Omorika Digital repository of the Faculty of Forestry, University of Belgrad
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Comparison of the physical properties of soils on transverse profiles along the gullies
No full textNatural processes and anthropogenic activity threaten soil as a resource.Soil degradation is a global problem intensifi ed by climate change, populationgrowth and economic development. Soil erosion is one of themost prevalent forms of degradation in Serbia. Soil resistance to erosiveprocesses largely depends on the soil‘s physical properties. Erosion processesaff ect changes in the physical characteristics of the soil. Therefore,the hypothesis is established: There is a diff erence between the physicalparameters of soil aff ected by erosion processes and soil on which thereare no visible indicators of the action of these processes.The investigatedarea is located in the southern, hilly part of Belgrade, in a degradedforest area vegetated by Hungarian and Turkey oak (Quercetum frainetto– cerris). Intensive landslide and gully erosion processes aff ect this area.The mechanism of occurrence of the erosion process is piping-erosion.Thirteen transverse profi les were selected on gullies where soil samplingwas performed. Sampling was performed on each profi le in the gullybed, in the left and right banks at two fi xed depths, zone 1, depth 5–10cm and zone 2, depth of 10–25 cm. Laboratory analyses included testsof volume weight, specifi c weight, soil particle size distribution, consistentstates and humidity. Parameters porosity and clay activity were alsoanalysed. Soil sampling and laboratory testing were done in accordancewith SRPS.U.B1 geotechnical testing standards. The comparison of the obtained results was made between the banks and the gully bed, as wellas between the zones using tests: t-test of mean values; W (Mann-Whitney;Wilcoxon) – median test. Hypothesis testing was performed with asignifi cance threshold p of 95.0 %. Testing was conducted in the statisticalanalysis program Statgraphics centurion XVIII (StatPoint Technologies, Inc.2019). Comparison of soil parameters in zone 1 had shown a statisticallysignifi cant diff erence for percentage of clay and sand, liquid limit, humidityand clay activity. Results of conducted comparison showed that inthe zone 2, a statistically signifi cant diff erence found for the parameterpercentage of clay and sand, between banks and gully bed soil samples.While no signifi cant statistical diff erence found for the other parameters.Analysing the results between zones, a signifi cant statistical diff erencewas found for the gully bed, left and right banks soil samples for theparameters volume weight (dry and humid) and porosity while for gullysamples there was signifi cant statistical diff erence for liquid limit, plasticlimit, humidity and clay activity. Comparing all samples of the zones 1 and2, a signifi cant statistical diff erence was found for the parameters volumeweight (dry and humid), porosity, percentage of sand particles, plasticlimit and current humidity
Gender structure of Tree-of-Heaven (Ailanthus altissima (Mill.) Swingle) in the protected natural area ‘Bajfordova šuma’ on the territory of Belgrade — the basis for biological control of its expansion and planned reduction
No full textPajasen (Ailanthus altissima (Mill.) Swingle) je invazivna vrsta u Srbiji, koja ugrožava florističkibiodiverzitet u prirodnim šumskim zajednicama i urbanim prostorima. To je heliofit, sa brzimrastom u početnoj fazi razvoja i izraženom adaptivnom sposobnošću na različite uslove sredineotvorenih staništa. Sa pojavom ranog polnog sazrevanja i, pretežno, svakogodišnjeg urodavelike količine plodova, koji se lako prenose na veću udaljenost od matičnog stabla, pajasenbrzo kolonizuje prirodne šumske zajednice i urbane prostore. To je dvodoma drvenasta biljka.Primenom polnog dimorfizma kod pajasena, kao kriterijuma za selekciju stabala u proredi,može se uticati na širenje vrste generativnim putem, a u okviru sastojinskog sklopa može seuticati na rast i održanje generativnog i vegetativnog potomstva. Diferenciranje rodnih-ženskihod nerodnih-muških stabala vrši se u fazi cvetanja na osnovu cvetno-plodnih cvasti, a odabirrodnih-ženskih stabala vrši se tokom cele godine na osnovu prisutnih plodova i cvetno-plodnih drški koje se dugo zadržavaju u krošnji po opadanju plodova. Polni dimorfizam ove vrste poslužioje kao osnova za utvrđivanje polne strukture stabala u zaštićenom prirodnom dobru ,,Bajfordovašuma” na području Beograda u cilju kontrole i zaustavljanja invazije u urbanom prostoru.Na površini zaštićenog prirodnog dobra 40,08 ha pajasen je zastupljen pojedinačno ili ugrupama, u odsecima na ukupnoj površini 27,09 ha sa 131 polno izdiferenciranih stabala čiji suprsni prečnici u rasponu 5-74 cm, a visine u rasponu 5-21 m.U okviru navedenog broja polno izdiferenciranih stabala pajasena zastupljenost ženskihi muških stabala je približno podjednaka, ali prostorno varira. Evidentirana ženska i muškastabla osnova su za monitoring, plansku redukciju i gajenje pajasena u neinvazivnom obliku uzaštićenom prirodnom dobru ,,Bajfordova šuma” u određenom prelaznom periodu.Tree-of-Heaven (Ailanthus altissima (Mill.) Swingle) is an invasive tree species in Serbiathat threatens the floristic biodiversity in natural stands and urban areas. It is a heliophyte withrapid growth in the initial phase of development and a well-expressed adaptability to differentenvironmental conditions in open habitats. With early maturity and abundant fruiting almostevery year, and the ability of seeds to be transported far from the maternal tree, the tree-of-heavencan rapidly colonize the stands (with disturbed stand structure) of other tree species. It is alsoa dioecious woody plant. If gender dimorphism of tree-of-heaven is used as a criterion for treeselection in thinning, it can be applied to affect the generative expansion of the species. Withinthe stand canopy closure, it can be used to influence the growth and survival of generative andvegetative offspring. Differentiation of fruit bearing-female and non-fruit-bearing-male treesis carried out during the flowering phase on the basis of its inflorescences. Selection of fruitbearing-female flowers is carried out during the whole year by checking for the presence offruit and inflorescence petioles that are retained in the crown after the fruit shedding. Genderdimorphism of the species served as the basis for the gender structure determination in theprotected natural area ,,Bajfordova šuma” in Belgrade.Out of 40.08 ha of the protected natural area, tree-of-heaven was recorded individually or ingroups, in an area of 27.09 ha, with 131 sexually differentiated trees with diameters within therange of 5-74 cm and heights within the range of 5-21 m.Within the aforementioned number of trees, the share of female and male trees is almostequal, but varies spatially. The recorded female and male trees are the basis for monitoring,planned reduction and tree-of-heaven growing in a non-invasive form in the protected naturalarea ,,Bajfordova šuma”
Synchrospora gen. nov., a New Peronosporaceae Genus with Aerial Lifestyle from a Natural Cloud Forest in Panama
No full textDuring a survey of Phytophthora diversity in Panama, fast-growing oomycete isolates were obtained from naturally fallen leaves of an unidentified tree species in a tropical cloud forest. Phylogenetic analyses of sequences from the nuclear ITS, LSU and beta tub loci and the mitochondrial cox1 and cox2 genes revealed that they belong to a new species of a new genus, officially described here as Synchrospora gen. nov., which resided as a basal genus within the Peronosporaceae. The type species S. medusiformis has unique morphological characteristics. The sporangiophores show determinate growth, multifurcating at the end, forming a stunted, candelabra-like apex from which multiple (8 to gt 100) long, curved pedicels are growing simultaneously in a medusa-like way. The caducous papillate sporangia mature and are shed synchronously. The breeding system is homothallic, hence more inbreeding than outcrossing, with smooth-walled oogonia, plerotic oospores and paragynous antheridia. Optimum and maximum temperatures for growth are 22.5 and 25-27.5 degrees C, consistent with its natural cloud forest habitat. It is concluded that S. medusiformis as adapted to a lifestyle as a canopy-dwelling leaf pathogen in tropical cloud forests. More oomycete explorations in the canopies of tropical rainforests and cloud forests are needed to elucidate the diversity, host associations and ecological roles of oomycetes and, in particular, S. medusiformis and possibly other Synchrospora taxa in this as yet under-explored habitat
Empirical and process-based models predict enhanced beech growth in European mountains under climate change scenarios: A multimodel approach
No full textProcess-based models and empirical modelling techniques are frequently used to (i) explore the sensitivity of tree growth to environmental variables, and (ii) predict the future growth of trees and forest stands under climate change scenarios. However, modelling approaches substantially influence predictions of the sensitivity of trees to environmen-tal factors. Here, we used tree-ring width (TRW) data from 1630 beech trees from a network of 70 plots established across European mountains to build empirical predictive growth models using various modelling approaches. In addi-tion, we used 3-PG and Biome-BGCMuSo process-based models to compare growth predictions with derived empirical models. Results revealed similar prediction errors (RMSE) across models ranging between 3.71 and 7.54 cm2 of basal area increment (BAI). The models explained most of the variability in BAI ranging from 54 % to 87 %. Selected explan-atory variables (despite being statistically highly significant) and the pattern of the growth sensitivity differed between models substantially. We identified only five factors with the same effect and the same sensitivity pattern in all empir-ical models: tree DBH, competition index, elevation, Gini index of DBH, and soil silt content. However, the sensitivity to most of the climate variables was low and inconsistent among the empirical models. Both empirical and process -based models suggest that beech in European mountains will, on average, likely experience better growth conditions under both 4.5 and 8.5 RCP scenarios. The process-based models indicated that beech may grow better across European mountains by 1.05 to 1.4 times in warmer conditions. The empirical models identified several drivers of tree growth that are not included in the current process-based models (e.g., different nutrients) but may have a sub-stantial effect on final results, particularly if they are limiting factors. Hence, future development of process-based models may build upon our findings to increase their ability to correctly capture ecosystem dynamics
Modeling and Mapping of Forest Fire Occurrence in the Lower Silesian Voivodeship of Poland Based on Machine Learning Methods
No full textIn recent years, forest fires have become an important issue in Central Europe. To model the probability of the occurrence of forest fires in the Lower Silesian Voivodeship of Poland, historical fire data and several types of predictors were collected or generated, including topographic, vegetation, climatic, and anthropogenic features. The main objectives of this study were to determine the importance of the predictors of forest fire occurrence and to map the probability of forest fire occurrence. The H2O driverless artificial intelligence (DAI) cloud platform was used to model forest fire probability. The gradient boosted machine (GBM) and random forest (RF) methods were applied to assess the probability of forest fire occurrence. Evaluation the importance of the variables was performed using the H2O platform permutation method. The most important variables were the presence of coniferous forest and the distance to agricultural land according to the GBM and RF methods, respectively. Model validation was conducted using receiver operating characteristic (ROC) analysis. The areas under the curve (AUCs) of the ROC plots from the GBM and RF models were 83.3% and 81.3%, respectively. Based on the results obtained, the GBM model can be recommended for the mapping of forest fire occurrence in the study area
Monitoring and control of forest seedling quality in Europe
No full textThe relationship between the quality of forest seedlings and their outplanting survival and growth has long been recognized. Various attributes have been proposed to measure the quality of planted seedlings in forest regeneration projects, ranging from simple morphological traits to more complex physiological and performance attributes, or a combination thereof. However, the utility and meaning of seedling quality attributes can differ significantly among regions, nursery practices, site planting conditions, species and the establishment purpose. Here, forest scientists compiled information using a common agreed questionnaire to provide a review of current practices, experiences, legislation and standards for seedling quality across 23 European countries. Large differences exist in measuring seedling quality across countries. The control of the origin of seed and vegetative material (genetic component of plant quality), and control of pests and diseases are common practices in all countries. Morphological attributes are widely used and mandatory in most cases. However, physiological attributes are hardly used at the operative level and mainly concentrated to Fennoscandia. Quality control legislation and seedling quality standards are less strict in northern European countries where seedling production is high, and quality control relies more on the agreements between producers and local plant material users. In contrast, quality standards are stricter in Southern Europe, especially in the Mediterranean countries. The control of seedling quality based on plantation and reforestation success is uncommon and depends on the conditions of the planting site, the traditional practices and the financial support provided by each country. Overall, European countries do not apply the "target seedling concept" for seedling production except for seed origin. Seedling production in many countries is still driven by traditional "know-how" and much less by scientific knowledge progress, which is not adequately disseminated and transferred to the end-users. Our review highlights the need for greater harmonization of seedling quality practices across Europe and the increased dissemination of scientific knowledge to improve seedling quality in forest regeneration activities
The Status and Swot Analysis of Roe Deer Population Management in the Hunting Grounds of Central Serbia
No full textThe purpose of this study is to examine the status of roe deer population in the hunting
grounds of Central Serbia, and perform a SWOT analysis of its management. The data
used herein on the number of roe deer individuals and culling events were obtained from
the Ministry of Agriculture, Forestry and Water Management - Forest Administration and
the Statistical Office of the Republic of Serbia. Moreover, the Law on Game and Hunting
was used for analysis purposes. The status of roe deer population in the hunting grounds
of Serbia is quite unsatisfactory, depending on the geographical area and wildlife
management practices. In 2021, a total of 86,755 individuals were recorded in the area of
Central Serbia, which accounts for 97.54% of the optimal population. However, the
number of roe deer in the individual hunting grounds of the Central and Eastern hunting
areas was above the optimal density, whereas the number of roe deer accounted for
88.58% and 89.12% of the optimal density in the individual hunting grounds of the
Southern and Western hunting areas, respectively. The largest number of individuals per
unit area (km2) was recorded in the Eastern (2.06) and Belgrade (2.02) hunting areas,
whereas the smallest number of individuals per unit area (km2) was recorded in the
Southern (1.02) and Western (1.34) hunting areas. The following issues were identified as
major impediments to the management of roe deer population in the hunting grounds
considered: legislative and regulatory instruments, non-compliance and non-enforcement
of a large number of regulations, roe deer monitoring issues, poor hunting ground
control, inapplicability of certain regulations in the field of veterinary medicine,
environmental protection, unresolved issues of trophy and game meat export, lack of
strategic planning (namely the hunting development strategies of the Republic of Serbia),
lack of deer habitat monitoring methodology and rating methodology, and unprofessional
planning and development of hunting ground management plans. The SWOT analysis
performed emphasized the strengths, weaknesses, opportunities and threats of roe deer
population management in Serbia
Financial consequences of ice breaks in state forests in eastern Serbia in 2014
No full textNegativni efekti klimatskih promena na prirodne resurse predstavljaju jedan od najvećih izazova sektora šumarstva. Uvećanje učestalosti i intenziteta pojave prirodnih nepogoda (snegoloma, ledoloma, vetroloma, itd.), kao i negativne ekonomske, ekološke i socijalne posledice, značajno utiču na obavljanje svih aktivnosti unutar sektora šumarstva. Cilj istraživanja je da se izuči odnos finansijskih posledica ledoloma (troškovi sanacije, prihodi od šumskih sortimenata i bioloških investicija i dobit) u odnosu na dva uticajna faktora (oštećenu drvnu zapreminu i oštećenu šumsku površinu). Za potrebe istraživanja, prikupljeni su i analizirani sekundarni podaci, dobijeni iz interne dokumentacije Javnog preduzeća „Srbijašume”. Utvrđeno je da su štete od ledoloma u istočnoj Srbiji 2014. god. obuhvatile površinu od 19.419,78 ha u državnim šumama, kao i da su pričinjene znatne direktne i indirektne ekonomske štete. Rezultati istraživanja ukazuju da, pri povećanju oštećene drvne zapremine za 1%, troškovi sanacije rastu za oko 0,67%, a prihodi za oko 0,65%. Takođe, sa porastom obima oštećene drvne zapremine za 1 m3 , dobit se smanjuje u proseku za oko 50.000 RSD. Ustanovljeno je i da se, sa povećanjem oštećene šumske površine za 1 ha, troškovi sanacije povećavaju u proseku za oko 21.000 RSD, dok dobit opada za oko 6.000 RSD
Climate and health ecosystem services of forests in the function of regional development - Bešnjaja forest complex, central Serbia
No full textU radu su prikazani rezultati istraživanja ekoloških uslova šumskog
kompleksa Bešnjaja, u centralnom delu Srbije, sa osvrtom na klimatske i
vegetacijske karakteristike. Rezultati analize klimatskih parametara ukazuju
da ovo područje raspolaže klimatskim odlikama i očuvanim kvalitetom okoline
koji, kao prirodni resursi, omogućavaju razvoj zdravstvenog turizma. Šume i
ostale površine pod vegetacijom predstavlјaju važan prirodni resurs i bitan
faktor u očuvanju ostalih elemenata životne sredine. Uticaj šuma na okolinu
ogleda se u značajnoj produkciji kiseonika i apsorpciji uglјen-dioksida u
vazduhu i lučenju ’vazdušnih vitamina' – fitoncida, što predstavlјa poseban
lekoviti faktor za ljudski organizam
Development of discoloration during conventional drying of oak timber
No full textThis research aimed to examine the development of inhomogeneous colour changes in oak timber
during conventional drying and its relation to moisture content distribution across the wood thickness.
To explore this phenomenon, control boards (quarter-sawn and flat-sawn, 38 mm thick) were cut from
two oak logs, one of the sessile oak (Quercus petraea) and one of the pedunculate oak (Quercus
robur). The control boards were dried in a conventional kiln according to the common drying
schedule, and at specific time intervals, samples were taken to determine the moisture content profile.
During each cutting of the samples, the appearance of discoloration was controlled. The results of the
study revealed that there is a connection between the moisture content distribution within the boards
and the appearance of discoloration. Furthermore, it was found that sessile oak timber dries more
slowly and with less intense discolourations than penduculate oak timber. It is confirmed that quarter- sawn boards dry slower compared to flat-sawn boards and this applies to both wood species