Krajinske spremembe na območju Pivke, Slovenija

Spontaneous afforestation is one of the biosystemic landscape change processes affecting landscape functioning. The process of overgrowing is highly dynamic, and the temporal dimension of changes in landscape structure can be of key importance for evaluating habitat suitability. A detailed study was carried out in the area of 19.52 km2 within the Pivka municipality, where land use is a mixture of traditional farmland, forests, and extended areas of abandoned former farmland with natural re-growth. In addition, this area is highly important for two bird species: the Barred Warbler (Sylvia nisoria) and the Red-backed Shrike (Lanius collurio). Both species are sensitive to forest spreading and prefer a mixture of extensive meadows with shrubs and hedgerows as their most suitable habitat. Digital BW orthophotos from the 1975 - 2000 period and colour digital orthophotos from 2009 have be enused for on screen digitizing of the EUNIS habitat classes. Indicators of landscape changes were derived from temporal based difference in the landscape structure (different structural indicators based on patch size, shape, distances and patch dynamics). All the details obtained were evaluated based on Earth observation data and GIS supported methods. The most valuable parts of the area for both species are, from a biodiversity point of view, the core forest areas and mixture of meadows with shrubs and hedgerows. Spontano zaraščanje je eden izmed biosistemskih procesov sprememb, ki vplivajona delovanje krajine. Zaraščanje je dinamično in časovna dimenzija sprememb v krajinski zgradbi je lahko ključnega pomena za ocenjevanje primernosti habitatov. Podrobnejšo analizo smo izpeljali na 19,52 km2 izbrane površine v občini Pivka, kjer gre za prostor, kjer je raba zemljišč preplet tradicionalnih kmetijskih zemljišč, gozdov in obsežnih predelov zaraščajočih se kmetijskih površin. Poleg tega je to območje zelo pomembno za dve vrst ptic: pisano penico (Sylvia nisoria) in rjavega srakoperja (Lanius collurio). Obe vrsti sta občutljivi za širjenje gozda, saj je njun habitat preplet ekstenzivnih travnikov z grmičevjem in živicami. Za zaslonsko digitalizacijo habitatnih razredov EUNIS smo uporabili digitalne črno-bele ortofoto posnetke iz obdobja 1975 - 2000 in barvni digitalni ortofoto iz leta 2009. Kazalce krajinskih sprememb smo izpeljali iz razlike v zgradbi krajine iz različnih let (različni kazalniki krajinske zgradbe, ki temeljijo na velikosti in obliki zaplat, medsebojnih razdaljah med njimi in časovni dinamiki). Vse pridobljene podatke smo ovrednotili na podlagi daljinsko pridobljenih podatkov v okolju GIS. Najvrednejši deli prostora so jedrne cone gozdov in prepleti travnikov z živicami in grmovjem.