DEVELOPMENT OF SPECIES DOMINANCE ALONG AN ELEVATIONAL GRADIENT: POPULATION DYNAMICS OF PINUS EDULIS AND JUNIPERUS MONOSPERMA

We evaluated species‐environment relationships within pinon‐juniper woodlands in northern New Mexico (United States) using canonical correspondence analysis (CCA). The first CCA axis was associated primarily with elevation. Our results showed separation between pinon and juniper along the elevation gradient, as expected: pinon is relatively more dominant at higher sites, whereas juniper is relatively more dominant at lower sites. To examine how this pattern of dominance might emerge with time, we plotted the position of centroids for three pinon and juniper size classes along the first CCA axis. We found that small pinons and junipers were distributed relatively uniformly across the gradient, whereas large pinons and junipers were strongly segregated along the gradient, with intermediate‐sized pinons and junipers intermediate on the CCA axis between small and large. This produced a pattern of increased divergence between the two species that increased with size. We suggest that this pattern emerges as a r...