Alien vascular plants in the Silesian Upland of Poland: distribution, patterns, impacts and threats

Abstract

Symptoms of anthropogenic changes in the flora include processes of extinction in some species and spread in others. These tendencies have increased in magnitude in recent centuries, adversely affecting natural biodiversity on a regional, national and continental scale. The main idea behind the project presented here was to investigate the diversity of the alien vascular flora at the regional scale and to update the list of invasive alien species for the Silesian Upland. The aim of this study is also to provide a synthesis of the knowledge accumulated to date on the conditions for their occurrence, their distribution patterns and the possible threat they might pose. The distribution of particular species at the regional scale was investigated by mapping the species on a 2 km x 2 km grid. The study showed that the list of alien plant species for the Silesian Upland encompasses 338 species, including 125 archaeophytes, 195 kenophytes (=neophytes) and 18 species of an uncertain status in the Polish flora. A threat evaluation was performed for particular species on the basis of the number of localities, the diversity of preferred habitats recorded, and their current (over the last decade) tendency to colonise new localities. As a result, a final list of 101 invasive species has been selected. Among the alien plant species considered to be invasive in the area of the Silesian Upland, 20 species are identified as Çweedsí (13 archaeophytes and 7 kenophytes), another 25 (exclusively kenophytes), penetrating into natural habitats, are defined as Çtransformersí.

Species-specific effects of plant invasions on activity, biomass, and composition of soil microbial communities

“…The lack of effects of S. gigantea or R. laciniata invasion on most soil microbial properties in our research was unexpected, as both species are considered, like R. japonica, Btransformers^that modify ecosystems considerably (Pyšek et al 2004;Tokarska-Guzik et al 2010). Other studies on the influence of S. gigantea on soil microbial properties provided inconsistent results, with positive, negative, or no changes in soil properties due to the invasion.…”

“…They exert negative influence on the biodiversity of valuable natural and extensively managed habitats (Zelnik 2012). These species are considered transformers (Tokarska-Guzik et al 2010), i.e., invasive species that Bchange the character, condition, form, or nature of ecosystems over a substantial area^ (Pyšek et al 2004); therefore, their effects on soil microbial processes and thus soil functioning (Nannipieri et al 2003) require detailed investigations. Previous research has been often conducted using either one or a small number of study sites, a single invasive species/ genus, and/or measuring few microbial properties, making generalizations on the impact of the invasion on soil functioning problematic Herr et al 2007;Scharfy et al 2009Scharfy et al , 2010Aguilera et al 2010;Dassonville et al 2011;Tharayil et al 2013;Mincheva et al 2014).…”

Changes in Vascular Flora of the Rzeszow Reservoir after 20 Years (SE Poland)

“…In the Tiber, the number of alien species after 30 years was 24.0% higher [64]. This is connected with the role of rivers in the spread of kenophytes, including invasive species, as reported in many publications [4,15,29,31,35,71,72]. Research conducted by Chappuis et al [16] shows that most invasive species are found in artificial water bodies or river valleys strongly transformed by human activity.…”

Differential influence of four invasive plant species on soil physicochemical properties in a pot experiment

“…Impatiens glandulifera, Reynoutria japonica, Rudbeckia laciniata, and Solidago gigantea are among the most frequent and aggressive invasive alien plants in natural, extensively managed, and man-made habitats in central Europe (Tokarska-Guzik et al 2010;Zelnik 2012). All these species are considered transformers that change Bthe character, condition, form or nature of ecosystems over a substantial area^due to, for example, excessive or limited use of resources, promotion of erosion or stabilization of soil, or accumulation of litter (Richardson et al 2000;Tokarska-Guzik et al 2010).…”

“…All these species are considered transformers that change Bthe character, condition, form or nature of ecosystems over a substantial area^due to, for example, excessive or limited use of resources, promotion of erosion or stabilization of soil, or accumulation of litter (Richardson et al 2000;Tokarska-Guzik et al 2010). However, some data indicated that the influence of invasion on ecosystems may considerably vary among transformer invasive species.…”