bluuebunny/crossref_metadata_2025 huggingface dataset:
Defining the nursing contribution to patient outcome: lessons from a review of the literature examining nursing outcomes, skill mix and changing roles
Authors: Spilsbury Karen , Meyer Julienne
Published: March 2003

•  A review of the evidence to define the nursing contribution to patient outcome is presented. The review relies on work related to nursing sensitive outcomes, skill mix and changing roles.

•  Methodological difficulties associated with these studies are highlighted.

•  Areas requiring further research are discussed.

•  It is suggested that experimental evidence is not always appropriate, when attempting to describe nursing activity. The authors advocate that new methodologies, in particular practitioner‐centred research, are needed to unpack the nature of nursing.
Energy and nutrient intake of patients in acute care
Authors: Kowanko Inge , Simon Stephen , Wood Jacquelin
Published: March 2003

•  There have been numerous reports that the nutritional intake of many hospitalized patients is sub‐optimal, but there is little published information about patients’ diets in Australian hospitals.

•  In this study, the nutritional intake of patients in general medical wards of an Australian acute care hospital was assessed.

•  Although the hospital diet can provide adequate energy and nutrients, many patients may not consume sufficient food to meet their needs.

•  The estimated energy intake of about one‐third of patients was very low, and vitamin C, calcium and zinc intakes were also of concern.

•  The implications are discussed and recommendations for improved nutritional care are suggested.
Interdisciplinary practice – a matter of teamwork: an integrated literature review
Authors: Mccallin Antoinette
Published: March 2003

• The aim of this literature review is to explore the development of interdisciplinary practice.

• The terms interdisciplinary, multidisciplinary, and inter‐professional are problematic. Definitions must be viewed carefully, as interpretations tend to reflect historical socialization patterns that are now out of kilter with contemporary understandings.

• Changing inter‐professional interactions, teams and teamwork are examined; findings indicate that explanations of interdisciplinary teamwork should be all‐inclusive of the particular cultural conditions and contextual determinants that affect team practice.

• Findings need to be viewed with caution because what is applicable in one country may not be automatically transferable to another, where particular socio‐political contexts shape interdisciplinary practice.
Healthcare personnel’s attitudes towards patients with urinary incontinence INFORMATION POINT: Regression analysis
Authors: Vinsnes Anne G. , Harkless Gene E. , Haltbakk Johannes , Bohm Jeppe , Hunskaar Steinar
Published: March 2003

• The aim of the study was to understand the variability of Norwegian staff’s attitudes towards patients with urinary incontinence across years and place of work, age and education levels.

• The Incontinence Stress Questionnaire – Staff Reaction (Norwegian version) (ISQ‐SR‐N) was used to measure staff’s reactions and feelings towards patients with urinary incontinence.

• A cross‐sectional survey design was used to gather self‐reported data. The research sites were five nursing homes, three home care districts and medical and surgical wards at a university hospital.

• Of the 745 staff invited, 535 (72%) returned the questionnaire. Staff members working in long‐term care units were older than staff members working in acute care units. Most of the registered nurses worked in acute care, whilst most of the nursing assistants worked in long‐term care.

• Stepwise regression analysis identified education, working in a medical/surgical units, and the interaction of education and working in a medical unit to be most predictive of attitudes.

• Nursing assistants had more positive attitudes than registered nurses. Working in medical/surgical units predicted the most negative attitudes. Only 15.2% of the variability of attitudes can be explained by the predictive variables.
The practice of community caregivers in a home‐based HIV/AIDS project in South Africa
Authors: UYS L. R
Published: March 2003

• The aim of this study was to describe the practice of community caregivers in a home‐based AIDS care project at seven sites in South Africa.

• The community caregivers felt positive about the contribution they made, but found it difficult to cope with the poverty and complexity of problems they were faced with.

• They visited each client an average of five times per month, and their care usually involved counselling and informing, symptom control, psychosocial support and welfare assistance.

• The caregivers worked in close collaboration with the South African Hospice Association and clinic staff, and each site developed a work pattern suitable to its resources.
Incidence of pressure ulcers due to surgery
Authors: SCHOONHOVEN LISETTE , DEFLOOR TOM , GRYPDONCK MARIA H. F.
Published: March 2003

• Patients undergoing surgery are prone to develop pressure ulcers during the surgical procedure.

• The aim of the study was to gain insight into the problem by describing the incidence, clinical features and progression of pressure ulcers and closed pressure ulcers in patients undergoing surgery lasting more than 4 hours.

• A prospective follow‐up study was conducted in a university hospital in the Netherlands.

• Two‐hundred and eight patients from nine surgical specialities were included in the study. The skin of patients was observed the evening before surgery and, if the patient's condition allowed it, directly postoperatively and subsequently daily for 14 days or until discharge, whichever occurred first. When patients developed a pressure ulcer they were observed daily until discharge or until the pressure ulcer had healed. The size and colour of the lesion, stage and skin condition were described every day. In addition, data were collected concerning the operation, postoperative period, and general characteristics.

• Forty‐four patients (21.2%) developed 70 pressure ulcers in the first 2 days following surgery. Twenty‐one pressure ulcers deteriorated in the days following surgery. More than half (52.9%) of the lesions developed on the heels, and 15.7% developed in the sacral area. Twenty‐five patients (12%) were impaired by the lesions they developed. None of the patients in the study developed closed pressure ulcers.

• Pressure ulcer development during a surgical procedure is a serious problem. Therefore, preventive measures should be taken during surgery and the first few days afterwards, until the patient is able to mobilize independently.
Stroke patients in nursing homes: eating, feeding, nutrition and related care
Authors: KUMLIEN SUZANNE , AXELSSON KARIN
Published: March 2003

• The purpose of this study was to explore eating, feeding and nutrition among stroke patients in nursing homes as described by their nurses and by assessments.

• Registered Nurses were interviewed about an individual stroke patient's state of health, care needs and nursing care received and nursing records were reviewed. Information on eating, feeding and nutrition was extracted from the interviews and nursing records. A comprehensive instrument, the Resident Assessment Instrument, was also used to assess these patients' state of health. The domains of eating, feeding and nutrition were focused on in this study. Manifest content analysis was used.

• The results showed that more than 80% of the stroke patients in nursing homes were assessed as having some sort of dependence in eating. According to the Registered Nurses, 22 out of 40 patients demonstrated different eating disabilities. The number of eating disabilities in individual patients ranged from 1 to 7, which emphasized the complexity of eating disabilities in stroke patients. Dysphagia was reported in almost one‐fourth of the patients and 30% were described and/or assessed as having a poor food intake or poor appetite. The Registered Nurses' descriptions of the eating disabilities, nutritional problems and their care were often vague and unspecific. Only six weights were documented in the nursing records and there were no nutritional records.

• The findings highlight the importance of making careful observations and assessments, and of maintaining documentation about eating and nutrition early after a patient's arrival in the nursing home to enable appropriate care and promotion of health.
Intranet‐based learning:a one‐year study of student utilisation
Authors: Herson K. , Sosabowski M. H. , Lloyd A. W.
Published: March 2003

In Higher Education in the UK, there have been marked developments of network technologies and increased demand for assessed quality in teaching and learning. At the School of Pharmacy and Biomolecular Sciences, University of Brighton, an Intranet learning resource has been implemented to meet the quality of service requirements and exploit these technologies. This paper reports on the undergraduate utilisation and evaluation of this resource over a one‐year induction period. Staff‐ and student‐based hurdles are identified; these include confidentiality, peer‐scrutiny, indolence and IT competence issues. Solutions to these problems, many of which are training‐based, are proposed.
Computer‐supported cooperative learning in a Virtual University
Authors: English S. , Yazdani M.
Published: March 2003

There is computer‐supported learning and cooperative learning at universities. There are also a few ‘virtual universities’. This paper links these three features in a way that reflects a vision of a future scenario for learners. The conclusions are based on the observation of the cooperative learning already taking place at Exeter University’s Computer Science Department.
Publishing mathematics on the World Wide Web
Authors: Majewski M.
Published: March 2003

This paper shows how mathematical concepts can be displayed on World Wide Web pages. A few of the most interesting solutions are outlined although a few others are missing and a few more will be invented very soon. It is for authors to decide which system is the most suitable for their purposes.
Networked learning with user‐enriched educational material
Authors: Vescoukis V. C. , Retalis S.
Published: March 2003

The scope and the philosophy of the use of New Technologies in education have still to be defined and important pedagogical issues arise. Based on experience of secondary technical vocational education, a general schema for Network‐Based Learning with strong learner participation is proposed. The main concept of this approach is that learner participation in the learning process can produce or at least motivate the production of learning material. A pilot implementation of such an activity produced quite interesting results and indicated that the content of the learning material can be enriched by material produced by the trainees themselves.
Programming by discovery
Authors: Ramadhan H. A.
Published: March 2003

Abstract The concept of Programming by Discovery refers to the process of designing programming environments and systems which use various visualisation, programming and interaction technologies in an effective way to help users, especially beginner programmers, in writing computer programs, understanding their dynamic behaviour, detecting any misconceptions and bugs associated with them, and seeing the effect of these programs on the underlying machine. A system for programming by discovery encourages a user to become an active learner by allowing him to form his own hypotheses, explore his own questions, and draw his own conclusions. This paper reports on the design and evaluation of a system for programming by discovery which embodies the principles outlined above. To assess the usefulness of the design framework presented in this paper, a pilot empirical evaluation was conducted. The results provided a number of interesting insights into the implication of incorporating visualisation and immediacy features along with graphical notional machine and algorithm‐like language into the design of programming systems.
Tools and strategies for searching in hypermedia environments
Authors: Beaufils A.
Published: March 2003

Abstract This paper presents the results of several investigations into the use made by students of a prototype system of help for the exploitation of hypermedia documents. This prototype was derived from a common type of educational CD‐ROM in which the presentation of the contents was improved and certain research and note‐taking tools added. The evolving, personalised note‐taking system interacts constantly with the environment being explored. Beyond the storage of personal notes (clues, personal knowledge of the area), it allows the student to keep the explored sections in mind and ultimately to plan further explorations. It also enables the extraction and structuring of the data retrieved from the body of the database. The role of this system is to facilitate more thorough searches for information which might sometimes require several sessions stretched out over a long period. It could be profitably used in the context of independent student activities.
Understanding multimedia dialogues in a foreign language
Authors: Merlet S.
Published: March 2003

Abstract The effects of lexical and semantic previews on the comprehension of a computer‐presented illustrated dialogue were examined. Based on a multilevel cognitive theory of comprehension, different types of preview were expected to influence specific aspects of the learners' activity. Thirty French undergraduate students of English as a foreign language were asked to study a computerised illustrated dialogue. A lexical preview decreased the frequency of control actions while listening (e.g. pauses, replays) while the semantic preview improved the quality of information recalled. It is concluded that a fine‐grain analysis of language comprehension processes can improve the design of educational multimedia products
Preschool children’s food problems and food‐related caregiving techniques
Authors: Hertzler Ann A. , Frary Robert B.
Published: March 2003

Abstract: Staff working with preschool children 3–5 years of age in child care centres for the United States Department of Agriculture (USDA) in the commonwealth of Virginia (USA) rated children’s food problems and caregiving techniques of families in their programme. Children’s food problems of greatest concern identified by the first staff group were liking fast foods (69%) and not tasting new food (63%), measures related to the ‘picky eater’ description (r=0.41 and 0.71 respectively). Frequently reported caregiving techniques reported in the same survey were ‘let the child watch too much TV’ (73%), ‘make the child clean the plate’ (33%), and ‘use food for punishment or reward’ (25%). Caregivers reporting parents punishing the child for not eating also tended to check for problems of providing excess cookies and cakes (r=0.39) and not eating vegetables (r=0.43). Similar findings were confirmed in a second survey. Problem food behaviours appear to be related to not exposing children to food choices and to inappropriate television viewing and caregiving techniques.
Dietary guidelines – a self‐assessment
Authors: Hertzler Ann A. , Frary Robert B.
Published: March 2003

Abstract: Men and women were asked to rate food choices by the dietary guideline messages and by nutrient analysis as a pilot to study a contemporary audience who were not main food preparers.
Impact of traditional Korean textile designs on the aesthetic evaluation of modern consumers
Authors: Lee Joohyeon
Published: March 2003

The modern meanings that apply to traditional Korean floral patterns were identified, and the impact of the design elements on the modern consumer’s aesthetic evaluation was studied. It was found that three modern meanings had replaced the traditional Confucian meanings that had applied to the floral textile designs during the Choson Kingdom period. Among the 15 design elements of traditional Korean floral patterns, hue and tone contrast had the most impact on the aesthetic evaluation of consumers. On the basis of the findings of this study, guidelines for successful modernization of traditional Korean floral patterns have been suggested.
Parental eating messages and dietary guideline compliance of college students
Authors: Hertzler Ann A. , Hutchinson Susan R.
Published: March 2003

The purpose of this study was to identify parental eating messages from the point of view of 340 college students and the relationship of these messages to dietary guideline practices. Four types of parental eating messages were identified: (1) threat or guilt, (2) picky eater, (3) food as health, (4) critical weight. Five types of dietary guide practices were identified: (1) fat meals and snacks, (2) vegetable–fruit, (3) sugar‐salt convenience food, (4) fitness–protein–carbohydrate, (5) fat add‐ons. The lack of association of parental eating messages with any of the dietary guideline factors suggests that messages are not affecting the food choices of these college students. Parental messages may in fact represent the way different cultures address eating, parenting and caring.
Abundance, distribution and life histories of grassland plants: a comparative study of 81 species
Authors: Eriksson Ove , Jakobsson Anna
Published: March 2003

1 This study examines the abundance and distribution of grassland plant species in particular relation to features affecting colonization. Seed production (inversely related to seed size) and recruitment success (positively related) affect colonization ability, suggesting that seed size can be used as a key trait.

2Data on seed size, dispersal mode, life form, geographical range size and abundance were gathered for 81 grassland plant species in a field study area in Sweden. Seed production and plant size were estimated for 69 of these species. Analyses were performed both across species, with species treated as independent data points, and for 43 ‘phylogenetically independent contrasts’.

3The cross‐species analyses suggested that local abundance was related to life forms but not dispersal or plant size. Perennials were generally most abundant, as were clonal species. If abundance reflects colonization we predicted that species with intermediately sized seeds (or intermediate seed production) would be most abundant, and this was supported by the phylogenetic contrast but not by cross‐species analyses. In the former analysis, a high abundance of species was significantly associated with a small seed size deviation (and seed number deviation) from the median values of these traits in the community.

4Local abundance, seed production and seed size deviation from the community median value were positively related to geographical range size in the cross‐species analysis, but no relationships were seen in the phylogenetic contrast analysis.

5We conclude that colonization processes do have a significant influence on abundance patterns in grasslands. Seed size is a key trait for colonizing ability, and the effects of the trade‐off of seed size vs. seed number must be considered. No single mechanism can be identified that influences both abundance and geographical distribution range.
The ecological significance of canopy seed storage in fire‐prone environments: a model for non‐sprouting shrubs
Authors: Enright Neal J. , Marsula Ralf , Lamont Byron B. , Wissel Christian
Published: March 2003

1 A comprehensive data set on age, survival and reproduction for the non‐sprouting (fire‐killed) shrub Banksia hookeriana, encompassing 13 years of measurements at 15 sites in south‐western Australia, and including 10 fires, was used to parameterize a computer model to investigate optimum plant life‐history strategies in a fire‐prone environment. Parameter ranges encompassed life‐history information for other non‐sprouting Banksia species from the same region.

2 The relationship between fire interval and level of canopy seed storage (serotiny) was analysed to identify the circumstances under which serotiny is favoured, and what degree of serotiny maximizes potential population growth rate. In addition to deterministic versions of the model, stochasticity in fire interval and conditions for recruitment were analysed.

3 The deterministic model indicated a maximum finite rate of natural increase (λ = 1.15) when the fire interval was 16 years and all seeds were retained on the plant until fire occurred. Although the model failed to predict the intermediate degrees of serotiny present in nature, it supported the optimum fire interval predicted from canopy seed bank dynamics.

4 Changes to biological attributes associated with timing of reproduction and longevity shifted the optimum fire interval and estimated rate of population growth, but did not alter the conclusions concerning serotiny. Although shorter seed longevity and increased rates of predation and/or decay reduced the value of serotiny, even very low levels of canopy seed storage increased species fitness under intermediate fire frequencies (10–20 years).

5 If the probability of inter‐fire recruitment and survival was increased, optimum growth shifted from strong serotiny under a regime of frequent fire (<20 year interval), to weak (or no) serotiny where the interval between successive fires was long (>40 year interval).

6 Stochasticity around mean fire interval resulted in intermediate to strong (but not complete) serotiny being predicted as optimal once the CV for fire interval approached 100%. This result is interpreted as a bet‐hedging strategy whereby spontaneous release of some seeds during the inter‐fire period permits recruitment on rare occasions where fire interval approaches or exceeds the species longevity.
Seed dynamics and seedling establishment in the invading perennialSolidago altissimaunder different experimental treatments
Authors: Meyer Andrea. H. , Schmid Bernhard
Published: March 2003

1Population increases inSolidago altissima, an aggressive invader in central Europe, can be due to clonal growth by rhizomes or sexual reproduction by seeds. We studied transitions between different reproductive stages, to assess the potential ofS. altissimato colonize new habitats by seed, and the influence of annual mowing on the dynamics of seeds and juvenile plants.

2The dispersal of the numerous achenes, their subsequent fate on and in the soil, and the growth and survival of seedlings and juvenile plants were followed from 1988 to 1990 in an old‐field population.

3The seed rain was 49 000 seeds m−2per annum in unmown and 1800 seeds m−2per annum in adjacent mown plots. Survivorship and germinability of seeds in the soil decreased rapidly in the first 3 months after dispersal. Thereafter the declines were much slower. Germination within the established vegetation was very rare: only 12 out of 150 000 experimentally sown seeds (0.008%) became seedlings.

4The survival and growth of seedlings transplanted into closed vegetation increased with age and developmental stage. Nevertheless, no transplants flowered during the 24 months over which their fate was followed.

5Mowing affected neither seed survival nor germinability, nor did it have any effect on the growth, survival and reproduction of seedlings or juvenile plants.

6The creation of 1‐m2openings in the vegetation strongly increased the number of emerging seedlings. Production of achenes was high (c. 20 000 per sexual shoot) and seed rain data suggested that 80–90% of all seeds may have been dispersed outside the study area. The colonization of nearby open sites is therefore quite probable.

7Thus, mowing in late summer to control the growth ofS. altissimadoes not provide opportunities for further seedling establishment in existing populations and may prevent the colonization of new sites by reducing seed supply from the source population.
Herbivory and ramet performance in the clonal herb Trientalis europaea L.
Authors: Piqueras Jesus
Published: March 2003

1 The intensity of leaf damage caused by invertebrate herbivores and grazing by vertebrates and their effects on clonal growth, survival and reproduction were examined in a population of the forest herb Trientalis europaea during 4 years.

2 Levels of herbivory were low and varied between years in the studied population. Larger ramets were exposed to a greater risk of both grazing and leaf defoliation. Ramets that suffered leaf damage in 1 year experienced an increased probability of leaf damage in succeeding years. The probability of suffering herbivore attack was independent among the ramets belonging to the same clonal fragment, suggesting that clonal propagation might operate as a risk‐spreading strategy in this species.

3 Leaf damage did not affect any measure of plant performance, probably due to the low amounts of leaf area removed by invertebrate herbivores. In contrast, vertebrate grazing affected all phases of the pseudo‐annual life cycle of T. europaea. Grazing prevented flowering and fruiting, increased ramet mortality during summer and decreased tuber production. Furthermore, grazed ramets produced shorter stolons and smaller tubers, which in turn had a lower winter survival and produced smaller ramets in the following growing season. The large impact of grazing was due to the consumption of the whole of the single shoot of ramets of T. europaea. Although regrowth was possible, secondary shoots were significantly smaller and assimilation was delayed.

4 Tubers originating from grazed ramets were placed shallower than tubers from ungrazed ramets. This could be due to an alteration in the growth pattern of stolons of the grazed ramets.
Vegetation characteristics and primary productivity along an arctic transect: implications for scaling‐up
Authors: Williams Mathew , Rastetter Edward B.
Published: March 2003

1  Arctic terrestrial ecosystems, which are important components of the global carbon (C) cycle, are expected to undergo considerable future climate change. However, predicting arctic C budgets is complex because the landscape is highly diverse and plant biomass very variable.

2  We investigated the diversity of vegetation at 14 sites along an arctic transect in northern Alaska, including sites on wet coastal tundra, tussock tundra, heath and shrub tundra. We applied these data to a model of the soil–plant–atmosphere (SPA) continuum, to investigate how variations in vegetation structure might affect landscape patterns of gross primary productivity (GPP).

3
 Although the dominant species varied, there was a highly significant relationship for vascular plants between the leaf area index (LAI) and total foliar nitrogen (N; g m–2 ground area) at each site.

4  A modelled response surface of GPP to changes in both N and LAI indicated that for tundra plants there is an almost constant ratio between the sensitivity of productivity to the two variables.

5  The conservative nature of canopy LAI–N ratios simplifies the task of generating regional predictions of C assimilation by vascular plants (for which LAI and N are key requirements) because measurements of LAI can be used to infer N.

6  Spatial and temporal patterns of LAI and N must be determined if the photosynthetic component of regional C budgets is to be modelled accurately for diverse arctic ecosystems. Patterns of solar irradiance, together with air temperature and soil moisture constraints, are also influential but less important. The contribution of bryophytes must be accounted for as well.
Seed mass and the competition/colonization trade‐off: a sowing experiment
Authors: Turnbull Lindsay A. , Rees Mark , Crawley Michael J.
Published: March 2003

1  A seed‐addition experiment using seven co‐occurring annual plant species with a range of seed masses was carried out in a limestone grassland in South Wales.

2  If seedlings compete for establishment sites, then large seed size may confer enhanced competitive ability. However, the simple reciprocal relationship found between seed mass and per capita seed output showed that species producing larger seeds suffer reduced fecundity. Seed size may therefore act as a surrogate in a competition/colonization trade‐off.

3  Equal numbers of seeds of all species were sown in a mixture over a range of densities. As sowing density increases, all species should reach a higher proportion of the available microsites. If large‐seeded species are the best competitors they are expected to win all the sites they reach, and hence to occupy an increasing proportion of sites as sowing density increases.

4  The three species with the largest seeds made up 49% of individuals at low‐density sown plots but 83% of individuals in high‐density sown plots. In addition, seed mass and plant density were not correlated in unsown plots, but were strongly correlated in high‐density sown plots. However, all small‐seeded species maintained a presence in sown plots.

5  Although species were sown at random with respect to one another, individuals were up to five times more likely than expected to have a conspecific as a nearest neighbour. This could be caused by interspecific competition and/or by environmental heterogeneity that favours different species in different patches.

6  The results suggest that seedlings do compete for establishment sites and that large‐seeded species generally win when in direct competition. In unsown areas small‐seeded species win many sites by forfeit (because large‐seeded species are strongly recruitment limited) but there may be a restricted subset of potential sites for which they are the best competitors and which they can win outright.
Pattern and process in south Swedish forests during the last 3000 years, sensed at stand and regional scales
Authors: Lindbladh Matts , Bradshaw Richard , Holmqvist Björn H.
Published: March 2003

1 Two palaeoecological data sets were used to study forest development in the boreo‐nemoral zone of southern Sweden during the last 3000 years. Maps of forest types present in 1250 bc, ad 500 and today were compiled from regional pollen data and these were compared with 16 stand‐scale pollen analyses.

2 The forest type maps showed a transition from mixed deciduous forest to coniferous forest consisting chiefly of Picea and Pinus. The stand‐scale studies recorded the same general development despite site‐specific trends. A detrended correspondence analysis displayed the successional trends of the stand‐scale sites. All stands moved away from the rich deciduous forest represented by Alnus, Corylus, Quercus and Tilia via Betula and Carpinus to Picea and Pinus forest or, in two stands, to Fagus forest.

3 A rate of change analysis covering the last 3000 years showed that the changes recorded from the last 150 years were the most rapid, but represented the culmination of a transformation that was initiated 850 years earlier. These recent changes completely overshadowed the previous record.

4 The regional maps recorded relatively high proportions of Pinus in the eastern part of the study area throughout the period under investigation. The stand‐scale studies indicated that this area had a high fire frequency, while the relatively recent increase in Pinus in south‐west Sweden was better explained by anthropogenic influences. The stand‐scale data suggested that the regional role of Pinus had been overestimated in southern Sweden

5 Corylus, Quercus and Tilia were the major species in the former forests, but began a slow decrease in importance around ad 700. The increasing cereal pollen record was related to the decline of the deciduous forest component, suggesting that anthropogenic activity has been the major driving force in its loss.

6 The combination of regional‐ and stand‐scale studies has provided new insights into forest pattern and process. The local records capture the essential features of the regional record of vegetation history, record forest composition more faithfully than regional sites, and additionally yield insight into processes such as fires that have a regional significance.
Modelling and analysis of peatlands as dynamical systems
Authors: Hilbert David W. , Roulet Nigel , Moore Tim
Published: March 2003

1 A general model of peatland dynamics is presented that emphasizes the interaction between water table depth and peat production. The model consists of two coupled, non‐linear differential equations representing change in depth of peat and depth to the water table. Several simplified models are also considered to show the logical development of this model from previously published ones. The model provides an integrated view of how peatlands function over long time scales, by focusing on the non‐linear interactions among peat production, decomposition and hydrology.

2 Analysis of the model shows that equilibrium peat accumulation and water table depth depend on the net water input to the peatland. In drier sites, peatlands with relatively deep water tables develop and the equilibrium peat depth increases with increasing water input. In very wet conditions, peatlands have water tables near the surface, peat accumulation is limited by low production rates, and equilibrium peat depth is lower than is possible in comparatively drier sites. Over a range of intermediate water balances, there are two simultaneous equilibrium states where deep, dry peatlands and shallower, wet peatlands can both occur. This sensitivity to water balance suggests that small changes in precipitation regime, such as are expected with climate variability and change, could rapidly convert peatlands that are now in equilibrium into either sources or sinks of carbon.
Short‐term effects of cyclone impact and long‐term recovery of tropical rain forest on Kolombangara, Solomon Islands
Authors: Burslem D. F. R. P. , Whitmore T. C. , Brown G. C.
Published: March 2003

1 We evaluate the effects of large‐scale disturbance on tropical tree communities by examining the population dynamics of all individuals > 4.9 cm in diameter at breast height (d.b.h.) of 12 tree species over 30 years (1964–94) in lowland tropical rain forest on Kolombangara, Solomon Islands.

2 During the study period Kolombangara was struck by four cyclones between 1967 and 1970. The last cyclone caused most damage to canopy structure. Mortality in the 6‐month interval spanning the first cyclone was 7.0% of all trees, while mean annual mortality for all other intervals (including those spanning other cyclones) was 1.4–2.2% year−1. Mortality varied between species but was independent of topography and geographical location.

3 Recruitment increased from very low rates (median 0.0% year−1) before the first cyclone to median values of 1.6–3.2% year−1during 1971–79, i.e. following a lag period of 3.5–8 years after the first cyclone. Recruitment rates were higher on plots showing greater mortality rates during this cyclone. Recruitment and mortality rates were still higher in 1994 than they had been before the 1967–70 cyclones.

4 Mean annual mortality rates were positively correlated with mean annual recruitment rates across species. This relationship reflects a continuum of life‐history characteristics and contributes to constancy in the relative abundance of the 12 species when the same sets of plots are compared over all measurement intervals up to 30 years.

5 We conclude that cyclone impacts have only short‐term effects on the relative abundance of common tree species on Kolombangara, and do not therefore prevent the establishment of an equilibrium rank abundance hierarchy or create spatial variation in tree species composition. Differences in forest composition across Kolombangara are more likely to have been caused by differential anthropogenic disturbance linked to settlement patterns.
Effects of elevated carbon dioxide and increased nitrogen deposition on bog vegetation in the Netherlands
Authors: Heijmans Monique M. P. D. , Berendse Frank , Arp Wim J. , Masselink Ab K. , Klees Herman , De Visser Willem , Van Breemen Nico
Published: March 2003

We studied the effects of elevated atmospheric CO2and increased N deposition on the plant species composition of aSphagnum‐dominated bog ecosystem in the Netherlands. Large peat monoliths (surface area 1 m2, depth 0.6 m) with intact bog vegetation were kept outdoors in large containers and were exposed to elevated CO2or increased N deposition for three growing seasons. Elevated CO2conditions (target concentration 560 µmol CO2 mol−1) were created using MiniFACE technology. In a separate experiment, N deposition was increased by 5 g N m−2year−1by adding dissolved NH4NO3at 3 week intervals during the growing season.

 Elevated atmospheric CO2increased height growth ofSphagnum magellanicum, the dominantSphagnumspecies, in the second and third growing seasons. Vascular plant biomass was not significantly affected by elevated CO2, but growth of species growing close to the moss surface was influenced negatively by the increasedSphagnumheight growth. Elevated CO2did not change allocation to below‐ground plant parts.

 Adding N increased above‐ground vascular plant biomass. The shallow‐rooted speciesVaccinium oxycoccusresponded most to the increased N deposition.Sphagnumgrowth was significantly reduced in the third growing season. This reduction was likely the result of the increased vascular plant cover, given the observed negative relation between vascular plant cover andSphagnumgrowth.

 The observed shifts in species composition as a result of species‐specific responses to treatments, and interactions between peat mosses and vascular plants will have important consequences for the sequestration of carbon in the bog ecosystem.
Competitive effects of grasses and woody plants in mixed‐grass prairie
Authors: Peltzer Duane A. , Köchy Martin
Published: March 2003

Variation in the competitive ability of plant species may determine their persistence and abundance in communities. We quantified the competitive effects of grasses and woody plants in native mixed‐grass prairie on the performance of transplant species and on resources.

 We separated the effects of grasses, shrubs and intact vegetation containing both grasses and shrubs by manipulating the natural vegetation using selective herbicides to create four neighbourhood treatments: no neighbours (NN), no shrubs (NS), no grasses (NG) and all neighbours (AN). Treatments were applied to 2 × 2 m experimental plots located in either grass‐ or shrub‐dominated habitats. The effects of grasses and shrubs on resource availability (light, soil moisture, soil available nitrogen) and on the growth of transplants ofBouteloua gracilis, a perennial tussock grass, andElaeagnus commutata, a common shrub, were measured over two growing seasons.

 Resource availability was two‐ to fivefold higher in no neighbour (NN) plots than in vegetated plots (NS, NG, AN) with grasses and shrubs having similar effects. Light penetration declined linearly with increasing grass or shrub biomass, to a minimum of about 30% incident light at 500 g m−2shoot mass. Soil resources did not decline with increasing neighbour shoot or root mass for either grasses or shrubs, suggesting that the presence of neighbours was more important than their abundance.

 Transplant growth was significantly suppressed by the presence of neighbours, but not by increasing neighbour shoot or root biomass, except for a linear decline inBoutelouagrowth with increasing neighbour shoot mass in plots containing only shrubs. Competition intensity, calculated as the reduction in transplant growth by neighbours, was similar in both grass‐ and shrub‐dominated habitats for transplants ofBouteloua, but was less intense in shrub‐dominated habitats for the shrubElaeagnus. Variation in the persistence and abundance of plants in communities may therefore be more strongly controlled by variation in the competitive effects exerted by neighbours than by differences in competitive response ability.
Grazing history versus current grazing: leaf demography and compensatory growth of three alpine plants in response to a native herbivore (Ochotona collaris)
Authors: McIntire Eliot J. B. , Hik David S.
Published: March 2003

1 We measured leaf births, leaf deaths and leaf length of three alpine perennial species, Kobresia myosuroides, Erigeron humilis and Oxytropis nigrescens, from sites with different grazing histories (strong or weak) in response to two levels of current season grazing (present or absent) by collared pikas (Ochotona collaris), a small lagomorph, in the south‐west Yukon.

2 All three species appeared to tolerate the removal of 58–61% of summer leaf production under natural conditions. Grazing history, which was defined by the location of plants located either < 2 m or > 6 m from boulderfields with a history of occupation by pikas, was the most significant factor determining shifts in leaf births and leaf deaths following herbivory.

3 The only detectable influence of current season herbivory for any measured species was a reduction of leaf length of Kobresia.

4 A comparison of historically grazed with historically ungrazed plants indicated several changes in leaf demography and morphology. Kobresia leaves were generally shorter and had higher rates of production of new leaves. Oxytropis had higher rates of new leaf production. Erigeron had fewer leaf births throughout the summer, but showed a large and highly significant delay in the timing of leaf senescence.

5 These responses can be largely understood as strategies to avoid the predictable intensive late season foraging that is characteristic of pikas. Morphological mechanisms allow these species to tolerate and, more importantly for the herbivore, persist under heavy and chronic grazing.
Pinus sylvestris treeline development and movement on the Kola Peninsula of Russia: pollen and stomate evidence
Authors: Gervais Bruce R. , MacDonald Glen M. , Snyder Jeffrey A. , Kremenetski Constantine V.
Published: March 2003

A sediment core recovered from Poteryanny Zub Lake on the Kola Peninsula of Russia (68°48′91″ N, 35°19′32″ E) provides fossil pollen and stomate evidence for Pinus sylvestris treeline development and movement. The site today lies in birch forest tundra, approximately 25 km north of the pine treeline and 90 km south of the Murman Coast.

The record begins approximately 10 050 14C years before present (bp). The post‐glacial tundra, typified by various herbaceous taxa and Artemisia, was followed by Betula‐dominated woodland forest with Polypodiaceae‐Gramineae pollen types. Such vegetation assemblages are not analogous to any in the western Kola Peninsula today.

Stomate evidence demonstrates that Pinus sylvestris immigrated to the study site as early as 8150 14C bp. Pine forest probably expanded northwards from sparse or small disjunct populations, which established c. 1000 14C bp before the expansion evident in the pollen and wood macrofossil records (7200 14C bp). Betula and other shrub and herb taxa declined at this time, possibly as a result of shading by the pine canopy.

The presence of fossil Pinus sylvestris stomates and wood, together with AP : NAP ratios, indicates that the pine treeline was some 100 km north of its present position by the end of the middle Holocene warming (7000–6000 14C bp). This places it near the Barents Sea coast, currently tundra vegetation. An approximate 2 °C increase in regional summer temperatures would be necessary to move the treeline to the present‐day coastline.

From 6000 14C bp the pine treeline gradually retreated southward to its present modern position. Birch woodland has grown at the site since c. 3000 14C bp.
Tree‐life history prior to death: two fungal root pathogens affect tree‐ring growth differently
Authors: Cherubini Paolo , Fontana Giovanni , Rigling Daniel , Dobbertin Matthias , Brang Peter , Innes John L.
Published: March 2003

This paper assesses whether tree‐ring patterns found in recently dead mountain pines (Pinus mugo Turra) infected by Armillaria spp. differ from those infected by Heterobasidion annosum, and determines whether and to what extent tree rings may be used as indicators of tree‐decline history (i.e. tree health conditions in relation to disease history) prior to death.

Dendroecological and phytopathological analyses were undertaken in the Swiss National Park. The calendar year of death of the standing dead trees was determined by cross‐dating ring‐width patterns of dead trees to reference chronologies from living trees. This procedure is not, however, exact as there may be multiple intermittent missing rings.

A remarkable discrepancy (up to 31 years) was found between the tree‐death year estimated through crown condition assessment (i.e. the presence or lack of green needles) and the date of the outermost tree ring (when tree‐ring production ceased). New needles may form and existing ones remain green for some years after the cambium at different heights along the stem has ceased activity and no new wood cells are being formed.

Ring‐patterns in trees infected by Armillaria differ from those in trees infected by H. annosum. All dead trees infected by Armillaria had a slow growth decrease indicating suppression for several decades, and suggesting that Armillaria attacked trees that were already weakened by competition. In contrast, trees infected by H. annosum died over a very short period of time, although they may have been infected a long time previously. Nevertheless H. annosum seems to infect and kill trees directly , whereas Armillaria, at this site, is a secondary pathogen.

This study demonstrates that tree rings may be used as indicators of the history of tree decline prior to tree death. However, the history of tree disease is difficult to reconstruct fully, e.g. tree rings do not enable the onset of infection to be dated.
Habitat configuration, species traits and plant distributions
Authors: Dupré Cecilia , Ehrlén Johan
Published: March 2003

In a metapopulation context, the distribution of a species in a patchy landscape is interpreted as the equilibrium outcome of extinction and colonization processes. Populations are thus more likely to occur in larger, better connected habitat fragments.

To test whether metapopulation models explain distribution patterns of plant species with different life histories we investigated the incidence of herbaceous species in deciduous forests in four provinces of south Sweden.

These data were correlated with habitat quality (soil pH, nitrogen mineralization and organic matter) and habitat configuration (patch area and distance to the nearest deciduous forest patch). We also examined whether habitat configuration affected the distribution of species with different life history attributes.

All ground layer plant species at 81 sites were recorded, and distribution patterns of 57 species were tested against seed mass, seed number, presence of a seed bank, plant height, life span, mode of pollination, dispersal mode and habitat preference.

Habitat quality, especially pH, was more important for the incidence of species than habitat configuration with patch area and isolation significantly affecting only 11 and four species, respectively. Species favoured by larger area were also disadvantaged by greater isolation.

The importance of habitat configuration to a species varied with life history. Species that were more negatively affected by patch isolation tended to be habitat specialists and clonal perennials and to produce fewer seeds. Animal‐dispersed species were more negatively affected by small stand size.

Habitat configuration may be less important for vascular plant distributions than habitat quality or the effects of land use history.