Wyniki wyszukiwania - BazTech

Ograniczanie wyników

1 Polish Journal of Ecology

1 2012

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: anthropogenic ecosystems

Sortuj według:

Ogranicz wyniki do:

The role of ecotones in man-disturbed landscape : boundaries between mixed forest and adjacent man-made ecosystems in the Kampinos National Park, Poland

Dąbrowska-Prot E., Wasiłowska A.

Polish Journal of Ecology

2012

Vol. 60, nr 4

677--698

Ecologists agree that one of the main effects of human activity is the decrease in patch size in the landscape and hence an increase in ecotone length as a transition zone between adjacent ecological systems. Theoretical and practical importance of this concept has become one of the leading issues in current ecological research. The ecological importance of the ecotones was investigated, in the boundary of natural forest complex of the Kampinos National Park and adjacent anthropogenic ecosystems. Quantitative and qualitative changes of plant communities and of dipterans (Chloropidae) – important pests of wild and crop plants – were recorded along four types of transects located at the distance of 3 km: 1/ mixed forest (Querco roboris-Pinetum Mat. 1981) – ecotone – managed meadow (Deschampsietum caespitosae Hor vatic 1930); 2/ mixed forest – ecotone – crop field (Arnoserido-Scleranthetum R.Tx.1937); 3/ mixed forest – ecotone – spontaneously growing 20-year-old birch wood; 4/ mixed forest – ecotone – planted 17-year-old pine wood. The exchange of plant and dipteran species between forest ecosystem and its surrounding was analysed. The role of ecotones as transit zone or barrier for such exchange and as optimum or exclusive habitat for plant and dipteran associations was evaluated. Botanical studies showed that the neighbouring, ecotone-forming communities differed markedly in the vegetation structure and species composition (similarity index between them varied from 8 to 47%). Width of contact zones was also different, ranging from 4 to 14 m. Therefore, two groups of transects were distinguished: mixed forest – young woods and mixed forest – agricultural communities which differed in plant species richness and vegetation structure in particular transect zones. It created clear contrast between ecosystems and their ecotones. Some species were being found exclusively in ecotones but these species differed among different ecotones. The so-called ‘edge effect’ was manifested in increased number of plant species in the ecotone compared with neighbouring ecosystems, higher density of some populations and their better life condition (reflected in individual’s size, earlier entering subsequent phenological phases, fecundity). Chloropidae mainly dwelled the transect of mixed forest – meadow (60% of all caught in study area) and mixed forest – crop field (24%). Only 16% of dipteran species were caught in the transect of mixed forest – woods. Phytophagous species dominated in the first two transects (80–86% of the total number). Saprophagous species were 4–6 time less numerous there. The proportions of both trophic groups were more uniform in the transect of mixed forest – woods. Of the 44 Chloropidae species only 10 (22%) were widely dispersed in the study area and only two species – the dangerous pests Oscinella frit L. and O. pusilla Mg. were noted in all zones of all studied transects. In the transects of mixed forest and anthropogenic ecosystems, only meadow and crop field created optimal habitats for Chloropidae They were ‘ecological traps’ that maintained over 66% of all dipterans caught in the study area. This finding contradicts the supposition of potential threat posed by these pests to protected forest grounds due to a proximity of nearby meadows and croplands. Similarly, there was no threat of penetrating the sustainable mixed pine forest complex by synanthropic plant species. They were mainly found in the crop field. Only 1/3 of these species permeated to the ecotone zone, but none to the forest.