(1) Background: the cambium has seasonal activity, forming earlywood and early phloem with relatively wide conducting cells, which will function during most favorable season, latewood late narrower typically less season. However, few studies have focused on when these two contrasting tissue types are formed in relation to climatic conditions. (2) Methods: senior author of this paper made weekly...

Chloroplast DNA (cpDNA) is frequently used for species demography, evolution, and species discrimination of plants. However, the lack of efficient and universal markers often brings particular challenges for genetic studies across different plant groups. In this study, chloroplast genomes from two closely related species (Quercus rubra and Castanea mollissima) in Fagaceae were compared to explo...

Regenerating oaks (Quercus spp.) has remained a widespread and persistent problem throughout their natural range. Research shows that abundant oak advance reproduction is crucial for success. Although it is recognized that oak advance reproduction accumulation is inversely related to site quality, there has been little effort to model oak advance reproduction density as a function of measured l...

—We radiotracked nine hoary bats (Lasiurus cinereus) and characterized 12 roosts during late spring and early summer in the Ouachita Mountains of central Arkansas. Hoary bats generally roosted on the easterly sides of tree canopies in the foliage of white oaks (Quercus alba), post oaks (Q. stellata) and shortleaf pines (Pinus echinata). Roost heights averaged 16.5 6 2.2 m and all roost trees we...

Variable, synchronized seed production, called masting, is a widespread reproductive strategy in plants. Resource dynamics, pollination success, and, as described here, environmental veto are possible proximate mechanisms driving masting. We explored the environmental veto hypothesis, which assumes that reproductive synchrony is driven by external factors preventing reproduction in some years, ...

Although prolonged seed retention, or serotiny, is believed to be an adaptation to highly variable environments such as the Mediterranean regions of California, no prior study has systematically investigated the prevalence of seed retention among California oaks (family Fagaceae), the dominant woody taxon in California foothill woodlands. We quantified the extent to which acorns were retained i...

Several squirrel species excise the embryo of acorns of most white oak species to arrest germination for long-term storage. However, it is not clear how these acorns counter embryo excision and survive in the arms race of coevolution. In this study, we simulated the embryo excision behavior of squirrels by removing 4 mm of cotyledon from the apical end of white oak acorns differing in embryo de...

Two aspects of the genetics of floral traits in Aquilegia have been studied: flower color and flower development. A recent comparative study showed that species that did not produce floral anthocyanins (the red and blue pigments in most flowers) also had significantly lower expression levels for multiple genes needed to produce the pigments. However, crossing studies suggest that a single gene ...

We compared five types of visual mast surveys with seed trap data from 105 white oaks (Quercus alba L.) during 1996-1997 in the Ouachita Mountains of Arkansas. We also evaluated these visual survey methods for their usefulness indetecting differences in acorn density among areas. Indices derived from all five methods were highly correlated with acorn densities derived from traps, and the Koenig...

Frelich, Lee E.; Reich, Peter B.; Peterson, David W. 2015. Fire in upper Midwestern oak forest ecosystems: an oak forest restoration and management handbook. Gen. Tech. Rep. PNW-GTR-914. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 64 p. We reviewed the literature to synthesize what is known about the use of fire to maintain and restore oak f...