R. ROE

Trenton Street, Kenmore, Queensland, 4069, Australia.
Formerly: CSIRO Division of Plant Industry, Black Mountain, Canberra, A.C.T. 2601.

Abstract

The density of established plants of Astrebla spp. on "Gilruth Plains" in the Warrego region of south-western Queensland was measured in 1986 following the appearance of a high population of seedlings in 1983.
A steady decline, from 3.3 7 to 0. 76 established plants/m² over the period 1943 to 1974 had previously been recorded. That decline was reversed by the population present in 1986. It was comparable to that in 1943, and was the first major recruitment to occur since that year.
Thus, the period between recruitments which are sufficiently large to prevent a decline in Astrebla density in the Warrego region, may be in excess of 40 years.