Overview

I'm interested in understanding how ecosystems and the biodiversity they support respond to human actions. I'm particularly interested in understanding how plants and animals utilize anthropogenic habitats and the properties of novel ecosystems. I'm currently a PhD student in the Integrative Ecology Lab at Temple University where my research is focused on understanding the linkages between biodiversity and ecosystem services in urban environments.  My MS  research at the University of Illinois at Urbana-Champaign focused on the amphibian communities of constructed farm ponds in southern Iowa. For my undergraduate research I tested a rapid assessment protocol to be used to identify vernal pools south-central Pennsylvania with high value to amphibian conservation.

 

Urban biodiversity and ecosystem services

Clockwise from top right: 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.

I am currently developing a doctoral research project focused on understanding patterns of biodiversity and ecosystem services along an urban-to-rural gradient. Though focused on terrestrial agricultural ecosystems, this work is a natural extension of my previous research on ecosystems created and modified by people. 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.

My work will focus on organic farms in Philadelphia and the various functions that biodiversity performs in these small-scale agroecosystems. As this research develops, I intend to explore the contribution of arthropod and avian biodiversity to natural pest control and pollination, two services that are critical to urban agriculture. By 2050, the majority of our planet’s human occupants will live in cities; and while the landscape experienced by urban dwellers is dominated by concrete, nature is no less important to their wellbeing and health.


Amphibians in Agricultural 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.

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. I'm also working with Jaime Coon to understand how the attitudes of landowners impact their management of ponds located on private lands.

 


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.