Root sprouting in Rumex acetosella under different nutrient levels

Growth of Rumex acetosella, a root sprouting plant, was studied in a pot experiment. Each plant of R. acetosella consisted of two ramets which were interconnected by a root about 9 cm long. One of the ramets was placed in a compartment with nutrient-rich soil, the other with nutrient-poor soil. The root connection between the ramets either remained intact or was severed at the nutrient interface after planting. Growth of new roots was prevented at the nutrient interface.The presence of a connection between the ramets did not affect biomass or shoot production in either soil compartment, indicating a poor integration of the interconnected plant systems. In the nutrient-rich environment, two to four times more shoots and biomass were produced than in the low nutrient regime. A large proportion of buds initiated on roots remained dormant, forming a bud bank. When the number of shoots or buds was expressed per g of root dry weight or per m of root length, the nutrient response was no longer evident or, in a few cases, a significant effect in the opposite direction was obtained. These results show that the greater production of buds and shoots in the nutrient-rich environment reflected an allometric relationship between root biomass and the number of buds and shoots initiated on the roots.