Distribution Of Forest Plant Species Research Articles

The Response of Vegetation on the Andean Flank in Western Amazonia to Pleistocene Climate Change

A reconstruction of past environmental change from Ecuador reveals the response of lower montane forest on the Andean flank in western Amazonia to glacial-interglacial global climate change. Radiometric dating of volcanic ash indicates that deposition occurred ~324,000 to 193,000 years ago during parts of Marine Isotope Stages 9, 7, and 6. Fossil pollen and wood preserved within organic sediments suggest that the composition of the forest altered radically in response to glacial-interglacial climate change. The presence of Podocarpus macrofossils ~1000 meters below the lower limit of their modern distribution indicates a relative cooling of at least 5°C during glacials and persistence of wet conditions. Interglacial deposits contain thermophilic palms suggesting warm and wet climates. Hence, global temperature change can radically alter vegetation communities and biodiversity in this region.

Factors influencing the spatial distribution of forest plant species in hedgerows of North-western Germany

In North-western Germany woodland fragmentation has caused a decline in many forest plant species. Hedgerows partly offer a similar environment as forests and have been identified as potential habitats for forest plants in various studies from North America and Western Europe. The objective of this study was to examine whether this applies also to Central Europe and which variables affect the spatial distribution and abundance of forest plant species in hedgerows on a local scale. Three hedgerow networks north of the city of Bremen, Germany, were selected as study areas and divided into totally 515 hedgerow segments. In each segment we recorded all vascular plants and a large number of explanatory variables relating to structure, spatial configuration, environment and management. Averaged across species there was a predominant effect of environmental factors on the occurrence of forest species in the hedgerows, followed by spatial configuration and management. Hedgerow structure was found to be less important. In general, forest species were favored by low nutrient and light availability as well as high connectivity with other hedgerows or forest; they avoided hedgerows with a west-easterly orientation and an adjacent land use in the form of fields or grasslands. Forest species found and not found in hedgerows did not differ in their environmental preferences or life history traits. The number of threatened forest species in the hedgerows, however, was lower than expected with respect to their overall proportion to the total number of forest species in the region.

Groupings of life‐history traits are associated with distribution of forest plant species in a fragmented landscape

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.

Groupings of life-history traits are associated with distribution of forest plant species in a fragmented landscape

Questions: 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.

Forest fragmentation effects on patch occupancy and population viability of herbaceous plant species

Habitat fragmentation is one of the major threats to species diversity. In this review, we discuss how the genetic and demographic structure of fragmented populations of herbaceous forest plant species is affected by increased genetic drift and inbreeding, reduced mate availability, altered interactions with pollinators, and changed environmental conditions through edge effects. Reported changes in population genetic and demographic structure of fragmented plant populations have, however, not resulted in large-scale extinction of forest plants. The main reason for this is very likely the long-term persistence of small and isolated forest plant populations due to prolonged clonal growth and long generation times. Consequently, the persistence of small forest plant populations in a changing landscape may have resulted in an extinction debt, that is, in a distribution of forest plant species reflecting the historical landscape configuration rather than the present one. In some cases, fragmentation appears to affect ecosystem integrity rather than short-term population viability due to the opposition of different fragmentation-induced ecological effects. We finally discuss extinction and colonization dynamics of forest plant species at the regional scale and suggest that the use of the metapopulation concept, both because of its heuristic power and conservation applications, may be fruitful.

Effects of tree species composition on within‐forest distribution of understorey species

AbstractQuestion: Do tree species, with different litter qualities, affect the within‐forest distribution of forest understorey species on intermediate to base‐rich soils? Since habitat loss and fragmentation have caused ancient forest species to decline, those species are the main focus of this study.Location: Three ancient forests, along a soil gradient from acidification‐sensitive to base‐rich, were studied: Limbrichterbosch and Savelsbos in The Netherlands and Holtkrat in Denmark.Methods: Canopy and soil surveys along transects generated data for Redundancy Analysis on tree – humus relationships. We analysed the distribution of forest plant species with Canonical Correspondence Analysis. The explanatory factors were soil characteristics (pH, organic matter, loam content and thickness of the humus layers), external crown projection, ground water and canopy data. We further analysed the relationship between forest species and humus characteristics with Spearman correlations.Results: Tree species have a significant impact on humus characteristics through the nature of their litter. Humus characteristics significantly explain the distribution of forest understorey species. The pH of the first 25 cm mineral soil and the thickness of the F‐ (fermentation) layer are the primary factors affecting the distribution of ancient forest species.Conclusion: This study indicates that the species composition of the forest canopy affects the distribution of forest understorey species. Ancient forest species are more abundant and frequent underneath trees with base‐rich litter. On acidification‐sensitive soils these relationships were stronger than on more base‐rich, loamy soils.

EcoPlant: A forest site database linking floristic data with soil and climate variables

Abstract. A new database is described, named EcoPlant, that currently holds data from 6432 phytosociological relevés of French forests. The aim of the database is to investigate and model the distribution of forest plant species, and their response to ecological factors, i.e. their ecological niche. Unlike other similar databases, a full environmental description is stored with the floristic data of each site. The climatic data at the site are included, and access to direct climatic variables is possible through geographic information system (GIS) modelling. Precise data on the soil are also stored for each site (soil profile and horizon descriptions, physical and chemical analyses of soil samples). The database is designed to enable linkages to existing soil, floristic or plant‐trait databases.

EcoPlant: A forest site database linking floristic data with soil and climate variables

A new database is described, named EcoPlant, that currently holds data from 6432 phytosociological releves of French forests. The aim of the database is to investigate and model the distribution of forest plant species, and their response to ecological factors, i.e. their ecological niche. Unlike other similar databases, a full environmental description is stored with the floristic data of each site. The climatic data at the site are included, and access to direct climatic variables is possible through geographic information system (GIS) modelling. Precise data on the soil are also stored for each site (soil profile and horizon descriptions, physical and chemical analyses of soil samples). The database is designed to enable linkages to existing soil, floristic or plant-trait databases.

Effects of environment, habitat configuration and forest continuity on the distribution of forest plant species

In present day European landscapes many forest plant species are restricted to isolated remnants of a formerly more or less continuous forest cover. The two major objectives of this study were (1) to determine the relative importance of habitat quality (mainly in terms of soil parameters), habitat configuration (patch size and isolation) and habitat continuity for the distribution of herbaceous forest plant species in a highly fragmented landscape and (2) to examine if groups of species with different habitat requirements are affected differently. Deciduous forest patches in northwestern Germany were surveyed for the presence of a large set of forest species. For each patch, habitat quality, configuration and continuity were determined. Data were analysed by Redundancy Analysis with variation partitioning for effects on total species composition and multivariate logistic regression for effects on individual species, for two different data sets (base‐rich and base‐poor forest patches). Overall, we found strong effects of habitat quality (particularly of soil pH, water content and topographic heterogeneity in the base‐rich forest patches; and of calcium content and disturbance in the base‐poor patches), but only relatively weak effects of habitat configuration and habitat continuity. However, a number of species were positively affected by patch area and negatively affected by patch isolation. Furthermore, the relative importance of habitat configuration tended to be higher for species predominantly growing in closed forests compared to species occurring both in the forest and in the open landscape.

Effects of environment, habitat configuration and forest continuity on the distribution of forest plant species

Abstract In present day European landscapes many forest plant species are restricted to isolated remnants of a formerly more or less continuous forest cover. The two major objectives of this study were (1) to determine the relative importance of habitat quality (mainly in terms of soil parameters), habitat configuration (patch size and isolation) and habitat continuity for the distribution of herbaceous forest plant species in a highly fragmented landscape and (2) to examine if groups of species with different habitat requirements are affected differently. Deciduous forest patches in northwestern Germany were surveyed for the presence of a large set of forest species. For each patch, habitat quality, configuration and continuity were determined. Data were analysed by Redundancy Analysis with variation partitioning for effects on total species composition and multivariate logistic regression for effects on individual species, for two different data sets (base-rich and base-poor forest patches). Overall, we...

Influence of environmental and spatial variables on regional distribution of forest plant species in a fragmented and changing landscape

During the past several centuries, forests in Europe and large parts of North America have been subject to extensive forest clearance. The last several decades, however, numerous new forest patches have been established onto former agricultural land. As a result, the present forest area often consists of a mixture of small forest patches of different age, area, habitat quality and connectivity embedded within a hostile agricultural landscape. In these patchy landscapes, distribution patterns of plant species may be affected by both regional and local factors, although the relative importance of both is still poorly understood. In this study, we investigated distribution patterns of 113 forest plant species in a fragmented landscape. Species abundances at the regional scale conformed to a clearly unimodal abundance distribution which we believe to be related to 1) environmental heterogeneity due to succession and 2) inequality in migration rates. Patch incidence was significantly related to life form, which in turn was correlated to seed mass and dispersal mechanism. Multiple logistic regressions showed that presence/absence of 59 species studied was significantly affected by patch connectivity, patch area and age for 35, 30 and 34 species, respectively. The results of this study indicate that distribution patterns of forest plant species are influenced by both local and regional factors. Moreover, they also demonstrate that next to spatial aspects of fragmentation, temporal patterns of landscape change may have far‐reaching effects on presence/absence patterns of plant species and therefore should be incorporated in studies dealing with regional population structures of plants.