Objective 1: Test degree of spatial association or dissociation

The location of white spruce regeneration (seedlings) was found to be positively correlated with the location of mature white spruce. Due to unspecified program errors, the association analysis could not be completed for two of the transects, lowering the sample size to 23.

Of the remaining transects, 12 showed a statistically significant positive association at an alpha level of 0.05. That number increased to 14 using the slightly less conservative alpha level of 0.1. Seven transects showed slight dissociation between seedlings and mature trees, but those results were statistically highly non-significant (P > 0.95).

Association significance (Xp)

The results of the spatial association analysis were mapped for each transect in order to visualize the spatial pattern of association. Follow the link below to see an example of the results.

Spatial association mapping example

Objective 2: Determine important factors affecting spatial relationships

None of the treatment variables had a statistically significant effect on the overall spatial association indices. There was a tendency for transects in cutblocks that were harvested during mast years to show a greater correlation between seedlings and mature trees (P=0.1622). Transects harvested during a mast year had an average overall association index (X) of 0.5149, compared to X=0.1460 for non-mast year transects.