When we hear the term ‘biodiversity,’ many of us think of it as a ‘good thing.’ But do we understand why? Nancy Olmstead, Conservation Ecologist with the Maine branch of The Nature Conservancy, helped us understand the ‘why’ on November 28th, while noting that biodiversity is just one factor contributing to ecological health. You can watch the presentation here or at the end of this summary.
Some important ideas from her talk include:
- We need to think about species decline long before populations get so small that a lot of genetic diversity is lost.
- Rarity is relative. A rare species that is endemic, (i.e. only exists in one area, such as the New England Cottontail) is very different from one that is rare locally but may be globally secure (such as the Black Crowned Night Heron).
- Preserving functional diversity — species that fill different ecological niches — is important (e.g. insectivore vs nectar eating birds and bats).
- We need to recognize patterns in biodiversity. For example, there are more species at the equator, and there are more where bioregions intersect. (Species diversity is high in southern central and midcoast Maine where three bioregions come together.)
How many species do we have in Maine? Insects and crustaceans provide the greatest diversity with over 7,950 species, followed by over 2,500 fungi, 2,100 vascular plants, but only 58 mammals and even fewer amphibians and reptiles.
Why is biodiversity important? Nancy shared many reasons, including:
- The intrinsic right of species to exist
- Benefits associated with individual species and ecosystems, such as food, water purification, wood and fiber, medicine, mental health, and climate mitigation.
- Biodiversity is often a source of resilience in the face of disturbance and non-indigenous pests.
- Some keystone species have a disproportionately positive impact on their environment, such as beavers, mangroves, and coral reefs.
Nationally, 34% of plants are at risk of extinction along with 40% of animal species. The top five threats to biodiversity are:
- Climate change
- Invasive species
- Changing uses of land and sea
- Over exploitation of species
Agriculture is a big threat to plants, animals, and other species as more natural lands are converted to crop land, eliminating habitat. The decline in insects, highlighted in this New York Times article, is a significant concern. Insects are at the bottom of the food chain and the removal of this food source has repercussions all the way up the food chain. Bird abundance is also declining, with one in eight bird species threatened with declining numbers.
Nancy closed with encouragement of the many things we can do to help preserve biodiversity and reduce human impacts on the natural world. This is not an exhaustive list and we encourage you to add your own ideas:
- Support land trusts that are working to conserve land and all the organisms that occupy them.
- Get involved with community science by collecting data that helps scientists understand how we are affecting the natural world. Examples include Signs of the Season, HERON, Mountain Birdwatch, E-bird, iNaturalist. Some of these have phone apps making data entry very easy.
- Manage invasive species on your own land or help manage them on public or land trust lands.
- Participate in the Chickadee checkoff on Maine taxes, which supports Maine Inland Fisheries and Wildlife’s threatened species work.
- Take steps to reduce your carbon footprint — there are so many ways to do this!
- Reduce pesticide use in and around your home.
- Vote for candidates who support a healthy environment and climate action, and let companies and public officials know that you’re paying attention to their policies and practices.
- Support diverse voices in conservation to ensure that all voices are represented in the environmental realm.