“When one tugs at a single thing in nature, he finds it attached to the rest of the world.”
– John Muir
Kicking off the new year of studies is ecology, the study of the interrelationships between organisms and their environments. In February, the conversation was started with bioecology, and there is still so much left to cover! Bioecology focused primarily on one division of ecology, autecology, which studies the relationship between a single organism, or single species, and its environment. This month, the focus is on the second branch of ecology, synecology.
All For One, and One For All
Synecology studies how multiple species, or communities, interact with one another. Communities consist of two or more different species in the same habitat at the same time. At Long Acres Ranch, communities include white-tail deer and coyotes, red-tailed hawks and cardinals, oak trees and hackberry trees, or all of them together. Once non-living components, like soil, sunlight, and water resources, are added to the mix, a community becomes an ecosystem. Throw multiple ecosystems together and voila! It's now a biome.
Biome is Where the Heart Is
Biomes are unique geographic areas with specific climates and distinctive water, plant, and animal resources. An example is a marine biome that has kelp forests, coral reefs, and deep-water ecosystems. Each of these ecosystems is different, but they all exist within an ocean. Broad classifications identify as few as six biomes which include grassland, marine, tundra, freshwater, forest, and desert biomes.
Even though some ecologists categorize biomes this broadly, it isn’t always the case. Others prefer more specific classifications, and identify dozens of biomes. Think for a moment about forests. Forests change depending on altitude and latitude. A deciduous forest in North America (a forest which has trees that lose their leaves once a year) is very different from a tropical rain forest in South America. Some ecologists say that these are two distinct biomes. There are also transition zones between biomes, such as where the grasslands meet the desert in Africa. Species from both may intermingle in this transition zone, but which biome does that area fall into?
Go With the Flow (of Energy)
Organisms are well adapted to living in the biomes and ecosystems that they do. Imagine a giraffe trying to live in a tropical rain forest or a polar bear making it in the desert. Plants and animals are unique to the biomes in which they live, and they also interact with one another in specific ways. Aside from a polar bear getting too hot in the desert, where and how would it get enough energy to survive? Nutrient and energy cycling in ecosystems is one area that shows the amazing connections between living things.
The Original World Wide Web
Energy transfer keeps organisms alive, and just as people need energy, plants and animals do too. Every living thing plays a part in the energy cycle, whether plant, animal, or fungi. This nutrient and energy cycling boils down to how energy develops and flows from one organism to the next. The way to demonstrate this flow is through food webs and food chains.
Organisms get energy from food they eat, and food chains show that energy transfer. However, in natural ecosystems, organisms are so interconnected that multiple food chains combine to form food webs rather than individual food chains. Food chains and webs start with producers - organisms that make their own food. All plants, and only plants, are producers. The producers are eaten by consumers - animals that get energy from eating other organisms. All animals are considered consumers because they have to eat plants or other animals to get energy. When producers or consumers die, there is still energy stored inside them. That energy is then used by organisms that break down dead and decaying organic matter. These organisms are called decomposers, and include fungi and bacteria. During this decomposition process, nutrients are returned to the soil which then help plants grow, and the cycle continues.
Each organism is part of an energy pyramid. This pyramid demonstrates trophic levels, which refers to how many steps it is from the start of the food chain. Primary producers are on the first level, with consumers in the following levels. Consumers can be considered primary, secondary, or tertiary. Primary consumers eat producers, secondary consumers eat primary consumers, and tertiary consumers eat secondary consumers. An example is leaves -> rabbit -> snake -> hawk. Since the hawk is three steps away from the start of the food chain, leaves, it is a tertiary consumer. The higher the trophic level, and farther up the food chain a consumer is, the less energy is obtained by the consumer.
The consumers at the top of the pyramid, and therefore at the top of the food chain, are called apex predators - these are the species that don’t have any natural predators themselves. Animals like orcas, great white sharks, grizzly bears, and bald eagles are considered apex predators.
Each ecosystem moves energy in this type of way, with species playing different roles in the community and its overarching ecosystem. The term for the role a species plays is called a niche. The way an organism uses resources that are available to it and the ways that its presence impacts the other organisms in the ecosystem describes its niche. Consider that an ecosystem is a subdivision and the habitat of an organism is similar to the home of a person. The person lives in their home and their niche is what they do, how they spend their time, the resources they use, and how they interact with their neighbors and others in the community. It’s the same for ecological niches.
Same Position Different Team
Most organisms occupy different ecological niches in their ecosystem, but species that occupy the same niche in the same ecosystem are in direct competition with each other. Competition isn't a problem during a year of abundant resources; however, in seasons when resources like food are scarce, they cannot provide for multiple species. This results in one species outcompeting the other for those resources.
Generally, there will only be one species that fits its niche in an ecosystem. Pretend an ecosystem is a football team and the niche is for quarterback. If two people want that role, they have to compete for it and the fittest person with the best skills plays. The same goes for an ecosystem.
However, within different ecosystems, there are different organisms that occupy the similar niches. Going back to football, two people can't play as quarterback on the same team, but different teams (or different ecosystems) have a quarterback. Looking at an ecological example, a kangaroo in Australia has a similar niche as a deer in the United States. It’s the same niche, but a different ecosystem.
Different Players All Together
On the other hand, some species have extremely specialized niches. Back to football - kickers have one job and that's to kick. That's what they do! The same goes for certain species, such as the giant panda. They don't kick, but, like the kicker, the giant panda does what no other species (or player) can. Unfortunately, this specialization comes at a cost. Since pandas feed exclusively on bamboo, when food sources are scarce their population becomes threatened. Whether it's because of human interference or natural causes, it is definitely something that limits panda populations and could have a negative impact.
Although this is the case with some species, many species can expand their niche and are more opportunistic. This means that they can be more flexible, allowing them to have greater rates of survival. Coyotes and raccoons are examples of generalist species. They’ve adapted to living in towns and cities, like Los Angeles and Houston, in addition to less human-inhabited areas. It's great to be so flexible!
Ecology is such a broad study, but luckily one that can be studied pretty much anywhere. Observation is the basis of learning about ecology and experience is the best teacher, so get outside and observe! Watch the animals outside for an afternoon or visit a park and take notes in a journal about the plant and animal species there. Interested in more? Join a Sci Starter Citizen Science Project. Projects include monitoring butterflies, connecting with pollinators, and so much more. Click HERE to find a project near you and start your own ecological study!
“Biomes.” National Geographic Society, education.nationalgeographic.org/resource/biomes.
“Biomes, Ecosystems, and Habitats.” National Geographic Society, education.nationalgeographic.org/resource/biomes-ecosystems-and-habitats.
“Grassland Biome.” National Geographic Society, education.nationalgeographic.org/resource/grassland-biome.
Latham, Donna. Biomes Discover the Earth's Ecosystems. Nomad Press, 2019.
“Niche.” National Geographic Society, education.nationalgeographic.org/resource/niche.
OpenStax, et al. “4.4 Community Ecology.” Environmental Biology, Open Oregon Educational Resources, openoregon.pressbooks.pub/envirobiology/chapter/4-4-community-ecology/.
Perdew, Laura. Biodiversity: Explore the Diversity of Life on Earth with Environmental Science Activities for Kids. Nomad Press / Bookmasters, 2019.
Pollock, Steve. Ecology EyeWitness Books. DK Publishing.
Spilsbury, Richard. Earths Natural Biomes: Forests. Hachette Childrens Group, 2017.