Physical Sciences and Mathematics Commons^™

Species Richness And Soil Properties In Pinus Ponderosa Forests: A Structural Equation Modeling Analysis, Daniel C. Laughlin, Scott R. Abella, W. Wallace Covington, James B. Grace

Public Policy and Leadership Faculty Publications

Question: How are the effects of mineral soil properties on understory plant species richness propagated through a network of processes involving the forest overstory, soil organic matter, soil nitrogen, and understory plant abundance? Location: North-central Arizona, USA. Methods: We sampled 75 0.05-ha plots across a broad soil gradient in a Pinus ponderosa (ponderosa pine) forest ecosystem. We evaluated multivariate models of plant species richness using structural equation modeling. Results: Richness was highest at intermediate levels of understory plant cover, suggesting that both colonization success and competitive exclusion can limit richness in this system. We did not detect a reciprocal positive …