Publications by authors named "David A Roon"

Article Synopsis
  • Wildfire regimes are altering, raising concerns for aquatic ecosystems and fish species, as predicting fish responses can be complex due to multiple wildfire impacts.
  • Whole-ecosystem approaches like food web modeling can help understand these interactions, showing how different wildfire severities affect aquatic life dynamics in streams.
  • Simulations reveal that wildfires can have varying effects on periphyton, invertebrates, and fish biomass, influenced by fire severity and environmental changes, indicating a need to consider context when assessing wildfire impacts on aquatic ecosystems.
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Resource managers in the Pacific Northwest (USA) actively thin second-growth forests to accelerate the development of late-successional conditions and seek to expand these restoration thinning treatments into riparian zones. Riparian forest thinning, however, may impact stream temperatures-a key water quality parameter often regulated to protect stream habitat and aquatic organisms. To better understand the effects of riparian thinning on shade, light, and stream temperature, we employed a manipulative field experiment following a replicated Before-After-Control-Impact (BACI) design in three watersheds in the redwood forests of northern California, USA.

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A fundamental challenge to estimating population size with mark-recapture methods is heterogeneous capture probabilities and subsequent bias of population estimates. Confronting this problem usually requires substantial sampling effort that can be difficult to achieve for some species, such as carnivores. We developed a methodology that uses two data sources to deal with heterogeneity and applied this to DNA mark-recapture data from grizzly bears (Ursus arctos).

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The use of noninvasive genetic sampling (NGS) for surveying wild populations is increasing rapidly. Currently, only a limited number of studies have evaluated potential biases associated with NGS. This paper evaluates the potential errors associated with analysing mixed samples drawn from multiple animals.

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