Nitrate and ammonium uptake in 21 common species of moss from Vancouver Island, British Columbia

Abstract

Mosses play key ecological roles in water and nutrient retention in many ecosystems, yet relatively little is known of the functional characteristics of moss species, particularly nutritional characteristics. We investigated the net flux of ammonium, nitrate, and protons, using a microelectrode ion flux measurement system, in the gametophytes of 21 common species of moss from three contrasting locations in southern coastal British Columbia. The general location from which mosses were collected did not significantly affect ammonium or nitrate uptake. Proton efflux was greatest in mosses from locations with high rainfall. Rates of nitrate uptake differed among moss families, but there were no significant differences in uptake among species within families. Ammonium net flux differed among moss families, but also among species nested within family, with some species showing uptake and other showing ammonium efflux. In general, moss species native to dry habitats appeared to have higher rates of nitrogen uptake when ammonium and nitrate were available under favourable conditions.