Naslov
Estimating plant species occurrence in MTB/64 quadrants as a function of DEM-based variables – a case study for Medvednica Nature Park, Croatia

Autori
Jelaska, D. Sven ; Antonić, Oleg ; Nikolić, Toni ; Hršak, Vladimir ; Plazibat, Miško

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
3rd European Ecological Modelling Conference : Book of Abstracts / Legović, Tarzan - Dubrovnik : Institut Ruđer Bošković, 2001, 18-18

Skup
European Ecological Modelling Conference (3 ; 2001)

Mjesto i datum
Dubrovnik, Hrvatska, 10.09.2001. - 15.09.2001

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
disciriminant analyses; logistic regression; classification trees

Sažetak
Croatia is a country with high biodiversity and tradition in flora and vegetation exploration. Despite these facts, constant lack of greater number of active botanists and inconsistency in gathering data in the field resulted that Croatia is among those rare European countries without an Atlas of Flora produced till today. Since no demographic expansion in Croatian botanist population is expected in the near future, an optimisation of the fieldwork is necessary. Recently, a standard for collection of data, based on the Central European MTB grid was proposed and tested in the field (each MTB unit was divided into 1/64 subunits with an area of approximately 225 ha), on the “Medvednica Nature Park” on Medvednica mountain near the city of Zagreb, where prevails forest vegetation, determined mainly by macroclimate and geomorphology. Using the data collected in 97 MTB/64 quadrants, we tested the potential of estimating plant species spatial distribution at the proposed grid by models in a function of the DEM-based variables, namely altitude (as an estimator of basic macroclimatic gradient) and terrain slope, terrain aspect and flow accumulation potential (as estimators). Because of the nature of the input data (presence/absence of plant species per MTB/64 quadrant) and mainly significant spatial variability of environmental factors within quadrants, pixel-to-pixel oriented approach wasn’t possible. Therefore, each MTB/64 quadrant was represented by descriptive statistics (median, 5-, 25-, 75- and 95-percentiles) of DEM-based variables. 35 plant species were selected arbitrarily, on the basis of their frequency in the studied area (40-60% of all quadrants). Three methods for development of predictive model were used and compared: discriminant analyses, logistic regression and classification trees. Yielded results suggest that spatial modelling could be applied in flora mapping in sense of generalization of sampled data, which would optimise fieldwork. For larger areas, inclusion of other environmental variables (macroclimatic, lithological, land-use) in models is needed. For rare species, it will be probably necessary to use areas in the field with lower variability in environmental factors which will be very likely much smaller than here used ones (i.e. 225 ha).

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA