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Abstract: Forest microclimate is strongly affected by local topography and management activities, as these directly alter overstory structure. In the present work we analysed the dependence of observed patterns of spatio-temporal microclimatic variations on topographic, canopy- and management-related factors. A forestry experiment was conducted in managed fir-beech forests in the Dinaric Mountains (Slovenia), which are characterized by rugged karstic terrain with numerous sinkholes. In 2012, cutting treatments representing a range in the intensity of overstory removal were performed: uncut controls (CON), 50% cut of stand growing stock (intermediate management intensity % IMI) and 100% cut (high management intensity % HMI) creating 0.4 ha canopy gaps. Fine-scale variation in aspect and slope and its effects on microclimate was assessed by comparing central, south-facing and north-facing within-sinkhole positions. We measured microclimatic variables (air temperature % T, relative humidity % RH) 0.5 m above the ground over three consecutive post-treatment growing seasons. Microclimatic variables showed an increase (T and vapour pressure deficit % VPD) or decrease (RH) with management intensity. Daily Tmax and VPDmax in HMI treatment were up to 5.9°C (on average 3.5°C) and up to 1.4 kPa (on average 0.6 kPa) higher than those in CON treatment, respectively, whereas daily RHmin was up to 22.7 (on average 13.0) percentage points lower. Regarding intra-seasonal patterns, microclimatic differences between treatments were largest during the summer. South-facing plots in the HMI treatment overall exhibited the most extreme conditions, i.e. the highest Tmax and lowest RHmin. Differences in microclimate between treatments were strongly modulated by canopy cover. The results also suggest that overstory removal increases topography-mediated variation in microclimate, as evidenced by significant differences in T, RH and VPD along the fine-scale topographic gradient within the created canopy gaps.
Keywords: tree cutting, air temperature, relative humidity, vapour pressure deficit, karst topography, canopy cover
Published in DiRROS: 08.10.2020; Views: 1345; Downloads: 567
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Abstract: Climate-growth relationships are usually analysed using monthly climate data. The dendroTools R package also provides methodological approaches that enable climate-growth analysis for daily climate data. Such analysis reveals more complete climate signal patterns. In this article, new functions of the dendroTools R package are presented. Partial correlation coefficients are now implemented and can be used to calculate the strength of a linear relationship between two variables, while controlling for a third variable. Bootstrapped correlations can then be used to provide insights into the confidence intervals of statistical estimates. The calculation of partial and bootstrapped correlations is available for daily and monthly data. Finally, data transformation, S3 generic plotting and summary functions are also presented here.
Keywords: dendroTools, daily climate data, partial correlations, bootstrap, dendroclimatology
Published in DiRROS: 24.09.2020; Views: 1268; Downloads: 573
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Abstract: The capital and income breeding concept links energy resources used during reproduction to the timing of their acquisition. During reproduction, capital breeders rely on resources gained previously and accumulated for reproductive investment. By contrast, income breeders use mainly resources collected during the period of reproductive activity. Most commonly, this concept is applied to females; relatively few studies have considered males. Moreover, there has been little attention to the link between the capital-income divide and other aspects of mating strategy. We studied adult males of three wild ungulates with different levels of polygyny. A large dataset (4,264 red deer, 53,619 roe deer, and 13,537 Alpine chamois, respectively) was obtained during 2007-2017 in the whole territory of Slovenia and in the Trento province, Italy. During the rut, body mass loss of males in highly polygynous species was more than twice that of weakly polygynous species: on average, red deer stags lost 19.5%; chamois bucks 16.0%; and roe deer bucks 7.5% of their body mass. This indicates potential for a hitherto unrecognized link between the degree of intrasexual competition and the degree of capital mating. The variability in body mass at the end of the rut was clearly reduced in both highly polygynous species (from 15.1 to 9.4% in red deer, and from 12.5 to 10.5% in chamois), but did not change in roe deer. Finally, roe deer bucks had recovered body mass to that of the pre-rut period by just 2 months after the rut, while red deer stags did not manage to compensate the loss of weight until the end of the year. We suggest that, at least in ungulates, there is a link between the degree of polygyny and that of capital breeding. Males of capital and income breeders underwent body mass changes resulting from different reproductive investment during the rut. Capital breeders lost considerably more weight, and invested a variable amount of energy among individuals or among years, possibly to cope with different environmental or body conditions. In so doing, they ended the rut with poorer but more even condition among individuals.
Keywords: capital-income breeding, male reproductive investment, Capreolus capreolus, Cervus elaphus, Rupicapra rupicapra
Published in DiRROS: 23.09.2020; Views: 1375; Downloads: 820
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Abstract: Ambrozijske podlubnike uvrščamo med najpomembnejše tujerodne invazivne organizme. Še posebej uspešna pri osvajanju novih območij pa je vrsta Xyosandrus germanus, ki je bila leta 2000 prvič najdena tudi v Sloveniji. Namen naše naloge je bil potrditi razširjenost in ugotoviti velikost populacije X. germanus v revirju Šentvid (KE ZGS Škofljica). Vrsto smo spremljali s pomočjo pasti iz odpadnih plastenk, ki smo jih naredili sami. Postavljene so bile v treh različnih gozdnih sestojih, in sicer smo v vsakem sestoju postavili štiri pasti z različnimi vabami (etanol, denaturiran etanol, kombinacija etanola in %-pinena ter kontrolna past brez vabe), v zbirni posodi je bil konzervans etilen glikol. Pasti smo spremljali osem tednov, v obdobju med 26. 4. 2017 in 20. 6. 2017, jih tedensko praznili, ulov pa determinirali v Laboratoriju za ekološke raziskave - entomologija, Oddelka za gozdarstvo in obnovljive gozdne vire BF. Ujeli smo 11.460 osebkov X. germanus, kar je v skupnem ulovu pomenilo kar 90,09 % celotnega ulova hroščev oziroma 95,30 % celotnega ulova podlubnikov. Tako številčen ulov kaže na to, da je populacija X. germanus na raziskovalnem območju velika. Poleg vrste X. germanus smo potrdili še enega tujerodnega ambrozijskega podlubnika, in sicer vrsto Gnathotrichus materiarius. Naši rezultati kažejo, da ni večjih razlik v učinkovitosti privabljanja vrste X. germanus med testiranimi vabami. Glede na število ujetih osebkov vrste X. germanus pa lahko trdimo, da so tudi doma narejene pasti iz odpadnih plastenk lahko primerno orodje za spremljanje tujerodnih ambrozijskih podlubnikov.
Keywords: gozdovi, ambrozijski podlubniki, invazivne tujerodne vrste, Xylosandrus germanus, spremljanje, pasti, vabe, Slovenija
Published in DiRROS: 09.09.2020; Views: 5503; Downloads: 1697
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Abstract: Soils harbor a substantial fraction of the world's biodiversity, contributing to many crucial ecosystem functions. It is thus essential to identify general macroecological patterns related to the distribution and functioning of soil organisms to support their conservation and consideration by governance. These macroecological analyses need to represent the diversity of environmental conditions that can be found worldwide. Here we identify and characterize existing environmental gaps in soil taxa and ecosystem functioning data across soil macroecological studies and 17,186 sampling sites across the globe. These data gaps include important spatial, environmental, taxonomic, and functional gaps, and an almost complete absence of temporally explicit data. We also identify the limitations of soil macroecological studies to explore general patterns in soil biodiversity-ecosystem functioning relationships, with only 0.3% of all sampling sites having both information about biodiversity and function, although with different taxonomic groups and functions at each site. Based on this information, we provide clear priorities to support and expand soil macroecological research.
Keywords: soil, biodiversity, ecosystem services, blind spots, macroecological research
Published in DiRROS: 27.08.2020; Views: 1529; Downloads: 1445
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