bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial pattern in the organic layer and tree growth: A case study from regenerating Picea mariana stands prone to paludification
Authors: Lavoie Martin , Harper Karen , Paré David , Bergeron Yves 
Published: February 2009

AbstractQuestions: 1. How does the spatial structure of the organic layer affect tree sapling physiology? 2. Are the organic layer and Picea mariana height growth spatially structured at different scales? 3. Does microtopography influence the accumulation of organic matter and does organic layer thickness affect height growth?Locations: Picea mariana forests, northwestern Quebec, Canada.Methods: We assessed the spatial pattern of each variable in one wildfire site and one harvest site using semivariograms and correlograms. We measured the cross‐correlation between relative elevation and organic layer thickness, and between organic layer thickness and growth using cross‐correlograms.Results: Picea mariana height growth was autocorrelated to a greater extent in the wildfire site (103 m) than in the harvest site (43 m). The spatial structure of organic layer thickness was similar in both sites. Deeper depressions in the harvest site, as illustrated by spatial variance in relative elevation at short distances (ca. 50 m), and by high autocorrelation values, increased the accumulation of organic matter within 20 m.Conclusions: The interaction between microtopography and organic matter accumulation led to paludification and poor growth of Picea mariana at the harvest site. Paludification at the wildfire site was independent of microtopography and was probably a result of stand development.
Integrating ecological features of species in spatial pattern analysis of a plant community
Authors: Pottier J. , Marrs R.H. , Bédécarrats A. 
Published: February 2009

AbstractObjective: This empirical study was designed to explore the role of ecological features of species in the spatial patterning of a grassland community.Location: Banks of the river Rhône in France.Material and Methods: First, we explored the spatial pattern of 29 species recorded in the community using spatial autocorrelation analysis of species cover values. Second, we then explored the relationship between the patterns found and a set of life attributes that characterized the ecological features of species for resource foraging or dispersion. Finally, we explored the spatial relationship of groups of species that shared the same ecological features using cross‐correlation analysis.Results: We found a significant relationship between the spatial pattern and life attributes of the species highlighting three groups of species: (1) species characterized as competitors, reproducing by runner clonal organs and forming large, dense patches; (2) species characterized as competitive‐rud‐erals, dispersing exclusively by seed production and forming small periodic patches; and (3) species classified as CSR, characterized by rosette morphology and short rhizomes as clonal organs without any significant spatial autocorrelation. Spatial segregation was found between group 1 and group 2 up to 14 m; no significant cross‐correlation between groups 1 and 3 between 0 and 3.5 m, and association between groups 2 and 3 up to 14 m.Conclusions: These results helped to understand how species attributes (relative to stature or dispersion abilities); external factors (such as disturbance) and biotic processes (competition) interplay in structuring the plant community under study in space.
Leaf dry matter content and lateral spread predict response to land use change for six subalpine grassland species
Authors: Gross Nicolas , Suding Katharine Nash , Lavorel Sandra 
Published: February 2009

AbstractQuestion: Land‐use change has a major impact on terrestrial plant communities by affecting fertility and disturbance. We test how particular combinations of plant functional traits can predict species responses to these factors and their abundance in the field by examining whether trade‐offs at the trait level (fundamental trade‐offs) are linked to trade‐offs at the response level (secondary trade‐offs).Location: Central French Alps.Methods: We conducted a pot experiment in which we characterized plant trait syndromes by measuring whole plant and leaf traits for six dominant species, originating from contrasting subalpine grassland types. We characterized their response to nutrient availability, shading and clipping. We quantified factors linked with different land usage in the field to test the relevance of our experimental treatments.Results: We showed that land management affected nutrient concentration in soil, light availability and disturbance intensity. We identified particular suites of traits linked to plant stature and leaf structure which were associated with species responses to these environmental factors. Leaf dry matter content separates fast and slow growing species. Height and lateral spread separated tolerant and intolerant species to shade and clipping.Discussion and Conclusion: Two fundamental trade‐offs based on stature traits and leaf traits were linked to two secondary trade‐offs based on response to fertilization shade and mowing. Based on these trade‐offs, we discuss four different species strategies which could explain and predict species distributions and traits syndrome at community scale under different land‐uses in subalpine grasslands.
Tree morphology in seasonally dry montane forest in Argentina: Relationships with shade tolerance and nutrient shortage
Authors: Easdale Tomás A. , Gurvich Diego E. , Sersic Alicia N. , Healey John R. 
Published: February 2009

AbstractQuestion: How does form (leaf and trunk morphology) relate to function (tolerance of shade and nutrient storage) in trees?Location: Los Toldos montane valley in NW Argentina.Methods: We analysed the relationships amongst (1) ten vegetative and four reproductive traits across 40 tree species, (2) a distribution based measure of recruitment under shade and (3) a distribution based measure of recruitment over a soil fertility gradient.Results: Ordinations revealed three main axes of species’ morphological differentiation: (1) evergreen species had leaves with a lower specific leaf area, greater tensile resistance and slower decomposition rate, denser wood and thinner bark than deciduous species; (2) tall tree species that lack spines and are anemochorous were separated from short, spinescent and zoochorous species and (3) species were distinguished according to clonal growth, seed mass and pollination syndromes. Notably, species’ recruitment under shade and over a soil fertility gradient were independent of each other, but both were correlated with species’ scores along the first axis of morphological variation (tolerant species have attributes that favour resource conservation). Different sets of traits were correlated with recruitment under shade and over a soil fertility gradient when traits where assessed individually. Amongst shade tolerant species, recruitment under shade was negatively correlated with species’ maximum height, suggesting differential responses to vertical gradients of light.Conclusions: These results provide new evidence of integration between leaf and stem morphology which is consistent with an evolutionary compromise between high rate of resource acquisition and resource conservation. Generalizations about the functional value of individual morphological characteristics and of ‘strategies’ vary with the resolution of analyses.
Shrub encroachment in the Alps gives rise to the convergence of sub‐alpine communities on a regional scale
Authors: Anthelme Fabien , Villaret Jean‐Charles , Brun Jean‐Jacques 
Published: February 2009

AbstractQuestion: How does Alnus alnobetula colonization affect plant communities in sub‐alpine grasslands undergoing land abandonment on a regional scale?Location: Savoie, French Alps.Methods: Variations within and between communities were monitored in 243 plots within three types of stands representing an A. alnobetula colonization chronosequence from grassland to dense vegetation. They were tested for species richness, species strategies and species distribution through multivariate analysis. Regional variations were assessed at three sites along a rain shadow gradient.Results: We detected a convergence of the understorey communities along an A. alnobetula colonization gradient at all sites, associated with a reduction in species richness and the replacement of stress related strategists by competitor strategists. This convergence was unaffected by the rain shadow gradient although it was a key factor of plant distribution.Conclusions: The dense cover and the soil properties provided by A. alnobetula stands buffered the heterogeneity of sub‐alpine communities induced by a rain shadow gradient throughout the study region. It facilitated the development a homogeneous understorey community dominated by competitor related strategists while excluding grasslands stress adapted species through competition processes. The resulting community, although species‐poor, has an interesting conservation value. Accordingly, as a ‘native invader’, A. alnobetula does not display typical traits of biological invaders. Future experimental research on the interactions between A. alnobetula and components of the understorey would be particularly interesting in a severe environment that promotes facilitation among plants.
Variation in juvenile survival and related physiological traits among dipterocarp species co‐existing in a Bornean forest
Authors: Aiba Masahiro , Nakashizuka Tohru 
Published: February 2009

AbstractQuestion: What environmental factors and physiological traits determine the juvenile survival rates of 11 dipterocarp species (Dipterocarpaceae) co‐occurring in a Bornean tropical rain forest?Location: Tropical northwestern Borneo.Methods: In 248 quadrats, distributed over 12 ha, the juvenile (height< 2.0 m) survival of 11 shade‐tolerant dipterocarp species was monitored for one year. The probability of survival for each species was expressed as a logistic function of plant height and three environmental factors: canopy openness, soil water potential and conspecific individual density. The correlation between survival under shaded conditions and several physiological traits of juveniles was tested by normal Pearson correlation and a phylogeny based manner using independent contrasts.Results: Seven species had increased survival under more open canopies, one species had increased and two species had decreased survival at drier sites. Six species had higher survival as the density of conspecifics increased, whereas two species had lower survival. The magnitudes of the effects for the three environmental factors were similar. However, the interspecific difference in survival was largely determined by a dependence of small seedlings on the light environment. Survival under low light was correlated positively with root dry mass and negatively with total leaf area of juveniles.Conclusions: Responses of seedlings to the fine‐scale gradient of light availability were considerably different among the 11 species. Species that suffered increased mortality under low light had a set of structural traits that would potentially allow rapid growth under bright conditions. Differential performance along the light gradient may contribute to the stable coexistence of these species.
Relationship between size hierarchy and density of trees in a tropical dry deciduous forest of western India
Authors: Bagchi Sumanta 
Published: February 2009

AbstractQuestions: Density dependence is thought to restrict exponential growth as well as give rise to size structure in populations. Size hierarchy in trees from tropical dry deciduous forests is studied to ask (1) whether nature of competition is symmetric or asymmetric and (2) what is the self thinning trajectory under a natural gradient of tree density.Location: Western India.Methods: Density was measured as the number of trees in 10‐m radius circular plots (n= 96) and size was measured at DBH. Size variation was evaluated by the Gini coefficient (n= 1239 trees).Results: Size inequality between neighbours decreased with density but in a non‐linear manner. In the backdrop of existing theory this indirectly suggests that competitive interactions may be symmetric over a ‘depletive’ resource such as below‐ground water (rather than a ‘pre‐emptive’ resource such as light), which is very plausible in a semi‐arid environment. The self thinning coefficient derived from the relationship between stem diameter and density (γ∼−1/4), is higher than expected from existing models of allometric plant growth (γ=−1/3) which are based on above‐ground interactions alone. Seen in conjunction, these results suggest that above‐ground structures, such as stem size, do not adequately represent the outcome of competitive interactions when below‐ground resources, such as water, may be more important under semi‐arid conditions.Conclusions: The non‐linear relationship between size inequality and density indicates that there exists a density threshold beyond which investment in above‐ground biomass becomes sluggish in semi‐arid, deciduous forests. Since current allometric models do not incorporate below‐ground biomass for trees, these data suggest that a more comprehensive allometric growth model may have higher predictive power and wider applicability.
Do vine species in neotropical forests see the forest or the trees?
Authors: Nesheim Ingrid , Økland Rune H. 
Published: February 2009

AbstractQuestions: Is the occurrence of vine species in neotropical rain forests primarily determined by properties of the forest (environmental factors), by properties of the trees (tree species or tree size) or are vines randomly distributed?Location: Maya Biosphere Reserve, Guatemala.Methods: In five 1‐ha plots that span variation from unlogged forest to forest impacted by recurrent human disturbance we recorded the presence of all climbing vine species on every tree. The presence of all free standing vine species and 11 environmental variables were recorded in 100‐m2 subplots. The relationship of host tree diameter and host tree identity on single tree vine species richness was investigated by GLM modelling. Partial redundancy analyses were used to partition the variation in vine species composition on two sources: environmental factors and tree species identity.Results: Single tree vine richness increased with increasing host tree DBH and differed significantly among host species. For climbing vines, the ratio of variation in subplot presence explained by tree species and by environmental variables was ca. 4:1 (in the most disturbed logged plots slightly lower), for free standing vines this ratio varied from 1:2 in the most disturbed logged plots to 9:1 in reserve plots, while a ratio of ca. 1:1 was found for all plots analysed together.Conclusion: Different tree species have different probabilities of being infested by vines. Vines see both the forest and the trees; the environment is more important in earlier developmental stages, properties of individual trees become more important from the time vines start to climb.
Predicting future community composition from random soil seed bank sampling – evidence from a drained lake bottom
Authors: Bossuyt Beatrijs , Van Wichelen Jeroen , Hoffmann Maurice 
Published: February 2009

AbstractQuestions: What is the accuracy and reliability of the commonly used random soil sampling methodology for predicting seedling density, species richness and composition of the emerging seedling community?Location: Lake Kraenepoel, western Belgium.Methods: We compared density, species composition and observed and rarefactioned species richness of the seedling community emerging on a soft water lake bed exposed after drainage with the seedling community germinating in the laboratory from random soil samples in the same plots.Results: Seedling density did not differ between the two methods and there was a significant correlation between seedling density on the exposed lake bed and in the soil samples. This indicates that future seedling density can be reliably predicted based on soil sampling, in particular for the most abundant species. The most frequently occurring and abundant species among the seedlings in the soil samples were also the most frequent and abundant species germinating on the exposed lake bed. In contrast, species richness was much higher on the exposed lake bed than in the soil samples, and this difference was still significant for annual species after correction for differences in sampling intensity by rarefaction. We found no correlation between the number of species retrieved by the two methods. Although seedlings of rare and target species emerged on the lake bed, random soil sampling clearly failed to detect seeds of most of these species.Conclusions: Random soil sampling at a commonly used intensity and using the standard germination conditions can accurately predict future total seedling density and the density of the most abundant species. However, the method is not reliable for predicting the probability of establishment of populations of uncommon species. When executing a seed bank study, sampling intensity and germination conditions need to be adapted to the nature and the level of detail of the research question to be answered.
Trait‐divergence assembly rules have been demonstrated: Limiting similarity lives! A reply to Grime
Authors: Wilson J. Bastow 
Published: February 2009

AbstractThe recent Forum contribution by Grime (2006) contrasts the MacArthur/Diamond assembly‐rule approach to studying plant communities with the study of environmental trait gradients. Both are valid and useful. In doing so, Grime declares that the assembly rules model, in which negative interactions between plants act with limiting similarity to cause local trait divergence, is “not supported by empirical study of plant communities”. This is, he says, the agony of community ecology. I show that there is now abundant evidence for assembly rules, and no agony.
Long‐term datasets: From descriptive to predictive data using ecoinformatics
Authors: Bekker Renée M. , van der Maarel Eddy , Bruelheide Helge , Woods Kerry 
Published: February 2009

AbstractThis Special Feature includes contributions on data‐processing of large ecological datasets under the heading ecoinformatics. Herewith the latter term is now al so established in the Journal of Vegetation Science. Ecoinfomatics is introduced as a rapid growing field within community ecology which is generating exciting new developments in ecology and in particular vegetation ecology. In our field, ecoinformatics deals with the understanding of patterns of species distributions at local and regional scales, and on the assemblages of species in relation to their properties, the local environment and their distribution in the region. Community ecology using ecoinformatics is related to bioinformatics, community ecology, biogeography and macroecology.We make clear how ecoinformatics in vegetation science and particularly the IAVS Working Group on Ecoinformatics has developed from the work of the old Working Group for Data Processing which was active during the 1970s and 1980s. Recent developments, including the creation of TURBOVEG and Syn Bio Sys in Europa and VEGBANK in the USA, form a direct link with these pioneer activities, both scientifically and personally.The contributions collected in this Special Feature present examples of seco‐infeveral types of the use of databases and the application of programmes and models. The main types are the study of long‐term vegetation dynamics in different cases of primary and secondary succession and the understanding of successional developments in terms of species traits.Among the future developments of great significance we mention the use of a variety of different large datasets for the study of the distribution and ecology and conservation of rare and threatened species.
Local above‐ground persistence of vascular plants: Life‐history trade‐offs and environmental constraints
Authors: Ozinga Wim A. , Hennekens Stephan M. , Schaminée Joop H.J. , Smits Nina A.C. , Bekker Renée M. , Römermann Christine , Klimeš Leoš , Bakker Jan P. , van Groenendael Jan M. 
Published: February 2009

AbstractQuestions: 1. Which plant traits and habitat characteristics best explain local above‐ground persistence of vascular plant species and 2. Is there a trade‐off between local above‐ground persistence and the ability for seed dispersal and below‐ground persistence in the soil seed bank?Locations: 845 long‐term permanent plots in terrestrial habitats across the Netherlands.Methods: We analysed the local above‐ground persistence of vascular plants in permanent plots (monitored once a year for ca. 16 year) with respect to functional traits and habitat preferences using survival statistics (Kaplan‐Meier analysis and Cox’ regression). These methods account for censored data and are rarely used in vegetation ecology.Results: Local above‐ground persistence is determined by both functional traits (especially the ability to form long‐lived clonal connections) and habitat preferences (especially nutrient requirements). Above‐ground persistence is negatively related to the ability for dispersal by wind and to the ability to accumulate a long‐term persistent soil seed bank (‘dispersal through time’) and is positively related to the ability for dispersal by water.Conclusions: Most species have a half‐life expectation over 15 years, which may contribute to time lags after changes in habitat quality or ‐configuration (‘extinction debt’). There is evidence for a trade‐off relationship between local above‐ground persistence and below‐ground seed persistence, while the relationship with dispersal in space is vector specific. The rate of species turnover increases with productivity.
Groupings of life‐history traits are associated with distribution of forest plant species in a fragmented landscape
Authors: Endels Patrick , Adriaens Dries , Bekker Renée M. , Knevel Irma C. , Decocq Guillaume , Hermy Martin 
Published: February 2009

AbstractQuestions: 1. Do relationships among forest plant traits correspond to dispersability‐persistence trade‐offs or other inter‐trait correlations found in the literature? 2. Do species groups delineated by trait similarity, differ in occurrence in ancient vs. new forests or isolated vs more continuous forest patches? 3. Are these patterns consistent for different forest types?Location: Central Belgium, near Leuven.Methods: We investigate the distributions of a large set of plant traits and combinations among all forest species occurring in patches with varying forest continuity and isolation. Through calculation of Gower's similarity index and subsequent clustering,‘emergent’ species groups are delineated. Then, the relative occurrence of these different groups in forest patches of different age and size, sustaining different forest types (alluvial vs. Quercion), and having different isolation status is compared through multivariate GLM analysis.Results: Correlations among several life history traits point towards trade‐offs of dispersability and fecundity vs. longevity. We distinguished three species groups: 1= mainly shrubs or climbers with fleshy or wind dispersed fruits and high dispersal potential; 2 = dominated by small, mainly vegetatively reproducing herbs; 3 = with spring flowering herbs with large seeds and mainly unassisted dispersal. Relative occurrence of these groups was significantly affected by forest age, area, isolation and forest type. Separate analyses for alluvial and Quercion forests indicated that the relative importance of these factors may differ, depending on forest type and species group. Both forest continuity and isolation are important in restricting the relative occurrence of forest species in alluvial forests, whatever their group membership. In Quercion forests forest patch area was the primary determinant of relative occurrence of species groups.Conclusions: It is very important to preserve the actual forest area including the spatial setting and the dispersal infrastructure within the landscape. Next, forest connectivity may be restored, but it is inherently a long process.