Šumarski list, Vol. 138 No. 3-4, 2014.
Izvorni znanstveni članak
FLORISTIC AND VEGETATION CHARACTERISTIC OF FOREST EDGES AND GRASSLANDS OF ĆIĆARIJA (CROATIA)
Ivana Vitasović Kosić
orcid.org/0000-0001-9372-5892
; Sveučilište u Zagrebu, Agronomski fakultet
Mihaela Britvec
; Sveučilište u Zagrebu, Agronomski fakultet
Sažetak
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 greater frequency (>40 %) on NL and NP (see Tab. 5, compare Vitasović Kosić et al. 2012). The occurrence of B. rupestre in Ćićarija is consistent with several studies, all of which emphasize the role of B. pinnatum and B. rupestre in the invasion of unmanaged grasslands through processes of competition and related problems of conservation (During & Willems 1984, Bobbink & Willems 1987). According to Grime (1973, 2001), B. rupestre possesses dominant features such as large size, strong vegetative reproductive capacity (with marked lateral spreading), growth from basal meristems (Stebbins 1972), and high phytomass production (Catorci et al. 2012). Moreover, its silica-rich leaves render this species poorly palatable for sheep (Grime et al. 1988), thus enabling the formation of a large amount of plant litter and a consequent decrease in floristic diversity (Bonanomi and Allegrezza 2004; Bonanomi et al. 2009).
Under-grazing and irregular mowing (i.e., low disturbance) lead to the floristic homogenization of a system (Vitasović Kosić et al. 2011), which ultimately leads to a reduction in plant diversity. Meadows are subjected to the invasion of B. rupestre to a larger extent and, as stated by Bennie et al. (2006), they are more vulnerable to the loss of floristic diversity than pastures after regular management ceases. For this reason, regular mowing should be maintained and intensified. As for dry pastures, a solution for more efficient management could be in using very low selective herbivores, such as cows, donkeys or horses, for grazing.
In conclusion, particular attention in the protection and preservation of grasslands should be given to certain management measures (grazing and mowing) in order to maintain biodiversity, prevent grassland succession, and maintain control of the spread of B. rupestre. The results of this research can provide the basis for the development of new management plans, which will require specific knowledge on the preservation of biodiversity, particularly in Special Protected Areas (SPA) within the Natura 2000 network.
Syntaxonomical interpretation:
FESTUCO-BROMETEA Braun-Blanquet et R. Tüxen 1943
SCORZONERO-CHRYSOPOGONETALIA Horvatić et Horvat (1956) 1958
Saturejon subspicatae Horvatić 1975
Carici humili-Centaureetum rupestris Horvat 1931
aa) subas. satureetosum variegatae Poldini 1989 (= as. Saturejo subspicatae-Caricetum humilis Trinajstić /1981/1999, corr.2007)
ab) subas. laserpitietosum sileris Kaligarič et Poldini 1997, variant with Laserpitium siler (so far observed only in Gorski Kotar)
ac) subas. seslerietosum juncifoliae Horvat 1962 (= as. Seslerio juncifoliae-Caricetum humilis Horvat 1930)
Scorzonerion villosae Horvatić 1949
Danthonio-Scorzoneretum villosae Horvatić (1956) 1958
subas. koelerietosum macranthae Vitasović Kosić 2011.
Bromo-Chrysopogonetum grylli Horvat 1960
BROMETALIA ERECTI Braun-Blaunquet 1936
Bromion erecti W. Koch 1926
Koelerio pyramidatae-Brachypodietum rupestris Trinajstić (1981) 2005
MOLINIO-ARRHENATHERETEA R. Tüxen 1937
ARRHENATHERETALIA Pawlowski 1928
Arrhenaterion elatioris Braun-Blaunquet 1926
subas. Anthoxantho-Brometum erecti Poldini 1980 (= subas. Arrhenatheretum elatioris brometosum erecti Poldini 1989) – first time recorded in Croatia
Ključne riječi
grasslands; Scorzonero-Chrysopogonetalia; Brachypodium rupestre; woody species; herbaceous species of the forest edge; Ćićarija; Croatia
Hrčak ID:
121737
URI
Datum izdavanja:
30.4.2014.
Posjeta: 2.349 *