Information from Healthy Soils Workshop Series at Codman Farm
This is a summary of what we shared in our workshops, and is based on research we found in the resources we have listed at the end of this page. We encourage you to pursue these additional resources and keep learning!
NATIVE PERENNIALS, SHRUBS, AND TREES INCREASE SOIL CARBON STORAGE, RESILIENCE TO CLIMATE CHANGE, AND ECOSYSTEM BIODIVERSITY
NATIVE PERENNIALS ARE PART OF THE SOLUTION TO CLIMATE CHANGE
First, what is a native perennial?
According to the National Wildlife Federation, a native plant is one that “has
occurred naturally in a particular region, ecosystem, or habitat without human introduction”. “Native plants have formed symbiotic relationships with native wildlife over thousands of years, and therefore offer the most sustainable habitat.” There is some discussion of how regionally-specific to get in defining “native” plants: native to North America? New England? Middlesex County? The New England Wildflower Society uses native to mean “ecoregions of New England”, where “ecoregions are areas where ecosystems (the type, quality, and quantity of environmental resources) are generally similar”.
Perennial means “through the years”, and perennial plants persist through multiple years. For some, the above-ground portion of the plant dies back and re-grows each year; others keep their above-ground foliage year-round. In New England, most natives are perennials.
Since native perennials are best adapted to our local ecosystems and have long-standing symbiotic relationships with native wildlife, they are generally the most resilient option in the face of our changing climate. That is with some caveats. Natives that prefer cold climates, for which Massachusetts was already at the warmest end of their ideal range, might not be the best choice in the face of climate change. And with climate change, we can expect more extremes of weather, with stronger storms and potentially longer dry periods, so hardier natives may do better.
Most native perennials have deep roots. This is critical for dealing with climate change. Not only do deep roots increase drought resistance in the face of climate change, they also store more carbon in soil, and store it deeper in the soil profile. Roots are incredibly important for soil carbon cycling and storage. Not only do decaying roots add carbon to soil; living roots actively pump carbon into the soil, which they do to recruit beneficial microbial partners. In exchange for plant carbon, microbes help the plant with numerous services such as nutrient acquisition and protection from pathogens. Root carbon is a primary source of soil carbon. Some roots, such as those of the native grass switchgrass, can go extraordinarily deep!
Soils are the largest active terrestrial carbon pool, storing more carbon than all above-ground biomass (plants, animals) and the atmosphere combined! That’s an estimated 2,500 gigatons of carbon. But deforestation, industrial agriculture, and other intensive land-use practices degrade soil health and result in carbon loss. Global estimates for carbon loss due to agricultural land uses over the past 12,000 years are an astounding 133 picograms carbon. With such a huge soil carbon deficit, through regeneration, soils have the potential to store more carbon, pulling it out of the atmosphere and sequestering that carbon for as long as thousands of years. As the latest Intergovernmental Panel on Climate Change (IPCC) report illustrates, a shift away from fossil fuels is no longer enough to avert a climate emergency. We also need to draw down atmospheric carbon. Soil carbon storage leverages a natural process, is immediately deployable, inexpensive, and the practices that promote increased soil carbon storage also foster soil biodiversity and resilience to climate change.
When it comes to carbon, new research shows that plant diversity is also very important. More plant diversity can help increase the persistence of soil carbon, meaning that once the carbon gets in the soil, it stays there (and out of the atmosphere) for longer. Also, more plant diversity promotes a more diverse soil microbial community, which in turn supports plant and soil health, making a more resilient ecosystem.
Planting a diverse array of native perennials is a fantastic way to get more carbon into soil, and at the same time, support a resilient and diverse ecosystem!
NATIVES FOR POLLINATOR PATHWAYS
Native plants support native wildlife. Pollinators are absolutely critical
members of our wildlife. Climate change, use of herbicides and pesticides, disease, and habitat degradation have severely reduced pollinator populations. About 75% of flowering plants globally rely on pollinators to reproduce, including about 35% of food crops. Declining pollinator populations are a major threat to food security.
As the Lincoln Land Conservation Trust (LLCT) explains: “Wild pollinators are a keystone species. Ecosystems with an abundance and diversity of wild pollinators are better able to adapt to and survive disruptive forces such as climate change and habitat loss. By focusing on plants that have co-evolved with pollinators, we expect to see dramatic improvements to the populations of these threatened species.”
LLCT has a Lincoln Pollinator Action Plan with a new pollinator corridor initiative. You may also see “Pollinator Pathway” signs around town. LLCT has toolkits which are planting palettes and management strategies to start your own pollinator space. LLCT is also working on three case study sites around town, conducting scientific research on pollinators. There are lots of exciting ways to get involved!
CHOOSING AND PLANTING NATIVES
Two great places to start if you are interested in planting native plants are
an annual native perennial plant sale. The Lincoln Conservation Commission also has a list of recommended native plants.
The Native Plant Trust is one place to source local plants. You can go to Garden in the Woods in Framingham to pick plants out.
CONVERTING LAWN TO MEADOW
Lawn grass “is the worst choice for carbon sequestration” according to the Native Plant Conservation Campaign. It has shallow roots and has very few ecosystem services (benefits to the ecosystem). In contrast, native perennial meadows are fantastic for storing carbon and are enormously beneficial for the ecosystem. They improve soil health, support a wide variety of wildlife including pollinators, improve water filtration and quality, and once established, require very little upkeep.
Meadows are also beautiful: from a mixed meadow to a more formal one like those by landscape architect Piet Oudolf. If there are areas of your lawn that you want to keep low and open, there are great options for native perennial sedges and ground cover such as wild strawberry.
While meadows are very low maintenance once established, it takes a little work to get them started.
Another great place for native perennials at home is perennial hedges around gardens. By choosing natives that attract pollinators and other beneficial organisms, you can help your garden.
Further reading on native plants