Flavonoids are secondary metabolites present in all terrestrial plants. The flavonoid pathway has been extensively studied, and many of the involved genes and metabolites have been described in the literature. Despite this extensive knowledge, the functioning of the pathway in vivo is still poorly understood. Here, we study the flavonoid pathway using both experiments and mathematical models. W...

The overarching issue for understanding biodiversity maintenance is how fitness advantages accrue to a species as it becomes rare, as this is the defining feature of stable coexistence mechanisms. Without these fitness advantages, average fitness differences between species will lead to exclusion. However, empirical evidence is lacking, especially for forests, due to the difficulty of manipulat...

BACKGROUND An important contributing factor to the success of terrestrial flowering plants in colonizing the land was the evolution of a developmental strategy, termed skotomorphogenesis, whereby postgerminative seedlings emerging from buried seed grow vigorously upward in the subterranean darkness toward the soil surface. RESULTS Here we provide genetic evidence that a central component of t...

Understanding global warming effects on forest ecosystems will help policy-makers and forest managers design forest management and biodiversity conservation strategies. We examined the change in woody plant structural diversity in response to topography-associated thermal gradients in a subtropical forest with diverse abundance patterns. We found that energy distribution in a warming trend acro...

Cold-acclimation-specific (CAS) gene expression has been examined by screening a cDNA library prepared from poly(A)(+) RNA of cold-acclimated seedlings of a freezing-tolerant variety of alfalfa (Medicago falcata cv Anik). Three CAS cDNA clones, pSM784, pSM2201, and pSM2358, representing different sequence species, have been used to investigate the relative abundance and time-course of accumulat...

The relative importance of livestock grazing in limiting or enhancing oak recruitment remains unclear because results from previous studies have been contradictory. In Santa Barbara County, we have replicated large-scale planting experiments from 1997 to 2001 to determine the effects of cattle and other factors on seedling establishment of valley oak (Quercus lobata) and coast live oak (Q. agri...

Both light and temperature have dramatic effects on plant development. Phytochrome photoreceptors regulate plant responses to the environment in large part by controlling the abundance of PHYTOCHROME INTERACTING FACTOR (PIF) transcription factors. However, the molecular determinants of this essential signaling mechanism still remain largely unknown. Here, we present evidence that the BLADE-ON-P...

Creation of mounds by plains pocket gophers (Geomys bursarius) may affect the distribution of meadow voles (Microtus pennsylvanicus) and subsequent patterns of herbivory. An association between abundance of meadow voles and density of neighborhood mounds might be expected if voles use mounds as feeding sites (positive association), or if vole avoid mounds due to lack of cover (negative associat...

The diversity of ectomycorrhizal (ECM) fungi on adult trees and seedlings of five species, Anthonotha fragrans, Anthonotha macrophylla, Cryptosepalum tetraphyllum, Paramacrolobium coeruleum and Uapaca esculenta, was determined in a tropical rain forest of Guinea. Ectomycorrhizae were sampled within a surface area of 1600 m(2), and fungal taxa were identified by sequencing the rDNA Internal Tran...

Seed dispersal and germination are critical to the fitness of all tree species. Moreover, among most trees the percentage of seeds that become seedlings, or “seedling success”, is very low. We examined seed success of a dominant lowland rainforest species, Pentaclethra macroloba, across a soil moisture gradient. Previous studies have established that P. macroloba has reduced seed germination ra...