Rastlinska vrstna diverziteta izbranih dobovih in gradnovih gozdov v Sloveniji

In Slovenia, the plant species diversity on 225 research plots dominated by pedunculate oak (Quercus robur L.) and by sessile oak (Quercus petraea (Matt.) Liebl.) has been analysed. Plots of Q. robur are located in five, andplots of Q. petraea in four semi-natural managed forest complexes. In the tree layer, 28 species were found beside the dominant two oak species, with Carpinus betulus L., Picea abies (L.) Karst., Quercus cerris L. and Fagus sylvatica L. having significant shares of growing stock. Based on the understorey vegetation (shrub and herb layer, terricolous mosses), the Ddetrended Correspondence Analysis (DdCA) made a clear distinction between plots with dominant Q. robur and those with Q. petraea. The understorey vegetation also proved to be a valuable indicator of the site conditions and of forest management in the past. Based on ordination, lowland pedunculate oak forests of relatively long standing near to natural management have been separated from the pedunculate oak forests where spruce was favoured by the forest management, and from the man-made pedunculate oak stands on primary sites of Q. petraea. DCA clearly differentiated the sessile oak forests in warmer climate of Sub-Mediterranean region, and in warmer meso-sites of Pre-Pannonian region from other sessile oak forests. The main gradients of vegetation structure and of species diversity, as well main ecological gradients in different oak forests were obtained by ordination technique.Na 225 raziskovalnih ploskvah v dobovih (Quercus robur L.) in gradnovih (Quercus petraea (Matt.) Liebl.) gozdovih smo analizirali rastlinsko vrstno pestrost. Dobove ploskve so postavljene v petih, gradnove pa v štirih gospodarjenih gozdnih kompleksih. V drevesni plasti preučevanih gozdnih ekosistemov se poleg dominantnih vrst hrasta pojavlja še 28 vrst, med katerimi so v lesni zalogi bolj zastopani beli gaber (Carpinus betulus L.), smreka (Picea abies (L.) Karst.), cer (Quercus cerris L.) in bukev (Fagus sylvatica L.). Ordinacija DCA (Detrended Correspondence Analysis) je samo na osnovi vrst v pritalnih plasteh vegetacije (grmovna in zeliščna plast, na tleh rastoči mahovi) jasno ločila ploskve s prevladujočim dobom od ploskev z gradnom. Vrste pritalnih plasti so dober indikator rastiščnih razmer kot tudi gospodarjenja z gozdovi v preteklosti. Nna tej osnovi je ordinacija ločila nižinske dobove gozdove z razmeroma sonaravnim gospodarjenjem v daljšem obdobju od dobovih gozdov, v katerih so v preteklosti pospeševali smreko, in od umetno zasnovanega dobovega gozda na primarnih rastiščih gradna. Analiza jeločila tudi gradnov gozd, ki uspeva v toplejšem podnebju v submediteranskem območju, in gradnov gozd na toplejših rastiščih v predpanonskem območju od preostalih dveh gradnovih gozdov. Ordinacija raziskovalnih ploskev dobro odseva razlike v floristični sestavi hrastovih gozdov, nakazuje gradiente pestrosti pritalnih plasti vegetacije in glavne ekološke gradiente

Using Lidar Data to Analyse Sinkhole Characteristics Relevant for Understory Vegetation under Forest Cover\u2014Case Study of a High Karst Area in the Dinaric Mountains

In this article, we investigate the potential for detection and characterization of sinkholes under dense forest cover by using airborne laser scanning data. Laser pulse returns from the ground provide important data for the estimation of digital elevation model (DEM), which can be used for further processing. The main objectives of this study were to map and determine the geomorphometric characteristics of a large number of sinkholes and to investigate the correlations between geomorphology and vegetation in areas with such characteristics. The selected study area has very low anthropogenic influences and is particularly suitable for studying undisturbed karst sinkholes. The information extracted from this study regarding the shapes and depths of sinkholes show significant directionality for both orientation of sinkholes and their distribution over the area. Furthermore, significant differences in vegetation diversity and composition occur inside and outside the sinkholes, which indicates their presence has important ecological impacts