Overview
I'm interested in understanding how ecosystems and the biodiversity they support respond to human activity. I'm particularly interested in understanding how plants and animals utilize anthropogenic habitats and the properties of novel ecosystems. I'm currently an assistant professor of restoration ecology in the Department of Biological & Environmental Sciences at Wittenberg University. My work is integrative across ecological and social science disciplines and includes work on field experiments to measure ecosystem function in invaded landscapes, urban biodiversity and ecosystem service relationships, and wildlife conservation in agroecosystems.
I am currently developing a project to monitor biodiversity and ecosystem services in Clark County Ohio. You can read more about it here.
Biodiversity and Ecosystem Function in Invaded Landscapes
Ecological communities in human-dominated landscapes contain hundreds of introduced, non-native species living alongside native species assemblages. I am investigating the role that these invasive species have in food webs and their influence on ecosystem function in these places. I am particularly interested in how invasive plants and insects integrate (or not) into the diets and habitat needs of animals including vertebrates.
This work couples field experiments with biodiversity and habitat assessments and undergraduate researchers are integral to its success. In Summer 2024, I worked with two undergraduate researchers at Wittenberg to use clay caterpillar models to test the role of invasive honeysuckle and autumn olive shrubs in food webs of southwest Ohio. In Fall 2024 I worked with a First Year Research Award student to identify the role of aposematic signaling in Spotted Lanternfly, a novel prey species our region, in diets of resident birds.
Clockwise from top left: An ‘old field’ habitat invaded by autumn olive (silvery gray shrubs) after cessation of agricultural activities. A great crested flycatcher eying a green clay caterpillar before nibbling it. Setting up a trail camera to capture caterpillar ‘predation’ events. Summer 2024 field crew collecting insects living in a non-native honeysuckle shrub using a “beat sheet” and “pooters”. A clay caterpillar riddled with beak marks from a bird.
Urban biodiversity and ecosystem services
Clockwise from top left: A garden snail found in a West Philly backyard. A vacant lot in Kingsessing, Philadelphia. A small organic urban farm nestled between residences on Chester Avenue. The invasive planthopper, the spotted lanternfly (Lycorma delicatula) at an outlet shopping mall in the Philly suburbs.
My work in urban biodiversity and ecosystem services has focused on understanding urban birds and other animals and the benefits that they provide to people in cities. Parks, gardens, urban farms, and even vacant lots provide habitat and resources for a unique assemblage of native and exotic plants and animals. These organisms in turn supply urban residents with critical ecosystem services in the form of cultural and spiritual value and material benefits like pest control and pollination.
My work focuses on birds in Philadelphia and their use of public green spaces, like vacant lots, parks, and playgrounds. I’m interested in linking the birds in these sites with the various functions and services they provide. In a paper in Landscape and Urban Planning (which can be read here), I show how we can use functional traits to assess the contributions of birds to cultural and regulating ecosystem services. Other work on littered food removal and the geographic distribution of urban ecology research is forthcoming.
Amphibians in Farm Ponds of Southern Iowa
Clockwise, from top left: Timothy dipnet sampling a small farm pond in 2016 (photo by Scott Nelson). A typical farm pond in Ringgold County, Iowa, with a small herd of cattle bathing in the pond. A gartsnake encountered at one of the farm ponds. A larger pond that was more easily traversed by kayak.
Farm ponds are a common feature of agricultural landscapes across the globe and are particularly abundant in the central United States. Recent estimates suggest that there may be as many as 3 million farm ponds in the Great Plains ecoregion alone. The majority of these ponds were constructed in the post-Dust Bowl era of the mid-20th century to provide water for cattle and aquaculture.
Today, however many of these ponds are now hotspots for aquatic biodiversity in landscapes historically lacking lentic water bodies. Despite their potential value for biodiversity conservation, these novel ecosystems continue to be understudied by scientists and ignored by government agencies, but see our review in Frontiers in Ecology and the Environment here.
My research on farm ponds in Southern Iowa has focused on understanding the habitat components that predict breeding occupancy of amphibians and how those components are linked to wetland sucession. You can read our publication in Ecological Applications here I'm also working with Jaime Coon to understand how the attitudes of landowners impact their management of ponds located on private lands. One of our collaborative projects was published in the journal Land and can be read here.
Vernal Pool Conservation in Pennsylvania
The images at right depict a vernal pool in early spring (top), an eastern newt (Notopthalmus viridescen, bottom left) and a female wood frog (Lithobates sylvatica, bottom right).
Vernal pools are seasonal wetlands that undergo an annual cycle of desiccation and inundation. When snowmelt and rain fill the pools in the spring, amphibians migrate to the pools en masse to breed. By mid-summer, most of the amphibian larvae have metamorphosed into miniature versions of their parents and leave the pools to seek shelter and food in the surrounding uplands. At this time, the pools have dried, leaving only a sparsely vegetated depression in the forest floor.
For my undergraduate honors thesis, I tested a set of rapid assessment tools developed for predicting the richness, diversity and abundance of amphibians in vernal pools based on the pool's biotic and abiotic features including water chemistry, vegetation, and size. Our published paper can be found here.