Short-Term Impacts of Harvesting Intensity on the Upper Soil Layers in High Karst Dinaric Fir-Beech Forests

Abstract

The present study addresses the short-term effects of different harvest intensities under close-to-nature selective management on the upper soil layers in Slovenian and Bosnian Dinaric karst fir-beech forests. The different harvest intensities coincided with the single-tree and irregular shelterwood management, common in the region. The effect of harvesting intensity on the upper soil layers (Ol, Of, Ol and 0–10 cm mineral soil) was investigated by a repeated measurements experiment in Slovenia on 27 research plots in close-to nature managed forests. The properties of the upper layers (concentration of SOC and TN, C/N ratio, weights, BD and SOC stocks) were analyzed twice, before (2011) and after (2014) treatment of 50% and 100% harvest intensity in relation to the total standing growing stock of trees. As a control, we used no-treatment <20% harvesting intensity plots. To extend this experiment, we added three comparable plots from the Bosnian site: one in an old-growth forest with 0% harvest intensity and two in the managed forest with <20% harvest intensity. The results of the assessment of mean differences indicated a significant influence of harvesting intensity on the decrease in SOC, TN concentrations, weights and SOC stocks in the organic layers and the increase in BD and SOC stocks in the 0–10 cm mineral soil. The highest relative decreases in Ol, Of and Oh SOC stocks occurred in 50% (−10 and −38%) and 100% (−16 and −49%) harvest intensities. Negligible relative differences in both organic and 0–10 cm mineral layers were found for the <20% harvest intensity in the region. The change in forest light conditions resulting from differences in canopy openness as a function of applied harvest intensity explained the significant difference in the properties of the upper soil layers. The impact of the short-term losses in SOC stocks, in terms of overall soil productivity, may depend on the regeneration dynamics and melioration methods.

Response of beech and fir to different light intensities along the Carpathian and Dinaric Mountains

“…Microsite position significantly influenced F (Lambers et al, 1998) of young beech and firs, which changed with gap size, explaining their difference in competitive ability (C ̌ater et al, 2014). The abundance of microsite light categories along the elevation gradient in two silvicultural systems well indicated the forest structure and its fragmentation, and after large scale disturbances (C ̌ater and Diaci, 2017;C ̌ater, 2021), with quantum yield (F) as the resulting trait. Such division may also be associated with spatial distribution of other ecological factors: direct radiation may be related with an increased evapotranspiration and higher drought probability, while diffuse radiation with rainfall patterns within gaps (Krecmer, 1967).…”

“…The resilience of plant species or populations depends on their ability to acclimatise to the new environmental conditions. Beech, on the other hand, shows an increase in abundance and a successful ability to regenerate after large-scale disturbances such as windthrow or sleat (C ̌ater and Diaci, 2017;C ̌ater, 2021).…”

“…Harvests alter micrometeorological stand's conditions and ecological processes in the understorey. They result in higher soil temperature and precipitation throughfall, which temporarily increase soil respiration (Londo et al, 1999;C ̌ater, 2021) and consequently increase the decomposition of soil organic matter. With reduced aboveground litter input, this leads to a loss of soil organic carbon (Hukićet al, 2021).…”

Tree and stand growth differ among soil classes in semi-natural forests in central Europe

“…In some forest areas fertilizing with N and P is practiced to compensate for leaching soil supplies (Binkley, 1990). In contrast, the impact of close-to-nature forestry on forest soil (Hukić et al, 2021) and other components of the forest ecosystem is assumed to be lower compared to that of industrial forest management. Close-tonature forestry is based on the natural regeneration of tree species, applies silvicultural systems that mimic natural stand dynamics, and prohibits the use of fertilizers and pesticides (Bončina, 2011;Schütz, 2011).…”

Canopy Gaps are Less Susceptible to Disturbance-Related and Invasive Herbs than Clear-Cuts: Temporal Changes in the Understorey after Experimental Silvicultural Treatments

“…Forest management has an impact on all groups of forest-dwelling organisms (Paillet et al, 2010, Chaudhary et al, 2016, Elek et al, 2018, Muys et al, 2022 and alterations in its type or intensity induce significant changes in forest communities, e.g., in the understorey vegetation (Halpern et al, 2005, Kelemen et al, 2012, Duguid and Ashton, 2013, Klynge et al, 2020, Kirby et al, 2022. The composition and density of the canopy control light availability and affect microclimate and soil conditions (Craig and MacDonald, 2009, Von Arx et al, 2013, Kermavnar et al, 2019, Kermavnar et al, 2020, Hukić et al, 2021. In managed temperate forests, species richness and cover of the understorey often increase greatly with the increase in available light (Moore and Vankat, 1986, Goldblum, 1997, Gálhidy et al, 2006, Dormann et al, 2020 as a result of different forestry treatments (Collins and Pickett, 1987, Tinya et al, 2019, Beese et al, 2022.…”