Ecological Archives E095-077-A1

Alice L. Miller, Jeffrey M. Diez, Jon J. Sullivan, Steven R. Wangen, Susan K. Wiser, Ross Meffin, Richard P. Duncan. 2014. Quantifying invasion resistance: the use of recruitment functions to control for propagule pressure. Ecology 95:920–929. http://dx.doi.org/10.1890/13-0655.1

Appendix A. A table of recruitment function parameter comparisons across habitats and cohorts after four years, a map of the study area in South Island, New Zealand, and a figure showing seedling recruitment and subsequent mortality over time in each of the six habitats.

Table A1. Recruitment function parameter comparisons across habitats and cohorts after four years.

 

Probability that
habitats differ

 

Probability that Cohort 1 > Cohort 2

Parameter

cohort 1

cohort 2

 

Forested creek margin

Intact forest

Treefall gap

Subalpine creek margin

Subalpine scrub

b (proportion safe sites)

> 0.99

> 0.99

 

0.13

0.13

0.48

0.66

0.65

n (number of sites)

0.91

0.95

 

0.84

0.71

0.7

0.87

0.72

λ (heterogeneity of sites)

0.67

0.94

 

0.8

0.37

0.38

0.43

0.24

Notes: Probabilities of habitat and cohort differences in different parameters were calculated within the MCMC model-fitting. Probabilities that habitats differ were calculated by subtracting the lowest habitat values from the highest habitat, and finding the cumulative probability that the posterior distribution is greater than zero. Similarly for finding cohort effects, cohort 2's value was subtracted from cohort 1's value for each parameter in each habitat, and the cumulative probabilities greater than zero are reported.

 

FigA1

Fig. A1. Map of the study area in South Island, New Zealand. Solid lines show rivers and creeks, dashed lines are minor roads, and a major road (SH73) is shown as three adjacent lines. Points with numbers are the elevations of peaks (meters above sea level). Boxes A and B demark the catchments included in the survey to quantify the abundance of Hieracium lepidulum in the field. The seventeen creeks randomly selected for surveying are shown as heavy lines and marked with an asterisk. Box C, which is also displayed as an enlarged panel, shows the Craigeburn Stream catchment where the seed addition experiment was carried out. In the enlarged panel C, the heavy dashed line is a road accessing the catchment, grey shading denotes forest and the unshaded area is above treeline. The filled circles show the locations of the 36 experimental seed addition blocks (18 in forest and 18 in subalpine habitats), with some circles obscured due to overlap. Seed for the seed addition experiment was collected from H. lepidulum populations in catchments in the Black Range.


 

FigA2

Fig. A2. Seedling recruitment and subsequent mortality over time in each of the six habitats. Shown here are numbers of seedlings per m², averaged across all blocks within each habitat for all of the plot censuses.


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