Before I answer the question “what is the biodiversity crisis?”, we need to understand the term ‘biodiversity’. Biodiversity refers to the variety and abundance of life residing in a particular space and scale. We can discuss biodiversity at a global scale, continental scale (e.g., North America), regional scale (e.g., Ohio; Appalachia), or local scale (e.g., Loveland, Ohio). Biodiversity comprises all the flora, fauna, fungi, protozoa, bacteria, and more found in these areas. The health of our environment is intimately tied to the health of biodiversity. Areas supporting greater and more abundant species are typically healthier, and the ecosystems upon which they rely function better due to their presence.
Now that we have defined biodiversity, next we will dive into the ‘biodiversity crisis’. Communities around the globe are experiencing significant losses of animals, plants, and other biodiversity as a result of shrinking and fragmented habitat, the spread of nonnative invasive species, the use and inadequate management of toxic materials, and, ultimately, a growing disconnect between people and the ecosystems that support us. Globally, wildlife populations plummeted by approximately 69% between 1970 and 2018, a dangerous decline resulting from climate change and other human activity (World Wildlife Fund 2022). Such losses leave our ecosystems at risk of collapse. When our ecosystems cannot sustain themselves, they cannot support the functions necessary for human civilization.
In North America, there are 3 billion fewer birds today than there were in 1970 (Rosenberg et al. 2019). That’s a loss of more than 1 in 4 birds. Many of the species with steepest declines are those that have traditionally been considered ‘common’. Grassland birds have declined the most, losing more than 720 million breeding individuals—a 53 percent decline—accounting for nearly a quarter of the birds lost since 1970. Habitat loss & degradation, outdoor cats, window strikes, and collisions with energy infrastructure have contributed to the steep decline in North America’s avian communities. Birds play integral roles in our ecosystems, including seed dispersal, pollination, pest management, and decomposition. Without our feathered brethren our landscapes would look, and sound, much different.
A recent study from here in Ohio found between 1996 and 2016 that total butterfly abundance declined by roughly 33 percent (Wepprich et al. 2019). While some species, like the monarch (Danaus plexippus), are known to be declining, many species that are generalist, widespread, and not considered vulnerable to extinction were also found to be declining at concerning rates. Butterflies play critical roles in our ecosystems pollinating many wild plants and serving as important prey for birds and other wildlife. Some of the stressors contributing to declines of butterflies include habitat loss & degradation, pesticide exposure, and pathogens.
Finally, at a local scale let's discuss another group of pollinators here in Loveland, Ohio. Historically, at least 15 species of bumble bees (Bombus) occurred here. I have intensively surveyed bumble bees in Loveland since 2018 and have found that 8 of the 15 species native to Loveland have been extirpated (i.e., local extinction). Of the remaining 7 species, 4 are uncommon and declining; only 3 species have large enough populations that they aren’t at risk of extirpation. Like butterflies, bumble bees are greatly affected by habitat loss & degradation and pesticide exposure (particularly systemic insecticides, including neonicotinoids). Additionally, bumble bees are adversely impacted by nonnative pathogens introduced via domesticated bumble bees and areas with high densities of European honey bees (Apis mellifera). Finally, climate change has been detrimental for a variety of bumble bees, particularly those accustomed to cooler climates at northern latitudes and higher altitudes (Soroye et al. 2020).
The best solution to halting and reversing these alarming declines is through the conservation of habitat that is managed to support diverse plant communities that form the foundation of our food webs. If we can grow enough food for wildlife, often they are better able to cope with the various other stressors that negatively affect them. Unfortunately, land conservation is not keeping pace with growing threats to our lands, waters, wildlife, and ways of life. Every 30 seconds, the United States loses a football field of natural lands to roads, houses, pipelines, and other development. Forty acres of farmland in the United States are lost to development every hour. While each of us may be unable to purchase and restore thousands of acres, we can choose to be good stewards to the land we do own and/or manage, including the land right here in our own neighborhoods. Over the next several newsletters we will be discussing a variety of conservation efforts we can implement to reverse loss of biodiversity at a local scale. Our goal is to create landscapes in southwest Ohio and abroad that are biologically rich and ecologically robust, making them capable of supporting numerous ecological functions and services (e.g., stormwater management; carbon sequestration; cooling urban environments). If you’d like to play a role in these community conservation efforts, please reach out to Doug (doug@loveourland.org) and/or Mike (mike@loveourland.org).
Together we can heal nature and our communities.
