Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Establishment of barbwire Russian thistle in desert environments.

Abstract

In 1973-9 the frequency of (a) Salsola paulsenii in a degraded plant community in the Carson desert of NW Nevada increased from 79 to 98% and of (b) S. iberica decreased from 11 to 0%. Seed production of (a) was correlated strongly with herbage yield and weakly with number of plants/m2, and was markedly lower than that recorded for (b). In trials in 1974-6 using seed sown at 5000/m2, (b) failed to become established and (a) achieved low levels of establishment under arid conditions, whereas establishment of (b) was 5 times that of (a) in a semiarid environment. Earlier maturation and seed dispersal, seed dispersal beneath the parent plant and less specific afterripening requirements appeared to favour establishment of (a) in arid areas.