An investigation of the invasion dynamics of Asparagus asparagoides (L.) Druce at the habitat level using spatial analytical techniques

Kris SiderovA,B, Nigel AinsworthC,B, Kim LowellD and Christopher BellmanA

A School of Mathematical and Geospatial Sciences, RMIT University, GPO Box 2476V, Melbourne, Victoria 3001, Australia.

B CRC for Australian Weed Management.

C Department of Primary Industries, PO Box 48, Frankston, Victoria 3199, Australia.

D CRC for Spatial Information, University of Melbourne, Ground floor, 723 Swanston Street, Victoria 3010, Australia.


Summary

Questions relating to management and dynamics of the early stages of weed invasion into remnant vegetation were investigated using Asparagus asparagoides, a bird-dispersed weed. An extensive data set was collected from fieldwork undertaken at two sites where A. asparagoides is a recent invader. These data were used to: develop a predictive model for A. asparagoides presence, question the previously accepted rate of dispersal for A. asparagoides and suggest that in the early stages of the invasion process, A. asparagoides enters the reserves via the track network. The spatial nature of the invasion was investigated using a number of spatial statistics that revealed a non-random occurrence of A. asparagoides within the reserves. The results of the spatial analysis also showed that the spatial pattern of A. asparagoides within the reserves might be the result of dispersal occurring at two different scales. Finally a number of recommendations regarding the direction of future research are discussed.

Keywords: Asparagus asparagoides, remnant vegetation, spatial analysis, weed invasion.

 

Plant Protection Quarterly (2006) 21 (2) 85-88.