Abundance mechanisms by a globally pervasive grass ( Dactylis glomerata).

摘要

Ecological dominance can result from a number of mechanisms ranging from trait-based (inherent, evolved) to circumstantial (stochastic disturbance, propagule pressure), which are difficult to distinguish once dominance has been attained. Here, I compared native range (Home) and non-native range (Away) populations of Dactylis glomerata to assess the role of trait evolution in the geographical expansion of this grass. I used common garden trials to quantify differences among Home and Away populations, and between a native species in one of its invaded ranges (British Columbia). I then used competition trials to determine the ecological relevance of these differences, if any, on competitive ability. Few significant differences were found between Home and Away Dactylis populations. In conclusion, the species appears to have been intentionally chosen from its native range because of traits promoting high growth and production, and subsequently introduced en masse globally in association with cultivation.