bluuebunny/crossref_metadata_2025 huggingface dataset:
Socioeconomic indicators and prosthetic replacement of missing teeth in a working‐age population–Results of the Study of Health in Pomerania (SHIP)
Authors: Mundt Torsten , Polzer Ines , Samietz Stefanie , Grabe Hans Jörgen , Messerschmidt Heidrun , Dören Martina , Schwarz Sabine , Kocher Thomas , Biffar Reiner , Schwahn Christian
Published: February 2009

Abstract – Objectives: To analyse the possible effects of the socioeconomic status (SES) on the prosthetic replacement of missing teeth in working‐age people and to explore the role of potential confounders.

Methods: Cross‐sectional data were collected from 2310 German adults aged 30–59 years. The relationship between each of the three SES indicators (education, income, and occupational status) and dental prostheses were examined by multinomial logistic regression analyses. For that, partially dentate participants with suboptimal and no replacement of missing teeth were compared with partially dentate participants having optimal replacement. Potential confounders (age, sex, dental status, social network and social support) were entered if their inclusion in the model led to ≥10% change in the coefficient of interest.

Results: Social network and social support did not meet the criterion for confounding. In the maxilla, having no replacement was positively associated with lower categories for each of the three SES indicators [Odds ratios (OR) between 1.6 and 2.1; 95% confidence intervals (CI) between 1.1 and 3.4]. Low occupational status was the single predictor for suboptimal dental prostheses (OR = 3.2; 95% CI: 1.6–6.2). In the mandible, occupational status showed no association with the prosthetic status, whereas low educational level and low household income were determinants for having no replacement (OR = 1.9 and 1.9, 95% CI: 1.0–3.5 and 1.1–3.0, respectively). Low household income was the single determinant for suboptimal replacement of missing teeth (OR = 2.4, 95% CI = 1.1–5.2).

Conclusion: The findings may indicate the relevance of the financing of prosthodontic treatment. The strong association between various forms of upper dentures and occupational prestige can be seen as key contributing concept to how individuals′ characteristics affect the outcome in prosthodontic care.
The incidence of idiopathic thrombocytopenic purpura among adults: a population‐based study and literature review
Authors: Abrahamson Page E. , Hall Susan A. , Feudjo‐Tepie Maurille , Mitrani‐Gold Fanny S. , Logie John
Published: February 2009

Published data on the epidemiology of idiopathic thrombocytopenic purpura (ITP) among adults are very limited. We conducted a study of ITP incidence using the General Practice Research Database in the United Kingdom. From 1992 to 2005, there were 840 cases of ITP among adults considering 21 749 623 person‐years (PYs) of follow‐up, for a crude incidence of 3.9 per 100 000 PYs [95% confidence interval (CI): 3.6, 4.1]. The incidence was higher among women [4.5 per 100 000 PYs (95% CI: 4.2, 4.9)] than men [3.2 per 100 000 PYs (95% CI: 2.8, 3.5)]. Among both women and men, incidence was higher at older ages and in later study years. In a systematic review of previously published literature, incidence of ITP among adults ranged from 1.6 to 2.68 per 100 000 persons per year; prevalence ranged from 9.5 to 23.6 per 100 000 persons. In order to improve the understanding of the disease burden of ITP, future studies should include a clearly defined definition of ITP and focus on well‐described source populations that are geographically and ethnically diverse.
In vitro activity of 20 agents in different prognostic subgroups of chronic lymphocytic leukemia – rolipram and prednisolone active in cells from patients with poor prognosis
Authors: Lindhagen Elin , Norberg Maria , Kanduri Meena , Tobin Gerard , Säisänen Laura , Åberg Magnus , Gustafsson Mats G. , Sundström Christer , Rosenquist Richard , Åleskog Anna
Published: February 2009

Background:  There is a need for development of new drugs for treatment of B‐cell chronic lymphocytic leukemia (CLL), especially for poor‐prognostic subgroups resistant to conventional therapy.

Objective:  The in vitro antileukemic activity of 20 different anticancer agents was characterized in tumor cells from CLL, aiming at identifying agents active in poor‐prognostic subgroups.

Design and methods:  In tumor cells from 40 CLL patients and in peripheral blood mononuclear cells (PBMC) from three healthy controls, the activity of 20 substances was assessed using a non‐clonogenic assay. The CLL samples were characterized regarding genomic aberrations by interphase fluorescence in situ hybridization and immunoglobulin heavy‐chain variable (IGHV) gene mutational status.

Results:  In line with clinical experience, cells from patients with unfavourable genomic aberrations [del(11q)/del(17p)] showed lower drug sensitivity to fludarabine and chlorambucil than cells from patients with favourable cytogenetics [del(13q)/no aberration]. Most investigated drugs demonstrated similar activity in CLL cells from patients with unmutated and mutated IGHV genes as well as in CLL cells vs. PBMC. Interestingly, prednisolone and rolipram displayed high CLL specificity, high activity in CLL cells with unmutated IGHV genes and retained the effect in several cases with 11q/17p deletion. Further studies on prednisolone and rolipram revealed a synergy when these agents were combined in CLL cells, and suggested correlation between drug sensitivity and difference in downstream signaling.

Conclusion:  Prednisolone and rolipram are interesting for further studies in CLL with inferior prognosis. The study can also be considered a basis for future efforts to find drugs active in subsets of CLL patients that are resistant to conventional therapy.
Memory keeps you at home: a mechanistic model for home range emergence
Authors: Van Moorter Bram , Visscher Darcy , Benhamou Simon , Börger Luca , Boyce Mark S. , Gaillard Jean‐Michel
Published: February 2009

Despite its central place in animal ecology no general mechanistic movement model with an emergent home‐range pattern has yet been proposed. Random walk models, which are commonly used to model animal movement, show diffusion instead of a bounded home range and therefore require special modifications. Current approaches for mechanistic modeling of home ranges apply only to a limited set of taxa, namely territorial animals and/or central place foragers. In this paper we present a more general mechanistic movement model based on a biased correlated random walk, which shows the potential for home‐range behavior. The model is based on an animal tracking a dynamic resource landscape, using a biologically plausible two‐part memory system, i.e. a reference‐ and a working‐memory. Our results show that by adding these memory processes the random walker produces home‐range behavior as it gains experience, which also leads to more efficient resource use. Interestingly, home‐range patterns, which we assessed based on home‐range overlap and increase in area covered with time, require the combined action of both memory components to emerge. Our model has the potential to predict home‐range size and can be used for comparative analysis of the mechanisms shaping home‐range patterns.
Experimental evidence of cost of lactation in a low risk environment for a long‐lived mammal
Authors: Bårdsen Bård‐Jørgen , Fauchald Per , Tveraa Torkild , Langeland Knut , Nieminen Mauri
Published: February 2009

In a previous experiment we have documented that organisms adopt a risk‐sensitive reproductive allocation when summer reproductive investment competes with survival in the coming winter (Bårdsen et al. 2008). This tradeoff is present through autumn female body mass, which acts as an insurance against unpredictable winter environmental conditions. We tested this hypothesis experimentally on female reindeer experiencing stable and benign winter feeding conditions. Additional supplementary feeding and removal of newborns represented two sets of experimental manipulations. Females in the supplementary feeding group increased more in winter body mass relative to control females. This manipulation, however, did not have any effect on summer body mass development for neither females nor offspring, but we found a positive effect of feeding on offspring birth mass for smaller females. In contrast, offspring removal did have a positive effect on summer body mass development as females in this group were larger in the autumn relative to control females. In essence, we documented two immediate effects as: (1) supplementary feeding did have a positive effect on spring body mass for smaller females; and (2) offspring removal did increase the female summer somatic growth as this had a positive effect on female autumn body mass. Additionally, we tested for lagged effects, but we could not document any biologically significant effects of neither manipulation in the coming spring. The fact that we only found rather weak effects of both manipulations was as expected for risk sensitive individuals experiencing benign environmental conditions over many years.
Blood flow measurements at different depths using photoplethysmography and laser Doppler techniques
Authors: Bergstrand Sara , Lindberg Lars Göran , Ek Anna‐Christina , Lindén Maria , Lindgren Margareta
Published: February 2009

Background/purpose: This study has evaluated a multi‐parametric system combining laser Doppler flowmetry and photoplethysmography in a single probe for the simultaneous measurement of blood flow at different depths in the tissue. This system will be used to facilitate the understanding of pressure ulcer formation and in the evaluation of pressure ulcer mattresses.

Methods: The blood flow in the tissue over the sacrum was measured before, during and after loading with 37.5 mmHg, respectively, 50.0 mmHg. The evaluation of the system consisted of one clinical part, and the other part focusing on the technicalities of the probe prototype.

Results: An increase in blood flow while loading was the most common response, but when the blood flow decreased during loading it was most affected at the skin surface and the blood flow responses may be different due to depths of measurement. Reactive hyperaemia may occur more frequently in the superficial layers of the tissue.

Conclusion: The study showed that the new system is satisfactory for measuring tissue blood flow at different depths. The laser Doppler complements the photoplethysmography, and further development of the system into a thin flexible probe with the ability to measure a larger area is required.
Facial Sweet syndrome mimicking photoallergic contact dermatitis
Authors: Johannemann Diana , Brunner Martina , Zouboulis Christos C.
Published: February 2009

Sweet syndrome (acute febrile neutrophilic dermatosis) usually presents with painful erythematous plaques, malaise, and fever. Histologically skin infiltration with neutrophils is characteristic. The etiology of the disease is unknown. Sweet syndrome can be subdivided into the classical form, which is usually idiopathic and is associated with some kind of inflammation, the paraneoplastic form and the drug‐induced one. We present the unusual case of an 83‐year‐old woman who appeared to have facial photoallergic contact dermatitis but turned out to have facial Sweet syndrome.
Physical sunscreens with high sun protection factor may cause perioral dermatitis in children
Authors: Abeck Dietrich , Geisenfelder Birgitt , Brandt Oliver
Published: February 2009

Perioral dermatitis is common in children and, if untreated, characterized by a chronic course lasting for months. Provocation factors known for adults, especially topical or inhaled corticosteroids, are relevant in children as well. We present eight children – all of them with dry skin – who developed perioral dermatitis after using sunscreens based on micropigments. This suggests that children with dry skin are at increased risk for perioral dermatitis. A history of sunscreen use should be specifically sought in children with perioral dermatitis.
Recombinase‐activating gene 1 immunodeficiency: different immunological phenotypes in three siblings
Authors: Pasic Srdjan , Djuricic Slavisa , Ristic Goran , Slavkovic Bojana
Published: February 2009

We report different immunological phenotypes in three siblings from consanguineous family with recombinase‐activating gene 1 (RAG1) gene mutations. Null mutations of RAG genes result in severe combined immunodeficiency (SCID) with absent T and B cells. Hypomorphic mutations with retained activity of RAG genes may lead to a ‘leaky’ SCID with some features of Omenn syndrome (OS) or typical OS. In our three patients, homozygous, hypomorphic RAG1 gene mutation (g.368–369delAA) was detected. Two patients presented with T−B−SCID phenotype while the youngest patient developed T+B+NK+SCID phenotype with expansion of autologous T‐cell receptor (TCR) γδ‐positive T cells, increased immunoglobulin levels and retained ability for antibody production. Similar to originally reported patients with this newly recognized immune phenotype, our patient developed disseminated cytomegalovirus (CMV) infection and autoimmune cytopenia.

Conclusion: In infants with disseminated cytomegalovirus infection and autoimmune cytopenia, even if basic immunologic investigation appears normal, RAG1 immunodeficiency should be considered.
Relative competitive performance of 63 species of terrestrial herbaceous plants
Authors: Keddy P. , Nielsen K. , Weiher E. , Lawson R.
Published: February 2009

Abstract. There is growing evidence that plant and animal species are arranged in hierarchies of relative competitive performance. More work is needed to determine which plant traits best predict relative competitive performance. We therefore measured relative competitive performance of 63 terrestrial herbaceous plant species using Trichostema brachiatum as a reference species (that is, phytometer or target species). The neighbour species came from a wide array of terrestrial vegetation types (e.g. rock barrens, alvars, old fields), and represented a wide array of growth forms (e.g. small rosette species such as Saxifraga virginiensis and large clonal graminoids such as Agropyron repens). The experiment was repeated with two pot sizes: large (control) and small (stress treatment). Relative competitive performance in large pots (controls) was highly correlated with that in small pots (stress treatment) (r= 0.90, p < 0.001). The hierarchy of relative competitive performance in the large pots was also highly correlated with the hierarchy in the small (stressed) pots (rs= 0.91, p < 0.001). Principal components analysis and multiple linear regression showed that plant size (measured by total biomass, above‐ground biomass, below‐ground biomass, canopy area, height and leaf area index) and leaf shape (measured as length to width ratio, length, width) were the two characteristics that best predicted relative competitive performance (large pots, r2= 0.55; small pots, r2= 0.48).
The influence of altitude on the distribution of subterranean organs and humus components in Vaccinium myrtillus carpets
Authors: Frak Elzbieta , Ponge Jean‐François
Published: February 2009

Abstract. Humus profiles were sampled along an altitudinal gradient in the Macot‐La‐Plagne Forest (France, northern Alps) to investigate variation occurring under carpets of Vaccinium myrtillus present within Picea abies forests. The vertical distribution of subterranean organs of V. myrtillus was compared with (1) that of P. abies roots and other accompanying vegetation and (2) other components of humus profiles, in particular humified organic matter mainly consisting of animal faeces. It was shown that V. myrtillus roots were mostly concentrated in mineral horizons, while P. abies roots and V. myrtillus rhizomes occupied litter horizons. This was interpreted in terms of competition for nutrient capture between P. abies and V. myrtillus. The effects of altitude were (1) a change in the vegetation accompanying V. myrtillus in dense V. myrtillus carpets, bryophytes at the montane level being replaced by forbs at the sub‐alpine level and (2) a decrease in the thickness of ecto‐organic horizons. This was interpreted as a shift from a moder system characterized by recalcitrant litter (moss) processed by an active faunal community (stabilized in the form of animal faeces) to a mor system characterized by low animal abundance but with litter of better quality which is easily leached in the absence of prominent faunal activity.
Seedling establishment of deciduous trees in various topographic positions
Authors: Nagamatsu Dai , Seiwa Kenji , Sakai Akiko
Published: February 2009

Abstract. We investigated the effect of topography‐related environmental factors (i.e., ground‐surface stability and soil moisture) on seedling establishment of 8 deciduous tree species. A field experiment was carried out using canopy species, which were classified into 3 groups based on the spatial distribution of adult trees (ridge, slope and valley). Demographic parameters were compared among species during the early stage of seedling establishment among 3 topographic positions in combination with gap and canopy conditions. The percentage of emerging seedlings tended to be lower on the ridge irrespective of the adult topographical distribution patterns. There was no clear trend in seedling emergence among the species groups classified by their spatial distribution. Seedling survival during 2 growing seasons was significantly different among species, topographic positions and light conditions. On the ridge, seedlings of the species dominating ridge tops had greater survival than those of other species, probably due to differences in demand for soil moisture. On the slope, frequent physical damage caused by surface material movement was observed and some species showed greater adaptability to the disturbed slope habitat. Survival of all seedlings was highest in the valley plots. Light conditions were the critical factor for seedling survival in some species. The results of this study suggest that topography creates diverse habitats for the establishment of tree seedlings. In addition to soil moisture, surface material movement may be a significant factor affecting seedling establishment.
Alternative stable states in a wet calcareous dune slack in The Netherlands
Authors: Adema Erwin B. , Grootjans Ab P. , Petersen Jörg , Grijpstra Johan
Published: February 2009

Abstract. Evidence is presented for the occurrence of alternative stable states in a wet calcareous dune slack on the Frisian island of Texel, The Netherlands. An early pioneer stage (0.5 kgm−2 total standing crop) and a more productive later successional stage (2.9 kg m−2) occur side by side, with sharp boundaries between them. The pioneer vegetation has been recorded at the site for more than 62 yr. These features indicate the occurrence of a positive‐feedback mechanism that has led to alternative stable states.

Analyses of ground and surface water composition, and decalcification depths, indicated that hydrologically the study site can be characterized as a flow‐through slack, with exfiltration of calcareous groundwater on one side and infiltration of surface water on the other side of the slack. These differences in hydrological conditions have led to distinct differences in environmental conditions within the dune slack. The occurrence of the two successional stages can, however, not be explained by differences in hydrological conditions since both stages occur side by side in the centre of the dune slack. It is, therefore, more likely that biotic interactions are the cause of the vegetation pattern. Three possible mechanisms for feedback processes are discussed: (1) enhanced nitrogen loss; (2) sulfide toxicity and (3) nutrient accumulation in internal cycle.
The role of spatio‐temporal heterogeneity in the establishment and maintenance of Suaeda maritima in salt marshes
Authors: Tessier Marc , Gloaguen Jean‐Claude , Bouchard Virginie
Published: February 2009

Abstract. The effects of disturbance and microtopography on the organization and dynamics of plant communities were studied in a European salt marsh located in the Bay of Mont St. Michel, France. The existence of seed trapping mechanisms was also tested. The study took place in the lower and middle marsh plant communities dominated by the perennials Puccinellia maritima and Halimione portulacoides, respectively and associated with the annual Suaeda maritima. Three treatments were used in series of plots placed in each community: (1) vegetation removal and root destruction to a depth of 10 cm and refilling, (2) non‐remnant herbicide treatment without vegetation removal and (3) creation of depressions (20 cm deep). These treatments were compared with adjacent control plots. The first year of the experiment showed that the perennials facilitated the establishment of Suaeda by trapping its seeds. Estimation of cover, density and biomass over 5 yr following the disturbances showed that in the first 2 yr Suaeda dominated the disturbed plots. Thereafter Suaeda was gradually eliminated by competitive exclusion after ca. 3 yr in the zone originally dominated by Puccinellia maritima and after 4 yr in the zone occupied by Halimione portulacoides. Depressions constituted refuge habitats for Suaeda by limiting competition with the perennials but also led to a high risk of mortality with temporal fluctuations in density. Despite a period of investigation limited to 5 yr, our study demonstrated that natural disturbances of various types occurred and influenced the dynamics of Suaeda, Halimione and Puccinellia. We deduced that natural disturbances and microtopography are responsible for the maintenance of the habitat in a state of non‐equilibrium by favouring the establishment of both spatial and temporal environmental heterogeneity. These conditions appear to be particularly favourable for the maintenance of annual species such as Suaeda maritima.
Pattern and process in Norwegian upland grasslands: a functional analysis
Authors: Vandvik Vigdis , Birks H. John B.
Published: February 2009

Abstract. Four classes of functional and morphological plant traits – established strategies (the CSR scheme sensu Grime 1979), life‐forms (sensu Raunkiaer 1934), morphology, and regenerative strategies – are used as tools for explaining vegetation gradients at summer farms in the mountains of western Norway. These farms are assembly points for free‐ranging domestic grazers, and differ floristically and ecologically from the surrounding heath or woodland vegetation. DCA and TWINSPAN are used to relate major gradients in a floristic data set from 12 summer farms to two sets of explanatory variables: (1) environmental variables representing physical factors, plot position, soils, and land use, and (2) the 4 classification schemes. The main floristic gradient parallels a spatial gradient from the centres of the farms to the surrounding vegetation. A functional interpretation based on the concurrent use of the 2 sets of explanatory variables suggests that the gradient is one of decreasing disturbance and increasing environmental stress caused by decreasing grazing and manure effects away from farms. Partial CCA is used to investigate the relationships between the 4 functional/morphological plant trait classes. The 4 classification schemes are partially redundant, and do not represent different trends of specialization within the landscape. There is no strong evidence for decoupling of the traits of the vegetative and regenerative phases within the data. The combination of general process‐based theories and specific plant attribute responses enhances the generality and interpretability of the study.
Validation of plant functional types across two contrasting landscapes
Authors: Kleyer Michael
Published: February 2009

Abstract. The validation of plant functional type models across contrasting landscapes is seen as a step towards the claim that plant functional types should recur regionally or even globally. I sampled the vegetation of an urban landscape on a range of sites representing gradients of resource supply and disturbance intensity. A group of plants with similar attributes was considered a ‘functional type’, if the species significantly co‐occurred in a certain segment of the gradient plane of resource supply and disturbance intensity. Vegetative and regeneration traits were considered. A similar study was performed in a nearby agricultural landscape (Kleyer 1999). The logistic regression models from the urban landscape were applied to the data set of the agricultural landscape and vice versa. Although the overall environment of the two landscapes was very different, recurrent patterns of several functional types were found. At high fertility and high disturbance levels, annual species predominated with a persistent seed bank, high seed output, and short vertical expansion. When disturbances changed from below‐ground to above‐ground, the sexual regeneration mode was replaced by the vegetative mode, while vertical expansion remained low. At medium disturbance intensities, the vertical expansion and vegetative regeneration increased with fertility, while the seed bank remained mostly transient to short‐term persistent and lateral expansion and sexual regeneration was intermediate. At low disturbances and low resource supplies, seed bank longevity, and vertical and lateral expansion tended to be long. Diversity of groups of plants with similar attributes was highest at intermediate disturbance levels and low fertility. These results correspond with Grime's humped‐back model and Connell's intermediate disturbance hypothesis.
Effects of regional climate and small‐scale habitat quality on performance in the relict species Ramonda myconi
Authors: Riba M. , Picó F.X. , Mayol M.
Published: February 2009

Abstract. The Mediterranean Basin harbours paleo‐endemic species with a highly restricted and fragmented distribution. Many of them might also be of the remnant type, for which the regional dynamics depends on the persistence of extant populations. Therefore, a key issue for the long‐term persistence of these species is to assess the variability and effects of ecological factors determining plant performance. We investigated the spatio‐temporal variability in plant traits and ecological factors of Ramonda myconi, a preglacial relict species with remnant dynamics, in 5 populations over 4–7 yr.

Ecological factors contributing to fecundity showed a high degree of between‐year variability. Pre‐dispersal fruit predation had a minor influence on total reproductive output, and most of the variability was found among individuals within populations and years. Spatio‐temporal variability in growth and survival was rather low but significant, whereas recruitment showed important between‐population variability. Among‐year variability in fecundity and growth was related to climatic fluctuations on a regional scale, notably rainfall and temperature in a particular period, while the spatial variability in survival and recruitment was explained by within‐population (patch) habitat quality. Although R. myconi is able to withstand repeated periods of drought, water availability seems to be the most important factor affecting plant performance in all the study populations. These findings suggest that the long‐term persistence of species showing remnant population dynamics in habitats under the influence of Mediterranean climate might be threatened by increased aridity as a result of climate change.
Validity of Ellenberg indicator values judged from physico‐chemical field measurements
Authors: Wamelink G.W.W. , Joosten V. , van Dobben H.F. , Berendse F.
Published: February 2009

Abstract.The relationship between mean Ellenberg indicator values (IV) per vegetation relevé and environmental parameters measured in the field usually shows a large variation. We tested the hypothesis that this variation is caused by bias dependent on the phytosociological class. For this purpose we collected data containing vegetation relevés and measured soil pH (3631 records) or mean spring groundwater level (MSL, 1600 records). The relevés were assigned to vegetation types by an automated procedure. Regression of the mean indicator values for acidity on soil pH and the mean indicator values for moisture on MSL gave percentages explained variance similar to values that were reported earlier in literature. When the phytosociological class was added as an explanatory factor the explained variance increased considerably. Regression lines per vegetation type were estimated, many of which were significantly different from each other. In most cases the intercepts were different, but in some cases their slopes differed as well. The results show that Ellenberg indicator values for acidity and moisture appear to be biased towards the values that experts expect for the various phytosociological classes. On the basis of the results, we advise to use Ellenberg IVs only for comparison within the same vegetation type.
Niche characteristics of Danish woody species as derived from coenoclines
Authors: Lawesson Jonas E. , Oksanen Jari
Published: February 2009

Abstract. A main floristic coenocline is extracted from a Danish forest vegetation data set with Detrended Correspondence Analysis. Huisman‐Olff‐Fresco (HOF) modelling of 262 species occurrences relative to site scores along the coenocline is compared with Gaussian and Generalized Linear Modelling. HOF models allow for responses of variously skewed forms, which may result from interspecific interactions. Most species have symmetric (60%) or skewed (29%), and only few species have flat or monotone response curves. This provides evidence for the generality of unimodal plant species response curves, provided the gradient in question comprises a sufficient amount of compositional turnover. The Gaussian niche width is correlated with density of optima and probability of occurrence of the species. Detailed analysis of HOF estimates for 28 woody species indicates that early succession species such as Pinus sylvestris and Populus tremula have wider niches than middle to late successional canopy species such as Alnus glutinosa, Carpinus betulus, Fagus sylvatica, Fraxinus excelsior, Quercus robur and Tilia cordata. A marked overlap in niche range along the coenocline is interpreted in terms of species competition. Rubus idaeus intrudes into the niches of all other shrub species. Several canopy tree species, such as Fagus sylvatica, Fraxinus excelsior and Quercus robur overlap more than 60% of the ranges of all other species, while their internal overlaps are fairly equal, presenting evidence for their likely co‐existence given more natural forest conditions. The combined analysis of coenoclines with HOF modelling of species behaviour is the most robust among the compared methods for estimating model parameters and niche characteristics of plant species. It is recommended for future ecological studies.
BOOK REVIEWS
Authors: Loope Lloyd
Published: February 2009

Brundu, G., Brock, J., Camarda, I., Child, L. & Wade, M. (eds.) 2001. Plant Invasions: Species Ecology and Ecosystem Management.
The carbon balance in natural and disturbed forests of the southern taiga in central Siberia
Authors: Vedrova E.F. , Shugalei L.S. , Stakanov V.D.
Published: February 2009

Abstract. We evaluated the balance of production and decomposition in natural ecosystems of Pinus sylvestris, Larix sibirica and Betula pendula in the southern boreal forests of central Siberia, using the Yenisei transect. We also investigated whether anthropogenic disturbances (logging, fire and recreation pressure) influence the carbon budget. Pinus and Larix stands up to age class VI act as a net sink for atmospheric carbon. Mineralization rates in young Betula forests exceed rates of uptake via photosynthesis assimilation. Old‐growth stands of all three forest types are CO2 sources to the atmosphere. The prevalence of old‐growth Larix in the southern taiga suggests that Larix stands are a net source of CO2. The CO2 flux to the atmosphere exceeds the uptake of atmospheric carbon via photosynthesis by 0.23 t C.ha‐1.yr‐1 (47%). Betula and Pinus forests are net sinks, as photosynthesis exceeds respiration by 13% and 16% respectively. The total carbon flux from Pinus, Larix and Betula ecosystems to the atmosphere is 10 387 thousand tons C.yr‐1. Net Primary Production (0.935 t‐C.ha‐1) exceeds carbon release from decomposition of labile and mobile soil organic matter (Rh) by 767 thousand tons C (0.064 t‐C.ha‐1), so that these forests are net C‐sinks. The emissions due to decomposition of slash (101 thousand tons C; 1.0%) and from fires (0.21%) are very small. The carbon balance of human‐disturbed forests is significantly different. A sharp decrease in biomass stored in Pinus and Betula ecosystems leads to decreased production. As a result, the labile organic matter pool decreased by 6–8 times; course plant residues with a low decomposition rate thus dominate this pool. Annual carbon emissions to the atmosphere from these ecosystems are determined primarily by decomposing fresh litterfall. This source comprises 40–79% of the emissions from disturbed forests compared to only 13–28% in undisturbed forests. The ratio of emissions to production (NPP) is 20–30% in disturbed and 52–76% in undisturbed forests.
A biogeochemistry‐based dynamic vegetation model and its application along a moisture gradient in the continental United States
Authors: Pan Yude , McGuire A. David , Melillo Jerry M. , Kicklighter David W. , Sitch Stephen , Prentice I. Colin
Published: February 2009

Abstract. We develop and evaluate a large‐scale dynamic vegetation model, TEM‐LPJ, which considers interactions among water, light and nitrogen in simulating ecosystem function and structure. We parameterized the model for three plant functional types (PFTs): a temperate deciduous forest, a temperate coniferous forest, and a temperate C3 grassland. Model parameters were determined using data from forest stands at the Harvard Forest in Massachusetts. Applications of the model reasonably simulated stand development over 120 yr for Populus tremuloides in Wisconsin and for Pinus elliottii in Florida. Our evaluation of tree‐grass interactions simulated by the model indicated that competition for light led to dominance by the deciduous forest PFT in moist regions of eastern United States and that water competition led to dominance by the grass PFT in dry regions of the central United States. Along a moisture transect at 41.5° N in the eastern United States, simulations by TEM‐LPJ reproduced the composition of potential temperate deciduous forest, temperate savanna, and C3 grassland located along the transect.
Influence of climate variability on plant production and N‐mineralization in Central US grasslands
Authors: Barrett J.E. , McCulley R.L. , Lane D.R. , Burke I.C. , Lauenroth W.K.
Published: February 2009

Abstract. We assessed the influence of annual and seasonal climate variability over soil organic matter (SOM), above‐ground net primary production (ANPP) and in situ net nitrogen (N) mineralization in a regional field study across the International Geosphere Biosphere Programme (IGBP) North American mid‐latitude transect (Koch et al. 1995). We hypothesized that while trends in SOM are strongly correlated with mean climatic parameters, ANPP and net N‐mineralization are more strongly influenced by annual and seasonal climate because they are dynamic processes sensitive to short‐term variation in temperature and water availability. Seasonal and monthly deviations from long‐term climatic means, particularly precipitation, were greatest at the semi‐arid end of the transect. ANPP is sensitive to this climatic variability, but is also strongly correlated with mean annual climate parameters. In situ net N‐mineralization and nitrification were weakly influenced by soil water content and temperature during the incubation and were less sensitive to seasonal climatic variables than ANPP, probably because microbial transformations of N in the soil are mediated over even finer temporal scales. We found no relationship between ANPP and in situ net N‐mineralization. These results suggests that methods used to estimate in situ net N‐mineralization are inadequate to represent N‐availability across gradients where microbial biomass, N‐immobilization or competition among plants and microbes vary.
Environmental benefits and sustainable land‐use options in the Jambi transect, Sumatra
Authors: Murdiyarso D. , Van Noordwijk M. , Wasrin U.R. , Tomich T.P. , Gillison A.N.
Published: February 2009

Abstract. Loss of environmental services provided by forests is a non‐linear process in Jambi Province, Sumatra, Indonesia. Intermediate‐intensity land‐use types in the form of complex agroforests have maintained global environmental benefits under a sustainable and profitable land use regime. Conversion to tree crop monocultures, however, poses a challenge to the environmental stakeholders and an opportunity from to stakeholders in the private economy. We quantified environmental indicators, as well as profitability and sustainability of a range of existing and possible production systems. Criteria and indicators were used at plot to landscape scales, taking into account local, national and global perspectives. Agronomic sustainability and profitability were assessed at plot level as they are of primarily local concern, while environmental services of forests, such as plant species and functional type richness, carbon stocks, greenhouse gas emissions, and trans‐boundary haze, which are of national and global concern, were assessed at landscape level. Quantitative trade‐offs and complementarities were analysed between global environmental benefits and local profitability. The current trend towards simplification of the complex agro‐ecosystems and inherent loss of environmental services of forests is driven by profitability. The sequence in which environmental services of forests are lost is: standing carbon stocks, biodiversity, and low or negative greenhouse gas emissions.
An international network to monitor the structure, composition and dynamics of Amazonian forests (RAINFOR)
Authors: Malhi Y. , Phillips O.L. , Lloyd J. , Baker T. , Wright J. , Almeida S. , Arroyo L. , Frederiksen T. , Grace J. , Higuchi N. , Killeen T. , Laurance W.F. , Leaño C. , Lewis S. , Meir P. , Monteagudo A. , Neill D. , Núñez Vargas P. , Panfil S.N. , Patiño S. , Pitman N. , Quesada C.A. , Rudas‐Ll. A. , Salomão R. , Saleska S. , Silva N. , Silveira M. , Sombroek W.G. , Valencia R. , Vásquez Martínez R. , Vieira I.C.G. , Vinceti B.
Published: February 2009

Abstract. The Amazon basin is likely to be increasingly affected by environmental changes: higher temperatures, changes in precipitation, CO2 fertilization and habitat fragmentation. To examine the important ecological and biogeochemical consequences of these changes, we are developing an international network, RAINFOR, which aims to monitor forest biomass and dynamics across Amazonia in a co‐ordinated fashion in order to understand their relationship to soil and climate. The network will focus on sample plots established by independent researchers, some providing data extending back several decades. We will also conduct rapid transect studies of poorly monitored regions. Field expeditions analysed local soil and plant properties in the first phase (2001–2002). Initial results suggest that the network has the potential to reveal much information on the continental‐scale relations between forest and environment. The network will also serve as a forum for discussion between researchers, with the aim of standardising sampling techniques and methodologies that will enable Amazonian forests to be monitored in a coherent manner in the coming decades.
JUICE, software for vegetation classification
Authors: Tichý Lubomír
Published: February 2009

Abstract. The program JUICE was designed as a Microsoft® WINDOWS® application for editing, classification and analysis of large phytosociological tables and databases. This software, with a current maximum capacity of 30 000 relevés in one table, includes many functions for easy manipulation of table and header data. Various options include classification using COCKTAIL and TWINSPAN methods, calculation of interspecific associations, fidelity measures, average Ellenberg indicator values, preparation of synoptic tables, automatic sorting of relevé tables, and export of table data into other applications (word processors, spreadsheet programs or mapping packages). JUICE is optimized for use in association with TURBOVEG which is the most widespread database program for storing phytosociological data in Europe.
Present and past old‐growth forests of the Lake Tahoe Basin, Sierra Nevada, US
Authors: Barbour M. , Kelley E. , Maloney P. , Rizzo D. , Royce E. , Fites‐Kaufmann J.
Published: February 2009

Abstract. We described 38 relictual old‐growth stands – with data on the mortality, regeneration, floristic richness, fuel load and disease incidence in our study area in the Tahoe Basin of California and Nevada. The stands are within the lower and upper montane zones (1900–2400 m a.s.l.) and they are rare, occupying < 2% of the land in the Basin's watershed. Correlation matrices and ANOVAs of forest types and conifer species with environmental gradients revealed significant relationships with elevation, distance east of the Sierran crest, slope aspect, annual precipitation, date of complete snow melt, litter depth and degree of soil profile development. Pathogens, parasites and wood‐boring insects were present on 23% of living trees; 16% of all trees were dead. We compared these stands to a reconstruction of pre‐contact Basin forests and to ecologically analogous old‐growth forests of Baja California that have never experienced fire suppression management. Currently, overstorey trees (> 180 yr old) in the Basin stands have ca. 33% cover, 54 m2.ha‐1 basal area and 107 individuals.ha‐1, values very similar to reconstructions of pre‐contact Basin forests and to modern Baja California forests. Understorey trees (60–180 yr old), however, are several times more dense than historic levels and species composition is strongly dominated by A. concolor, regardless of the overstorey composition. The ratio of Pinus: Abies has increased – and the age structure of extant stands predicts that it will continue to increase – from approximately 1:1 in pre‐contact time to 1:7 within the next century. Disease incidence and mortality in Baja forests were lower. Although we quantitatively defined current Basin old‐growth forests – in terms of stand structure – we realize that our definition will differ from that of both past and future old‐growth forests unless management protocols are changed.
Are nutrient availability and acidity‐alkalinity gradients related in Sphagnum‐dominated peatlands?
Authors: Bragazza L. , Gerdol R.
Published: February 2009

Abstract. Gradients in acidity‐alkalinity and nutrient availability were studied in 2 Sphagnum‐dominated peatlands on the southeastern Italian Alps. Decreasing concentrations of most mineral elements (Ca2+, Mg2+, Mn2+, Al3+ and Si4+) in pore water indicated a progressively lower influx of mineral‐soil water from the slightly minerotrophic conditions in the peatland margins to ombrogenous conditions in the central part of the peatlands. This was paralleled by decreasing concentrations of ash, bulk density, Ca, Fe and, partly, Mn in the peat. The nutrient gradient, as defined by pore water concentrations of N and P, was largely independent of the acidity‐ alkalinity gradient: NO3‐ and PO43‐ had similar concentrations throughout the gradient, whereas NH4+ concentrations increased with increasing pore‐water pH. In contrast, the peat nutrient gradient coincided with the acidity‐alkalinity gradient, with total concentrations of N and P decreasing from the margin to the centre. Bryophytes and vascular plants had different responses along the acidity‐alkalinity gradient and the nutrient gradient. Bryophyte distribution reflected the acidity‐alkalinity gradient both in pore water and in peat. Vascular plant distribution was mainly influenced by variations in nutrient availability.
Plant communities of a Central Namib inselberg landscape
Authors: Burke Antje
Published: February 2009

Abstract. Three granite inselbergs and six dolerite dykes and their surroundings were investigated in the Central Namib, at the interface between the Namib Desert and Nama Karoo biomes. The main objectives of this study included a phytoso‐ciological interpretation of the described plant communities, explanation of the correlation of the communities with environmental variables and quantification of the relative contribution of different types of variables to structuring plant communities. Nine grassland and shrubland plant communities were recognized, largely organized according to general habitat, elevation, size of inselberg and geology. Soil properties, often thought to play an important role in arid environments, showed no clear patterns in the level of analyses used in this study. Other environmental parameters of importance in arid mountain habitats, such as slope aspect and angle, also played a minor role. The main implications of the study are: 1. Central Namib inselbergs, particularly granite domes, harbour diverse plant communities, often with species from neighbouring higher rainfall areas, and are thus of high conservation value. 2. The poor contribution of environmental variables in this study, which are conventionally used in field studies of plant community – environment relationships, may demand a critical review of additional parameters to be included when analysing plant community – environment relations in arid environments. In particular between‐season variation, phytogeographic aspects and the heterogeneity of microhabitats, often contained within a plant community, need to be taken into account.
Inherently slow growth in two Caribbean epiphytic species: A demographic approach
Authors: Schmidt Gerold , Zotz Gerhard
Published: February 2009

Abstract. In relation to the drought‐prone and nutrient‐poor habitat, vascular epiphytes are routinely referred to as inherently slow‐growing plants, although actual evidence is rare. To test this notion we measured in situ growth of the understorey orchid Aspasia principissa and the tank bromeliad Vriesea sanguinolenta, and, for the latter species, also the growth under favourable conditions in the greenhouse. Using growth analysis we show: (1) that in an intraspecific comparison, small to intermediate individuals yield the highest relative growth rates (RGR) in situ: A. principissa: 1.6 10–3 d‐1; V. sanguinolenta: 3.3 10–3 d‐1; (2) that the bromeliad reaches maximum size after ca. 15 yr, while the orchid needs at least 20 yr; and (3) small V. sanguinolenta plants exhibit a highly plastic growth response to favourable conditions in the greenhouse, reaching an almost 10‐fold increase in RGR. In spite of a substantial increase in growth under more favourable conditions, our results are consistent with the notion that epiphytes are inherently slow growing organisms.