The percentage of area within each community type and the percentage of sample plots without Douglas-fir seedlings for each community type for three study sites in Washington and Oregon, 2000. Community types appear in order of most resistant to least resistant to Douglas-fir seedling establishment. A separate likelihood ratio chi-square test analysis is reported for each site.
Study area (%) | Community type | Plots without Douglas-fir (%) |
---|---|---|
TCW | ||
9 | Herb | 100* |
9 | Tree/tall shrub | 98* |
43 | Shrub | 89* |
24 | Herb/shrub | 74 |
15 | Alder | 69 |
(Chi-square = 44.3; DF = 4; N = 463; P < 0.0001) | ||
CRG | ||
5 | Herb | 95* |
55 | Tree/tall shrub | 90* |
4 | Broom | 84 |
9 | Herb/shrub | 79 |
26 | Shrub | 77 |
(Chi-square = 13.8; DF = 4; N = 461; P < 0.01) | ||
WF | ||
12 | Tree/tall shrub | 82* |
18 | Shrub | 77* |
24 | Broom | 61 |
2 | Herb | 60 |
42 | Herb/shrub | 49 |
(Chi-square + 32.8; DF = 4; N = 452; P < 0.0001) |
↵* Observed number of plots without Douglas-fir more than expected by random chance.