Current and ongoing projects
Cumulative ecological effects of an invasive forest understory shrub, Berberis thunbergii (Japanese barberry).
Invasive plant species often induce profound ecological effects, especially when the invader becomes a dominant physical and chemical presence in the habitat it prefers. Berberis thunbergii, an armed shrub native to East Asia that was introduced through the ornamental plant trade, is rapidly spreading throughout the understory of secondary growth forests in northeastern North America. Multiple studies have documented elevated densities of ticks that host Lyme disease in B. thunbergii-infested understories. However, ecological impacts that this invasion induces are not well documented despite the fact that this shrub often becomes very densely populated in infested forests.
We are investigating the effects of B. thunbergii invasion on multiple structural and functional attributes of forest understory ecosystems in the Pittsburgh region. Organisms we focused on to determine how barberry invasion affects ecosystems include vascular plants, snails, amphibians, and ground-dwelling arthropods. We have also started experimentally managing B. thunbergii on small plots to determine how plant communities and soil attributes respond to eradication. Regardless of what our team finds, B. thunbergii invasion causes substantial changes to the forest understory, as anyone who has attempted a hike through a patch can attest. Future work on this project may involve research inquiries that determine how B. thunbergii might be controlled or eradicated on a much larger scale and how communities respond to such actions.
Posters associated with this project:
Mycorrhizal relationships to barberry (Daugherty et al. 2016, PA Botany Symposium)
Native tree seedling densities within barberry (Snyder et al. 2016, PA Botany Symposium)
Native tree seedling growth and survivorship in barberry-infested soils (Link et al. 2017, Mid-Atlantic Ecological Society of America Conference)
Long-term, intensive monitoring of a network stream ecosystems along a watershed urbanization gradient
Stream ecosystems in urban environments become severely degraded due to myriad physical and chemical stressors. However, a strong impetus for improving the ecological integrity of streams exists because of their proximity to dense concentrations of humans. Although urbanized streams will never return to the ecological state that existed prior to urban development, certain actions can significantly improve some key environmental parameters.
Researchers in the lab are maintaining a network of environmental sensors in streams throughout the Pittsburgh metropolitan region to quantify how our waterways are changing over time. Dissolved oxygen, conductivity, and temperature are currently recorded every 15 minutes in all network sites. Sensors in adjacent riparian zones record air temperature, humidity, and barometric pressure at the same frequency. Chemical parameters we hope to add to stream arrays include chlorophyll-a, turbidity, pH, and dissolved organic matter.
High-frequency time series of environmental data readily reveal interesting patterns. For example, diel temperature fluctuations appear to control dissolved oxygen in the smallest, least-urbanized network streams while biological respiration and photosynthesis regulate dissolved oxygen in larger, urbanized sites. We have also detected episodic anoxic events occurring in pool habitat of Nine Mile Run, a heavily urbanized stream that has been targeted for restoration.
Posters associated with this project:
Event-scale dissolved oxygen dynamics in an urban stream network (Bookout & Utz 2017, Symposium on Urban Stream Ecology)
Biodiversity monitoring of western Pennsylvanian nocturnal Lepidoptera
Approximately 1,300 species of moths inhabit the forests and fields of western Pennsylvania. The ecological services provided by this diverse assemblage are diverse: moths serve as pollinators, prey species for larger animals such as birds and bats, and process organic matter during the larval stage. Additionally, many moth species are agricultural or forest pests. Yet we understand relatively little about this important and diverse taxon of insects, perhaps because they are most active while we sleep.
In a project started by MSUS student Catherine Giles, we are monitoring the species richness and relative abundance of moths on a daily basis at Eden Hall as part of the Discover Life mothing project. The protocol involves attracting organisms to a large, white board illuminated by a broad spectrum of light and photographing each individual for later identification. Phenological patterns of emergence associated with lunar cycles and weather patterns will eventually be explored once we reach a critical mass of data. Meanwhile, the project is yielding spectacular images of creatures that few people observe despite their ubiquity in our back yards.
If you are interested in this project, we enthusiastically welcome you to join our mad moth team! Contact us to learn more about opportunities to come sample moths with us at Eden Hall.