Initial understory vegetation responses following different forest management intensities in Illyrian beech forests

Abstract

Background and questions: How forest vegetation responds to disturbance continues to be a focal point, especially in the context of biodiversity conservation. To investigate the short-term effects of forest management on understory vegetation, we asked: (a) Are there any plant indicator species associated with different felling intensities? (b) What are the differences in abundance of plant functional types along the disturbance gradient? (c) How do typical forest species respond to silvicultural treatments? Location: Dinaric Mountains, Slovenia.Methods: At each of three study sites in Illyrian beech forests, nine plots (4,000 m 2 ) were established, comprising a total of 27 plots. Three different felling intensities were implemented at each site, with one third of the plots assigned to each treatment: control, 50% of the growing stock removed and 100% of the growing stock removed. In the centre of each plot, a vegetation survey of vascular plants was done before (in 2012) and two years after (in 2014) felling in a circular sampling area of 400 m 2 . We employed indicator species analysis, and species were grouped into functional types with respect to their traits.Results: Understory species composition differed significantly between treatments.Forty-seven species (out of 251) were significantly associated with the 100% felling intensity. This relatively high number of indicators was due to the post-disturbance colonization of early-successional, non-forest species, coupled with the expansion of pre-treatment resident species. Only one species was a strong indicator for the 50% felled plots, while three species showed a preference for the unfelled plots.Graminoids, tall perennial forbs, annual/biennial forbs and legumes exhibited the most prominent increase in cover at the 50% and 100% felling intensity. Ferns showed non-significant changes, whereas woody plants exhibited a decrease in the most intensive treatment. In general, most of the typical forest species responded with increased frequency and/or abundance after felling. Conclusions:The post-treatment taxonomic and functional composition of plant communities exhibited the largest changes in the most intensively felled stands.Overall, in the short term, ecological conditions in canopy gaps were not modified to an extent that would be detrimental to the persistence of typical forest species. K E Y W O R D SAremonio-Fagion, Natura 2000, felling disturbance gradient, indicator species analysis, plant functional types, typical forest plant species | 49

Anthropogenic disturbances alter the conservation value of karst dolines

“…These results are in line with other studies that demonstrated the potential of plantation forests to maintain the populations of valuable species (Sutton 1999;Brockerhoff et al 2008). They also highlighted that there is an urgent need to improve our understanding about the effects of disturbance and ecosystem characteristics (e.g., duration and intensity of disturbance, resilience and resistance of ecosystem functions, and recovery time) on the local and regional species composition and diversity (O'Brien et al 2018;van de Leemput et al 2018;Kermavnar et al 2019).…”

Evaluating Short-Term Impacts of Forest Management and Microsite Conditions on Understory Vegetation in Temperate Fir-Beech Forests: Floristic, Ecological, and Trait-Based Perspective

“…Although partial cutting and canopy gaps promoted the establishment of many light-demanding, non-forest plant species, it is always important to ask how typical forest specialists (including tree species) responded to intensive cutting treatments. In our previous study [36], we have shown that these understory species, presumably more sensitive to disturbance, tolerate a wider range of light conditions and are, shortly after cutting, able to persist in canopy gaps.…”

“…Tree cutting was performed between June and August 2012. Detailed information about our experimental design can be found in the works of [36,37].…”

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Effects of Disturbance on Understory Vegetation across Slovenian Forest Ecosystems

“…In most IM sites, most disturbances occurred in the overstory canopy, resulting in the reduction of tree-layer cover and consequent increases in light reaching the forest floor. As shown in many previous studies [61][62][63], typical forest understory species, presumably more sensitive to disturbance, are able to tolerate a wider range of light conditions.…”