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Full-Text Articles in Life Sciences

Impact Of Minimum Winter Temperatures On The Population Dynamics Of Dendroctonus Frontalis, J. KhảI TrầN, Tiina Ylioja, Ronald F. Billings, Jacques Régnière, Matthew P. Ayres Apr 2007

Impact Of Minimum Winter Temperatures On The Population Dynamics Of Dendroctonus Frontalis, J. KhảI TrầN, Tiina Ylioja, Ronald F. Billings, Jacques Régnière, Matthew P. Ayres

Dartmouth Scholarship

Predicting population dynamics is a fundamental problem in applied ecology. Temperature is a potential driver of short-term population dynamics, and temperature data are widely available, but we generally lack validated models to predict dynamics based upon temperatures. A generalized approach involves estimating the temperatures experienced by a population, characterizing the demographic consequences of physiological responses to temperature, and testing for predicted effects on abundance. We employed this approach to test whether minimum winter temperatures are a meaningful driver of pestilence from Dendroctonus frontalis (the southern pine beetle) across the southeastern United States. A distance-weighted interpolation model provided good, spatially explicit, …


Nitrogen Budgets Of Phloem-Feeding Bark Beetles With And Without Symbiotic Fungi, Matthew P. Ayres, Richard T. Wilkens, Jonathan J. Ruel, María J. Lombardero, Erich Vallery Aug 2000

Nitrogen Budgets Of Phloem-Feeding Bark Beetles With And Without Symbiotic Fungi, Matthew P. Ayres, Richard T. Wilkens, Jonathan J. Ruel, María J. Lombardero, Erich Vallery

Dartmouth Scholarship

The nitrogen content of plant tissue is low relative to that of herbivores; as a consequence, dietary N can limit the growth and reproduction of herbivores and select for attributes that increase N acquisition. Bark beetles face a particularly severe challenge because the phloem that they consume is very low in nitrogen and phosphorus relative to their requirements. We quantified variation in the phloem concentrations of N and P in the host tree, Pinus taeda, and evaluated the following hypotheses regarding the role of symbiotic fungi in nutrient budgets of the herbivore Dendroctonus frontalis: D. frontalis experience variation …