European plants with C4 photosynthesis: geographical and taxonomic distribution and relations to climate parameters

Abstract

A survey of C4 plants in Europe was performed with 216 species based on information in the literature and new studies. C4 species were found in 10 families: the eudicots Amaranthaceae, Chenopodiaceae, Euphorbiaceae, Molluginaceae, Nyctaginaceae, Polygonaceae, Portulacaceae and Zygophyllaceae and the monocots Cyperaceae and Poaceae. The majority of the C4 species belong to four families, Amaranthaceae (23), Chenopodiaceae (65), Cyperaceae (27) and Poaceae (88). In central and southern Europe, the abundance of native C4 plants varied between 44 and 88% of total C4 plants occurring, the rest being invasive C4 species. The occurrence of total C4 species, C4 monocots and C4 Chenopodiaceae was assessed for five major phyto-geographical regions of Europe (north-west, north-east, central, south-west, and south-east). The abundance of C4 plants of total C4 dicots, C4 Chenopodiaceae, total C4 monocots, C4 Poaceae and C4 Cyperaceae was related to the climatic variables of annual mean daily temperature, annual precipitation and DeMartonne's aridity index. The abundance of total C4 plants decreases with increasing temperature and expression of aridity (decreasing aridity index) and is not correlated with precipitation. The abundance of total C4 dicots and C4 Chenopodiaceae is correlated with precipitation and aridity but not temperature, whereas the abundance of total C4 monocots, C4 Poaceae and C4 Cyperaceae is correlated with temperature and aridity but not precipitation.