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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.

Ecological importance of meadow patches in protected forest area : floristic diversity and the dynamics of insect communities

Dąbrowska-Prot E., Wasiłowska A.

Polish Journal of Ecology

2010

Vol. 58, nr 4

741-758

The present studies deal with the practical and theoretical problems of meadows in structure and functioning of the forest complex. Floristic, phytosociological and entomological studies involved fragments of two meadows located in large forest complex Kampinos National Park (Central Poland): a 'mid-forest' meadow surrounded by forest and 'near-forest' meadow situated in the boundary between forest and open area. The plant community developed on mid-forest meadow can be classified as Lysimachio-Filipenduletum ulmarie Hadc et al. 1997, on near-forest meadow as Deschampsietum caespitose Horvatic 1930. Both studied meadow communities are very widespread in Kampinos National Park and in whole Poland. Insect community containing various trophic guilds from Chloropidae family (Diptera) was chosen as representative of the entomocoenosis. From the standpoint of landscape ecology the processes of plant and insects species dispersion from meadow to forest and vice versa, across the forest meadow ecotone were analysed. The obtain results revealed that the meadows and their ecotones are refuge habitats for many plant and Chloropidae species increasing plant and entomofauna biodiversity of forest landscape. Proximity of meadows did not cause significant changes in the floristic composition of forest vegetation. Fears concerning the negative impact of meadows on natural forest vegetation through penetration of alien plant species and phytophagous Chloropidae seem to be unfounded. Ecotone was an important barrier for most plant and Chloropidae species in their dispersion from meadow to forest and vice versa. In the case of mid-forest meadow 93% of plant species did not cross ecotone, for near-forest meadow it was 83%. A high index of dispersion of Chloropidae species in mid-forest transect and poor differentiation of their numbers between zones indicate substantial colonisation of the whole system by Chloropidae, however, ecological properties of this fauna (saprophage species, a lack of distinct dominant, low density) minimised the risk it might pose to meadow complex or to adjacent forest. Near-forest meadow with much richer and diverse Chloropidae fauna contributed minimally to the fauna of ecotone and adjacent forest. Only 25% of species number of Chloropidae colonised all zones of the transect there and their majority (55%) exclusively inhabited the meadow ecosystem. It was found, that, from the point of view of natural forest protection, the role of adjacent meadows is very significant. They make 'traps' for certain groups of phytophagous insects.