Intraspecific genetic variation in foundation species such as aspen ( Michx.) shapes their impact on forest structure and function. Identifying genes underlying ecologically important traits is key to understanding that impact.
View Article and Find Full Text PDFCondensed tannins (CTs) are abundant, ecologically-relevant secondary metabolites in many plants, which respond to variables associated with anthropogenic environmental change. While many studies have reported how genetic and environmental factors affect CT concentrations, few have explored how they influence CT molecular structure. Here, using trembling aspen (Populus tremuloides) as a model organism, we report how foliar CT concentrations, polymer sizes, representation of procyanidins and prodelphinidins, and stereochemistry vary in response to changes in air temperature (warming and freeze damage), air composition (elevated CO and O), soil quality (nutrients and microbiome), and herbivory (mammal and lepidopteran).
View Article and Find Full Text PDFTrembling aspen (Populus tremuloides) is arguably the most important deciduous tree species in the Intermountain West of North America. There, as elsewhere in its range, aspen exhibits remarkable genetic variation in observable traits such as morphology and phenology. In contrast to Great Lakes populations, however, relatively little is known about phytochemical variation in western aspen.
View Article and Find Full Text PDFClimate warming can influence interactions between plants and associated organisms by altering levels of plant secondary metabolites. In contrast to studies of elevated temperature on aboveground phytochemistry, the consequences of warming on root chemistry have received little attention. Herein, we investigated the effects of elevated temperature, defoliation, and genotype on root biomass and phenolic compounds in trembling aspen (Populus tremuloides).
View Article and Find Full Text PDFPlant phenolic compounds (phenylpropanoids) act as defense chemicals against herbivores and can mediate ecosystem processes. Tropospheric ozone (O) pollution alters concentrations of plant phenolics; however, little is known about how these phytochemicals respond to different levels of O exposure. Here, we investigated the effects of five different O exposure levels on foliar concentrations of phenylpropanoids (53 compounds in total) and antioxidative capacity in hybrid Populus (Populus euramericana cv.
View Article and Find Full Text PDFBackground And Aims: Intraspecific variation in foundation species of forest ecosystems can shape community and ecosystem properties, particularly when that variation has a genetic basis. Traits mediating interactions with other species are predicted by simple allocation models to follow ontogenetic patterns that are rarely studied in trees. The aim of this research was to identify the roles of genotype, ontogeny and genotypic trade-offs shaping growth, defence and reproduction in aspen.
View Article and Find Full Text PDFCommunity genetics aims to understand the effects of intraspecific genetic variation on community composition and diversity, thereby connecting community ecology with evolutionary biology. Thus far, research has shown that plant genetics can underlie variation in the composition of associated communities (e.g.
View Article and Find Full Text PDFIntroduction: Condensed tannins (CTs) are proanthocyanidin heteropolymers that are widely distributed among plants. Their biochemical properties are determined by molecular structure (e.g.
View Article and Find Full Text PDFAnticipated consequences of climate change in temperate regions include early spring warmup punctuated by intermittent hard freezes. Warm weather accelerates leaf flush in perennial woody species, potentially exposing vulnerable young tissues to damaging frosts. We employed a 2 × 6 randomized factorial design to examine how the interplay of vernal (springtime) freeze damage and genetic variation in a hardwood species (Populus tremuloides) influences tree growth, phytochemistry, and interactions with an insect herbivore (Chaitophorus stevensis).
View Article and Find Full Text PDFAnthropogenic activities are altering levels of atmospheric carbon dioxide (CO) and tropospheric ozone (O). These changes can alter phytochemistry, and in turn, influence ecosystem processes. We assessed the individual and combined effects of elevated CO and O on the phytochemical composition of two tree species common to early successional, northern temperate forests.
View Article and Find Full Text PDFNumerous studies have explored the impacts of intraspecific genetic variation and environment on the induction of plant chemical defenses by herbivory. Relatively few, however, have considered how those factors affect within-plant distribution of induced defenses. This work examined the impacts of plant genotype and soil nutrients on the local and systemic phytochemical responses of trembling aspen (Populus tremuloides) to defoliation by gypsy moth (Lymantria dispar).
View Article and Find Full Text PDFMicrobial symbionts are becoming increasingly recognized as mediators of many aspects of plant - herbivore interactions. However, the influence of plant chemical defenses on gut associates of insect herbivores is less well understood. We used gypsy moth (Lymantria dispar L.
View Article and Find Full Text PDFPoplar (Populus) and birch (Betula) species are widely distributed throughout the northern hemisphere, where they are foundation species in forest ecosystems and serve as important sources of pulpwood. The ecology of these species is strongly linked to their foliar chemistry, creating demand for a rapid, inexpensive method to analyze phytochemistry. Our study demonstrates the feasibility of using near-infrared reflectance spectroscopy (NIRS) as an inexpensive, high-throughput tool for determining primary (e.
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