measures of trait variability, such as trait size or organismal condition.
Important aspects of nursing care in surgical wards as expressed by nurses
Authors: IDVALL EWA , ROOKE LISELOTTE 
Published: March 2003

• The aim of this study was to find out clinical nurses' perceptions of important aspects of nursing care that might have an impact on quality of care in surgical wards.• A qualitative approach using focus group interviews was used.• The data analysis revealed 15 categories of important aspects of care which could be condensed into two dimensions, here called `prerequisites' (i.e. staffing, routines and attitudes) and `elements of performance' (i.e. detecting and acting on signs and symptoms and acting on behalf of the patients). These aspects could be a starting point for developing quality indicators.• Carper's four fundamental patterns of knowing were used to make a theoretical interpretation, and three of them were identified.
Teaching sociology to nurses: exploring the debate
Authors: WILLIAMSON GRAHAM R. 
Published: March 2003

• This article reviews literature on the current debate concerning teaching sociology to nurses.• The debate is limited because it does not take into account the work of Donald Schön, or Anthony Giddens.• The article also discusses theories of adult education which support teaching sociology in nurse education.• Sociology is essential for nurses, because it can help to develop an understanding and analysis of the context and substance of nursing practice.
Operational and resource management of an RCT: some of the pitfalls and lessons learned
Authors: DOLAN GINA , BROOMFIELD JACKIE , LEWITH GEORGE , WATKINS ALAN 
Published: March 2003

• Nurses frequently fulfil important functions within a research team involved in clinical trials. This paper describes the challenges inherent in developing and managing a large clinical trial involving the evaluation of homoeopathy and asthma.• Teamwork, a clear and comprehensive understanding of the research protocol, marketing the project, and the ability to manage human resources within both a primary and secondary care environment are all essential aspects of clinical research.• Our experience in establishing and managing this project has suggested to us that a high standard of clinical research demands an open approach to problem‐solving as well as the realization that efficient research is as much about the management of people as it is about scientific rigour.