Spontaneous Hybridization betweenPinus mugoandPinus sylvestrisat the Lithuanian Seaside: A Morphological Survey
We address the problem of spontaneous hybridization between an exotic speciesPinus mugoand the native/localP. sylvestrisat the seaside spit of Kursiu Nerija in Lithuania. The objective was to identify spontaneous hybrids betweenP. mugoandP. sylvestrisbased on morphology traits among the individuals naturally regenerating at the seaside spit. The field inventory was carried out over the entire Lithuanian part of the spit, and 200 individuals morphologically intermediate betweenP. sylvestrisandP. mugowere identified. Based on a weighted trait index, the intermediate individuals were grouped into two groups, one morphologically close toP. sylvestrisand another close toP. mugo. The needle micromorphological traits of the putative hybrids were of intermediate values betweenP. mugoandP. sylvestris. The results provide a strong evidence of spontaneous hybridization betweenP. mugoandP. sylvestrisin Lithuanian seaside spit of Kursiu Nerija.