Presenter Information

Trevor WeeksFollow

Presentation Type

Poster

Faculty Mentor’s Full Name

Mark Hebblewhite

Faculty Mentor’s Department

Department of Ecosystem and Conservation Sciences

Abstract

Predator-prey effects that alter the abundance, biomass, or productivity of a population community across more than one link in a food web are referred to as trophic cascades. Trophic cascades often specifically refer to “top-down” effects of predators on the rest of the ecosystem. These effects have been extensively studied in aquatic environments, however very few studies have examined trophic cascades in terrestrial ecosystems. The posterchild for terrestrial trophic cascades studies in recent years has been Yellowstone’s wolves. Their influence on aspen and willow communities via the regulation of elk has been well established, however no research has yet been done to understand the effect that wolves may have on a grassland system. To that end, I sought to answer the question of whether top-down effects regulate grassland biomass in a wolf-elk system. To answer my question, I utilized the extensive dataset collected over the last two decades during the Ya Ha Tinda Long-term Elk Monitoring Project. The Ya Ha Tinda is a mountain prairie ecosystem located on the eastern boundary of Banff Park in Alberta, Canada. The Elk Monitoring Project there is one of the longest continuous elk and predator research projects in the world. The sheer variety and volume of data collected over the course of this project provided me with the unique opportunity to address the complexity of terrestrial trophic cascades that has so often precluded studies in such systems. My study serves not only to help fill an egregious hole in this field of ecological research, but is also especially relevant as predators in North America are recolonizing much of their historic range. Understanding what impacts these reappearing predators may have on the ecosystem beyond their prey populations is therefore vital for management, conservation, and reintroduction efforts across North America.

Category

Life Sciences

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Analyzing Predator Impacts on Biomass in a Grassland System

Predator-prey effects that alter the abundance, biomass, or productivity of a population community across more than one link in a food web are referred to as trophic cascades. Trophic cascades often specifically refer to “top-down” effects of predators on the rest of the ecosystem. These effects have been extensively studied in aquatic environments, however very few studies have examined trophic cascades in terrestrial ecosystems. The posterchild for terrestrial trophic cascades studies in recent years has been Yellowstone’s wolves. Their influence on aspen and willow communities via the regulation of elk has been well established, however no research has yet been done to understand the effect that wolves may have on a grassland system. To that end, I sought to answer the question of whether top-down effects regulate grassland biomass in a wolf-elk system. To answer my question, I utilized the extensive dataset collected over the last two decades during the Ya Ha Tinda Long-term Elk Monitoring Project. The Ya Ha Tinda is a mountain prairie ecosystem located on the eastern boundary of Banff Park in Alberta, Canada. The Elk Monitoring Project there is one of the longest continuous elk and predator research projects in the world. The sheer variety and volume of data collected over the course of this project provided me with the unique opportunity to address the complexity of terrestrial trophic cascades that has so often precluded studies in such systems. My study serves not only to help fill an egregious hole in this field of ecological research, but is also especially relevant as predators in North America are recolonizing much of their historic range. Understanding what impacts these reappearing predators may have on the ecosystem beyond their prey populations is therefore vital for management, conservation, and reintroduction efforts across North America.