Everyone needs a helping hand sometimes.  Working together is not limited to humans striving toward a common goal; it also applies to animals and plants in nature.  There are seven types of companionable relationships in nature.  Some of these relationships benefit both parties, while some benefit one more than the other.  The seven types of relationships are symbiosis, mutualism, predation, competition, commensalism, amensalism, and parasitism.

Symbiosis

Symbiosis is a relationship in which both parties benefit, and the organisms live in close contact.  A well-known example of symbiosis is seen in lichens.  Lichens are made up of algae and fungi.  The fungus provides the habitat, while the algae provide food.  This way, both organisms benefit from each other.  When they continue to interact, they change each other over time.

Mutualism

Mutualism is a relationship in which both organisms profit.  It is a type of symbiosis.  A local example of mutualism is with the green lynx spider and the tarflower.  The green lynx spider lives in the tarflower plant.  The tarflower, as its name implies, is covered in a sticky substance that traps crawling insects like flies and beetles.  The lynx spider patrols the plant and easily secures a meal—the tarflower benefits from its presence as a protector.  The spider selectively attacks and consumes chewing, mining, and sap-sucking herbivores (such as caterpillars and beetles) that attempt to eat the plant's nutrient-dense leaves, buds, and stems.

 Predation

Predation is a relationship in which one organism kills and eats the other.  Here, the predator benefits while the prey is harmed.  Predation is one of the more common relationships found in the world.  An alligator killing fish or other animals within its reach is a classic example of predation in Florida.

 Competition

Competition is when organisms fight for the same food, space, or materials.  Competition can occur between organisms of different species or of the same species.  Here, both parties lose.  A prime example is the introduction of non-native species into an area—for example, the American alligator and the Burmese python.  Pythons are non native and are vying for the same food source in the same location as the alligators.  Eventually, the food source may run out in an area, and neither can survive.

Commensalism

Commensalism is a type of relationship in which one party benefits while the other party is neutral.  Neither party is harmed, but one species may not survive without the other.  Examples of this are the gopher tortoise and the Florida mouse.  A gopher tortoise digs a large burrow underground.  A Florida mouse will build an offshoot off of the main gopher tortoise tunnel and live within it.  The mouse benefits by protection from predators, extreme temperatures and wildfires.  This relationship goes as far back as 1.35 million years!

 Amensalism

Amensalism is a type of relationship in which one party is harmed while the other is neutral.  Again, we look to invasive species and the relationship between Brazilian pepper and native Florida hardwoods, such as live oaks.  This highly invasive shrub releases biochemicals into the soil that actively stop native plants from growing around its root system.  While the native hardwoods are choked out, the pepper tree experiences no direct biological impact from the hardwood's presence.  This reduces competition for space and nutrients.  The Brazilian pepper is unaffected, but surrounding plants are harmed.

 Parasitism

Parasitism is a relationship in which one party benefits while the other is harmed.  The organism that benefits is called the parasite, and the organism that is harmed is called the host.  The parasite lives on or within the host and gets food and nutrients from it.  Parasites behave in this way because they cannot find food and nutrition on their own, and so they depend on the host.  Ticks are common parasites found on animals.  They pierce the skin of the animal and suck its blood.

Cuscuta is a parasitic plant that winds around and pierces the stem of its host.  It takes in food and nutrients from the host, as it is not capable of doing so on its own.  There are over 200 species of red, yellow and orange cuscuta, also known as dodder or amarbel.

 Conclusion

The relationships in nature are vital for the survival of the environment.  Many organisms depend on them to survive.  Even though these relationships harm some organisms, they are needed to keep the environment in check.  Plants and animals benefit from these relationships to keep our Florida ecosystem in balance. Photos courtesy of Phyllis Wehner, Invasive Species Biologist, NPBCID