Taxonomic and ecological patterns in root traits of Carex (Cyperaceae)

Abstract

Plants can develop various root traits which may contribute to their nutrient acquisition. We investigated the occurrence of five root traits among species of genus Carex to determine their frequency, mutual associations and dependence on taxonomy (subgenus) or habitat. Root samples of 40 species were collected in their natural habitats within Russia and Belarus. They were examined microscopically to quantify the abundance of AM-fungal hyphae (H), arbuscules (A) and vesicles (V), dark septate endophyte (DSE), typical (long) root hairs (TRH), bulbous (shortened) root hairs (BRH) and dauciform roots (DR). The frequency of root traits decreased in the order TRH (100% of the species), DSE (80%), BRH (43%), A and V (25%) and DR (23%). Most species possessed 2–4 different traits, but up to five were possible, even on a single plant. Traits occurred largely independently of each other. DR were only found in subgenus Carex and mainly in grasslands. DSE and BRH were more abundant in subgenus Carex. BRH were most abundant in wetlands, TRH were shortest and thinnest in grasslands. A diversity of root traits exists in the genus Carex, with variation both among and within species. The abundance and size of traits exhibits some taxonomic and ecological patterns, which differ for each trait.