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ŠUMARSKI LIST 1-2/2019 str. 39     <-- 39 -->        PDF

by algal limestones, dolomites and dolomites with the limestone lens. Its main lithological characteristic is alteration of dolomites and limestones. The younger member 3J3 is represented by algal-foraminiferal limestones and dolomites from the Lower Malm. Various types of limestones with mud or sparicalcitic cement and crystalinic dolomites are a characteristic feature of this member (Velić and Sokač, 1981). The Quartar sediments are mostly eroded, but they appear locally in the doline as the rock-creeped breccias. In the tectonic structure of the researched area, intense tectonic fractures can be distinguished. The facilitating factor for the genesis of the doline was its position on the interception of faults, with the spreading directions NW – S, SE and NE – SW, and also the presence of a few secondary fractures. Due to the limestone/dolomite alternation and by tectonic stress dense network of fissures the doline is characterized by intense rock disintegration and slope processes, especially in the part built of dolomite. Along the fault lines there are steeper slopes with rock debris at the base. Different slope inclination and geomorphological processes therefore resulted in pedogenesis (alternation of bare rocks, shallow brown soils on limestones and dolomites, thicker colluvium deposits below steep slopes), local hydrological paths of water infiltration and microclimate (exposition and humidity).
To gain wider perspective of the investigated area, a few different types of research were included in this study, such as geomorphological, microclimatic and floristic research.
Geomorphological research included the field work, where geomorphological forms and processes were observed, followed by the analysis of cartographic sources. Morphometric analyses were made on Croatian base map 1:5000 (URL 1).
Microclimatic measurements in the doline were performed during the vegetation period of 2015, from April to September, using three data loggers (Onset HOBO Pro v2). They recorded air temperature, relative humidity and dew point temperature with the measurement interval of 30 minutes. Measuring points were set on the slope of the southern exposition (z = 508 m a. s. l.), at the bottom of the doline (z = 464 m a. s. l.) and on the slope of the northern exposition (z = 508 m a. s. l.). Data loggers were set on a tree, fixed on the trunk 1 meter above the ground. The loggers were facing north, to protect them from the direct solar radiation. During the measuring period, two out of three data loggers stopped working due to the battery error.
Floristic research was conducted during the vegetation season of 2015, to investigate the floristic structure on the slopes of the doline of different expositions. Plant taxa were recorded on the slopes of the southern and northern expositions, and at the bottom of the doline. The taxa were mostly identified in the field, with some exceptions, which were collected and identified subsequently using standard floristic literature (Tutin et al., 1968 – 1980, 1993; Pignatti 1982; Jávorka and Csapody, 1991; Domac, 1994). The plant material is partly deposited in the Herbarium Collection of the Croatian Natural History Museum (CNHM). The nomenclature follows Flora Croatica Database (Nikolić, 2018).
We have performed taxonomic, chorological, Ellenberg’s indicator values (hereafter: Eiv) and life form analyses. Besides the analysis of the total flora, the floristic analysis for different parts of the doline was also performed, using the Sörensen index of similarity. Legal protection of taxa was determined according to the Nature Protection Act (Official Gazette 80/2013) and the Ordinance on Strictly Protected Species (Official Gazette 144/2013, 73/2016). Moreover, the taxa listed in the Red Book of Vascular Flora of Croatia (Nikolić and Topić, 2005) were marked using the adequate IUCN designations: VU – Vulnerable, NT – Near Threatened, LC – Least Concern, DD – Data Deficient.
Chorological analysis follows the classification used by Horvatić et al. (1967 – 1968). The chorological groups used in this paper are: 1 – Mediterranean, 2 – Illyrian-Balkan, 3 – South-European, 4 – Atlantic, 5 – East European-Pontic, 6 – Southern-East European, 7 – Central European, 8 – European, 9 – Eurasian, 10 – Circumholarctic, 11 – Widespread. The data were taken from the Flora Croatica Database (Nikolić, 2018) and from the following literature sources: Tutin et al. (1993), Pignatti (1982), Buzjak (2001), Pandža (2010), Nežmah and Ljubičić (2012), Britvec et al. (2014).
Life forms and ecological indicator values were given according to Ellenberg and Leuschner (2010). The data were mostly taken from the Flora Croatica Database (Nikolić, 2018) and supplemented with the following sources: Ellenberg and Leuschner (2010), Pignatti (2005). The following abbreviations were used for the presentation of life forms: P – Macrophanerophytes, N – Nanophanerophytes, Z – Woody Chamaephytes, C – Herbaceous Chamaephytes, H – Hemicryptophytes, G – Geophytes and T – Therophytes. Ecological indicator values included in the analysis were: L – light, T – temperature, F – soil moisture and R – reaction. For three taxa (Cardamine waldsteinii Dyer, Piptatherum virescens (Trin.) Boiss., Polystichum × illyricum (Borbás) Hahne) some of the above mentioned data were not available in the literature; therefore these taxa were excluded from the analysis.
Geomorphology – Geomorfologija
Regarding the morphometrical features, the Sovljak doline has a perimeter axis of 310 m in the N-S direction, and 450 m