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Pesky Plant Trackers Citizen Science

Pesky Plant Trackers are citizen scientists who make careful observations of wild parsnip (Pastinaca sativa) and Japanese knotweed (Fallopia japonica). Specifically, Pesky Plant Trackers are trained to watch for and record the plants’ seasonal changes, such as development of buds, flowers, and seeds.

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What does it mean to track a plant?

Pesky Plant Trackers first identify individual “pesky plants” in their daily environments. Then, they record how these plants change over time. How do Trackers do this? The Pesky Plants program offers free training and resources showing what to look for, how to stay safe while working around these plants, and how to share observations. In the summer months, Trackers visit their patch of plants at least once a week to observe the development of buds, flowers, and seeds. Then Trackers report what they see using Nature’s Notebook. This project fits within a greater discipline called phenology, the study of recurring life cycle events of living things. The Pesky Plants program partners with the USA-National Phenology Network and is loosely associated with the Minnesota Phenology Network.

What makes these plants pesky?

Wild parsnip and Japanese knotweed are highly damaging invasive plants in North America. In addition to degrading natural habitats and crowding out native plants, these plants present real problems for humans. The sap of wild parsnip contains a chemical that causes severe skin burns. Protective clothing is required when working around wild parsnip. Additionally, one must avoid exposure to sap by taking care not to break any part of the plant. (Click here for safety information.) Japanese knotweed spreads aggressively and can damage property. It does so by sending out underground roots and rhizomes that exploit cracks or weaknesses in pavement, building foundations, retaining walls, drainpipes, and other features of the built environment. Japanese knotweed reproduces vegetatively, meaning that escaped plant fragments (e.g., a piece of root) can grow into clone plants that colonize new areas and form dense stands.

Why track these plants?

Because of their pesky impacts on nature and people, wild parsnip and Japanese knotweed are targets for management and removal. Both plants are defined as prohibited noxious weeds in Minnesota. This project works closely with partners at the Minnesota Department of Agriculture to ensure that methods comply with Minnesota Noxious Weed Law and research goals address knowledge gaps

Removing these plants is complicated work that must be timed with plant life cycle stages. For example, wild parsnip plants can be mowed before they flower. However, if plants within the treatment area have seeds, then mowing exacerbates the problem by helping the plant spread. In order to improve management of these plants, we need to understand them better, especially the timing of their annual cycles. Join the effort to understand wild parsnip and Japanese knotweed by becoming a Pesky Plant Tracker. As a Tracker, you will learn to identify these plants, collect scientifically valuable information, and ultimately, help restore Minnesota environments.

How will my observations be used?

Land managers who control invasive plants need to predict when plants flower, form seeds, go dormant, or enter other key phases. Making predictions is difficult because within a single species, individual plants develop at different rates depending on where they are and year-to-year variations in weather. Moreover, climate change causes observable shifts in plant phenology and this could be true for wild parsnip and Japanese knotweed. To improve our predictions, we need more observations, especially observations from many different places. Your observations will be analyzed by the Pesky Plants research team to create predictive models. Those models will be integrated into USPEST.org, where land managers can find out when to mow, apply herbicide, or take other control measures.

How else are these plants being studied?

Pesky Plant Trackers is part of a larger investigation into the phenology of wild parsnip and Japanese knotweed. Controlling these plants requires an understanding of how their growth varies with environmental conditions. One way to build that understanding is to involve citizen scientists who share observations from many locations. A second way is to run experiments in controlled environments. The overarching research plan combines both approaches, and can be thought of as having three components:

  1. Pesky Plant Trackers Citizen Science: Participants monitor plants growing in their local environments and share what they see using Nature's Notebook.
  2. Common Gardens: The core team plants five "common gardens" at research facilities spread across Minnesota. Each site has a specialized volunteer, a Common Garden Observer, who monitors the plants and collects phenology data.
  3. Growth Chamber Experiments: The core team observes these plants growing in controlled, indoor facilities called growth chambers. Each chamber runs a distinct treatment, or environment with a fixed temperature and light cycle.

These three components allow us to build a robust, multidimensional understanding of wild parsnip and Japanese knotweed phenology.