Co-Occurrence of Vulpia Species on the Northern Tablelands of New South Wales

Abstract

A survey of 100 sites on the northern tablelands, New South Wales (Australia) was conducted to determine the composition of Vulpia populations in ruderal and pasture habitats. Of the four species recorded, two were widespread and common [Vulpia bromoides (L.) Gray and V. myuros (L.) Gmel.] and two were rare and newly recorded for the region [V. muralis (Kunth) Nees and V. ciliata (Pers.) Link]. Mixed stands of the two common species occurred at 88% of the sites sampled, although V. bromoides was more abundant with an average frequency of 61% compared with 38% for V. myuros. Two forms of V. myuros were present and these usually occurred in mixed stands, with forma myuros more widespread and abundant than forma megalura [V. megalura (Nutt.) Rydb.].

Relative frequencies were compared for a range of site characteristics: habitat type, parent material, latitude, aspect and altitude. However, variation in abundance of V. bromoides and V. myuros in relation to these factors was insignificant, suggesting that both species have a broad ecological amplitude. Although ecological differentiation between species could not be detected at the scale of this survey, it is likely that such differences may exist at a smaller spatial, or on a temporal scale.