Rationale: Changes in fine-root morphology are typically associated with transitions from the ancestral arbuscular mycorrhizal (AM) to the alternative ectomycorrhizal (ECM) or non-mycorrhizal (NM) associations. However, the modifications in root morphology may also coincide with new modifications in leaf hydraulics and growth habit during angiosperm diversification. These hypotheses have not been evaluated concurrently, which limits our understanding of the causes of fine-root evolution. Methods: To explore the evolution of fine-root systems, we assembled a 600+...

The expansion of woody plants into grasslands and old fields is often ascribed to fire suppression and heavy grazing, especially by domestic livestock. However, it is also recognized that nutrient availability and interspecific competition with grasses and other woody plants play a role in certain habitats. I examined potential factors causing range- and niche expansion by the eastern redcedar Juniperus virginiana, the most widespread conifer in the eastern United States, in multifactorial experiments in a...

Local community structure is shaped by processes acting at local and landscape scales. The relative importance of drivers operating across different spatial scales are difficult to test without observations across regional or latitudinal gradients. Cities exhibit strong but predictable environmental gradients overlaying a mosaic of highly variable but repeated habitat types within a constrained area. Thus, cities present a unique opportunity to explore how both local and landscape factors influence local biotic communities. We used...

1. Plant responses to major environmental drivers like precipitation can influence important aspects of carbon (C) cycling like soil CO2 efflux (JCO2). These responses may be predicted by two independent classes of drivers: plant size—larger plants respire more and produce a larger quantity of labile C, and plant economics—plants possessing more acquisitive plant economics strategies (i.e., high metabolic rate and tissue nutrient content) produce higher-quality tissue that respires rapidly and decomposes quickly. 2. At two...