Nemeža biotopu pārkrūmošanās Rīgā. II. Robinia pseudoacacia un R. luxurians izplatība, ekoloģija un augu sabiedrības | Shrub encroachment in non-wooded habitats in Riga. II. Distribution patterns, ecology and plant communities of Robinia pseudoacacia and R. luxurians

anglais. In our study, 19 sites with communities with Robinia pseudoacacia and R. luxurians were described and analysed by using TWINSPAN and DCA. The community was classified as association Chelidonio-Robinietum Jurko 1963 and divided into two variants – typicum and var. Festuca rubra. The species characteristic for var. typicum are Aegopodium podagraria (V contancy class), Taraxacum officinale, Stellaria media, Glechoma hederacea, Chelidonium majus and Impatiens parvifora (III–IV constancy class). The species typical for var. Festuca rubra are Dactylis glomerata and Elytrigia repens (IV constancy class) and Festuca rubra (III constancy class). In var. Festuca rubra, there is larger proportion of plant species typical for moist soils and species with sub-oceanic distribution, while in var. typicum the largest proportion of species are nitrophilous, characteristic for moderately moist soils and with oceanic to sub-oceanic distribution.

letton. Aprakstītas 19 baltās un greznās robīnijas augu sabiedrības, kas atbilst asociācijai Chelidonio-Robinietum Jurko 1963. Ar TWINSPAN un DCA analīzi augu sabiedrības grupētas divos variantos – tipiskajā un Festuca rubra variantā. Tipiskā varianta augu sabiedrībām raksturīgākās sugas ir: Aegopodium podagraria (V konstantuma klase), Taraxacum officinale, Stellaria media, Glehoma hederacea, Chelidonium majus un Impatiens parviflora (III–IV). Festuca rubra variantam raksturīgas ir graudzāles – Dactylis glomerata, Elytrigia repens (IV) un Festuca rubra (III). Festuca rubra varianta augu sabiedrībās lielāks ir valgu augteņu un subokeāniskas izplatības augu sugu īpatsvars, turpretī tipiskā varianta augu sabiedrībām raksturīgas ir nitrofīlu, mēreni mitru augteņu sugas, ar okeāniskisubokeāniskiem areāliem.