Modelling early plant primary succession on Mount St. Helens
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Abstract
Understanding the mechanisms that control the rate and trajectory of primary succession can lead to insights for ecosystem rehabilitation. Proposed mechanisms include life history traits and nutrient limitation. To explore how these mechanisms can drive successional dynamics, I devised a stoichiometric ecosystem-level model that considered the role of nitrogen and phosphorus limitation in plant primary succession in conjunction with life history traits. This model was applied to the plant community on Mount St. Helens to check the validity of the mechanisms. The results show the competitive hierarchy of plants at the local scale can be explained by nutrient limitation and plant stoichiometry. At regional scales, life history traits interact with local processes to shape community structure and successional dynamics. At all scales, the presence of Lupinus lepidus, a nitrogen-fixer, significantly altered community dynamics and succession. This study suggests that primary succession can be examined within the framework of ecological stoichiometry.