Silver fir (Abies alba Mill.) distribution in Slovenian forests

We analysed the characteristics of silver fir (Abies alba Mill.) occurrence and distribution in Slovenia using databases of the Slovenian Forest Service (SFS). Silver fir is the third most widely distributed tree species in Slovenia, occurring in approximately 40 % of total forest area, but abundantly in less than 10 %. Its share in total growing stock varies between separate forest management regions. It is more abundant in the Dinaric and part of the Pre-alpine phytogeographic regions. The highest share in total growing stock reaches at altitudes between 800 m and 1000 m above sea level, forests with silver fir cover the most extensive surface in the altitude belt from 1000 to 1200 m. Silver fir occurs abundantly in 11 syntaxes. Between them, silver fir-beech forests (Abieti-Fagetum dinaricum TREG. 57, syn.: Omphalodo-Fagetum (TREG.57 corr. PUNC.80) MAR et al. 93) strongly prevail, followed by fir forests with fern (Dryopterido-Abietetum KOŠ.65, syn.: Galio rotundifolii-Abietetum BARTSCH.40). Silver fir diameter distribution considerably varies between separate forest management regions. The regions with the highest share of silver fir (Postojna, Kočevje) dominate also in having large diameter silver fir trees, whereas in other regions (e.g. Nazarje, Kranj, Maribor) small diameter silver fir trees are prevalent. Ddevelopmental stage structure shows that in forest stands with silver fir there is a higher share of timber phase, stands in regeneration, youth stands and selective forests. Considering regeneration we can conclude, that more intensive decreasing trend in silver fir share is expected in the Ddinaric phytogeographic region than in northern parts of Slovenia. Successful regeneration due to lower red deer population and balanced stem diameter structure with higher proportion of small diameter trees promise easier conservation of silver fir in northern parts

Razširjenost jelke (Abies alba Mill.) v slovenskih gozdovih

We analysed the characteristics of silver fir (Abies alba Mill.) occurrence and distribution in Slovenia using databases of the Slovenian Forest Service (SFS). Silver fir is the third most widely distributed tree species in Slovenia, occurring in approximately 40 % of total forest area, but abundantly in less than 10 %. Its share in total growing stock varies between separate forest management regions. It is more abundant in the Dinaric and part of the Pre-alpine phytogeographic regions. The highest share in total growing stock reaches at altitudes between 800 m and 1000 m above sea level, forests with silver fir cover the most extensive surface in the altitude belt from 1000 to 1200 m. Silver fir occurs abundantly in 11 syntaxes. Between them, silver fir-beech forests (Abieti-Fagetum dinaricum TREG. 57, syn.: Omphalodo-Fagetum (TREG.57 corr. PUNC.80) MAR et al. 93) strongly prevail, followed by fir forests with fern (Dryopterido-Abietetum KOŠ.65, syn.: Galio rotundifolii-Abietetum BARTSCH.40). Silver fir diameter distribution considerably varies between separate forest management regions. The regions with the highest share of silver fir (Postojna, Kočevje) dominate also in having large diameter silver fir trees, whereas in other regions (e.g. Nazarje, Kranj, Maribor) small diameter silver fir trees are prevalent. Ddevelopmental stage structure shows that in forest stands with silver fir there is a higher share of timber phase, stands in regeneration, youth stands and selective forests. Considering regeneration we can conclude, that more intensive decreasing trend in silver fir share is expected in the Ddinaric phytogeographic region than in northern parts of Slovenia. Successful regeneration due to lower red deer population and balanced stem diameter structure with higher proportion of small diameter trees promise easier conservation of silver fir in northern parts.S podatki o gozdnih fondih Slovenije 2003 Zavoda za gozdove Slovenije smo analizirali značilnosti pojavljanja in razširjenosti jelke v Sloveniji. Jelka je tretja najpogostejša drevesna vrsta v Sloveniji, pojavlja se na kakih 40 % površine gozdov, obilneje pa na manj kot 10 %. Njen delež po gozdnogospodarskih območjih močno variira, obilneje se pojavlja na dinarskem in delu predalpskega fitogeografskega območja. Nnajvišji delež v lesni zalogi doseže v gozdovih na nadmorski višini 800-1000 m, površinsko pa so gozdovi z jelko najbolj razširjeni v nadmorskem pasu 1000-1200 m. Jelka se obilneje pojavlja v 11 sintaksonih. Močno prevladujejo dinarska jelova bukovja, tem sledijo jelovja s praprotmi. Debelinska struktura jelke je med območji zelo različna. Območja z najvišjim deležem jelke (Postojnsko, Kočevsko) zbujajo pozornost tudi glede debelega lesa, nasprotno je v drugih območjih (Nazarje, Kranj, Maribor) razmeroma velik delež tankega drevja jelke. V sestojih z jelko je spremenjenost drevesne sestave v povprečju manjša kot na celotni površini gozdov. Struktura gozdov z jelko po razvojnih fazah kaže, da je v primerjavi z vsemi gozdovi tu več debeljakov, pomlajencev, prebiralnega gozda in mladovja. Upoštevajoč pomlajevanje lahko zaključimo, da se v dinarskem delu na splošno nakazuje bolj izrazit trend zmanjševanja deleža jelke v gozdovih kot v severnih območjih (Maribor, Nazarje). Uspešnejše pomlajevanje zaradi manj jelenjadi, ugodnejša debelinska struktura z relativno večjim deležem tanjšega drevja jelke obeta verjetno uspešnejše ohranjanje jelke v teh gozdovih

Management of silver fir (Abies alba Mill.) in Slovenia

V prispevku analiziramo strukturo in razvojne značilnosti sestojev z jelko, gospodarjenje in posek jelke po stirih rastiščnih skupinah (A-D) glede na gojitveno ekološke značilnosti jelke na podlagi podatkovnih zbirk Zavoda za gozdove Slovenije. V lesni zalogi jelke prevladuje srednje debelo (d=30-49 cm)in debelo drevje (d=50 cm in veè) (84,9 %). Najveè (45 %) debelih jelk je vdinarskih jelovjih in jelovih bukovjih (skupina B), razvojno najmlajsa je jelka v jelovjih s praprotmi in na drugih jelovih rastiščih na nekarbonatu (skupina C). Analiza debelinske strukture jelke in stevila dreves iz prve in druge izmere na stalnih vzorčnih ploskvah ter naraščanje povprečnega premera posekanih jelk v obdobju zadnjih 14 let nakazujejo staranje in regresijo jelke, ki sta izrazitejša v skupini B. Vraščanje jelke prek meritvenega praga je največje v skupini C (19,2/ha/10 let) in se statistično značilno razlikuje od drugih skupin. Najmanjšo vrast jelke ugotavljamo v skupini B (4,2/ha/10 let), jakost poseka jelke je tu najvišja (22,3 % LZ) z najvišjim povprečnim premerom posekanih jelk (42,5 cm) in 48 % sanitarne sečnje. Za aktivno ohranjanje jelke je pomembno predvsem zmanjšanje vpliva jelenjadi in skrbno ter diferencirano gojitveno ukrepanje z daljšimi parcialnimi pomladitvenimi dobami. Predlagamo tudi nekatere druge ukrepe.In the paper, we analysed the structure and developmental characteristics of forest stands with silver fir in Slovenia, the management and cut in four forest site strata, where silver fir occurs. We used databases from the Slovenia Forest Service. In growing stock (GS) of silver fir, large (dbh=30-49cm) and very large (d=50 cm and more) diameter trees account for 84.9 % at the national level. The highest share of very large diameter silver fir trees (45 %) is in Dinaric silver fir forests and silver fir-beech forests(B), the lowest in silver fir forests with fern and silver fir forests on non-carbonate ground (C). The dbh structure of GS, number of silver fir trees recorded from two subsequent measurements from permanent sampling plots,rising mean dbh of harvested silver fir trees all indicate general agingand regression of silver, which is typical of stratum B but not in all other strata. The ingrowth of silver fir in 10 years is highest in stratum C (19.2 trees/ha), the lowest in B (4.2 trees/ha). In the latter, cut intensity (22.3 % of GS), the mean dbh of harvested silver firs are highest, too. For active conservation of silver fir, reduction of the impact of large ungulates and differentiated silviculture with longer regeneration periods is of crucial importance. Some other measures are also suggested

Understanding private forest owners’ conceptualisation of forest management : Evidence from a survey in seven European countries

Acknowledgements This paper is written as a part of Cost Action FP1201, Forest Land Ownership Changes in Europe: Significance for Management and Policy (FACESMAP). Laura Bouriaud thanks the Romanian Agency UEFISCDI for helping finance this research through the project PN-II-RU-TE-2014-4-0017. Philippe Deuffic and Elodie Brahic thank Centre National de la Propriete Forestiere (CNPF). The authors are also grateful to the people involved in data collection in the seven European countries. The authors thank the three anonymous reviewers for their useful comments that helped to improve the article.Peer reviewedPostprin

What influences European private forest owners’ affinity for subsidies?

We acknowledge the funding from the whole team from FACESMAP FPS COST Action FP1201. Also VJ was supported by the Czech National Agency for Agricultural Research (NAZV) under the contract QJ1530032.Peer reviewedPostprin

Private forest owners\u27 social economic profiles weakly influence forest management conceptualizations

Although several private forest owner studies have dealt with how private forest owners understand forest management, little is known about the determinants of specific forest management concepts. The study expands previous latent variable models of the perception of forest management by European private forest owners by looking at how age, income, education, annual cut, and holding size and type influence specific understandings of forest management. We applied a multiple indicators multiple causes (MIMIC) structural equation model on a representative sample of 754 private forest owners from Slovenia. The MIMIC model confirmed the influence of six covariates on three concepts of forest management: the maintenance concept, the ecosystem-centered concept, and the economics-centered concept. The strongest determinants of perception were education and holding type. The maintenance concept was predominantly associated with less educated older full-time or part-time farmers working on smaller family farms and doing regular cuts. The perception of forest management as an economics-centered activity increased with increased education and dependence on income from intensive cuts. The ecosystem-centered concept was most strongly associated with younger, better-educated owners with smaller holdings and, surprisingly, not to non-farmers but to small-scale family farmers. However, the proportion of the variance of latent variables explained by the six covariates was low, ranging from 2.4% to 5.1%. Taking into account the influence of education and holding type on private forest owners’ perception of forest management, by increasing the level of education and raising the proportion of absentee owners in Europe, we expect a shift from the maintenance concept toward either an economics-centered or ecosystem-oriented concept for forest management. Despite the weak influence of private forest owners’ social economic profiles on forest management conceptualizations, governments should be aware of the trend and actively seek to prevent the polarization of forest management concepts

Bayesian evaluation of smartphone applications for forest inventories in small forest holdings

There are increasingly advanced mobile applications for forest inventories on the market. Small enterprises and nonprofessionals may find it difficult to opt for a more sophisticated application without comparing it to an established standard. In a small private forest holding (19 ha, 4 stands, 61 standing points), we compared TRESTIMA, a computer vision-based mobile application for stand inventories, to MOTI, a smartphone-based relascope, in measuring the number of stems (N) and stand basal area (G). Using a Bayesian approach, we (1) weighted evidence for the hypothesis of no difference in N and G between TRESTIMA and MOTI relative to the hypothesis of difference, and (2) weighted evidence for the hypothesis of overestimating versus underestimating N and G when using TRESTIMA compared to MOTI. The results of the Bayesian tests were then compared to the results of frequentist tests after the p-values of paired sample t-tests were calibrated to make both approaches comparable. TRESTIMA consistently returned higher N and G, with a mean difference of +305.8 stems/ha and +5.8 m$^2$/ha. However, Bayes factors (BF$_{10}$) suggest there is only moderate evidence for the difference in N (BF$_{10}$ = 4.061) and anecdotal evidence for the difference in G (BF$_{10}$ = 1.372). The frequentist tests returned inconclusive results, with p-values ranging from 0.03 to 0.13. After calibration of the p-values, the frequentist tests suggested rather small odds for the differences between the applications. Conversely, the odds of overestimating versus underestimating N and G were extremely high for TRESTIMA compared to MOTI. In a small forest holding, Bayesian evaluation of differences in stand parameters can be more helpful than frequentist analysis, as Bayesian statistics do not rely on asymptotics and can answer more specific hypotheses