bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporal and spatial expansion of the Egyptian goose Alopochen aegyptiacus in The Netherlands, 1967–94
Authors: Lensink Rob
Published: March 2003

In this paper, the temporal and spatial expansion of the Egyptian goose in the Netherlands are described and analysed. The species bred near The Hague for the first time in 1967. In 1983 a second settlement developed in Drenthe. Both settlements expanded. Together, they contained about 1340 breeding pairs in 1994. For both settlements a linear relationship exists between the square root of the area occupied and time. In both cases, population growth is exponential. The bird behaves as a resident species. Thus, in winter numbers in The Netherlands also increase exponentially. The Egyptian goose seems to be sensitive to severe winters, which cause a high mortality. The observed velocity of range expansion is compared with the velocity as calculated with the expansion model of Van den Bosch et al. (1990). The observed velocity was about 3.0 km per year, which is about 20% lower than expected, but not significantly different. Population growth was estimated using a projection matrix. In the first 10 years after its settlement near The Hague, the actual population growth was larger than the calculated growth. There is evidence for good breeding success during the first years due to mild winters between 1972 and 1978. In the second settlement, Drenthe, the same rapid population growth occurred. Here, a low but regular influx of birds from a nearby city park was probably the main factor. In the near future, further temporal and spatial expansion can be expected, in the direction of Germany and Denmark in the east and Belgium and France in the south. Towards the east the severity of the winters might limit further range expansion, possibly coinciding with the 0o isotherm in January.
Land crisis on the Mambila Plateau of Nigeria, West Africa
Authors: Hurault Jean
Published: March 2003

The Mambila plateau in Nigeria features unique physical and climatic conditions for human settlement as for cattle breeding: it is within such an environment that the Mambila farmers have settled and developed as a dense population. During the 19th century the highlands became the main sources of slaves for the Muslim Fulani kingdoms of Banyo and Gashaka. Although resisting strongly, the Mambila villages fell one after the other. This resulted in a demographic collapse: by 1930 the Mambila were reduced to a population of 16,000. In the 1920s Mbororo and Fulani graziers began to settle in the region: their livestock became the main cause of environmental degradation. Severe erosion of the grazed land can now be observed, mainly characterized by the deepening of the river beds and the collapse of river banks. Such a phenomenon is attributed to a change in the rainwater flows due to the exhaustion of the vegetation cover. The uncontrolled growth of livestock has been followed by high competition for land between the graziers and those Mambila farmers who survived the Fulani occupation. The graziers holding most of the political power have progressively deprived the farmers of their lands: the latter are now confined within isolated small enclaves. They have lost their economic independence and are reduced to work for the graziers or to emigrate to Cameroon. Furthermore, in a large part of the Mambila plateau, the pastoral range has been divided between the graziers, excluding the Mambila farmers, as well as the poorest Fulani, from land ownership and enhancing their dependency on the graziers. Such an explosive situation is illustrated by two surveys of the Kuma and Leme regions. Over the 78 km2 studied in Kuma, the Mambila possess only 22% of the area; the survey found 132 herds (at an estimated total of 9475 cattle) with a population density of 1.5 cattle per ha, almost totally owned by Muslim graziers. The area studied in Leme covers 113.5 km2 of uneven land. Although confined to nine enclaves, the Mambila owned 32% of the land, while the Muslim graziers possess 67%. 145 herds have been counted (at an estimate total of 10,215 cattle): 63% are owned by the Mbororo, 20% by Fulani and the Haoussa from Gembu, 10% by the Mambila, and 7% by the recent Yamba migrants.
Ecological comparisons between Eastern Asia and North America: historical and geographical perspectives
Authors: Guo Qinfeng
Published: March 2003

The close floristic affinities between eastern Asia and North America have long been recognized and intensively studied, however, the ecological and biogeographical consequences of such a floristic relationship between these two remotely separated regions has been largely neglected until recently. Quantitative investigations of such relationships could greatly improve our understanding of many global and historical aspects of species diversity, vegetation dynamics, and biogeography, especially with the rapid developments of cladistic methods of phylogenetic reconstruction. All comparisons and predictions will depend on understanding past and present physical and biological processes (i.e. geological history of the continents and the evolutionary history of organisms), as well as human impacts in both regions. Both species level (life history characteristics, distribution, ecological functions) and community level (species composition, structure, endemism) variables should be investigated. Comparisons should be conducted spatially across vegetation zones and temporally through geological episodes. Emphases on the phylogeny and geological history of component taxa by analysing and synthesizing multidisciplinary data would be helpful, especially with regard to the current trends in global climate change. Diversity measured on different scales (i.e. α‐, β, and g‐diversity) could provide invaluable information about local‐regional relationships and their ecological implications in continental or even global biodiversity patterns.
The epiphyte vegetation of Annona glabra on Barro Colorado Island, Panama
Authors: Zotz Gerhard , Bermejo Patricia , Dietz Hansjörg
Published: March 2003

Aim Information on the community composition, structure, and dynamics of epiphyte vegetation is scarce. A survey of the epiphytes occurring on all individuals of one particular host tree species in a well‐studied neotropical research site allowed us a comparison of the epiphyte flora of this tree with the local epiphyte flora, the analysis of spatial distribution patterns and the use of these patterns as indications for changes in time. In the future, our results can be used as a baseline data‐set for the direct observation of the long‐term dynamics in epiphyte communities.

Location The study was conducted on Barro Colorado Island (BCI), Panama.

Methods We recorded all individuals of the vascular epiphytes growing on Annona glabra L., a flood‐tolerant, multiple‐stemmed tree, which is restricted to the shoreline of BCI. Data on tree biometrics, epiphyte species, and epiphyte abundances were collected for more than 1200 trees.

Results In total, we encountered almost 15,000 epiphytic individuals in sixty‐eight species, corresponding to more than one third of the entire epiphyte flora of Barro Colorado Island. The component species differed strongly in abundance: the four most important species accounted for >75% of all individuals. In most cases, the same four species were also the first to colonize a tree (=phorophyte). Colonization patterns indicated no replacement of early colonizers by late arrivals. Species richness and epiphyte abundances showed a positive correlation with the size and the density of the host trees. All species showed a highly clumped distribution and the physiognomy of epiphyte communities of individual trees was dominated either by one or several of the four most common species or by a set of frequently co‐occurring tank bromeliads. Other species were dominant only in exceptional cases. Most species were always rare. A distance effect on community composition was mostly confined to a local scale with an increased similarity in the species assemblage of stems of a tree v. neighbouring trees.

Main conclusions The epiphytes on a single small phorophyte species may encompass a surprisingly large proportion of the local epiphyte flora. The observations that most tree crowns are inhabited by a single or only very few species, and that all epiphyte species show highly clumped distributions suggest a predominance of very local dispersal within a tree crown, which is only infrequently interrupted by successful long‐distance dispersal between crowns.
Neotropical seasonally dry forests and Quaternary vegetation changes
Authors: Toby Pennington R. , Prado Darién E. , Pendry Colin A.
Published: March 2003

Seasonally dry tropical forests have been largely ignored in discussions of vegetation changes during the Quaternary.

We distinguish dry forests, which are essentially tree‐dominated ecosystems, from open savannas that have a xeromorphic fire‐tolerant, grass layer and grow on dystrophic, acid soils. Seasonally dry tropical forests grow on fertile soils, usually have a closed canopy, have woody floras dominated by the Leguminosae and Bignoniaceae and a sparse ground flora with few grasses. They occur in disjunct areas throughout the Neotropics. The Chaco forests of central South America experience regular annual frosts, and are considered a subtropical extension of temperate vegetation formations.

At least 104 plant species from a wide range of families are each found in two or more of the isolated areas of seasonally dry tropical forest scattered across the Neotropics, and these repeated patterns of distribution suggest a more widespread expanse of this vegetation, presumably in drier and cooler periods of the Pleistocene.

We propose a new vegetation model for some areas of the Ice‐Age Amazon: a type of seasonally dry tropical forest, with rain forest and montane taxa largely confined to gallery forest. This model is consistent with the distributions of contemporary seasonally dry tropical forest species in Amazonia and existing palynological data.

The hypothesis of vicariance of a wider historical area of seasonally dry tropical forests could be tested using a cladistic biogeographic approach focusing on plant genera that have species showing high levels of endemicity in the different areas of these forests.
Biogeographical implications of mitochondrial DNA variation in the Bockadam snake (Cerberus rynchops, Serpentes: Homalopsinae) in Southeast Asia
Authors: Karns Daryl R. , O’Bannon Ashley , Voris Harold K. , Weigt Lee A.
Published: March 2003

Aim The biogeography of Southeast Asia has been greatly affected by Pleistocene sea‐level changes and the consequent alteration of coastline and land mass configurations. We investigated the effect of these Pleistocene events on genetic divergence in Cerberus rynchops, the Bockdam, an Asian water snake (Homalopsinae) associated with tidal mudflats and coastal mangrove forests in Southeast Asia.

Location Localities for the Cerberus included the Andaman sea coast of Thailand, Sumatra, and Borneo (Sunda Shelf localities), the Philippines and Sulawesi, and from northern Australia (Sahul Shelf).

Methods We analysed mtDNA sequences (12 s, 16 s, and cyt b) from seven C. rynchops populations (twenty‐six specimens), from two specimens of Cerberus microlepis (a freshwater species known only from Lake Buhi in the Philippines), and from one Enhydris enhyris (Schneider), another homalopsine used as an outgroup.

Results We found a strong correlation between genetic divergence and geographical distance (r = 0.922, P < 0.001) and the biogeographic history of the region. Cerberus rynchops populations from the Sunda Shelf localities, the Philippines, Sulawesi and C. microlepis from the Philippines were genetically similar (mean divergence = 2.1%, range = 0.7–2.8%) compared to the C. rynchops population from northern Australia (mean divergence from all other Cerberus populations = 6.6%, range = 6.0–7.3%). This divergence was comparable to that observed between the E. enhydris outgroup and all Cerberus populations (mean distance = 7.3%, range = 6.8–8.6%).

Main conclusions These findings suggest a relatively high degree of movement and gene flow among Sunda Shelf localities, the Philippines, and Sulawesi (biogeographic region west of Weber’s Line) and isolation of the northern Australian (Sunda Shelf) Cerberus. Taxa will be differentially affected by these Pleistocene sea level changes dependent on their physiology and ecology. We discuss how the dispersal of the coastal, saltwater tolerant C. rynchops would have been affected by changing configurations of Pleistocene coastlines and the implications of these results for the systematics of Cerberus.
Effects of fire protection on savanna structure in Central Brazil
Authors: Moreira Adriana G.
Published: March 2003

Aim

Fire protection gradually changes the density of woody plants in numerous savannas around the world. In this study changes of structure in two tropical savanna areas with contrasting history of fire protection in the central Brazilian Cerrado is documented.

Location

Vegetation was sampled with line intercept transects in two adjacent sites in Brasilia, Federal District. These transects were located within a nature reserve protected from fire since 1972 and within an adjacent reserve area that burns every 2 years.

Methods

Five savanna physiognomies, from a low forest (‘cerradão’) to an open savanna (‘campo sujo’), were sampled in both sites.

Results

Fire protection increased the abundance of woody plants and favoured fire‐sensitive species. With some exceptions, shrubs tended to be less affected by fire than trees. Species distribution was affected by a complex interaction of fire and physiognomy. Fire had the strongest effect on ‘campo sujo’ savanna, and a less significant effect on the intermediate physiognomies.

Main conclusions

Protection permits the establishment of fire sensitive species. A long enough protection against fire could lead to the appearance of more wooded physiognomies in the Cerrado.
A phytogeographical characterization of the vine flora of the Sonoran and Chihuahuan deserts
Authors: Krings Alexander
Published: March 2003

Aim  This study presents a phytogeographical characterization of the vine flora of two lower North American desert regions as a biogeographical framework for further ecological inquiry into desert vines.

Location  The phytogeography of the vine flora of the Sonoran and Chihuahuan Deserts was c haracterized based on 263 known species.

Methods  Checklists of the vines of each desert were developed. Represented genera were then grouped into 10 phytogeographical elements based on worldwide distribution patterns. To compare the floristic composition of the desert floras, an index of species similarity was calculated.

Results  About a third more species of vines occur in the Sonoran Desert than in the Chihuahuan Desert. Based on the analysis, cosmopolitan genera are the only group more numerous in absolute terms in the Chihuahuan Desert than in the Sonoran Desert. Tropical elements are represented in about the same proportion in each desert as the number of species, however, nearly twice as many pantropical and neotropical genera are represented in the Sonoran Desert as in the Chihuahuan Desert. Proportionately, more genera of temperate elements occur in the Chihuahuan Desert than in the Sonoran desert, although the absolute number of genera is slightly higher in the latter.

Main conclusions  As these deserts are relatively recent ecological formations and as vines evolved in forest ecosystems, the composition of the desert vine floras is the result of the interaction between historical vegetation types, their constituent taxa and climatic and geological history. The main differences in the vining floras of the present‐day Sonoran and Chihuahuan Deserts appear to be the result of greater historical influence in the Sonoran Desert of (1) tropical vegetation types and (2) the emergence of the Gulf of California. The Chihuahuan Desert vine flora seems to be the result of (1) a more pronounced historical temperate vegetation, (2) the lack of an important isolating event, such as the creation of the Baja California peninsula, and (3) a cooler climate with shorter growing seasons.
The climatic response of Phyllocladus aspleniifolius (Labill.) Hook. f in Tasmania
Authors: Allen K. J. , Cook E. R. , Francey R. J. , Michael K.
Published: March 2003

Aim

To examine the response of ring widths of Phyllocladus aspleniifolius to maximum and minimum temperatures and to a zonal index (ZI).

Location

Tasmania, Australia.

Methods

Between two and four increment cores were obtained from approximately 20 trees at each of 16 sites of P. aspleniifolius across Tasmania. Four regions were defined and temperature data for climate stations from each of these regions were transformed into dimensionless time series appropriate for each region. The ZI was constructed from Melbourne and Hobart mean sea level pressure (MSLP). Correlations were calculated between climate data and ring widths over most of the 20th century. Data were then segregated into two subperiods to assess whether or not temporal changes in ring width response have occurred over the 20th century.

Results

The dominant feature of the correlation functions was a negative correlation with temperatures of the previous growing season. Correlation between the ZI and ring width is most significant, and positive, in November and March of the previous growing season. Differences in the shape of the correlation functions, and their strength is apparent over the course of the century. In general, correlations have become weaker and less consistent among the 16 sites for the latter part of the century. Temperatures have generally increased during the 1900s over which time period correlations have been calculated.

Main conclusions

The temporally changing climatic response in ring widths is consistent with a hypothesis of competition for resources between different parts of a plant. A nonlinear response to climate over a short‐time period violates one of the basic assumptions of dendroclimatology, therefore suggesting further investigation of both the physiology of trees used for dendroclimatological purposes and the statistical methods used for climatic reconstruction.
Role of isolation and habitat quality in shaping species abundance: a test with badgers (Meles meles L.) in a gradient of forest fragmentation
Authors: Virgós Emilio
Published: March 2003

Aim

This paper describes badger (Meles meles L. 1758) abundance in remnant forests of the two Iberian plateaux. The relative role of factors related to habitat quality and to isolation were tested in order to explain variations in badger abundance according to forest‐scrubland cover at the landscape scale. It was predicted that isolation would be more important where there is less forest cover (greater fragmentation), while habitat quality would predominate in areas where forest cover is greater (less fragmentation).

Location

Thirty‐six forests (> 90 ha) were sampled, 16 in the North and 20 in the South plateau. Twelve forests were sampled in each one of the following categories of regional forest‐scrubland cover in the landscape (10 × 10 km): < 20%, 20–30%, > 30%.

Methods

In each forest, 4‐km transects were followed to look for badger setts. The number of badger setts km–1 was used as a surrogate of badger abundance. The transects were divided into 250 m segments in which a series of environmental variables related to habitat quality were estimated. Moreover, for each forest patch three variables related to isolation on a landscape or regional scale were measured on forest maps (1 : 400,000): the distance to riparian woodland, distance to the mountains of Central Spain and distance to other large forests on the plateau (> 10,000 ha). The prediction through Pearson correlations was tested and forward stepwise multiple regressions performed with the different subsets of data (different forest‐scrubland categories).

Results

The results support the established prediction, in areas with under 20% forest cover, that isolation was the best predictor of badger abundance in forest fragments, while in areas with over 20% cover, the most important predictors were those associated with intraforest habitat quality (shrub cover and rock cover).

Main conclusions

Data for badger abundance in fragmented forests indicate that factors determining species distribution and numbers in heterogeneous environments are highly dependent on landscape pattern. Isolation is the main factor explaining distribution in highly fragmented situations in which the pattern can be explained through metapopulation models. However, in less fragmented situations, distribution models are more easily described in terms of habitat suitability (niche models).
Historical biogeography of Indo‐western Pacific coral reef biota: is the Indonesian region a centre of origin?
Authors: Santini Francesco , Winterbottom Richard
Published: March 2003

Aim

To apply the modern theory of vicariant biogeography to the study of evolution of the coral reef fauna in the Indo‐western Pacific region.

Location

Indian and western Pacific Oceans.

Methods

Use of taxa ladograms and Brooks Parsimony Analysis to reconstruct relationships between geographical areas.

Results

The analysis seems to indicate that the Indonesian region, long stated to be a `centre of origin' for most of the Indo‐West Pacific marine fauna, is a very derived area in the general area cladogram; and that most of the lineages may have originated in the western Indian Ocean, Australia, or the South‐western Pacific (probably from lineages that had remained isolated after the breakup of the Gondwanan supercontinent, or because of the movement of island arcs). A series of events that fragmented an originally widespread biota seems to be highly congruent with geological events that caused the break up of Gondwanaland.

Main conclusions

Contrary to several previous claims, based mostly on descriptive, rather than analytical, studies, most lineages of coral reef fauna inhabiting the Indo‐western Pacific region probably originated through vicariant events associated with, and following the break up of Gondwana. A general pattern of biotic distribution that is highly congruent with geological data shows that even if long range dispersal and sympatric speciation may in some cases have taken place, they have not probably been the predominant mechanism of speciation in the clades examined.
Biogeography of spiders on remote oceanic islands of the Pacific: archipelagoes as stepping stones?
Authors: Gillespie Rosemary G.
Published: March 2003

Aim

The composition of species in any given island community may directly reflect the processes of immigration such that species on a more remote island comprise a nested subset of those on the nearest less remote land mass. Alternatively, new species can arise on islands by less frequent colonization but subsequent evolutionary differentiation. In the current study the species composition of spiders is examined in native communities on three remote oceanic archipelagoes to test hypotheses concerning the relative importance for species accumulation of (i) immigration from the nearest land mass, vs. (ii)in situspeciation.

Location

The study focuses on three volcanic hot‐spot archipelagoes in the Pacific: the Hawaiian, Marquesas and Society Islands.

Methods

Tetragnathaspiders were collected from the three remote Pacific archipelagoes as well as Australasia and America. Sequences of mitochondrial DNA (Cytochrome Oxidase I and 16S ribosomal DNA) were obtained from the spiders and a phylogenetic approach was used to examine relatedness among island endemic lineages of spiders, as well as associations between species on different archipelagoes with continental congeners.

Results

Within archipelagoes, species groups are largely monophyletic. When species groups are compared between archipelagoes, those on one archipelago are never the sister group to those on another archipelago. Rather, each archipelago has a mainland congener as its closest sister group.

Main conclusions

First, colonization of the Hawaiian, Marquesas and Society archipelagoes byTetragnathaspiders appears to have occurred independently, most likely in each case from a continental source, but not from the nearest archipelago. Secondly,in situspeciation has occurred in the Marquesas and Society Islands in a similar manner to that in Hawaii, although apparently on a smaller scale.
Elevated genetic heterogeneity and Pleistocene climatic instability: inferences from nrDNA in New Zealand Coprosma (Rubiaceae)
Authors: Wichman Stephen R. , Wright Shane D. , Cameron Ewen K. , Keeling D. Jeannette , Gardner Richard C.
Published: March 2003

Aim

To examine patterns of hybridization and genotype mixing within the genus Coprosma J.R.Forst. & G.Forst. (Rubiaceae).

Location

New Zealand

Methods

Nucleotide sequence was determined for the internal transcribed spacer (ITS) and external transcribed spacer (ETS) regions of nuclear ribosomal DNA for fifty individuals from thirty‐six taxa within the New Zealand component of the genus Coprosma.

Results

Mixed sequences were found to be widespread in Coprosma. Direct sequencing of ITS polymerase chain reaction (PCR) products from seven polyploid taxa showed evidence of sequence mixtures. Cloning and sequencing of individual PCR products from two polyploids confirmed the presence of multiple templates, one of which corresponded to that of a diploid. Intra‐individual heterogeneity was also seen in a hybrid diploid taxon, with the mixed nucleotides corresponding to those of the parental lineages. Finally the ITS sequences of twenty‐two diploid taxa showed that eleven contained intra‐individual heterogeneity.

Conclusions

We conclude that the widespread occurrence of sequence mixtures in Coprosma results from of frequent hybridization. We also conclude that concerted evolution of the ITS and ETS regions is depressed. We propose that these characteristics evolved as a mechanism to maintain high levels of heterogeneity and suggest that this is adaptive for Coprosma in climatically unstable and physically complex New Zealand landscapes. These landscapes have been subjected to repeated oscillations between stadial and interstadial environments during the Pleistocene.
Changes in distribution of birches and birch‐feedingEriocraniamoths in St Petersburg, Russia, between 1986 and 2001
Authors: Kozlov Mikhail V.
Published: March 2003

Aim and location

I aimed to assess changes in number and quality of suitable habitats, as well as in habitat occupancy byEriocranialeafminers (Lepidoptera, Eriocraniidae), which have occurred in central parts of the city of St Petersburg between 1986 and 2001.

Methods

The study compares results of 2000/2001 with the data of 1986 (published by Kozlov, M.V.,Zhurnal Obzsej Biologii (Moscow), 1988,49, 670;Journal of Biogeography, 1996,23, 95) and is based on (1) mapping of birch trees in two representative plots (20–25 ha) in downtown and on the periphery of the densely built city area, (2) survey of 133 isolated or semi‐isolated habitats that were found suitable forEriocraniain 1986, and (3) presence/absence records of birches (Betula pendulaandB. pubescens) andEriocraniaminers in Petrogradskaya area by using 160 × 160 m regular grid (same as in 1986; 379 cells).

Results

Both number of habitats suitable forEriocraniaand number of birch trees in these habitats increased since 1986. Colonization of vacant habitats in the area of sporadic distribution in the years 2000/2001 exceeded the extinction rate by a factor of 4; probability of extinction was highest in low densityEriocraniapopulations associated with small habitat patches, like solitary birch trees in densely built areas. Proportion of the occupied habitat patches within the zone of sporadic distribution in 2000 (92.4%) was much higher than in 1986 (50.4%); thus the area of the lacuna in distribution range ofEriocraniaspecies, associated with the historical centre of St Petersburg, has decreased since 1986.

Main conclusion

The data of 2000/2001 fit the prediction (Kozlov, 1996) thatEriocraniamoths are able to re‐colonize the city areas built before 1950s, where they have been extinct or almost extinct by the mid‐1980s.
Grasslands, heathlands and shrublands in coastal New England: historical interpretations and approaches to conservation
Authors: Motzkin Glenn , Foster David R.
Published: March 2003

Abstract Aim  This study evaluates the long‐term history of grassland, heathland and shrubland communities that are high priorities for conservation in the north‐eastern US and support numerous globally rare species. Such an historical perspective is necessary in order to develop appropriate conservation and management approaches for these communities.

Location  The study area encompasses the coastal region that extends from Cape Cod, MA to Long Island, NY, including the islands of Nantucket, Martha's Vineyard, and Block Island.

Methods  In order to determine whether open‐land habitats occurred in the study region prior to European arrival in the seventeenth century and to assess changes to these communities through the historical period, a wide range of palaeoecological, archaeological, ethno‐historical, biological and field data were reviewed. Information about the history of human impacts on these communities was used to interpret landscape change over time and to evaluate current and potential conservation and management approaches.

Results  The region was predominantly wooded prior to widespread Euro‐American land clearing beginning in the seventeenth century, with some areas of early successional habitats, primarily on exposed sites and near Native American settlements. Grasslands, heathlands and shrublands increased dramatically as a result of intensive and primarily agricultural disturbance through the historical period. The decline in recent decades of these communities results from extensive residential and commercial development, and from widespread abandonment of traditional agricultural practices, especially intensive grazing.

Main conclusions  Despite considerable uncertainty as to the pre‐European distribution and abundance of species characteristic of grasslands, heathlands and shrublands, historical disturbances have been sufficiently widespread and severe that it is unlikely that modern species assemblages closely resemble those that occurred prior to European arrival. Management aimed at perpetuating early successional species assemblages on sites other than exposed, coastal locations may require use of traditional land‐use practices or appropriate substitutes of comparable intensity.
Seeing is believing — picture building: a key component of telephone triage
Authors: Edwards Bernie
Published: March 2003

• This paper describes one part of a major study aimed at building a substantive theory of the triage process.

• The paper reports on some early findings of a major component of the reasoning strategy utilized by nurses when making triage decisions via the telephone.

• The study reveals that in telephone triage nurses compensate for the absence of face‐to‐face contact by creating a mental image of the caller and the situation being dealt with. This forms the basis of the nurses' assessment of the urgency of the problem.

• The properties that contribute to this process of ‘visualization work’ are presented and the linkages with current thought in relation to clinical reasoning are explored.
Nursing assessment and diagnosis of respiratory distress in infants by children's nurses
Authors: ARMITAGE GERRY
Published: March 2003

• Many children's nurses have significant contact with children who have breathing difficulties and should be using systematic criteria to assess their nursing needs.

• Children's nurses do not appear to follow systematic criteria but are strongly influenced by the medical model and this may be detrimental to holistic assessment and the development of nursing diagnoses based on nursing needs.

• As nursing, along with other disciplines, develops evidence‐based practice, childern's nurses should develop evidence for best practice mindful of children's views, parental needs and the education of future practitioners.
A multicentre comparative evaluation: washable pants with an integral pad for light incontinence
Authors: CLARKE‐O'NEILL SINEAD , PETTERSSON LENA , FADER MANDY , DEAN GRAHAM , BROOKS RODNEY , COTTENDEN ALAN
Published: March 2003

• The Continence Product Evaluation Network (CPE network) is funded by the Medical Devices Agency (MDA) of the Department of Health, to undertake comparative evaluations of continence products.

• There are a wide variety of continence products on the UK market and very little information is available to aid product selection. The aim of this study was to evaluate washable pants with integral pads for women with light incontinence.

• A randomized multiple cross‐over design was used. Seventy‐two women tested each of the 10 products that were available on the UK market at the time of the evaluation. Both subjective and objective outcome measures were used to evaluate the products.

• Products performed similarly in terms of leakage but there were statistically significant differences in other performance aspects, e.g. fit and discreteness.

• This study should be valuable in enabling purchasers, carers and users to make informed decisions when purchasing products.
Barriers that delay children and young people who are dependent on mechanical ventilators from being discharged from hospital
Authors: NOYES JANE
Published: March 2003

• A qualitative study of user perspectives published previously by the author found that children and young people who are dependent on ventilators spend many months and in some cases years in hospital when they no longer had a medical need or wanted to be there.

• This second paper is drawn from the same qualitative study and reports on the barriers that the children and young people who are dependent on ventilators, and their parents, described as important factors in preventing their discharge from hospital.

• Six issues were identified as significant barriers that prevented the children and young people from being discharged. These were: the attitudes of professionals; the lack of joint commissioning and accounting responsibility; general poor management both within the health service and in collaborating with other services; complex social issues; housing problems; and a general lack of auditing and outcome measures.

• The generalizability of the findings is unknown. However, recommendations are made in relation to the need to establish joint commissioning and accounting responsibility for care and services, and to establish outcome measures to monitor the effectiveness and appropriateness of the care and services provided.
An action research project to evaluate the clinical practice facilitator role for junior nurses in an acute hospital setting
Authors: KELLY DANIEL , SIMPSON SUSAN , BROWN PAULINE
Published: March 2003

• It has been well documented that newly qualified nurses require support in developing confidence and professional competence. Although preceptorship models have gone some way in addressing this need, innovative and flexible models of facilitation and development are also required to respond to local demands.

• In the project reported here a number of supernumerary clinical practice facilitators (CPFs) were appointed to support both healthcare assistants and newly qualified registered nurses to enhance their competence and clinical skills. It was anticipated that they might also encourage awareness of other professional issues, such as evidence‐based practice, as well as having a positive influence on the clinical learning environment and staff morale.

• This article describes how an action research approach was used to establish the CPF role in a variety of clinical areas across a large inner‐city National Health Service Trust. It outlines the evaluation undertaken and the further contribution that such roles could provide.
The relationship of perceived control to outcomes in older women undergoing surgery for fractured neck of femur
Authors: Shaw Chris , Mccoll Elaine , Bond Senga
Published: March 2003

• This paper examines the relationship between internal locus of control and recovery from surgery for fractured neck of femur in women over the age of 65 years, in order to inform strategies for nursing care.

• Structured interviews were carried out at 5 and 30 days postsurgery with 112 women (mean age 78.6 years) in five general hospitals in the North of England.

• Locus of control was assessed as a factor associated with the outcomes of physical disability (measured as dependence in activities of daily living) and psychological distress (measured using the Hospital Anxiety and Depression Scale).

• Internal locus of control was significantly related to less physical disability, but no association was found between locus of control and depression and anxiety at 30 days postsurgery when age, 5‐day measures and other 30‐day outcome measures were controlled.

• The findings suggest that nursing interventions that enhance perceived internal control by patients during rehabilitation may result in better physical outcomes. Further work is required to explore the relationship of control to psychological outcomes.
Using cost‐effectiveness analysis to compare Hospital at Home and in‐patient interventions. Part 1
Authors: Jester Rebecca , Hicks Carolyn
Published: March 2003

• An economic analysis was conducted as an integral part of a comparison of the effectiveness and suitability of Hospital at Home (HaH) and in‐patient interventions. The sample comprised of 109 adult primary total joint replacement patients and 21 of their coresident informal carers.

• The paper is presented in two parts. Part 1 includes the background and rationale for the study and the findings from the comparison of the effectiveness of the two interventions using multiple data collection sources.

• Data were collected using questionnaires, audit and semi‐structured interviews.

• Hospital at Home was found to be significantly more effective in terms of patient satisfaction and reduced joint stiffness and as least as effective as in‐patient care in relation to levels of joint pain, joint disability and incidence of postoperative complications. In addition informal carers reported 107 positive comments compared with 36 negative comments related to HaH care and all except one of the 21 carers would choose HaH again in preference to in‐patient care.
Evaluation and design of technologies to meet learning outcomes
Authors: Sharpe R. , Bailey P.
Published: March 2003

Professional development for staff in higher education is developing rapidly in response to current national developments. As staff seek support and development to cope with the changes in their students, appropriate teaching, learning and assessment methods and rising use of learning technologies, institutions must be in a position to provide relevant programmes of development. Increasingly staff will be required to give evidence of their own development and institutions should be able to offer suitable and accessible systems which allow them to easily document their progress and gain accreditation. Two case studies are presented: the first uses the outcomes of a graduate teaching assistants course to evaluate the effectiveness of using a computer conferencing system. The second case study uses outcomes to redesign, to a web‐based open learning system, the teaching and learning in a higher education course for teaching staff.
The ecological significance of canopy seed storage in fire‐prone environments: a model for resprouting shrubs
Authors: Enright Neal J. , Marsula Ralf , Lamont Byron B. , Wissel Christian
Published: March 2003

1 Based on a parameter set describing mean life‐history attributes for the resprouting shrub Banksia attenuata in south‐western Australia, the relationship between fire interval and extent of canopy seed storage (serotiny) was analysed. Deterministic and stochastic computer models were used to try to identify the circumstances under which serotiny is favoured, and what degree of serotiny maximizes the estimated finite rate of natural increase (λ) for species which, in addition to serotiny, have the capacity to resprout vegetatively.

2 The deterministic model indicated a maximum finite rate of natural increase (λ = 1.015) when the fire interval was 13 years and all seeds were retained on the plant until fire occurred (i.e. complete serotiny). Populations were predicted to decline if the fire interval exceeded about 40 years.

3 Changes to biological attributes associated with timing of reproduction shifted the optimum fire interval but did not change the overall pattern in relation to serotiny. Reduction in the probability of adults resprouting after fire also shifted the optimum, so that as probability of resprouting declined, optimum fire interval increased.

4 Increasing stochasticity around the mean fire interval (CV > 50%) under regimes of frequent fire (fire interval <20 years) led to strong, but not complete, serotiny as the optimum strategy (λ = 1.009 ± 0.001). If fire was less frequent, and the probability of inter‐fire recruitment was similar to that of post‐fire recruitment, then the optimum strategy was zero serotiny.

5 The probability of seedling recruitment was low after most fires due to low seed availability and high seedling mortality over the first summer. Stochastic weather (variation in summer rainfall) resulted in a higher rate of population growth (λ = 1.019) than under constant average weather conditions, emphasizing the importance of rare recruitment events in the population behaviour of resprouting species.

6 Resprouters were able to cope with more frequent fire than non‐sprouters, but there was no evidence to support the contention that they are also favoured under regimes of infrequent fire.
Effects of vertebrate herbivores on soil processes, plant biomass, litter accumulation and soil elevation changes in a coastal marsh
Authors: Ford Mark A. , Grace James B.
Published: March 2003

1 Submergence of coastal wetlands in Louisiana is currently rapid and widespread. A number of factors contribute to this loss of habitat, including the activities of herbivores. The objective of this study was to examine the effects of large mammals, predominantly nutria and wild boar, on processes controlling soil elevation in coastal marshes.

2 Effects of herbivores on soil and vegetation were assessed by the use of paired fenced and unfenced plots over two successive growing seasons. Above‐ground biomass, litter production, changes in soil elevation, vertical soil accretion, shallow subsidence, below‐ground production of roots and rhizomes, the thickness of the root zone, soil bulk density, and soil organic matter were measured.

3 Above‐ground biomass, below‐ground production, soil elevation and the expansion of the root zone decreased due to herbivore activity. Litter production, the rate of soil surface accretion and shallow soil subsidence were all higher in grazed compared to ungrazed plots, while soil organic matter and bulk density did not differ significantly between treatments.

4 The results indicate that herbivores can have a negative effect on soil building processes, primarily by reducing below‐ground production and expansion of the root zone. Where natural rates of mineral sediment deposition are high, coastal marshes are expected to persist, despite herbivore activities. However, where sediment inputs are substantially less, herbivores may lead to destruction of habitat.
Forest fragmentation effects on palm diversity in central Amazonia
Authors: Scariot Aldicir
Published: March 2003

1The effects of fragmentation on quantitative measures of floristic diversity in a palm community were examined in the Biological Dynamics of Forest Fragments study area in central Amazonia. Three 1‐ha, three 10‐ha, two 100‐ha and three continuous forest reserves, distributed among three sites, were surveyed. In each reserve, 10 20 × 20 m plots were sampled, resulting in a total of 110 plots representing 4.4 sampled hectares.

2The taxon composition of this palm community was dominated by stemmed, understorey palms. A total of 23 225 individuals from 36 taxa was recorded; five of the taxa were not sampled in continuous forest.

3Taxa richness did not vary across reserve size or sites unless taxa not sampled in the continuous forest were removed from the analysis. Smaller forest fragments then harboured fewer taxa in the seedling stage than large forest fragments or continuous forest, despite the short time since isolation (10–15 years). There was a significant effect of location on the number of taxa per plot for all life stages, but only seedling and total were significantly affected by reserve size.

4Reserve size did not affect the Shannon and Evenness indices. Reserves of similar sizes were floristically more similar than reserves of very different sizes.

5Palms are important for the structure and composition of the forest. Their conservation may require the establishment of a number of large reserves.
Spatial and temporal dynamics of epidemics of the rust fungus Uromyces valerianae on populations of its host Valeriana salina
Authors: Ericson L. , Burdon J. J. , Müller W. J.
Published: March 2003

1 Analysis of the dynamics of rust disease caused by Uromyces valerianae in 30 discrete populations of Valeriana salina occurring on an archipelago of small islands in the Gulf of Bothnia, central Sweden, showed strong temporal and spatial effects.

2 Over a 13‐year period, the population dynamics of the pathogen varied across the metapopulation, with disease incidence (presence/absence), prevalence and severity all showing strong population and year effects, indicative of heterogeneity among years and host populations in the suitability of conditions for the pathogen. While some individual populations were infected for the entire study period, others were infected for only 1 or 2 years. Local pathogen population extinction and recolonization events were relatively common, with annual recolonization rates of previously healthy populations ranging from 0% to 13.3%.

3 The incidence of disease within individual host populations was significantly affected by host population size, the prevalence of disease in the previous year and the proximity of neighbouring populations that were infected in the current year. The prevalence of disease in infected populations only depended on the prevalence of disease in the previous year. There was little to choose between disease prevalence and severity in predictive power.

4 Overall, the dynamical behaviour of this set of pathogen demes best fit that predicted for a metapopulation with considerable asynchrony in epidemiological patterns between different demes, despite evidence of among‐population migration.