The quantity and quality of seedlings in the nursery has an impact on the success of re-establishment and later growth. High germination rates enable a sufficient number of seedlings, and their quality is assessed using a number of parameters, including seedling height and root collar diameter. These parameters are influenced in some species by seed size, but the correlation between them is species-specific. The model species in this research was sweet chestnut (Castaneasativa Mill.), and seeds from 12 populations from two distinct biogeographical regions of Croatia were collected. We examined the influence of seed size on four parameters: germination rate, seedling height, root collar diameter and sturdiness quotient. Seed size has been shown to have a positive influence on both seedling height and root collar diameter, whereas no such correlation was noted for germination rate and sturdiness quotient. Significant differences in nut size and seedling growth parameters were found between the Mediterranean and continental populations, with higher values observed in the coastal Mediterranean populations. We concluded that seed origin and seed size have a significant impact on seedling growth and are important factors to consider when choosing seed material. Further nursery operations should consider seed origin and local environmental conditions when choosing seedlings for reforestation efforts and general forest operations.

When natural regeneration of Quercus robur stands is hampered by an insufficient acorn yield, human assisted sowing of acorns collected in non-affected stands and stored for some period of time is performed. To inhibit the development of fungi and acorn deterioration during storage, thermotherapy is usually applied by submerging acorns for 2.5 h in water heated to 41 °C. This research aimed to test the effect of four thermotherapy treatments of different durations and/or applied temperatures as well as short-term storage at −1 °C or 3 °C on acorn internal mycobiota and germination. Fungal presence in cotyledons was analyzed in 450 acorns by isolation of mycelia on artificial media, followed by a DNA-based identification. Germination of 2000 acorns was monitored in an open field trial. Thermotherapy significantly decreased fungal diversity, while storage at 3 °C increased the isolation frequency of several fungi, mainly Penicillium spp. The most frequently isolated fungi did not show a negative impact on acorn germination after short-term storage. The study confirmed the efficiency of thermotherapy in the eradication of a part of acorn internal mycobiota, but also its effect on the proliferation of fast-colonizing fungi during storage. However, the latter showed to be more stimulated by storage conditions, specifically by storage at 3 °C.

U ovom stručnom članku detaljno su opisani svi čimbenici koji utječu na uzgoj kvalitetne šumske sadnice poljskog jasena za umjetnu obnovu i pošumljavanje. Do sada se pozornost nije poklanjala kvaliteti sadnica s obzirom na nove i...

Urbana stabla i šume doprinose kvaliteti života stanovnika urbanog područja i pružaju brojne koristi. Međutim, stabla u urbanim područjima su izložena različitim abiotskim i biotskim poremećajima koji utječu na njihov razvoj. Gljive truležnice se ističu kao bitan uzročnik pojave loma stabla. Dijagnostički instrumenti koji mjere određena svojstva drva se koriste u arborikulturi kao dopuna vizualnoj prosudbi urbanih stabala. Zvučni tomograf je uređaj koji mjeri brzinu prolaska zvučnih valova kroz drvo u radijalnom i tangentnom smjeru kako bi se prosudile unutarnje greške drva. Cilj istraživanja je bio odrediti veličinu i položaj zdravog i trulog drva te odrediti točnost zvučnog tomografa kod deset stabala hrasta kitnjaka u Parku Maksimir u Zagrebu. Usporedili smo rezultate grafičkih prikaza zvučnog tomografa (tomograme) sa fotografijama presjeka panjeva stabala koja su posječena radi potvrde truleži drva. Trulež drva je bila vidljiva na osam od deset istraživanih stabala koji su imali simptome truleži pri vizualnom pregledu. Trulež drva je potvrđena kod sedam stabala na panjevima nakon sječe. Kod tri stabla zabilježen je početni stadij truleži drva, dok su četiri stabla imala aktivnu trulež drva i pojavu šupljina. Oblik tomograma odgovarao je fotografijama presjeka panjeva kod osam stabala, a pozicija trulog drva je odgovarala fotografijama presjeka panjeva kod devet stabala. Područje trulog drva različitih kategorija je bilo točno prepoznato na tomogramima za šest od deset istraživanih stabala. Zvučni tomograf je podcijenio površinu zdravog drva, precijenio površnu drva u početnim stadijima truleži i točno predstavio područja s aktivnom truleži drva i šupljinama.

The article defines the term forest fruit trees or forest fruits that have been present in Croatian forestry for years and compares the term with other terms that are not synonymous and refer to forest trees, shrubs and ground growth of edible and medicinal fruits, wild fruits and domesticated fruits. Typical species representatives are listed for each term. The production by types of trees in the nurseries of Hrvatske sume d.o.o. is shown. in 2019/2020 years according to Forest Administration (FD), organizational units and nurseries. Regarding the production of forest fruit trees, edible and medicinal fruit trees, wild fruits and domesticated fruits, it is present in only three nurseries of Hrvatske sume d.o.o. (Zelendvor, Ostarije and Lukavec). In these three nurseries, a total of only four species from the above four categories are produced (2019/2020): service tree, wild cherry, sweet chestnut and black walnut. All four species are produced in the Zelendvor nursery, while in the Ostarije nursery, wild cherry seedlings are also produced, and in the Lukavec nursery only wild cherry seedlings are produced. The production and delivery of planting material of these species from the nursery of Hrvatske sume d.o.o. is shown. for the period 2012 to 2017. In stock or in production, in all nurseries of Hrvatske sume d.o.o. for the period from 2012 to 2018, there were mostly black walnut seedlings in the amount of 183,670 pieces, followed by seedlings of wild cherry with 132,069 pieces, sweet chestnut with 53,010 pieces and wild pear with 4,882 pieces. The most delivered seedlings, according to production, were black walnuts in the amount of 191,435 pieces, followed by wild cherry seedlings with 71,954 pieces, sweet chestnuts with 28,515 pieces and wild pears with 2,860 pieces. In the observed research period (20122018) in all nurseries of Hrvatske sume d.o.o. only 4 species from the above categories were produced with a total stock or production of 373,631 pieces of forest seedlings and a delivery of 294,764 pieces. In total, for all four species, it can be seen that 78,867 pieces of seedlings were grown more than delivered. Due to the possibility of organic farming, good adaptability of species to global climate change, providing incentives and not too demanding care, in the near future there will be increasing emphasis on species breeding to obtain secondary or non-timber forest products in plantations. Due to changing climatic conditions and the synergy of a number of unfavorable biotic and abiotic factors, many indigenous species are endangered today and are gradually or abruptly drying up and decaying. Some species of forest fruit trees, forest trees, shrubs and ground growth of edible and medicinal fruits, wild fruits and domesticated fruits will benefit from climate change, which will lead to the expansion of their natural range with increasing potential areas suitable for artificial cultivation.