Linking Lakes to Land: Understanding the Spatial and Temporal Aspects of Allochthonous Subsidies

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

Non-Technical Abstract: C.Gratton Proposal Number: DEB-0717148 Proposal Title: Linking Lakes to Land: Understanding the Spatial and Temporal Aspects of Allochthonous Subsidies Our understanding of how lakes and land are linked is poor, despite the fact that lakes are important components of many terrestrial landscapes. Most research to this point has focused on how watershed characteristics or land use affect downstream surface waters, but we know little about reverse interactions. This study will investigate lake-to-land linkages at Lake Mývatn, a nutrient-rich lake in Northern Iceland with exceptional, natural, large-scale midge (aquatic insect) outbreaks that occur every 5-7 yr. During these outbreaks, millions of midges enter surrounding terrestrial ecosystems, where they affect everything from plant productivity to herbivorous insects and their spider predators. Through a series of manipulative experiments, remote sensing analyses, and empirical modeling, this system will serve as a model to study ecological linkages at the landscape scale and will address the fundamental question of how food webs on land are influenced by energy, materials, and organisms originating from separate and distinct lake ecosystems. Broadening our studies of terrestrial communities to explicitly include interactions with other elements of the landscape will allow us to better understand and manage our environment by considering multiple habitats simultaneously. Landscapes are being altered via both natural (e.g., invasive species) and anthropogenic forces (e.g., urbanization or agriculture). Determining how these dynamic patchworks of habitats affect each other will be essential to understanding how disturbances propagate through landscapes and to better managing our terrestrial ecosystems.