Iskanje po repozitoriju

A+ | A- | | SLO | ENG

Povzetek: Heat islands (HI) are a common anthropogenic phenomenon and are defined as artificial surfaces (urban areas) that have a higher average temperature than their surroundings (rural areas). The aim of this work was to determine the influence of land use on the spatial distribution and intensity (HIi ) of HI in Slovenia. The MODIS Land Surface Temperature (LST) and Corine Land Cover (CLC) databases were used to perform the analysis. Within the identified HI, two HI levels were determined based on temperature difference. The results revealed a statistically significant negative correlation between HIi and both forest co%ver and forest fragmentation (forest edge density and ratio of mean forest patch size to HI size). Artificial surface was positively correlated with HIi . The results contribute to the understanding of the spatial distribution of HI and HIi and provide informati%on for spatial planning and policy-making to reduce the negative impact of HI.
Ključne besede: heat island, forest cover, artificial surface, forest fragmentation
DiRROS - Objavljeno: 17.08.2021; Ogledov: 621; Prenosov: 311
Celotno besedilo (1011,73 KB)

Povzetek: Intenziteta glivnega razkroja je v največji meri odvisna od vrste lesa, temperature in padavinskih dogodkov. Če želimo oceniti življenjsko dobo in intervale vzdrževanja lesenih objektov, moramo oceniti, kako se bo v določenem okolju les obnašal. V ta namen so nam na voljo raznoliki modeli. V praksi se največ uporablja pristop, ki ga je razvil Theodore Scheffer. Scheffer je predlagal klimatski indeks (Schefferjev klimatski indeks - SCI), ki temelji na številu padavinskih dni in povprečni mesečni temperaturi. Na podlagi teh klimatskih podatkov smo izračunali Schefferjev klimatski indeks za izbrane lokacije v Sloveniji. Rezultati analize klimatskih razmer kažejo, da je Schefferjev klimatski indeks v večini analiziranih krajev v Sloveniji višji, kot je bil pred desetletji. Intenziteta razkroja se je povečala v vseh analiziranih krajih z izjemo Portoroža. Največje zvišanje Schefferjevega klimatskega indeksa smo zaznali v Ratečah.
Ključne besede: les, Schefferjev klimatski indeks, razkroj, podnebne spremembe, temperatura, padavinski dogodki
DiRROS - Objavljeno: 17.08.2021; Ogledov: 475; Prenosov: 249
Celotno besedilo (1004,81 KB)

Povzetek: The structure and function of the soil microbiome of urban greenspaces remain largely undetermined. We conducted a global field survey in urban greenspaces and neighboring natural ecosystems across 56 cities from six continents, and found that urban soils are important hotspots for soil bacterial, protist and functional gene diversity, but support highly homogenized microbial communities worldwide. Urban greenspaces had a greater proportion of fast-growing bacteria, algae, amoebae, and fungal pathogens, but a lower proportion of ectomycorrhizal fungi than natural ecosystems. These urban ecosystems also showed higher proportions of genes associated with human pathogens, greenhouse gas emissions, faster nutrient cycling, and more intense abiotic stress than natural environments. City affluence, management practices, and climate were fundamental drivers of urban soil communities. Our work paves the way toward a more comprehensive global-scale perspective on urban greenspaces, which is integral to managing the health of these ecosystems and the well-being of human populations.
Ključne besede: soil biodiversity, structural diversity, functional diversity, urban soils
DiRROS - Objavljeno: 15.07.2021; Ogledov: 307; Prenosov: 209
Celotno besedilo (4,34 MB)

Povzetek: esearch Highlights: Data of advanced-age provenance tests were reanalyzed applying a new approach, to directly estimate the growth of populations at their original sites under individually generated future climates. The results revealed the high resilience potential of fir species. Background and Objectives: The growth and survival of silver fir under future climatic scenarios are insufficiently investigated at the xeric limits. The selective signature of past climate determining the current and projected growth was investigated to analyze the prospects of adaptive silviculture and assisted transfer of silver fir populations, and the introduction of non-autochthonous species. Materials and Methods: Hargreaves% climatic moisture deficit was selected to model height responses of adult populations. Climatic transfer distance was used to assess the relative drought stress of populations at the test site, relating these to the past conditions to which the populations had adapted. ClimateEU and ClimateWNA pathway RCP8.5 data served to determine individually past, current, and future moisture deficit conditions. Besides silver fir, other fir species from South Europe and the American Northwest were also tested. Results: Drought tolerance profiles explained the responses of transferred provenances and predicted their future performance and survival. Silver fir displayed significant within-species differentiation regarding drought stress response. Applying the assumed drought tolerance limit of 100 mm relative moisture deficit, most of the tested silver fir populations seem to survive their projected climate at their origin until the end of the century. Survival is likely also for transferred Balkan fir species and for grand fir populations, but not for the Mediterranean species. Conclusions: The projections are less dramatic than provided by usual inventory assessments, considering also the resilience of populations. The method fills the existing gap between experimentally determined adaptive response and the predictions needed for management decisions. It also underscores the unique potential of provenance tests.
Ključne besede: climate change, common garden, provenance test, silver fir, grand fir, Balkan firs, drought stress, resilience, climate transfer distance, adaptation
DiRROS - Objavljeno: 05.07.2021; Ogledov: 274; Prenosov: 85
Celotno besedilo (1,46 MB)

Povzetek: Two comparable sites with uneven-aged mixed forest stands with more than 20% Douglas-fir in the growing stock at an altitude of 650 m a.s.l. were selected. The physiological response of young trees to different light intensities was measured during the main growing season in three consecutive years, and four different light categories, which were determined from hemispherical photographs. The four light intensity categories were defined according to Indirect Site Factor (ISF%): in the open (A-ISF > 35%), at the outer forest edge (B-25% < ISF < 35%), at the inner forest edge (C-15% < ISF < 25%), and under complete canopy under mature forest stand (D-ISF < 15%). Climate data were obtained from the Royal Netherlands Meteorological Institute %Climate Explorer% website. For the intensive micrometeorological observations, four monitoring sites were established along the elevation gradient at each site during summer and late fall to record relative humidity (RH%) and temperature (°C) with a 30 min recording interval sequence. Measured assimilation responses (A) and light use efficiency (%) at one site followed the expected pattern, while humidity combined with microsite conditions proved significant in explaining the specific response of young Douglas-fir to the different light intensity at the other site. For higher survival and optimal future development of Douglas-fir in the changing environment, microsites with higher capacity for storage moisture and favorable microclimate should generally be preferred to exposed and dry sites.
Ključne besede: Douglas-fir, light response, photosynthesis, light use efficiency, silviculture
DiRROS - Objavljeno: 28.05.2021; Ogledov: 340; Prenosov: 219
Celotno besedilo (1023,09 KB)