Analiza hemisfere drevesnih krošenj v dinarskem jelovo-bukovem gozdu (Omphalodo-Fagetum) z uporabo fotografije hemisfere

Sven D. Jelaska

Povzetek

Fotografija hemisfere je vsestransko uporabna za različne monitoringe, modeliranja in raziskave okolja. Ker so svetlobne razmere v plasti pod krošnjami zelo pomembna determinanta vegetacijskega vzorca, sem pri raziskavi v območju dinarskih jelovo-bukovih gozdov Hrvaške posnel fotografije hemisfere drevesnih krošenj na 151 vzorčnih ploskvah. Fotografije sem skeniral in klasificiral na podlagi kvalitete kontrasta in analiziral s programom Gap Light Analyzer Software. Izračunal sem odstotke odprtosti krošnje in LAI (leaf area index). Rezultate sem analiziral z deskriptivno statistiko, linearno regresijo in analizami CART. Za del vzorčenega območja so bili na voljo satelitski posnetki ETM+, ki so mi omogočili primerjavo lastnosti krošenj z NDVI (Normalized Difference Vegetative Index). Pri fotografijah z najboljšim kontrastom sem opazil statistično značilno negativno korelacijo (odvisnost) med odprtostjo krošnje in NDVI, medtem ko je bil pri vseh analiziranih fotografijah LAI v pozitivni korelaciji z NDVI in pri fotografijah z najboljšim kontrastom v negativni korelaciji s številom prisotnih rastlinskih vrst. Po analizah CART je bil LAI pomemben kazalnik v oceni števila prisotnih rastlinskih vrst. Rezultati, ki sem jih dobil, so pokazali, katere metodološke korake moramo izboljšati, da bi usmerili bodoča raziskovanja h kar najširši uporabi fotografije hemisfere.

Ključne besede

Omphalodo-Fagetum, fotografija hemisfere, krošnja, CART, LAI, NDVI, Hrvaška

Celotno besedilo:

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Literatura

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