Comparison of selected landscape ecological forest metrics in two different landscape types

Z analizami sprememb krajinske zgradbe lahko tudi spremljamo, kako to vpliva na ocenjevanje pestrostne vloge gozda. V raziskavi smo ocenili, kateri kazalci za izračunavanje površin, jedrnih con in teženj k združevanju, katerih izračun omogoča program Fragstats 4.2, so najprimernejši glede na naše potrebe, kakšne so njihove omejitve in na kaj moramo biti še posebej pazljivi. Upoštevali smo različno ločljivost vhodnih podatkov ter različna pravila za izračune med rastrskimi celicami. Oboje smo primerjali za gozdove v dveh različnih krajinskih tipih, Kočevske in Slovenske Istre. Kot primerna se izkažeta osnovna kazalca površin CA in PLAND, za zahtevnejše potrebe tudi AREA_AM. Pri oceni jedrnih con sta prav tako najprimernejša osnovna kazalca površin TCA in CPLAND, poleg njiju je uporaben še kazalec števila jedrnih con na enoto površine DCAD, za podrobnejše prostorske ocene jedrnih con pa sta primerna kazalca CORE_AM in DCORE_AM. Pri oceni teženje k združevanju je najbolj uporaben kazalec gostote zaplat PD.By analysing changes in landscape structure we can trace the influence they have on the evaluation of the diversity function of a forest. In the presented research, it was assessed which indices for computing areas, cores and aggregation tendencies that can be calculated with the Fragstats 4.2 programme best meet our needs, what limits they have and what we should pay special attention to. We considered differences in the resolution of incoming data and different rules for the calculation of raster cells. Both were compared for forests in two different landscape types: Kočevje and Slovenska Istra. The basic surface indices CA and PLAND proved to be the most suitable, while for more demanding purposes, AREA_AM can be used as well. For the evaluation of core areas, basic indices proved to be the most suitable, too, specifically TCA and CPLAND. Other important indices were the index of the number of core areas per surface unit DCAD and indices CORE_AM and DCORE_AM for a more detailed spatial evaluation of core areas, whereas most useful for the evaluation of aggregation tendency proved to be the patch density index PD