Experiments

Experiment 322 - Cascading effects of wolf recolonization at Cedar Creek Ecosystem Science Reserve

Because humans eliminated top predators from most terrestrial ecosystems long before the advent???of modern ecology, it remains largely unclear how top predators affect population and community dynamics. After having been extirpated for approximately a century, wolves (Canis lupus) have recently recolonized the north side of Cedar Creek Ecosystem Science Reserve. If trophic cascades are strong and readily reversible, wolf recolonization should cause rapid and dramatic changes in population???dynamics, food web structure, and ecosystem functioning. Cedar Creek is an ideal site to study predator recolonization because of the baseline established by many decades of comprehensive ecological research, including data from thousands of plots in dozens of multi-decadal long-term studies spread across the 21 km2 property. The proposed project will determine the local abundances and spatial distributions of wolves and their prey throughout Cedar Creek and will test for possible cascading impacts of wolves on plant communities and soil nutrients by comparing measurements of plants and soils inside and outside herbivore exclosures before and after wolf recolonization.

The proposed project investigates two questions:
(1) Does wolf recolonization result in strong??? trophic cascades that rapidly alter the abundances and spatial distributions of their herbivorous prey species, thereby???also affecting plant biomass production and soil nutrient availability?
(2) Do prey species???avoid wolves and, if so, are the impacts of such top-down trophic cascades on plants and soil nutrients weak, or possibly even reversed, in the refuges where prey initially become concentrated?

The goals of this project are to:
(1) determine wolf movements inside and outside Cedar Creek, including dispersal to establish new packs;
(2) measure the impacts of wolves on wildlife, biodiversity, and ecosystem functioning; and
(3) provide wolf-related educational programming to K-12 students and visitors.

We will achieve these goals and outcomes by:
(1) using GPS collars to track wolves;
(2) establishing a network of trail cameras to assess wolf impacts on wildlife abundances and locations;
(3) using existing data and new measurements to assess wolf impacts on plants and soils; and
(4) bringing K-12 students to Cedar Creek for field trips and developing a website for citizen scientists.

Methods for e322

Datasets