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Relationship between plant species richness and age of woodland patches (Ojców National Park, Poland)

Moszkowicz Ł.

Polish Journal of Ecology

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2014

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Vol. 62, nr 4

649--664

EN

Woodlands in different regions of Central Europe are mosaics diversified by floristic richness and age. The age of woodlands is understanded as the period of permanent existence of woodland phytocenosies, or at least a woodland site, without any transformations, even for a short period of time, to agricultural fields or any other areas managed in different ways. Forests which occur in identical habitats are often differentiated of their species richness. Data gathered from studies carried out to date, indicate that the age of a forest plays a significant role in the way plant communities develop. This relationship, however, is modified by a number of other factors. In this paper, an attempt was made to answer the following questions: 1) are there any differences in this relationship between woodland age and richness, and species composition of recent and ancient forests, 2) does the age of a forest affect the richness of vascular plant species in the layers of their vertical structure, the number of species of various phytosociological groups, 3) which of the selected factors affecting the processes of migration and colonization, alongside age, affect the richness of species noted in forest communities. The Ojców National Park (OPN) was chosen as a study area because its forests are diversified by age, from the younger than 71 to the older than 216 years and because the history of the forests there have been well documented. Age of selected woodland patches was determined using a ‘Map of distribution woodlands of different age in the Ojców National Park’, whereas the remaining factors were either measured or determined in the field or using available sources. In order to establish relationships, a multiple regression model was used.The results obtained in the study prove that, in OPN, the age of the forest is the principal factor affecting the overall number of vascular species. Old forests are most abundant in species, and many plant taxa occur only in such forests. Within the same age classes, the number of taxa is often diversified because of the impact of habitat factors e.g., humidity, and it is also linked to the history of the development of these forests. The factors which affect the species richness in a particularly beneficial way is the presence of rocks, as well as the diverse relief of a given area. Much less significant are exposure and inclination of the terrain. The age of a forest significantly affects the number of species in the herb layer, whereas it does not demonstrate significant correlations with respect to shrub or tree layers. The number of species in fertile deciduous forests are also positively affected, whereas no such relations were found in coniferous forest species. The results also indicate that the forest’s surface area, along with a specific combination of factors, may only have a limited effect on the richness of plant species in the area.

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Floristic analysis of the two woodland-meadow ecotones differing in orientation of the forest edge

Orczewska A., Glista A.

Polish Journal of Ecology

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2005

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Vol. 53, nr 3

365-382

EN

Studies on the transition zones between plant communities using the statistical method by Matuszkiewicz, have been predominantly conducted in forest communities or in ecotones between wetland and meadow communities. Although boundaries between forest and meadow (as a result of human pressure on the landscape, namely forest fragmentation) are of ecological interest, no previous attempts have been made to estimate the width of such ecotones using Matuszkiewicz.s approach. We applied the method in the studies on floristic changes across two, woodland.meadow ecotones (Arrhenatheretum elatioris/Tilio cordatae-Carpinetum betuli typicum and Scirpetum sylvatici/Tilio cordatae-Carpinetum betuli corydaletosum communities), located at forest edges differing in their orientation. The aim of the research was to estimate the width and character of those ecotones and to investigate whether the possible differences in vegetation are related to the prevailing aspect (orientation) of the woodland edge. To characterise the floristic composition of the two adjacent communities, the method of Greig-Smith.s square (16 quadrats of 4 m2 each) was chosen. To determine the floristic changes across each ecotone, transects 38 m in length and formed of 2 x 2 m quadrats were set perpendicularly to the woodland-meadow boundary. Diagnostic species for the main communities were determined and their incidence along the transect was observed. Differences in species composition that were observed along the transects allowed us to distinguish three contrasting sectors. The first one represents typical meadow communities, the second sector represents a typical ecotone, and the third one contains typical woodland communities. Our results showed that the width of the ecotones differed depending on the orientation of the woodland edge. In the transect between Arrhenatheretum elatioris and Tilio cordatae-Carpinetum betuli typicum communities, situated on a SE-oriented forest edge, it was estimated at 10 m, whereas in the second transect, the transition zone between the Scirpetum sylvatici and Tilio cordatae-Carpinetum betuli corydaletosum was narrower, reaching 6 m. This was located on a NW-oriented woodland edge. Our observations confirm the results of many other studies, which show that transition zones between woodland and meadow are wider on edges that receive more light, than in north-facing ones. The differences in the size of the transition zone at the two study sites are clear despite the fact that the two types of meadow communities differed in the number of mowing cycles per season. The Arrhenatheretum elatioris community is mown twice a year, and its ecotone with the woodland is wider than in the case of the Scirpetum sylvatici community. The latter is mown only once in the vegetation season but its transition zone remains 4 m narrower than in the first situation. It seemed that the increase in vegetation management (two mowing cycles instead of one) did not contribute to the reduced width of the ecotone. When looking at the distribution of species representing different syntaxonomic groups, in both transects, no meadow plants from the Molinio-Arrhenatheretea class or other species of open habitats were recorded deeper than 6 m into the woodland interior. On the other hand, forest species from the Querco-Fagetea class were found much further into the area of meadow. Thus, no strong pressure of meadow communites on woods was recorded, but the opposite situation, where forest species extended into the meadow area, took place. Such a tendency was observed regardless of the aspect of the woodland edge. Differences in physiological amplitude of species allowed us to distinguish, after Ranney et al. (1981), a group of: meadow-oriented species, which neither occurred in ecotone nor woodland, strongly edge-oriented species, and strongly forest interior-oriented species, avoiding the ecotones and meadows. A group of species present along the whole transect (ubiquitous) was very poorly represented. Contact zones between woodlands and meadows observed in the course of our studies and statistical analysis, give support to the model of a discontinuum. In both ecotones studied, the edge effect was recorded; in transect 1 it can be described as a 'double edge effect' (variable = species richness, has both maximum and minimum in the ecotone close together); negative on the meadow side and positive on the woodland side of the ecotone, and at the second study site as the 'positive edge effect'.

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Vegetation of the proposed "Bażantka" nature reserve on Głubczyce Plateau in the light of current threats to the forested habitats

Orczewska A.

Zeszyty Naukowe. Inżynieria Środowiska / Uniwersytet Zielonogórski

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2004

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nr 131(12)

295-305

EN

The vegetation cover of a small isolated woodland located in the agricultural landscape of the Głubczyce Plateau was studied. The following forest communities of natural character were present there: Ribeso nigri-Alnetum, Fraxino-Alnetum and Tilio cordatae-Carpinetum betuli. The main evidence of transformation of the vegetation cover of the woodland is the presence of the Picea abies-Impatiens parviflora secondary community and the abundant occurrence of Impatiens parviflora in some parts of the natural communities. Another expansive species which, like Impatiens parviflora, contributes to a decrease in the biodiversity of the herb layer, is Carex brizoides. Although some evidence of past disturbance was noticed, the vegetation cover of the wood is relatively well preserved. A proposal has been made to protect the whole woodland as a nature reserve.

PL

Przeprowadzono badania nad roślinnością małego, izolowanego przestrzennie lasu, położonego w rolniczym krajobrazie Płaskowyżu Głubczyckiego. Stwierdzono tu obecność następujących zbiorowisk leśnych o charakterze naturalnym: Ribeso nigri-Alnetum, Fraxino-Alnetum oraz Tilio cordatae-Carpinetum betuli. Głównymi przejawami transformacji pokrywy roślinnej badanego obszaru była obecność zbiorowiska zastępczego Picea abies-Impatiens parviflora, rosnącego na siedlisku grądu oraz masowe występowanie Impatiens parviflora w niektórych partiach lasu. Innym ekspansywnym gatunkiem, który tak jak i niecierpek drobnokwiatowy, przyczynia się do spadku bogactwa gatunkowego w warstwie runa, jest Carex brizoides. Pomimo przejawów działających w przeszłości zaburzeń o charakterze antropogenicznym pokrywa roślinna badanego obiektu jest stosunkowo dobrze zachowana. Z tych względów proponuje się objąć go ochroną rezerwatową.