41. Contrasting resource dynamics in mast years for European Beech and Oak - a continental scale analysisAnita Nussbaumer, Arthur Gessler, Sue Benham, B. De Cinti, Sophia Etzold, Morten Ingerslev, Frank Jacob, François Lebourgeois, Tom Levanič, Hrvoje Marjanović, 2021, izvirni znanstveni članek Povzetek: Resource allocation to different plant tissues is likely to be affected by high investment into fruit production during mast years. However, there is a large knowledge gap concerning species-specific differences in resource dynamics. We investigated the influence of mast years on stem growth, leaf production, and leaf carbon (C), nitrogen (N), and phosphorus (P) concentrations and contents in Fagus sylvatica, Quercus petraea, and Q. robur at continental and climate region scales using long-term data from the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) and similar datasets. We discussed the results in the light of opposing resource dynamics hypotheses: (i) resource accumulation before mast years and exhaustion after mast years (resource storage hypothesis), (ii) shifting resources from vegetative to generative compartments (resource switching hypothesis), and (iii) investing resources concurrently in both vegetative and generative compartments (resource matching hypothesis). Linear mixed-effects modelling (LMM) showed that both stem growth and leaf production were negatively influenced by weather conditions which simultaneously lead to high fruit production. Thus, the impact of generative on vegetative growth is intermixed with effects of environmental factors. Superposed epoch analyses and LMM showed that for mast behaviour in F. sylvatica, there are indicators supporting the resource storage and the resource switching hypotheses. Before mast years, resources were accumulated, while during mast years resources switched from vegetative to generative tissues with reduced stem and leaf growth. For the Quercus species, stem growth was reduced after mast years, which supports the resource storage hypothesis. LMM showed that leaf C concentrations did not change with increasing fruit production in neither species. Leaf N and P concentrations increased in F. sylvatica, but not in Quercus species. Leaf N and P contents decreased with increasing fruit production in all species, as did leaf C content in F. sylvatica. Overall, our findings suggest different resource dynamics strategies in F. sylvatica and Quercus species, which might lead to differences in their adaptive capacity to a changing climate.
Ključne besede: climate change, Fagus sylvatica, long-term monitoring, mast fruiting, Quercus petraea, Quercus robur, resource dynamics
Objavljeno v DiRROS: 15.07.2021; Ogledov: 872; Prenosov: 642
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42. Stanje in spremembe slovenskih gozdov v zadnjih dveh desetletjih - rezultati velikoprostorskega monitoringa gozdovMitja Skudnik, Jernej Jevšenak, Aleš Poljanec, Gal Kušar, 2021, izvirni znanstveni članek Povzetek: V prispevku so predstavljeni rezultati velikoprostorskega monitoringa gozdov in gozdnih ekosistemov (MGGE), ki je na sistematični mreži trajnih vzorčnih ploskev (4 km x 4 km) prek celotne Slovenije potekal v letih 2000, 2007, 2012 in 2018. Predstavljeni so osnovni znaki o stanju (lesna zaloga in volumen odmrlih lesnih kosov) in spremembah (prirastek, posek, volumen novih sušic) slovenskih gozdov. Lesna zaloga merskega drevja se je med letoma 2000 in 2012 povečala iz 299 na 334 m3 ha-1. V letu 2018 je bila ocena za povprečno lesno zalogo 330 m3 ha-1. Vzorčna napaka ocene lesne zaloge je znašala od 4 do 5 %. Med letoma 2012 in 2018 se je predvsem zmanjšala lesna zaloga iglavcev, in sicer iz 156 na 144 m3 ha-1. Poglavitni razlog je bil povečan posek, ki je bil posledica številnih ujm in gradacij podlubnikov. Tako se je povečal posek, in sicer iz 4,3 v obdobju 2007/12 na 6.3 m3 ha-1 leto v obdobju 2012/18. K povečanemu poseku večinski delež prispevajo iglavci. V zadnjem obdobju je bil bruto prirastek z vrastjo in prirastkom posekanih dreves ocenjen na 7,9 m3 ha-1 leto. Ocena volumna odmrlih lesnih kosov za leto 2018 je znašala 24 m3 ha-1. V prispevku je podrobno predstavljena tudi metodologija izračunov ocen povprečij na podlagi sistematičnega vzorčenja. Podatki MGGE so bili uporabljeni predvsem za potrebe mednarodnega poročanja o stanju in razvoju slovenskih gozdov ter v omejenem obsegu tudi za nacionalno poročanje o trajnostnem razvoju slovenskih gozdov. Prednost vzpostavljenega sistema je mednarodno usklajena metodologija popisa na sistematični mreži ploskev preko celotne države. Trenutni sistem ima tudi določene omejitve, in sicer malo vzorčnih ploskev, kar vodi v večjo vzorčno napako pri izračunih nekaterih dendrometrijskih kazalnikov. V letu 2020 smo sistem MGGE nadgradili v kontinuiran panelni sistem, katerega osnova bodo nove trajne vzorčne ploskve na neuravnani sistematični mreži gostote 2 km x 2 km, kar je dobro izhodišče za uvedbo Nacionalne gozdne inventure (NGI) v Sloveniji.
Ključne besede: monitoring gozdov in gozdnih ekosistemov, lesna zaloga, prirastek, mortaliteta, odmrla biomasa, posek, sušice
Objavljeno v DiRROS: 12.07.2021; Ogledov: 1266; Prenosov: 497
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43. Predlogi za pravno ureditev področja upravljanja s smrekovimi podlubnikiNikica Ogris, Andreja Kavčič, Marija Kolšek, Maarten De Groot, 2021, elaborat, predštudija, študija Ključne besede: Ips typographus, pravilnik o varstvu gozdov, osmerozobi smrekov lubadar, pasti, skladišča gozdnih lesnih sortimentov, monitoring, zatiranje, optimizacija
Objavljeno v DiRROS: 29.06.2021; Ogledov: 859; Prenosov: 0 |
44. Green space area and type affect bird communities in a South-eastern European cityMaarten De Groot, Katarina Flajšman, Tomaž Mihelič, Urša Vilhar, Primož Simončič, Andrej Verlič, 2021, izvirni znanstveni članek Povzetek: Urbanization decreases the species richness and results in the homogenization of bird communities. Bird species are important indicator species for biodiversity and reflect the habitat quality of urban forests and other green spaces. In this study we investigated the key drivers that influence bird communities in urban forests and green spaces in the Southeastern European city of Ljubljana, Slovenia. We were interested in how the number of species, species dissimilarity and indicator species are affected by the type of green space (urban forest vs park), area of green space and type of urbanization (urban vs peri-urban areas). We sampled birds twice in 2012 in 39 standardized point counts across Ljubljana. We found that the abundance was influenced by the area of the green space. Species dissimilarity and species turnover are affected by the area and type of green space. Interestingly, the analysis showed that the species composition of peri-urban areas was similar to that of urban areas. Indicator species were found for all environmental variables. On the basis of the results, we suggest the strategy that would increase the diversity of birds and increase the stability of their populations in urban areas. Urban planners should encourage 1) both forests and parks since they harbour different species of birds, 2) larger green spaces since larger areas have species that are more typical of larger areas and 3) a mosaic of a larger number of smaller forest remnants combined with larger forest complex serving as source areas.
Ključne besede: urban forest, bird species composition, forest remnant, urbanization, peri-urban forest, bird monitoring, species richness
Objavljeno v DiRROS: 14.06.2021; Ogledov: 1208; Prenosov: 565
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49. Reconstruction of brown bear population dynamics in Slovenia in the period 1998-2019 : ǂa ǂnew approach combining genetics and long-term mortality dataKlemen Jerina, Andrés Ordiz, 2021, izvirni znanstveni članek Povzetek: Reliable data and methods for assessing changes in wildlife population size over time are necessary for management and conservation. For most species, assessing abundance is an expensive and labor-intensive task that is not affordable on a frequent basis. We present a novel approach to reconstructing brown bear population dynamics in Slovenia in the period 1998-2019, based on the combination of two CMR non-invasive genetic estimates (in 2007 and 2015) and long-term mortality records, to show how the latter can help the study of population dynamics in combination with point-in-time estimates. The spring (i.e. including newborn cubs) population size estimate was 383 (CI: 336-432) bears in 1998 and 971 (CI: 825-1161) bears in 2019. In this period, the average annual population growth rate was 4.5 %. The predicted population size differed by just 7 % from the non-invasive genetic size estimate after eight years, suggesting that the method is reliable. It can predict the evolution of the population size under different management scenarios and provide information on key parameters, e.g. background mortality and the sex- and age-structure of the population. Our approach can be used for several other wildlife species, but it requires reliable mortality data over time.
Ključne besede: genetic estimates of population size, mortality records, population monitoring, population size, predictive modelling, brown bear
Objavljeno v DiRROS: 28.03.2021; Ogledov: 4053; Prenosov: 2357
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50. Spremljanje koncentracije askospor glive Eutypella parasiticaTine Hauptman, 2021, strokovni članek Povzetek: Gliva Eutypella parasitica izvira iz Severne Amerike in povzroča bolezen, imenovano javorov rak. V Sloveniji so jo prvič našli leta 2005, zdaj je razširjena po vsej državi, izkoreninjenje bolezni ni več mogoče. Da bi preprečili nadaljnje širjenje bolezni in zmanjšali število novih okužb, je treba okužena drevesa posekati. Pri tem velja navodilo, da okuženi del debla izrežemo vsaj 50 cm nad rano in pod njo, izrezani del pa nato na mestu sežgemo ali pa položimo na gozdna tla tako, da je rakava rana usmerjena proti tlom. Učinkovitost slednjega ukrepa smo želeli preverjati s spremljanjem koncentracij askospor glive E. parasitica v zraku, pred izvedenim ukrepom in po njem. Spremljanje ni bilo uspešno, tako da učinkovitosti ukrepa ne moremo potrditi. V prispevku predstavljamo metode spremljanja in razpravo o morebitnih razlogih za neuspešno lovljenje askospor glive E. parasitica.
Ključne besede: javorov rak, Eutypella parasitica, monitoring, volumetrični vzorčevalnik, Slovenija
Objavljeno v DiRROS: 08.03.2021; Ogledov: 1382; Prenosov: 392
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