How many neophytes hybridize with native plant species in Germany?
Interspecific hybridization between invasive neophytes and native plant species is widely recognized as an important evolutionary process associated with biological invasions. However, the quantitative dimension of this phenomenon is still largely unknown. A list of interspecific hybrids between neophytes and native species has been drawn up for Germany. A total of 668 neophytes are included in the German databases FloraWeb and/or BioFlor. Of these neophytes, 150 (22%) are known to form hybrids with native species or with other neophytes. In total, there are 141 hybrids between neophytes and native species, of which 92 have already been found in Germany. The abundance and fertility of these hybrids vary. Some of them have only been found a few times, others are common. Most of the time, the distribution of these hybrids is unknown because it is difficult to recognize them in the field.
Hybridization between invasive neophytes and native plant species has important consequences for native biodiversity. Firstly, hybridization leads to the evolution of new hybrid species which may be better adapted to the local conditions than their parental species. Secondly, introgressive hybridization with invasive neophytes results in an irreversible change of the gene pool of certain native plant species (horizontal gene flow).
Sources
Bleeker W, Schmitz U, Ristow M, Mühlausen A (2006) How many neophytes hybridize with native plant species? In: Neobiota. From Ecology to Conservation. 4th European Conference on Biological Invasions. Vienna (Austria), 2006-09-27/29, BfN-Skripten 184: page 81
Flora Web: http://www.floraweb.de/