By Caleb Kaczmarek
Each intern in the Nature Academy internship program at Matthaei Botanical Gardens & Nichols Arboretum chooses a summer project to research and report on. The project culminates in a poster displayed in Matthaei’s public indoor spaces. Interns also write a blog post about their project concept or the research they’ve conducted.
A degraded landscape at Matthaei Botanical Gardens, characterized by grass maintained by mowing and invasive Verbascum thapsus.
A stand of native Rudbeckia hirta (black-eyed Susan) and Monarda fistulosa (wild bergamot or bee balm) at Matthaei Botanical Gardens.
The first thing my supervisor stressed to me and my fellow interns in the Nature Academy intern program was the importance of seeing natural areas on a spectrum ranging from “severely degraded” to “completely untouched.”
It’s our job to push areas toward that completely untouched status, in the direction of their potential had Michigan never known invasive species and the industrial agriculture that promoted them.
Former farm lands are often the most difficult areas to push back. They were cleared of their native flora, and then tilling opened the seedbed to more than just the desired crops. Seeds for non-native grasses, forbs (herbaceous flowering plants), and occasionally even woody plants got pushed into the soil and become permanent and self-sustaining features of the degraded landscape.
After months of instruction and experience with these landscapes as an intern I see them just about everywhere. Roadsides are wastelands and my neighbor’s gardens are, despite their aesthetics, hotspots for invasives.
Of course, we have a large set of tools we can use to combat the invasives. They range from the expected methods of manually pulling plants to the more creative, such as facilitating the plants’ natural herbivores. With the concentrated and correct application of our tools, we can remove most of the unwanted species from an area.
After that, however, to say our work is complete would be a drastic overstatement. Seedbeds will become dominated by invasive species that can last for years, so even if there are no unwanted stems, undesired species will continue to crop up for years, with minimal native replacement. We have to take another step to support the landscape’s return to a clean space.
This is where native seeds come into play. There are still reservoirs of native plants across Matthaei Botanical Gardens & Nichols Arboretum, places where invasives have been blocked from entering. Curated garden spaces exhibiting specific species or collections are examples, but there are natural sites scattered about that managed to avoid being farmed years and years ago. In other cases, the seeds may be found in other botanical gardens and greenhouses. In areas at or near saturation for a species of plant, at least some of the plant’s seeds generated each year will fail to germinate. This allows some seeds to be taken from an individual plant without harming its reproductive success. The overall methodology behind native seed redistribution is simple: collect from areas with plenty of seeds, then spread them in areas where they are best suited to grow.
Cleared areas tend to be intentionally over-seeded with the seed mixes. As in wild areas, most seeds will fail to germinate, and even the ones that do germinate have limited chances of eventually producing seeds of their own. This means that far more seeds than one might expect are collected. The timing windows for collection are, of course, restricted to when plants are bearing seed. It’s then we collect seeds en masse and plant them later as needed. As long as the seeds are kept in a dry, dark place they can last through the winter. Some seeds can last for years in the paper bags they’re stored in. What results is a small library of species waiting to be spread across our natural areas.
With proper mixing, application, and light watering, the seeds will settle into the soil and may sprout the following spring. The young plants will struggle past the groundcover and grasses, then compete with the seedbank’s non-native remnants and each other for sunlight and water. Matthaei-Nichols staff, probably including interns like me, will remove some of the invasive plants to give the native plants an edge. Come late summer and fall, the stems from the planted seeds, if pollinated, will produce their own progeny that will fall into the seedbed and continue the cycle for another year. With the aid of being moved into the right area and being supported in growth, native plants will retake an area and return it to a wild Michigan ecosystem. Natural propagation would take decades, but instead seed redistribution allows native plants to be seen and enjoyed in just a few years.
This summer I designed a database that I hope will make this process easier. Previously, the Gardens’ methods for keeping track of the seeds that were collected and sowed was manually intensive and time-consuming. If one wanted to make a mixture of seeds designed for a certain environment, they would have to either know the ideal habitat for each entry or look it up. In an attempt to streamline this process, the database I’ve designed links the complete information of each species to each entry. Functions are built in to sort the database using this linked information. Its modular structure also allows further additions, including specific planting instructions that some species may have. All of this loses none of the functionality of the original system, and it can be filled out with simple fill-in-the-blank forms. With the database fully running, it should lessen the time spent working with spreadsheets so that more time may be spent on our main goal: environmental restoration.
Caleb Kaczmarek, from Bay City, Michigan, is a natural areas intern working with Matthaei-Nichols Natural Areas Specialist Steven Parrish this summer. He is excited to learn about practical conservation and Michigan’s unique ecosystems. Ecology, evolution, and biodiversity is one of his minors, along with computer science and a major in cellular and molecular biology. Caleb’s internship was made possible by gifts from Jan Onder and Bertram and Elaine Pitt to support, restore, and protect the natural areas of Matthaei Botanical Gardens & Nichols Arboretum.