individuals present in the plot the previous year. Negative 

 growth rates reflect a decreasing population size. 



Discussion 

 I. Long-term monitoring studies 



1. The severe drought that occurred in 1988 appears to 

 have influenced total fruit production at both Charleys 

 Gulch and Birch Creek (Table 1) . During that year, the 

 percentages of fruiting plants reached the lowest 

 recorded levels. However, over the three study years, 

 at both sites, there has been an increase in the 

 fecundity (# fruits/fruiting plant) of the reproductive 

 individuals. 



2. The slight negative population growth rate at the 

 Charleys Gulch site may be due, in part, to the impacts 

 of cattle trampling, which was very evident at this 

 site in both 1988 and 1989. 



II. Spotted knapweed removal studies 



1. Yearly removal of spotted knapweed from randomly 

 selected plots in the study transects has resulted in a 

 decrease (but not eradication) in the mean percent 

 canopy cover of spotted knapweed in those plots, at 

 both Charleys Gulch and Birch Creek (Table 2) . 



2. At Charleys Gulch, an increase in plant densities 

 occurred in the spotted knapweed removal plots over the 

 three-year study period (Table 3) . At Birch Creek, a 

 drastic increase was detected in 1988, followed by a 

 decrease in 1989 (Table 4) . In the control plots, 

 densities remained fairly constant at Charleys Gulch, 

 and decreased slightly in 1989 at Birch Creek. These 

 data suggest that reduction of interspecific 

 competition from spotted knapweed may allow increased 

 establishment of A. fecunda plants. The population 

 growth statistics reflect these changes. 



3. The fecundity parameters were apparently heavily 

 influenced by the drastic climatic fluctuations during 

 the three-year study period. To fully assess the 

 potential influence of spotted knapweed competition on 

 fecundity, additional transect readings over several 

 more years are needed. 



