50 research outputs found
Statistical detection of spatial plant patterns under the effect of forest use
The analysis of the consequences of land use (in particular forest use) may be considered as a partial step towards an integrated modelling of a land system. In the paper a forest territory is considered, where a gap-cut is made, and after a given time period the eventual change in the spatial distribution of undergrowth plants and tree seedlings is to be detected. Floristic data are collected along a line transect. A method for the detection of the change in the plant distributions along the transect is proposed to see whether this occurs at the geometric frontier of the human intervention.
Since in the considered case the distribution of the change-point estimate is not known, as a substitute of its confidence interval, the so-called change-interval is calculated, using an adaptation of the bootstrap method. As an illustration, for a concrete plant species, the maximum likelihood estimation of the change-point and the calculation of the above mentioned change-interval is presented. Finally, the validation of the proposed method against some typical ecological situations is also presented, which provides a justification of the used algorithms
Geological Heritage, Geotourism and Local Development in Aggtelek National Park (NE Hungary)
We examine how geoconservation and geotourism can help the local development of an economically underdeveloped karst area. First, we briefly present the geoheritage of Aggtelek National Park, which largely overlaps the area of the Aggtelek Karst. The area is built up predominantly of Triassic limestones and dolomites. It is a typical temperate zone, medium mountain karst area with doline-dotted karst plateaus and tectonic-fluvial valleys. Besides caves, the past history of iron mining also enriches its geoheritage. Aggtelek National Park was set aside in 1985. The caves of Aggtelek Karst and Slovak Karst became part of the UNESCO World Heritage in 1995 due to the high diversity of cave types and morphology. Socially, the area of the national park is a disadvantaged border region in NE Hungary. Baradla Cave has always been a popular tourist destination, but visitor numbers fell significantly after 1985. Tourism is largely focused on Baradla Cave, and thus it can be considered “sensu lato” geotourism. Reasons for the changes in visitor numbers are discussed in this paper. Tourist motivations, the significance of geotourism and other tourism-related issues were explored in our study by questionnaire surveys and semi-structured interviews. Furthermore, the balance of geoconservation versus bioconservation is also examined. Finally, the relationship of geotourism, nature protection and local development is discussed. We conclude that the socio-economic situation of the Aggtelek Karst microregion is relatively better than that of the neighbouring regions, and this relative welfare is due to the existence of the national park and Baradla Cave
A novel forest state assessment methodology to support conservation and forest management planning
A new forest state assessment methodology to complement existing conservation and forestry data has been developed. The aim is to provide tools for strategic planning including spatial distribution of conservation priorities. The method is point-based using a dense systematic sampling grid and provides more detailed information than vegetation maps or forest subcompartment descriptions, but requires less effort than forest inventories. Indicators include canopy composition and structure, deadwood, herbs, microhabitats, disturbances, shrubs and regeneration. The results can inform managers about the structural and compositional diversity of forest stands in the form of thematic maps and can provide the basis for analysis of habitat suitability for forest-dwelling organisms. A smartphone application has been developed to enable electronic data collection. PostGIS and Python scripts were used in the data flow. In this paper, we outline the development of the assessment protocol, and present the sampling design and the variables recorded. The main advantages of the survey methodology are also shown by case-studies based on data collected during the first field season in 2014. The protocol has been designed for low mountain forests in Hungary, but it can be modified to fit other forest types
Strict Forest Reserve Research in the Margin of the Carpathians, the Vár-hegy Case-Study
Sixteen forest reserves are situated in the northern part of Hungary which belongs to the Carpathian region according to EURAC delimitation (Ruffini et al. 2006). These Hungarian forest reserves expand the natural forest remnant/forest reserve net of the Carpathians towards the lower hilly region, representing the deciduous beech and oak forest belts near their lower (xeric) distribution limits. This paper outlines the Hungarian forest reserves belonging to the Carpathian region and the preliminary results of current projects in the Vár-hegy Forest Reserve (Bükk Mts., Hungary) as a case study. The alteration of tree species composition was investigated here based on the reconstruction of forest history in the previous 130 years (management period) and analyses of forest stand inventory. In another project CO2 sequestration changes of these forest stands were modeled since the clear-cutting in the 1880th and carbon stored in the forest ecosystem compartments was estimated. Our results show that the forest reserve stands are presently in a transition state from the managed forest towards a more natural mixed forest with several age-classes
The effects of stand characteristics on the understory vegetation in Quercus petraea and Q. cerris dominated forests
The shelterwood system used in Hungary has many effects on the composition and structure of the herb layer. The aim of our study was to identify the main variables that affect the occurence of herbs and seedlings in Turkey oak-sessile oak (Quercus cerris and Q. petraea) stands. The study was carried out in the Bükk mountains, Hungary. 122 sampling plots were established in 50-150 year old oak forests, where we studied the species composition and structure of the understorey and overstorey. The occurence of herbs was affected by canopy closure, the heterogenity and patchiness of the stand, the slope and the east-west component of the aspect. The composition of saplings was significantly explained by the ratio of the two major oak species in the stand and the proximity of the adult plants. An important result for forest management was that sessile oaks were able to regenerate almost only where they were dominant in the overstorey
Climate change and oak growth decline: Dendroecology and stand productivity of a Turkey oak (Quercus cerris L.) old stored coppice in Central Italy
Substrate specificity and community structure of bryophyte vegetation in a near-natural montane beech forest
Bryophyte vegetation on volcanic rock outcrops and dead wood is studied in a near-natural montane beech stand in northern Hungary. Substrate specificity of the species and the existing interspecific relationships are described. The most important species combinations and their diversity are evaluated using information theoretical functions and Monte-Carlo simulations. All analyses are based on presence/absence data of 33 species in 1508 100 cm2 microplots. Most species exhibit strong substrate specificity. Of the species that occurred with frequencies higher than 10, 8 are associated to rock, 5 to dead wood and 5 to both substrate types. Analyses of interspecific associations and agglomerative classification reveal that frequent species of species-poor bare rocks are separated from species-rich assemblages of humus-rich outcrops and coarse woody debris. Monte Carlo simulations reveal that many species combinations are significantly more frequent than expected under the assumption of random combining of species. Observed number, diversity and evenness of species combinations are significantly lower, whereas interspecific constraint (expressed as associatum) is significantly higher than under the neutral models even when data are stratified according to substrate type. The presence of coarse woody debris, not only provides habitat for wood inhabiting bryophytes, but also results in diverse rupicolous bryophyte assemblages on humus-rich outcrops
A study of gap characteristics in the Néra Forest Reserve (Romania) using satellite image analysis
A comparison of vegetation patterns in the tree and herb layers of a hardwood forest
Meta-analysis is used to compare the patterns of the tree and the herb layers in a Central-European deciduous hardwood forest. Vegetation patterns are represented by distance matrices and dendrograms. The significance of the relation between the patterns is evaluated through permutation (Mantel) tests and full randomization (Monte Carlo simulation) tests. The relationship between the two layers is significant but weak. When using ecological indicators as variables for characterising the herb layer, the relation is stronger. Distance matrices and dendrograms describe the vegetation pattern similarly. However, the results of pairwise tests of significance strongly depend on the “level” of comparisons, i.e., whether distance matrices or dendrograms are compared. This follows perhaps from the differences between permutation and full randomization tests