Ecological Monitoring: Process and Purpose

Volunteers use binoculars to search for dragonflies.

Volunteers search for dragonflies at the Arboretum’s Schmidt Lagoon in 2018.

Ecosystems are dynamic, with vegetation and animals changing seasonally and over long time periods. Ecological monitoring is an important scientific practice of taking systematic, repeated measurements of environmental conditions, using the same methods in the same places over time so long-term comparisons can be made. Long-term data is extremely valuable in understanding changes in ecosystem health brought on by climate change, invasive species, urbanization, and extreme weather events such as flooding and drought. It can also help explain other interactions between species and their environment.

Monitoring can be passive or question driven. In passive monitoring, data is collected out of curiosity. Standardized monitoring protocols may still be used so the data can be applied to answer questions later. Question-driven monitoring projects are designed to answer a specific question or questions. Both kinds of monitoring can be conducted by scientists or citizen scientists.

The Arboretum’s 1,200-acre property in Madison comprises woodlands, oak savannas, prairies, and wetlands surrounded by an urban landscape. We also manage more than 500 acres of outlying properties throughout the state, most of them small remnants of original woodland, oak savanna, prairie, and wetland habitats. The diverse habitats are home to hundreds, if not thousands, of plant and animal species, many of which are listed as state or federally threatened or endangered.

Plant monitoring provides valuable data about ecosystem dynamics and species diversity. Arboretum staff, with help from faculty, students, volunteers, and external partners, conduct semiregular systematic surveys of woodland and prairie plant communities, including Noe Woods, Curtis Prairie, Greene Prairie, and the outlying properties Abraham’s Woods and Faville Prairie. In addition, we annually track the status of rare plants like the eastern prairie-fringed orchid as well as non-native invasive plants like garlic mustard and porcelain berry.

Two young northern green frogs
Two young northern green frogs

Some animals can serve as indicators of ecological health. For example, the presence of frogs, toads, and dragonflies can indicate healthy, functioning wetlands and clean water. The Wisconsin Department of Natural Resources (WDNR) has tracked statewide frog and toad populations for more than 35 years. The Arboretum, home to nine of the twelve Wisconsin species, has served as a long-term monitoring site since the program began.

In 2018, we started a dragonfly monitoring program with the goal of collecting baseline data on the number of species and population abundance at Arboretum ponds and wetlands. In our first survey season, nine citizen scientists observed thirteen unique species. We hope to see these numbers increase in 2019. Both programs engage volunteers to collect the data, giving participants an opportunity to learn new skills and apply knowledge to help answer scientific questions.

With the arrival in Wisconsin of white-nose syndrome (a fungal disease that has decimated bat numbers across North America), tracking bat numbers and health is especially critical. The WDNR monitors statewide bat populations, and the Arboretum has served as a long-term monitoring site. An acoustic data logging station counts bats as they fly overhead and records species based on their unique high-frequency calls. Seven of the eight Wisconsin bat species have been recorded at the Arboretum over the past 10 years. Volunteers also collect data using hand-held recording devices at specific sites throughout the state.

Phenology is the study of the timing of biological events, such as the first bluebird arrival or pasque-flower bloom in spring. Aldo Leopold and Sarah Jones first started tracking phenology at the Arboretum in 1935. Since that time, others have collected regular data, and our ranger unit and volunteers continue to track more than 200 events annually. Used in tandem with climate data, long-term observations can help track how climate change affects phenological patterns of plants and animals. Please visit our display in the Visitor Center to learn what has been recorded this year and add your own observations.

National Atmospheric Deposition Program monitoring equipment
National Atmospheric Deposition Program monitoring equipment

The Arboretum has recently become a site for the National Atmospheric Deposition Program (NADP). The NADP monitors a range of chemicals in the air and precipitation with the goal of measuring atmospheric deposition to study its effects on the environment. The instruments here include a bucket sampler for measuring nutrients and mercury in rainwater, a minute-by-minute rain gauge, and an instrument to measure dry deposition of gas-phase ammonia. This station provides an opportunity to link atmospheric chemistry to long-term ecological restoration.

These are just a few examples of ecological and environmental monitoring at the Arboretum. Some projects are conducted by staff, while others are done in partnership with colleagues from UW–Madison, other colleges and universities, state agencies, nonprofits, and volunteers. The data from these projects helps inform land management decisions and often leads to new research questions. You can learn more about long-term ecological monitoring and citizen science monitoring projects on our website.

—Brad Herrick, ecologist and research program manager