The Tundra Ecosystem
Courtney Cryan and Grace Lacher
There are two distinct types of tundras: arctic tundra and alpine tundra. Arctic tundras are located in the upper latitudes of the Northern Hemisphere in countries such as Canada, Russia, Greenland, and Scandinavia. Alpine tundras on the other hand occur near mountain tops, where the climate is incredibly cold as a result of the high altitude. The region is relatively dry, with typical annual rainfall of less than 10 inches. The tundra is the coldest of all the biomes. With an average winter temperature of -30 degrees Fahrenheit (-34 degrees Celsius) and average summer temperatures ranging from 37-54 degrees Fahrenheit (3-12 degrees Celsius), tundra wildlife has been forced to adapt to survive some of the world’s most extreme conditions. Winters in the Arctic tundras are especially cold, as for part of the year the region is completely dark all day. The area remains cold throughout the summer even when it is permanently light out, as the light’s intensity is very low due to the high latitude. The region is so cold that part of it remains frozen all year round. Underneath an initial strip of active soil, the tundra sits on top of a layer of permanently frozen ground called permafrost. Composed of sediment and dead matter, permafrost is a defining characteristic of the tundra biome. Starting shortly below the surface, the permafrost can extend down to almost 1,500 feet. Alpine tundras do not possess permafrost as the ground instead contains mostly rock.
The tundra’s growing season is very short as the region’s temperatures are only above freezing for a few months. This means that most tundra plants are perennials: plants that sit dormant during the winter before returning every summer. Tundra plants must grow very quickly in order to take advantage of the brief summer. A distinct feature of the region’s flora is its inability to grow long roots. Tundra plants cannot develop extensive root systems, as they only have a short layer of soil before they hit the impenetrable permafrost. Without long roots, plants rely on the annual melting to obtain enough water. In the summer, the uppermost layer of frozen topsoil begins to thaw, causing bogs to form at the surface from which the plants’ short roots are able to collect water. Along with their lack of deep root systems, tundra plants possess more adaptations that allow for their survival. Growing close to one another allows the plants to protect themselves from the extreme temperatures, and remaining short and low to the ground protects them from heavy winds. Although life in the tundra may be difficult, many different plant species are well enough adapted to survive there. Tundra ecosystems contain an estimated 1,700 different types of plants, including shrubs, mosses, lichens, sedges, and many others. Notably missing from the lineup are trees – not one tree species is native to tundras. In fact, the name tundra actually comes from the Finnish word “tunturia” meaning treeless. The biome’s permafrost does not allow for the level of root growth needed to support trees. The low levels of rainfall and heavy winds further prohibit trees from growing there.
Animals found in the Tundra Ecosystem
The animal species found in the Tundra feature herbivores and carnivores. Some herbivores that reside there are the arctic hare, caribou, arctic ground squirrel, lemmings, and voles. Some carnivores found there are polar bears, arctic foxes, and wolves. There is a wide range of bird species in this ecosystem, as there are ravens, snow buntings, falcons, loons, sandpipers, terns, gulls, Snowy Owls, and the semipalmated plover. Another animal found in the Tundra is the Musk Ox. Fish that are found there are cod, Flatfish, salmon, and trout. Though the tundra is very cold, it still has insects. For example, there are mosquitoes, flies, moths, black flies, and grasshoppers. The Tundra has relatively low biodiversity because of the lack of food and the cold. These animals must nurture their young quickly during the summer months. Most of the animals found there have white fur as they have adapted to camouflage with the snow and ice around them.
Issues within the Tundra Ecosystem
Climate change presents a serious problem for tundras, as the frozen ecosystem is especially vulnerable to warming temperatures. The region may be changing even more dramatically than others – according to the National Snow and Ice Data Center, the Arctic has warmed at twice the rate of the rest of the world. Such change permanently alters the biome’s characteristics. Existing tundras are beginning to recede as their southern regions transform into boreal forests. The tundra’s defining layers of permafrost were originally named for their permanence, however with substantial warming the upper layers are beginning to thaw. Such a change could affect local plant composition, further transforming the ecosystem.
The effects of melting permafrost will be felt far beyond just the tundras. The frozen ground is partially built up of undecomposed dead matter that contains carbon. Once thawed this dead matter decomposes, releasing the stored carbon into the atmosphere as carbon dioxide or methane. By emitting more greenhouse gases, the thawing permafrost contributes to further global warming.
Greenhouse gases are not the only airborne chemicals jeopardizing the safety of the tundras. Abnormally high levels of gaseous mercury exist in the Arctic ecosystem. A 2017 study led by Daniel Obrist discovered the way in which the chemical has severely contaminated the tundra. Plants first absorb the atmospheric gas, storing it in their tissues until they die, after which the mercury enters the soil. Once in the soil the mercury can move throughout the ecosystem, affecting all levels of the region’s wildlife. Arctic mercury pollution results largely from the anthropogenic burning of coal and oil, however global warming may generate mercury emissions from another source. Not only does the Arctic’s permafrost contain large deposits of carbon, it also hides millions of gallons of mercury. As warming temperatures thaw the permafrost, the mercury reserves will be released into the surrounding environment.
According to a study from the US Geological Survey, Arctic habitats hide 13% of the world’s untapped oil reserves and 30% of its undiscovered natural gas. Many countries have begun to analyze these deposits as potential sites for future drilling. Development of these sites would require disruption of the natural ecosystem in order to build the infrastructure necessary for drilling. Seismic exploration, the building of roads, and the resulting noise pollution are just some of the ways that oil development would affect the ecosystem. Along with the physical alteration of the tundra, drilling development also creates opportunities for oil spills and exposure to fracking chemicals.
Policies Addressing the Issues
The Kyoto Protocol is an international treaty that brings countries together to reduce climate change, while also coming up with better ways to cope with the damage that’s already been done. The goal for this policy is to reduce the emissions of 6 greenhouse gases that affect global warming. This placed restrictions on large polluters, found a better use for renewable resources, and managed transportation to slow emissions from cars. This has helped the global warming issues as it is helping keep the pollution limits in check.
The Montreal Protocol is a global agreement that helps to repair the ozone hole by phasing out the usage of certain ozone depleting substances. The ozone is important as it filters out harmful ultraviolet radiation that increases health issues, reduces farming productivity, and can disturb marine environments. This helps the ecosystem by reducing the chemicals that are ruining the ozone and creating more problems. This will allow the icebergs to reduce melting.
In the United States, we have certain regulations in place that help with how they are extracting the resource, treating it, and protecting the ecosystem. These regulations were put into place after the Deepwater Horizon spill and the BP oil spill. This helps mitigate damage to the environment and potential damage to the health of the animals if the oil does spill. One of them is the Oil Pollution Act which has enacted a tax on oil. The funds raised through taxes are utilized to clean up oil spills when organizations act irresponsibly. The second one is the Marine Protection, Research, and Sanctuaries Act which prohibits transportation of material from the US to be disposed of in the ocean and any material dumped in US waters from outsiders. This protects the waters from pollutants which harm animals in many ecosystems.
How Animals are Affected
As warming temperatures alter the face of the tundra, many areas no longer meet the needs of the animals who live there. Tiny lemmings rely on the land’s snow cover for protection and insulation, and increased meltage leaves them more vulnerable to predators and increased exposure to the elements. Many larger animals naturally prey on lemmings, such that a reduction in lemming populations would likely have consequences throughout the tundra food chain. Herbivorous animals may also struggle to feed themselves in this new environment, as the warmer weather causes changes in local plant composition. Increased snow melt creates additional issues for herbivores as the water eventually refreezes into icy layers, making it difficult for animals to access the vegetation. If serious warming continues, animals originally adapted to tundra conditions may no longer be able to survive there. A report from the World Wildlife Fund states that a doubling of greenhouse gas concentrations could eliminate 30% of existing tundra, removing the species’ habitats right out from under them.
While increasing temperatures may hurt the tundra’s native species, they make the region more suitable for animals from warmer climates. The entrance of non-native species into the area creates new competition for the already-struggling Arctic animals. One example of this is the plight of the arctic fox. Warmer temperatures allow red foxes to move farther north into areas previously inhabited solely by arctic foxes. The non-native foxes are a more dominant species, outcompeting arctic foxes in areas where their populations now overlap. In addition to taking up valuable resources such as food and den space, red foxes also introduce new diseases to the native foxes.
The tundra’s mercury pollution creates further health risks for tundra wildlife, as the chemical moves from the atmosphere into the animals themselves. Runoff carries mercury from the soil into nearby waters, where bacteria can convert the element into dangerous methylmercury. Methylmercury first accumulates in fish. When a smaller predator eats these fish the chemical then accumulates in the tissues of the animal. The process continues when larger predators consume those smaller ones, and through this predation the mercury accumulates in all levels of the tundra food web. The dangers of mercury exposure are well-understood in humans, and the chemical has detrimental effects on animals as well. Mercury contamination can cause neurological and developmental issues and hinders reproduction processes, threatening individual animals’ health and the future of their populations.
Oil production in the Arctic results in habitat fragmentation that further endangers tundra wildlife. Drilling requires roads, pipelines, and additional drilling infrastructure to be built throughout the habitat, reducing the amount of area accessible to animals. With less land accessible, species may struggle to find the resources necessary for their survival. Fragmentation can be particularly troublesome for migratory species, who may not be able to follow their traditional migration routes with these new obstacles. Human activity and noise pollution as a result of drilling may deter animals from entering areas near the drill sites. If this occurs near a species’ breeding ground, it could result in them abandoning the area all together. Such is the concern with Alaska’s Porcupine Caribou populations – many conservationists are worried about the way oil drilling near the caribou’s breeding ground could affect their herds.
What You Can Do
The first thing you can do to help the Tundra today is sign petitions to put an end to oil drilling and other practices that further exacerbate global warming.
The second thing that you can do is educate yourself on different environmental issues and vote for the person who protects nature the most.
The third option is that you adopt a polar bear through organizations like the World Wildlife Fund, and donating to organizations like this that work to help the animals and our environment.
Sources – National Geographic; World Wildlife Fund; Scientific American; UC Museum of Paleontology; US Energy Information Administration; National Snow and Ice Data Center; US Fish and Wildlife Service; National Oceanic and Atmospheric Association; Alaska Department of Fish and Game; NH PBS; Ohio State University; U.S. Department of State; ThoughtCo.; Environmental Protection Agency