Flavonoids are important secondary metabolites that play an integral role in protecting plants against UV radiation and other forms of environmental stress. Given widespread impacts of environmental effects associated with latitude on a multitude of biological systems and a well-documented increase in solar radiation towards the equator, plant flavonoid production is expected to increase as a response to factors associated with decreasing latitude. Using data from a Neotropical genus (Ruellia) that spans an exceptionally broad latitudinal gradient, we tested a hypothesis of a positive latitudinal gradient in flavonoid concentration and assessed other factors that influence flavonoid production including habitat type (xeric vs. wet), altitude, phylogenetic relatedness, and pleiotropic effects. Two flavones with peak absorbance in ultraviolet wavelengths, apigenin and luteolin, were detected across all species. Transcriptome data confirm high expression of the gene required for flavone biosynthesis, flavone synthase (FNS). Contrary to our prediction, data revealed a positive correlation between flavone concentration and higher latitudes. Further, we recovered strong impacts of xeric habitat, pleiotropy, and phylogenetic relatedness on flavone concentrations. This study documents a complex interplay of ecological, historical, phylogenetic relatedness, and pleiotropic factors driving plant flavonoid production.

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Mastication is a forest fuel thinning treatment that involves chipping or shredding small trees and shrubs and depositing the material across the forest floor. By decreasing forest density mastication has been shown to lessen crown fire hazard, yet other impacts have only recently started to be studied. Our study evaluates how mastication treatments alter the density and composition of soil seed banks in three Colorado conifer forest types. The three forest types were (1) lodgepole pine, (2) ponderosa pine and (3) pinyon pine-juniper. Results showed that masticated sites contained higher seed bank densities than untreated sites: a pattern primarily driven by treatment effects in ponderosa pine forests. The seed bank was dominated by forbs regardless of forest type or treatment. This pattern of forb dominance was not observed in the aboveground vegetation cover as it demonstrated more even proportions of the functional groups. Graminoids showed a higher seed density in treated sites than untreated and, similarly, the identified non-native species only occurred in the treated ponderosa pine sites suggesting a potential belowground invasion for this forest type. These results suggest that presence of masticated material might not be creating a physical barrier hindering the transfer of seeds as predicted. OPEN ACCESSForests 2015, 6 3061

| 4719 www.ecolevol.org | INTRODUC TI ON"Endless forms most beautiful" have motivated biologists for centuries (Carroll, 2005;Darwin, 1859), and the remarkable floral diversity of angiosperms is one prime example. Floral diversity could have arisen via random drift in floral characters over time (Freckleton et al., 2002;Revell et al., 2008), with floral diversity being higher by chance in older and more diverse clades because they have had greater evolutionary history over which to accumulate floral differences. It is thought, however, that most floral diversification in angiosperms is linked to interactions with animal pollinators, given that most angiosperms (~88%) are animal pollinated-a number that rises to 94% within tropical plant communities (Ollerton et al., 2011).