Nitrogen availability and weed invasion in a remnant native woodland in urban Melbourne

Abstract

The woodlands of Studley Park, and the greater Yarra Bend Park, are within 4 km of the centre of the city of Melbourne and total more than 200 ha. Weeds are major contributors to the loss of diversity of native species. We examined the hypothesis that an increase in the availability of nitrogen (N) may be responsible for the increase in weed abundance. In a small field trial, nitrogen availability was greater in areas invaded by weeds and weeds had greater nitrate reductase activity than native species. Both invaded and uninvaded areas were well-supplied with weed seed, although the composition of the seed bank varied greatly between sites. Diaspores of the weed Romulea rosea were abundant i..