Early responses of biodiversity indicators to various thinning treatments in mountain beech forestsValeria Altieri
, Roberto Tognetti
, Lado Kutnar
, Bruno Lasserre
, Marco Marchetti
, Carmen Giancola
, Simone Di Benedetto
, Stefania Di Lella
, Fabio Lombardi
Povzetek: In recent decades, the conservation of biodiversity has become one of the main areas under consideration in managing forests in an ecologically sustainable way. Forest management practices are primary drivers of diversity and may enhance or decrease forest biodiversity, according to the measures applied (thinning options). We have focused on three beech (Fagus sylvatica L.) forests across a latitudinal gradient in Italy, characterised by different structures resulting from dissimilar management. We tested the short-term effects of differently-based silvicultural intervention vs. stands where no silvicultural practices were applied on biodiversity indicators and related proxies: deadwood amounts, microhabitat density, floristic richness and life form abundance. In each study area, the occurrence of the above indicators and proxies was evaluated before and after the implementation of crop tree thinning (CTT) and thinning from below (LT) methods, comparing them with control areas where no interventions were performed. After two years, the management options resulted in different responses of the investigated parameters. The CTT increased deadwood amounts in comparison with the LT ones, while stumps increased significantly after the LT thinning. Microhabitats increased significantly where intervention was not undertaken. On the contrary, they remained unaltered after the LT treatments. CTT thinning created favourable conditions for the development of microhabitats and their proliferation in the long term. Two years after the application of the CTT thinning treatment, all forest stands demonstrated a significant increase in their floristic richness and herb layer cover. Significant differences were also found in both the frequency and cover of life forms in relation to silvicultural treatment. These findings provide a better understanding of short-term effects of silvicultural treatment useful for maintaining biodiversity in mountain beech forests.
Ključne besede: deadwood, microhabitats, understory vegetation, mountain forests, sustainable forest management, Italian forests
DiRROS - Objavljeno: 04.10.2018; Ogledov: 72; Prenosov: 3
Celotno besedilo (835,42 KB)
Varstvo gozdnih tal z vidika zakonodaje : ali obstajajo omejitve pri rabi sodobnih tehnologij?Janez Krč
, Matevž Mihelič
, Špela Pezdevšek Malovrh
Povzetek: Čeprav so tla ključnega pomena za trajnostni razvoj, se v zadnjem desetletju povečuje degradacija tal v EU. Izvzeta niso niti gozdna tla, ki so v zadnjih letih zaradi povečanega obsega naravnih nesreč in posledične rabe sodobnih tehnologij v Sloveniji vse pogosteje izpostavljena različnim degradacijskim procesom, med katerimi se najpogosteje pojavlja zbijanje tal. Prispevek s pomočjo analize vsebine analizira obstoječe politične dokumente, ki se nanašajo na področje varstva tal s poudarkom na zbitosti tal ter omejitve, ki lahko vplivajo na rabo sodobnih tehnologij, na mednarodni EU in nacionalni ravni. Rezultati so pokazali, da je EU sprejela ambiciozne cilje, povezane s preprečevanjem nadaljnje degradacije tal in ohranjanja funkcij tal v Tematski strategiji za varstvo tal, kjer je opredeljeno osem glavnih nevarnosti za tla, med katerimi je tudi zbitost tal. Ker pa na podlagi Strategije predlagana Direktiva o določitvi okvira za varstvo tal ni bila sprejeta, so različni vidiki varstva tal razdrobljeni na številna področja politik EU, pri čemer ima okoljska pomembnejšo vlogo. Kljub temu, da je zbitost tal identificirana kot ena izmed groženj tlom, je v političnih dokumentih EU relativno slabo zastopana in obravnavana. Gozdarska zakonodaja trenutno varstvo gozdnih tal obravnava le posredno predvsem v smislu izvajanja del v gozdovih, ki naj bi čim manj ogrožala gozdni ekosistem. V prihodnosti je treba k problematiki varstva (gozdnih) tal pristopiti veliko bolj konkretno kot do sedaj, predvsem zaradi vse pogostejše rabe sodobnih tehnologij v gozdarstvu, in predvsem postaviti dopustne meje uporabe sodobnih tehnologij na posameznih talnih tipih.
Ključne besede: politični okvirji, zakonodaja, gozdna tla, varstvo tal, degradacijski procesi, degradacija tal, zbitost tal, sodobne tehnologije
DiRROS - Objavljeno: 07.09.2018; Ogledov: 163; Prenosov: 10
Celotno besedilo (1,31 MB)
Vplivni dejavniki poseka v zasebnih gozdovih Slovenije v obdobju 1995-2014Andrej Bončina
, Andrej Ficko
, Domen Češarek
Povzetek: Analizirali smo posek v zasebnih gozdovih Slovenije v obdobju 1995-2014. V raziskavo smo vključili odseke, ki so v popolni zasebni lasti (n = 16.234). Z multiplo linearno regresijo smo analizirali vpliv devetih naravnih, štirih gozdnogospodarskih in treh socioekonomskih spremenljivk na letni hektarski posek in srednje posekano drevo. Ugotovili smo, da z naraščanjem velikosti parcele in posesti narašča tudi povprečni letni posek, medtem ko se z večanjem števila (so)lastnikov v odseku, naklonom, oddaljenostjo od ceste in oddaljenostjo od naselja, potencialnim deležem smreke v odseku in deležem sukcesijskih stadijev v odseku posek zmanjšuje. Na višino poseka pozitivno vplivajo še: delež smreke v odseku, potencialna produkcijska sposobnost rastišča, razdalja od centroida odseka do najbližjega gozdnega roba, odprtost in delež bukve v odseku. Na srednje odkazano drevo najbolj pozitivno vpliva potencialna produkcijska sposobnost rastišča, najbolj negativno pa oddaljenost od ceste.
Ključne besede: gospodarjenje z gozdovi, posek, zasebni gozd, razdrobljenost posesti
DiRROS - Objavljeno: 07.09.2018; Ogledov: 191; Prenosov: 13
Celotno besedilo (5,40 MB)
Resin yield of Pinus nigra and Pinus sylvestris in the Slovenian KarstRobert Brus
, Kristjan Jarni
, Miha Brecelj
, Domen Gajšek
Povzetek: The aim of our research was to study the impact of various environmental factors on the resin production of pines in the Slovenian Karst. Five plots were established % three in Pinus nigra (Arnold) stands and two in Pinus sylvestris (L.) stands. On each plot, the 19-20 most vigorous dominant or codominant trees with a minimum diameter at breast height (DBH) of 20 cm were selected and their resin yield analysed in 2012. Resin yield in P. nigra was considerably higher than that in P. sylvestris. The average resin yield per tree during the study period of 102 days was 1.144 kg for P. nigra and 0.612 for P. sylvestris. There were substantial differences in resin yield among individual trees in the study period: 0.336-2.487 kg for P. nigra and 0.249-1.270 kg for P. sylvestris. The resin yield in P. nigra was considerably higher for the trees with larger DBH, while this was not the case in P. sylvestris. Tree species was the most important factor in resin yield. Increased precipitation resulted in higher resin yields on most plots, whereas better site productivity positively affected resin yield on all P. nigra plots but not on P. sylvestris plots.
Ključne besede: Black pine, Scots pine, resin production, resin yield, Slovenian Karst
DiRROS - Objavljeno: 05.07.2018; Ogledov: 347; Prenosov: 27
Celotno besedilo (1,78 MB)
Phytosociological description of mesophilous colline-submontane Fagus sylvatica and Carpinus betulus forests in Slovenian IstriaZvone Sadar
, Igor Dakskobler
Povzetek: A phytosociological analysis of 46 relevés of mesophilous colline and submontane Fagus sylvatica as well as (or) Carpinus betulus forests was conducted in Slovenian Istria. It was established that they are frequently syndynamically interrelated: in places, common hornbeam stands are merely a degradation stage on beech sites, and can be classified into the subassociation Ornithogalo pyrenaici-Fagetum fraxinetosum orni (its locus classicus is in the Goriška Brda Hills) and into the new subassociation Ornithogalo pyrenaici-Carpinetum betuli seslerietosum autumnalis. Compared with similar submontane stands from other parts of the western and southwestern Slovenia they are slightly poorer in species, with fewer diagnostic species of alliances Erythronio-Carpinion, Aremonio-Fagion and Tilio-Acerion, order Fagetalia sylvaticae and class Vaccinio-Piceetea, and with more diagnostic species of the order Quercetalia pubescenti-petraeae. Geographically, they are characterised by the taxon Helleborus odorus subsp. istriacus. Although they cover small areas these forests generate high yields and are therefore important both economically and as biotopes of protected species.
Ključne besede: phytosociology, synsystematics, beech sites, Ornithogalo-Carpinetum, Ornithogalo-Fagetum, Istria, Slovenia
DiRROS - Objavljeno: 15.06.2018; Ogledov: 258; Prenosov: 3
Celotno besedilo (3,43 MB)Gradivo je zbirka in zajema 1 gradivo!
Genetic diversity of core vs. peripheral Norway spruce native populations at a local scale in SloveniaHojka Kraigher
, Gregor Božič
, Marjana Westergren
Povzetek: We investigated the levels of genetic diversity and population differentiation among core and peripheral populations of Norway spruce along an altitudinal gradient (from inversions to upper tree line) using isoenzymes (ISO) and nuclear simple-sequence repeats (SSR) markers on overlapping set of populations. Twenty-seven to seventy trees from 11 and 7 populations were genotyped with isoenzymes and SSRs, respectively. The results partially conform to the expectations of the central-peripheral hypothesis (CPH) and are consistent for both marker sets. Genetic differentiation among peripheral populations was low but significantly different from zero (FST-ISO = 0.013, FST-SSR = 0.009) and higher than that among core populations (FST-ISO = 0.007, FST-SSR = 0.005), conforming to central peripheral hypothesis. Contrastingly, levels of genetic diversity assessed by both richness and equitability measures did not significantly differ between peripheral and core populations (AR-ISO = 2.20 vs. 2.14, AR-SSR = 17.16 vs. 17.68, HE-ISO = 0.183 vs. 0.185, and HE-SSR = 0.935 vs. 0.935 for peripheral and core populations, respectively).
Ključne besede: central peripheral hypothesis, Picea abies (L.) Karst., genetic diversity, genetic differentiation, upper tree line, inversion
DiRROS - Objavljeno: 07.05.2018; Ogledov: 270; Prenosov: 13
Celotno besedilo (561,16 KB)
Green water reconstructed for Rižana watershed, SW SloveniaTom Levanič
, Urša Vilhar
, Simon Poljanšek
Povzetek: In this case study, set in south-west Slovenia, the feasibility of reconstructing green water (the combined amount of evaporated and transpired water in trees and available in the soil) was investigated. In a simplifed scheme, the amounts of green water were calculated as the diference between precipitation and discharge of the Rižana river. Based on the methods of dendroclimatology, the climate signal was tested on black pine (Pinus nigra Arnold) trees growing in the south-western part of the Rižana watershed near the Slovenian sea coast. Results showed that the measured tree-ring parameters of tree-ring width and density are strongly dependent on the amount of green water. The strongest correlation was between available green water in the period May-August and tree-ring width (r=0.61) and latewood width (r=%0.64) (both n=46, p<0.001). The climate signal is signifcant and stable through time, which enabled the reconstruction of green water data into the period before instrumentally measured data. Green water data from the May-August period were extended from 1966 back to 1937 using tree-ring width, and back to 1940 using latewood width. With additional coring of older trees and the extension of existing chronologies, even longer reconstructions could be developed.
Ključne besede: tree-ring width, tree-ring density, dendrochronology, dendroclimatology, reconstruction
DiRROS - Objavljeno: 18.04.2018; Ogledov: 275; Prenosov: 14
Celotno besedilo (1003,43 KB)
Growth response of different tree species (oaks, beech and pine) from SE Europe to precipitation over timeSaša Orlović
, Stefan Stjepanović
, Bratislav Matović
, Tom Levanič
, Dejan Stojanović
Povzetek: Changing climatic conditions can have various consequences for forest ecosystems, from increasing frequencies of forest fires, ice and windstorm events to pathogen outbreaks and mass mortalities. The Standardized Precipitation Index (SPI) was chosen for the evaluation of drought impact on the radial growth of trees after extensive preliminary testing of various calculated monthly climate parameters from the CARPATCLIM database. SPI was calculated for periods between 3 and 36 months for different sites (lowland and mountainous parts of Serbia, Southeast Europe), from which Quercus robur, Q. cerris, Fagus sylvatica and Pinus sylvestris samples were acquired. Bootstrapped Pearson%s correlations between SPI monthly indices and radial growth of tree species were calculated. We found that 12-month SPI for summer months may be a good predictor of positive and negative growth of different species at different sites. The strongest positive correlations for five of six tree-ring width chronologies were between 12-month June and 14-month September SPI, which implies that high growth rates can be expected when the autumn of the previous year, and winter, spring and summer of the current year, are well supplied with precipitation, and vice versa (low precipitation in given period/low growth rates).
Ključne besede: standardized precipitation index, SPI, climate change, tree mortality, Quercus sp., Fagus sylvatica, Pinus sylvestris
DiRROS - Objavljeno: 18.04.2018; Ogledov: 311; Prenosov: 14
Celotno besedilo (2,91 MB)
DendroTools : R package for studying linear and nonlinear responses between tree-rings and daily environmental dataTom Levanič
, Jernej Jevšenak
Povzetek: We introduce in this paper the dendroTools R package for studying the statistical relationships between tree-ring parameters and daily environmental data. The core function of the package is daily_response(), which works by sliding a moving window through daily environmental data and calculating statistical metrics with one or more tree ring proxies. Possible metrics are correlation coefficient, coefficient of determination and adjusted coeffi- cient of determination. In addition to linear regression, it is possible to use a nonlinear artificial neural network with the Bayesian regularization training algorithm (brnn). dendroTools provides the opportunity to use daily climate data and robust nonlinear functions for the analysis of climate-growth relationships. Models should thus be better adapted to the real (continuous) growth of trees and should gain in predictive capabilities. The dendroTools R package is freely available in the CRAN repository. The functionality of the package is demonstrated on two examples, one using a mean vessel area (MVA) chronology and one a traditional tree-ring width (TRW).
Ključne besede: dendroclimatology, daily climate data, running window, nonlinear modelling, tree-ring proxies, climate reconstruction
DiRROS - Objavljeno: 16.04.2018; Ogledov: 364; Prenosov: 18
Celotno besedilo (1,19 MB)
Occurrence of invasive alien plant species in the floodplain forests along the Mura River in SloveniaLado Kutnar
, Aleksander Marinšek
Povzetek: Background and purpose: The objectives of our study were to identify invasive alien plant species (IAS) in the main Natura 2000 forest habitat types (FHT) along the Mura River in Slovenia, and to estimate their abundance and cover. The aim of our study was to find out a) Which IAS appear in the research forests? b) What is their frequency and cover percentage? c) Whether individual IAS prosper better in some FHT than others? d) What is the correlation between the cover of IAS and the tree layer cover? Materials and methods: We analysed the fidelity of invasive plant species to individual FHT. The studied FHTs along the Mura River were the following: 91E0* (Alluvial forests with Alnus glutinosa and Fraxinus excelsior), 91F0 (Riparian mixed forests of Quercus robur, Ulmus laevis and Ulmus minor, Fraxinus excelsior or Fraxinus angustifolia, along the great rivers) and 91L0 (Illyrian oak-hornbeam forests). Two forest areas of about 600 ha were studied in total. With the intention to calculate number and cover of IAS some statistical analysis was made. In addition, correlations between the abundances of the most present IAS and cover of upper tree layer were carried out. Results: In total, 15 IAS were recorded in studied FHTs. Some species, like Robinia pseudoacacia, Impatiens glandulifera, I. parviflora, Fallopia japonica (incl. F. x bohemica), Erigeron annuus, Ambrosia artemisiifolia, Amorpha fruticosa, Conyza canadensis and Juncus tenuis occur only in one or two FHTs, while some species can be found in all studied FHTs (e.g. Solidago sp.). We found out that the most threatened forests are those with prevailing Salix alba, Alnus glutinosa, Fraxinus angustifolia and Ulmus laevis tree species. Those are the forests of FHT 91E0 which have less dense tree canopies, grow closest to the river and on the wettest sites. We found a statistically significant higher number and cover of IAS in the FHT 91E0 and the lowest number and cover in FHT 91L0. Conclusions: Alluvial forests with Alnus glutinosa and Fraxinus excelsior (FHT 91E0) along the Mura River are most prone to invasion of IAS. The increasing presence of IAS in the study areas seriously affects natural regeneration, stability, and continuity of floodplain forests in all other FHTs in the study area. At the same time the amount of IAS in these forests also depends on management measures and their intensities which accelerate light availability. Some measures and guidelines for managing of these forests with the purpose of reducing IAS impacts are suggested in this study.
Ključne besede: non-native plants, riparian vegetation, habitat types, conservation management, forest management
DiRROS - Objavljeno: 16.04.2018; Ogledov: 234; Prenosov: 15
Celotno besedilo (1,03 MB)