Connection between vegetation types of lowland forests, regarding of micro-relief, soil types and complex vegetation types (including soil properties and water availability) were analysed by GIS based on vegetation, topographical and forestry maps. Most important factors affecting vegetation are water availability (characterised by micro-relief) and genetical soil types. Complex site types including more characteristics give better results. Forestry data can be used with certain limitations.
In this paper, we use decision trees to construct models for predicting vegetation types from environmental attributes in a salt marsh. We examine a method for evaluating the worth of a decision tree and look at seven sources of uncertainty in the models produced, namely algorithmic, predictive, model, scenario, objective, context and scale. The accuracy of prediction of types was strongly affected by the scenario and scale, with the most dynamically variable attributes associated with poor prediction, while more static attributes performed better. However, examination of the misclassified samples showed that prediction of processes was much better, with local vegetation type-induced patterns nested within a broader environmental framework.
In this paper, we examine possible sources of hierarchical (nested) structure in vegetation data. We then use the Minimum Message length principle to provide a rational means of comparing hierarchical and non-hierarchical clustering. The results indicate that, with the data used, a hierarchical solution was not as efficient as a nonhierarchical one. However, the hierarchical solution seems to provide a more comprehensible solution, separating first isolated types, probably caused from unusual contingent events, then subdividing the more diverse areas before finally subdividing the less diverse. By presenting this in 3 stages, the complexity of the non-hierarchical result is avoided. The result also suggests that a hierarchical analysis may be useful in determining homogeneous areas.
The effects of stand structure, tree species composition, proportion of habitat types and land use history on breeding bird assemblages in temperate mixed forests in Western Hungary were studied. The species richness, the abundance and the composition of the whole breeding bird assemblage and of some groups formed on the basis of nesting site and rarity were examined. Stand structural variables had the highest impact on the breeding bird assemblage, while tree species composition, the varying proportion of vegetation types and land use history had no significant effect. In the case of the species richness, the abundance and the composition of the whole assemblage, the most important variables were the mean diameter of trees, the vegetation cover of the forest floor and the dead wood volume. The explained variance in the linear models of different groups varied between 20% and 60%, and the relative importance of these three variables also differed considerably. These results indicate that forest management may considerably influence the diversity and the composition of birds, as all the structural elements affecting birds deeply depend on it. Within the shelterwood management system, the elongation of the rotation and regeneration periods, and the relatively high proportion of retention tree groups after harvest could contribute to the conservation of forest birds. Our results also showed that for the forest bird communities, both the prevalence of big trees and the presence of a dense understory layer are important. Management regimes which apply continuous forest cover might be more appropriate for providing these structural elements simultaneously on small spatial scales, and for the maintenance of a more diverse bird community, thus healthier forest ecosystems.
Authors:C. Thiel-Egenter, A. Risch, M. Jurgensen, D. Page-Dumroese, B. Krüsi, and M. Schütz
Interactions between grassland ecosystems and vertebrate herbivores are critical for a better understanding of ecosystem processes, but diverge widely in different ecosystems. In this study, we examined plant responses to simulated red deer (
L.) grazing using clip-plot experiments in a subalpine grassland ecosystem of the Central European Alps. We measured aboveground net primary production (ANPP) and phosphorus (P) concentration of leaf tissue from plants of two vegetation types with different grazing history. The experimental plots were placed on a soil-P gradient and subject to two different clipping treatments, which simulated moderate and heavy grazing, respectively. We found distinct differences in the response of both ANPP and P concentration in leaf tissues in the two vegetation types. Compared to moderate, heavy grazing simulation did not affect ANPP in the vegetation type adapted to grazing, but decreased ANPP in the non-grazing adapted vegetation type. High soil-P levels also had different effects on the response of the vegetation to clipping in the two vegetation types with different grazing history. ANPP correlated positively with soil-P in non-grazing adapted tall-grass vegetation, while in grazing adapted short-grass vegetation a positive relationship between soil-P and the P concentration in leaf tissues was found. Our experiments provide data for a better understanding of ecosystem processes in high-elevation grasslands of the Alps with possible implications for both nature conservation purposes in protected areas and the management of agriculturally used grasslands.
Authors:Zs. Molnár, M. Biró, J. Bölöni, and F. Horváth
Actual distribution maps of vegetation types are important data sources of basic and applied research, respectively. Though there were several attempts to map the actual vegetation of Hungary, the MÉTA program was the first to map all the (semi-)natural habitat types on the whole territory of Hungary. The paper discusses the habitats with treeless vegetation. 45 habitats are presented and discussed. The paper provides additional data on the area and distribution of the habitats mainly at the physical geographical macroregion scale.
Authors:J. Bölöni, Zs. Molnár, M. Biró, and F. Horváth
Actual distribution maps of vegetation types are important data sources of basic and applied research, respectively. Though there were several attempts to map the actual vegetation of Hungary, the MÉTA program was the first to map all the (semi-)natural habitat types on the whole territory of Hungary. The paper discusses the woodland and shrubland habitats. 41 habitats are presented and discussed. The paper provides additional data on the area and distribution of the habitats mainly at the physical geographical macroregion scale.