Humans as a Keystone Species: Design Engineers
By Allie Mason
Reading Time: ~10 min
Humans, as a keystone species?
A keystone species plays a critical role in maintaining the structure, balance, and health of an ecosystem. Its impact on the ecosystem is disproportionately large compared to its abundance or biomass. It is easy to draw the connection between the latter part of this description of a keystone species and human impact on the natural world; as for the former, to have a critical role in ecosystem flourishing, that is where perhaps we currently fall short in terms of our collective role, but it is where, as design engineers, we strive to realize our potential.
It could be all-too-easy to sink into despair, to say that the Earth would be better off without humans; however, that zero-effort conclusion is what is driving humans as a species further into an ecological role that is mis-matched for the times, for our evolutionary potential, and for the more-than-human world. Participation, even if we don’t get it right all of the time, is what will move us towards the better world we know--or at least wish--to be possible. The type of participation required for humans to be a keystone species, to self-actualize as a species, calls for deeper listening and conversing across the species boundary.
If we have the goal of becoming a keystone species that is cohesive and coherent with the more-than-human world, we could look to find a close mirror of ourselves in the environment. We could look for an animal that greatly modifies its environment to make a habitat suited for its use, or an “ecosystem engineer” of sorts. Applied in the context of design engineers and the field of hydrology, we find none other than the beaver to be an excellent example of how to restore streams, rivers, and floodplains as a result of making a place for itself. (If you’ve read any of RDE’s previous notes or examined our logo, you know we have a deep fondness for beaver.) Beaver knows how to “bend but not break” an ecosystem, and this is what we are looking to do as a species at this time of biospheric uncertainty and climate chaos. Examining beaver is an examination of how we can include ourselves in the picture of Earth’s future as a restored, resilient sphere of complex ecosystems. Beaver can also shows us that an ecosystem is not “better off without” such a key player and how removing ourselves from the greater web of life is not the answer to restoring planetary health.
Woody dams created by the American Beaver. Photography by Ronnie Howard.
In identifying key similarities and differences between how beavers engineer their environment and how humans engineer their environment, it becomes apparent where we might make shifts or changes that could take us from destructive to constructive from the perspective of a healthy ecosystem.
For example, beavers are limited to resources in their immediate environment because they are limited to “calorie-power”; humans can extract across space (trade, mining) and time (oil) and we use our calorie-power mostly as thought-workers to design technologies that amplify our access to and use of widespread resources. We rely most heavily on finite resources: we extract minerals, metals, and oil at a rate far greater than they would ever be replenished and convert them into forms that could never disintegrate back into their original forms on the planet. We take them out of the earth’s recycling process and cause degradation across time; we remove them from their original environments and cause degradation across space.
When we use materials near or on-site for stream restoration projects or living shorelines, we move closer to working with nature’s cycles and processes because of how these materials interact with the rest of the ecosystem; we also prevent negative impacts off-site by forgoing resource extraction. Instead of artificially hardening stream banks or shorelines, we support the systems in finding their way back to balance once again (after it was most likely anthropogenic factors that contributed to the original degradation of the system) through means such as beaver dam analogues for streams or natural brush materials for wave attenuation along shorelines (read more on “messy restoration” by Chris Grose here). Hand-built restoration, when the scale of a project allows, also makes installation and repair less expensive and less disruptive to the surrounding environment (such as our project at Givens Estates). It allows for the possibility of a project to be carried out as a community effort, sourcing more local hands instead of one big machine. It fosters a deeper sense of connection to place for all of those involved and serves as an opportunity for land stewardship.
Hand-built woody check dams at Givens Estate, Asheville, North Carolina
We can also consider when beaver is considered beneficial versus problematic. Beaver, like human, can be known as a nuisance in areas where their [dam-building] activities conflict with [human] land use or cause significant damage. Beaver dams can cause unwanted flooding, which may damage roads, homes, agricultural land, and other human infrastructure. They are primarily problematic in agricultural areas, where their activity can flood fields, damage crops, or disrupt irrigation systems, leading to economic losses for farmers. Outside of human disturbance, in some cases, beaver dams can disrupt the natural flow of rivers and streams, potentially harming fish populations and altering water temperatures in ways that are detrimental to certain species. As they fell trees to build their dams and lodges, this can lead to the loss of“valuable” timber, ornamental trees, or trees that provide important ecological services.
That said, the disturbance and damage to human infrastructure and agriculture occurs because of human encroachment on the floodplain, an area that would ideally be protected from development if humans were acting as a keystone species in the ecosystem. Modern-day large-scale conventional agriculture is also out of alignment with our role as a beneficial keystone species, especially in a flood plain since these methods are not compatible with seasonal flooding, unlike older methods that tolerated and were in fact designed for seasonal variation (e.g. farming in the Nile River floodplain). These conflicts reveal the deeper parallel between human and beaver and when they become problematic in the environment - that is, when they encroach on other species’ habitat and alter the environment in a way that ultimately decreases local biodiversity instead of increasing it over time, consume faster than the cycles of replenishment, and have no checks and balances with either a predator or cap on resource availability.
(Left) A section of Wash Creek flowing through Laurel Green Park before construction. This creek showed signs of erosion, with steep banks and underutilized green space. (Right) Floodplain Activation Areas after construction, they are intentionally designed to enhance habitat space, increase flood storage, and boost ecosystem services.
What is unique to humans, though, is that we have the ability, through protracted, thoughtful observation and the ability to plan and predict, to avoid destruction. Unlike beaver, who will work by instinct and a biological drive to create dams, we can choose to not follow the compulsion to develop, scale, pave, and profit. We can slow down. We can evaluate all of our options by gathering data, collaborating across space and time, and observing the bigger picture before acting.
Although it’s very much our minds that have driven us to industry, and, as a byproduct, a suffering planet and a deep disconnection with the more-than-human world, by slowing down, it’s our minds that will lead us forward to apply biomimicry and place ourselves back within the greater web of life. It’s our minds that can make us once again a keystone species.
Allie and Amy at the annual RDE retreat amongst coworkers rudbeckia, purple aster, sweetgum, sourwood, and eastern red cedar.