Barbara Tokarska-Guzik

Extinct and endangered archaeophytes and the dynamics of their diversity in Poland

Extinct and endangered archaeophytes and the dynamics of their diversity in Poland

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

Alien vascular plants in the Silesian Upland of Poland: distribution, patterns, impacts and threats 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 ‘weeds’ (13 archaeophytes and 7 kenophytes), another 25 (exclusively kenophytes), penetrating into natural habitats, are defined as ‘transformers’

A Survey of Genetic Variation and Genome Evolution within the Invasive Fallopia Complex

The knotweed taxa Fallopia japonica, F. sachalinensis and their interspecific hybrid F. × bohemica are some of the most aggressive invaders in Europe and North America and they are serious threats to native biodiversity. At the same time, they constitute a unique model system for the creation of hybrids and studies of the initiation of evolutionary processes. In the presented study, we focused on (i) examining genetic diversity in selected populations of three Fallopia taxa in the invaded (Poland) and native ranges (Japan), (ii) establishing genome size and ploidy levels and (iii) identifying ribosomal DNA (rDNA)-bearing chromosomes in all of the taxa from the invaded range. We found that the genetic diversity within particular taxa was generally low regardless of their geographical origin. A higher level of clonality was observed for the Polish populations compared to the Japanese populations. Our study suggests that the co-occurrence of F. sachalinensis together with the other two taxa in the same stand may be the source of the higher genetic variation within the F. × bohemica hybrid. Some shift towards the contribution of F. japonica alleles was also observed for selected F. × bohemica individuals, which indicates the possibility of producing more advanced generations of F. × bohemica hybrids. All of the F. sachalinensis individuals were hexaploid (2n = 6x = 66; 2C = 6.01 pg), while those of F. japonica were mostly octoploid (2n = 8x = 88; 2C = 8.87 pg) and all of the F. × bohemica plants except one were hexaploid (2n = 6x = 66; 2C = 6.46 pg). Within the chromosome complement of F. japonica, F. sachalinensis and F. × bohemica, the physical mapping of the rDNA loci provided markers for 16, 13 and 10 chromosomes, respectively. In F. × bohemica, a loss of some of rDNA loci was observed, which indicates the occurrence of genome changes in the hybrid.

Alien plants in Poland: research directions and putting the results into practice

Abstract The aim of this study was: (i) to complete and verify the prior review of research on alien plants conducted in Poland and the practical use of their results, and (ii) to attempt to assess the contribution of the research from the area of Poland to the research conducted on an international level. The analysis was performed based on the information gathered during a literature search which covered the last 200 years, using over 1400 publications out of the 3000 which were available in the pool. As a result, the main areas of biological sciences in the context of the research undertaken on alien plants in Poland (distribution, ecology and biology of the species), the most common thematic studies (new species, new localities, and lists of alien species), and the most often investigated species, as well as tendencies over time were indicated. Although studies on the migration and distribution of alien plants in Poland have over 100 years of tradition, and the part of the studies conducted by Polish researchers contributes to the international scale research, it is still necessary to further analyse many issues and answer numerous questions.

Simple yet effective: Historical proximity variables improve the species distribution models for invasive giant hogweed (Heracleum mantegazzianum s.l.) in Poland

Species distribution models are scarcely applicable to invasive species because of their breaking of the models’ assumptions. So far, few mechanistic, semi-mechanistic or statistical solutions like dispersal constraints or propagule limitation have been applied. We evaluated a novel quasi-semi-mechanistic approach for regional scale models, using historical proximity variables (HPV) representing a state of the population in a given moment in the past. Our aim was to test the effects of addition of HPV sets of different minimal recentness, information capacity and the total number of variables on the quality of the species distribution model for Heracleum mantegazzianum on 116000 km2 in Poland. As environmental predictors, we used fragments of 103 1×1 km, world- wide, free-access rasters from WorldGrids.org. Single and ensemble models were computed using BIOMOD2 package 3.1.47 working in R environment 3.1.0. The addition of HPV improved the quality of single and ensemble models from poor to good and excellent. The quality was the highest for the variants with HPVs based on the distance from the most recent past occurrences. It was mostly affected by the algorithm type, but all HPV traits (minimal recentness, information capacity, model type or the number of the time periods) were significantly important determinants. The addition of HPVs improved the quality of current projections, raising the occurrence probability in regions where the species had occurred before. We conclude that HPV addition enables semi-realistic estimation of the rate of spread and can be applied to the short-term forecasting of invasive or declining species, which also break equal-dispersal probability assumptions.