Temporal fluctuations of Parkinsonia aculeata L. seedling germination and growth in three Australian rangelands habitats

摘要

Rainfall in the Australian rangelands is highly variable and as a result, weed invasions and weed seedling recruitment are generally episodic. The amount and frequency of rainfall influence the extent of habitat and portion of the landscape that a weed species might invade. To define a weed's habitat it is necessary to determine the moisture requirements that will allow the weed to germinate and establish. These moisture requirements can be used to help define the extent of suitable habitat. A modelof seedling survival was created for Parkinsonia aculeata L. using a combination of historical rainfall data and information on the growth and development of the weed. The growth data were obtained from glasshouse experiments. The model predicts whetherP. aculeata seedlings would grow and survive for an 18 week period, given daily rainfall and climatic conditions for that period. The model was used to predict the frequency of seedling survival and habitat suitability for P. aculeata in Darwin, ChartersTowers and Alice Springs using climate records from 1950 to 2000.