Animals’ Contributions to Their Ecosystems

All animals have vital roles in their ecosystems and their presence helps maintain the delicate balance required for ecosystems to thrive.  An ecosystem, in its simplest form, is a community of living things and nonliving things that rely on each other for functions that help the others survive.  Each animal, plant, and organism relies on the others for survival, and with this comes an intricate system that is specifically tailored to each animal’s abilities.  From the smallest insect to the largest animal, all living things serve a specific purpose to the environment.

Ants are some of the smallest living visible creatures that have a large impact on ecosystems across the globe.  Their tunnels and digging serves to aerate the ground and allow for new growth in almost every type of plant. They also eat decomposing organic matter and this not only helps keep the ecosystem clean, but also provides a space for things like fungus to grow.  Bees are another insect that play a significant part in the maintenance of the plants in ecosystems. Their purpose is to spread pollen to all plants, most of which are not able to survive and reproduce without the aid of these tiny workers. It is estimated that bees pollinate over a third of the fruits and vegetables that we eat throughout the year.

On the other end of the scale, some of the largest animals also contribute to the ecosystems in which they reside.  Elephants are seen as some of the largest gardeners of the animal kingdom. Because their roaming patterns often vary greatly, they have an impact on wide expanses of land.  African forest elephants are responsible for the management of acacia trees that often dominate these ecosystems. The acacia trees usually grow quickly and have leaves that block light from reaching the ground.  When these elephants knock down or uproot the acacia trees, they are creating space and opening up parts of the forest with more light that will reach the ground. With this assistance, biodiversity on the forest floor can flourish.  During their search for food, elephants also knock off excess leaves and fruit that is then picked up by other smaller herbivores, like antelope. The elephants also perform another critical task every gardener knows well, fertilization.  Elephants in healthy conditions can produce up to 300 pounds of dung a day. Their dung is more nutrient rich than the dung of many other animal. In fact, most plants actually grow better in elephant dung than other animal dung.

One interesting case of an ecosystem that was dramatically affected by the loss of an animal species is the elimination and reintroduction of gray wolves in Yellowstone National Park.  In the 1930s, the population of gray wolves in Yellowstone was wiped out due to hunting. The elimination of this predator led to a chain of events that even altered the plant life in the park.  Because the wolf was no longer around to hunt the elk, the elk began to become less nomadic and remained in one area for extended amounts of time. This means that the elk ate a large amount of the same plants, rather than a variety.  This change in behavior was so drastic that aspen and cottonwood trees declined in numbers, as well as riverside willows. The drop in riverside willows are depended upon by both beavers and songbirds.

The reintroduction of gray wolves by Yellowstone Park officials in 1995 has been monitored closely to see the stabilization of all animal and plant populations in the area.  While elk numbers did decline at first, the population numbers have been stable over the last decade. Without the heavy amount of grazing by elks, willows have been growing better and providing shelter for many smaller animals, like songbirds.  With this, the park has also gone from only having one beaver colony to having nine colonies. Yellowstone has been monitoring these effects closely to demonstrate the impact one species can have on the environment in which they live. It should also be noted that these wolves were not the only predator relying on elk, however, the absence of just one of these predators has caused such a sweeping change in the overall functionality of Yellowstone, that many are now taking notice of the delicate balance nature maintains. This study is an ongoing, first-hand account of the factors that can change an ecosystem.  The loss of one species will have a cascading range of effects throughout the environment, affecting things from migratory patterns to population increase or decrease of almost all animals and plants involved.

Sources: African Journal of Ecology, Michigan State University Department of Entomology, Nikela, Save the Elephants, Space for Life Montreal, Yellowstone National Park