Invasive populations of Spiraea tomentosa (Rosaceae) are genetically diverse but decline during succession in forest habitats

A Community-Based Framework Integrates Interspecific Interactions into Forest Genetic Conservation

Forest genetic conservation is typically species-specific and does not integrate interspecific interaction and community structure. It mainly focuses on the theories of population and quantitative genetics. This approach depicts the intraspecific patterns of population genetic structure derived from genetic markers and the genetic differentiation of adaptive quantitative traits in provenance trials. However, it neglects possible interspecific interaction in natural forests and overlooks natural hybridization or subspeciation. We propose that the genetic diversity of a given species in a forest community is shaped by both intraspecific population and interspecific community evolutionary processes, and expand the traditional forest genetic conservation concept under the community ecology framework. We show that a community-specific phylogeny derived from molecular markers would allow us to explore the genetic mechanisms of a tree species interacting with other resident species. It would also facilitate the exploration of a species' ecological role in forest community assembly and the taxonomic relationship of the species with other species specific to its resident forest community. Phylogenetic β-diversity would assess the similarities and differences of a tree species across communities regarding ecological function, the strength of selection pressure, and the nature and extent of its interaction with other species. Our forest genetic conservation proposal that integrates intraspecific population and interspecific community genetic variations is suitable for conserving a taxonomic species complex and maintaining its evolutionary potential in natural forests. This provides complementary information to conventional population and quantitative genetics-based conservation strategies.

The Data Portal "Chromosome Numbers of the Flora of Germany": Progress After Five Years, Recent Developments, and Future Strategies

Chromosome numbers and information on ploidy level are of great importance for better understanding of plant evolution and taxonomy but also for species identification. Technical developments in flow cytometry dramatically improved the measurement of genome size and triggered a renewed interest in chromosome numbers. Web-based portals make these kind of data accessible for a wide audience in both academia and citizen science. The specialised database of German plant chromosome counts and ploidy estimates comprises to date more than 14,000 records covering 52% of the German taxa. The database is accessed about 70 times per month and became an integral part of several more comprehensive initiatives. One example is the Rothmaler Flora of Germany, which now for the first time features chromosome data with verified origin from the region of interest. Another is the German plant information hub FloraWeb currently amended by several new data sources with the chromosome number database as a major component.