Variability of Phenological Behaviours of Wild Fruit Tree Species Based on Discriminant Analysis.

Vegetation phenology is considered an important biological indicator in understanding the behaviour of ecosystems and how it responds to environmental cues. The aim of this paper is to provide information on the variability of phenological behaviours based on discriminant analysis using the R software package with the following libraries: ggplot2, heplots, candisc, MASS, car, and klaR. Three phenological phases were analysed with eight wild fruit tree species from a forest ecosystem in the southwestern part of Romania (44°05'19.5" N 23°54'03.5" E). It was found that there is a large and very large variability for the "bud burst" phenophase, medium and low for "full flowering", and reduced for the "all petals fallen" phenophase. For the analyzed data, the discriminant analysis model has high accuracy (accuracy: 0.9583; 95% CI: (0.7888, 0.9989). Partition plots show the results of "full flowering" and "all petals fallen" as a function of the "bud burst" of pockmarks when separated into eight clusters and eight clusters of "full flowering" as a function of "all petals fallen". The differences observed, from a phenological point of view, are not only due to the different cold requirements of these species but also to the temperatures during the spring.