ft. Marion Andrews Holmes
Inside a forest, there’s always more to see beyond the great trees that block the canopy.
“My mother and grandparents would point out species like teaberry, jack in the pulpit, and club mosses from the earliest times I remember being in the forest. Forest herbs are fascinating if, like me, you like to observe and pay close attention to small details. They are beautiful; forest wildflower walks are popular for a reason!” biologist Marion Andrews Holmes begins her story.
As a professional ecologist, Marion’s fascination with forest herb communities only grows. These plants are incredibly diverse, it is not uncommon to see more than 100 species at a single site.
This species count is not just a number — it reflects the diversity of stories inside the forest. There are plants that switch between male and female flowers from year to year. Fruits that explode to launch their seeds as far as possible. Plants that don’t even photosynthesize.
For us humans, some of these herbs are important in our culture or as medicines, so the relationships between forest herbs and their environment include humans as well.
This aspect is central to Marion’s research, which focuses on how forests regrow in places that were once farmlands. Most forests in eastern North America and Northern Europe have an agricultural past, so understanding the legacies of land-use history is critical to understanding how forest ecology works.
When plants recolonize farmlands, different species take root in young forests at different rates. Unlike trees, many forest herbs are not adapted to spread their seeds far and wide, making them less likely to return. This prevents various herb species from returning even after human settlers left.
To Marion, the wild ginger is a prime example for this: its seeds are dispersed by ants, so it does not make it into regrowth forests when the insects’ habitats are fragmented.
“Agricultural legacies of biodiversity loss in the herb layer persist for more than 80 years after the forest has regrown — and ginger is frequently one of the species lost.”
Marion Andrews Holmes a freelance ecologist in Pittsburgh, Pennsylvania, USA. Get to know Marion and the understories of post-agricultural forests.