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ŠUMARSKI LIST 3-4/2014 str. 69     <-- 69 -->        PDF

The aim of this study was to determine grassland flora (Tab. 2) and vegetation, and frequency of occurrence of woody and herbaceous species of the forest edge at different grassland management localities (Tab. 6, see Tab. 5). The field research of flora and grassland vegetation (2008–2010) was conducted at 27 localities (Tab. 1, Fig.1). A total of 103 relevés using the Braun-Blanquet (1964) method amounting to 100 m2 was made, while the description of habitats included geographical coordinates, altitude, inclination, exposure, land forms, and grassland management.
Woody species and herbaceous transgressive species from the Trifolio-Geranietea sanguinea class (according to Kaligarič 1997) were selected from the relevés (Vitasović Kosić 2011) and are hereinafter referred to as "herbaceous species of the forest edge". The presence and frequency of each taxon in relation to the type of grassland management were determined. For each taxon, Braun-Blanquet’s values were calculated as percentage of ground cover (%) on a particular grassland type and classified according to grassland management type. From a total of 103 relevés, 35 relevés were abandoned pastures (NP), 23 relevés abandoned meadows (NL), 20 relevés used pastures (KP) and 25 relevés used meadows (KL). The diversity of environmental grassland parameters and grassland management type was determined using modified Ellenberg indicator values (EIV) adjusted for the Mediterranean (Pignatti et al. 2005). The descriptive statistical analysis of environmental variables (Box & Whiskers diagrams) was conducted using the STATISTICA software package (StatSoft Inc. 2005).
A total of 624 plant taxa classified in 275 genera and 62 families was recorded whereas the top six families according to number of taxa (Asteraceae, Fabaceae, Poaceae, Lamiaceae, Liliaceae and Rosaceae) encompassed more than half (51.28 %) of the total recorded flora (Tab. 3).
According to phytogeographical analysis (Tab. 4), the nearly equal representation of the Mediterranean floral element (31.15 %) and Eurasian floral element (29.97 %) indicated that the studied area is located at the transition between the sub-Mediterranean and Mediterranean-mountain vegetation belt. Prevalent life forms include hemicryptophytes (53.83 %), which are typical for the grassland flora of pastures and meadows and indicate anthropogenic influence reflected in the form of grazing and burning. The relatively high prevalence of woody plants in the grassland habitats (N and P, 5.59 %) indicated processes of succession at some of the localities (Fig. 2).
The Ćićarija grasslands belong mostly to the Scorzonero-Chrysopogonetalia order (pastures) and partially to the Arrhenatheretalia order (meadows) (Poldini 1989, Kaligarič 1997, Poldini & Kaligarič 1997, Vitasović Kosić et al. 2011, 2012). A syntaxonomical interpretation of these associations is shown below.
From the total flora, 35 woody species (5.61 %) and 74 herbaceous species of the forest edge (11.86 %) from the class Trifolio-Geranietea sanguinei were singled out, indicating processes of vegetation succession at some of the localities (Tab. 5, Tab. 6). Among the endangered species, Gentiana symphyandra (EN) and the vulnerable Lilium bulbiferum (VU) should be noted.
According to grassland management, the largest number of woody and herbaceous species of the forest edge was detected within abandoned areas: NP – 58 taxa and NL – 28 species, while the used areas KL (16 taxa) and KP (7 species) contained significantly less.
The analysis of ecological indicator values (EIV) for woody and herbaceous species of forest edges (Fig. 3) showed that KP distinguished among the grassland management types, as can be seen by EIV nutrients, continentality, and light. Used pastures are generally homes to species that grow in poor soil nutrients (e.g., Genista sylvestris and Inula hirta), subcontinental (e.g., Asparagus tenuifolius), and continental species (e.g., Chamaecytisus hirsutus). As for the EIV of light, used pastures have more half-shade species, some of which cannot grow under full light (e.g., Helleborus multifidus subsp. istriacus). Contrary are used meadows where generally full-light species appear (Orobanche minor, Scabiosa columbaria, Rhinanthus aristatatus, etc.).
It is known that grassland management acts as a driving force in the diversity of the plant community (MacDonald et al. 2000, Kahmen et al. 2002, Wilson et al. 2003). During the last six decades, the abandonment of the traditional way of raising sheep resulted in different succession changes and significantly influenced biodiversity (Zupančić and Žagar 2002, de Bello et al. 2007). The main overgrowth of vegetation occurred in the contact zones between inadequately mowed and grazing plots. Other means of spreading woody species may include forest edges and shrub communities that occur as a phase in the very dynamic process of re-overgrowth, which most often has an anthropogenic origin (Čarni et al. 2002).
Immediately after a plot ceases to be mowed or used for grazing, the occurrence of a high percentage of successional species is almost instant (Poldini 1989, Kaligarič & Poldini 1997, see Tab. 6). Due to the low usage intensity of grasslands, the colonizing grass Brachypodium rupestre spread across the entire plot (Catorci et al., 2011, 2012). In this study B. rupestre appeared at a large frequency (<40 %) on KL and KP, and with an even