Tundra by Gabrielle McMahon

Fun Facts

24mcmahong2 — 2023-12-20 01:37:10 UTC

Less precipitation falls in tundra than in deserts
The sun never sets during the tundra's summer season
Tundra covers ~10% of the earth's surface
Hattie took many of the photos on this Padlet including the background picture! :)

(Sources: Britannica, National Geographic (Image))

Economic Importance

24mcmahong2 — 2023-12-20 01:39:34 UTC

Tundra provides many different economic benefits. This includes oil and gas reserves, as there are numerous deposits of oil and natural gas. There are also mining benefits. Mining industries extract precious metals, most commonly diamonds and gold. Due to the abundance of fish, many commercial fisheries residing in coastal areas rely on fish species. The large amounts of sunlight and wind in tundra ecosystems allows for opportunities of renewable energy (wind and solar energy). Tundra acts as a home for many Indigenous communities. This includes the Aleut, Alutiiq, Inupiat, Central Yup'ik and Siberian Yupik. It provides sources of hunting, fishing, and communal activities.

(Sources: National Geographic, Britannica, National Geographic (Image))

Ecological Importance

24mcmahong2 — 2023-12-20 01:47:15 UTC

Many tundra species cannot be found elsewhere. Few species of plants and animals can survive in these harsh conditions and are highly vulnerable to environmental changes. The biome is an important contributer to global biodiversity despite the low number of species. Tundra ecosystems provide foraging areas for large herbivores. This is because it is a treeless ecosystem, containing matted and grassy landscapes. Additionally, they also support a wide variety of species like arctic foxes, polar bears, gray wolves, caribou, snow geese, and musk oxen. This build up of manure stimulates plant growth by adding nitrogen and other nutrients to the soil. Tundra has an abundance of bacteria and fungi, which are essential not only to a proper functioning ecosystem in the biome, but also contribute to nutrient regeneration and the carbon cycle.

(Sources: NHPBS, National Geographic, Britannica, Wikipedia (Image))

Anthropogenic Threats

24mcmahong2 — 2023-12-20 02:14:40 UTC

Humans have exploited tundra ecosystems for their economic benefits. Many extraction practices by oil, gas, and mining industries can damage fragile tundra habitats. This occurs by well drilling, which can thaw permafrost. It can also threaten soil and vegetation growth by heavy vehicles and pipeline construction sites. Overall, this human activity can increase chances of toxic spills. In 1980, seismic testing for oil and gas systems left tracks on tundra still visible today.

Human activity has significantly increase air pollution, having negative impacts on tundra ecosystems. Arctic clouds are sensitive to air pollution, and can have a blanketing effect. Black carbon from diesel engines, fires, and other combustion can settle on snow. This decreases the ability for surfaces to reflect sunlight (lower albedo) and causes faster melting (positive feedback system). Chemicals used in coolants and aerosol sprays have caused ozone depletion at North and South Poles, letting in stronger UV light rays. Coal burning and industrial activity has released toxic mercury into the atmosphere. As it accumulates in arctic tundra, it threatens the health of both humans and animals. This can cause harm or kill lichen - an extremely important food source.

The overall increase in climate has directly impacted the tundra. The ecosystem has a high sensitivity to global warming, warming faster than other regions. Many species have migrated north, now competing with other species. This risk of invasive species can damage other populations. For example, species like caribou have decreased due to an increase in parasites, disease, and limited food sources.

(Sources: National Geographic, PBS, Britannica (Image))

24liangh — 2023-12-21 13:34:22 UTC

Introduction to Tundra

24mautnermazlens — 2023-12-21 13:34:35 UTC

There are two types of tundra: arctic and alpine. The tundra is classified as a biome with a very short growing season, incredibly cold temperatures, and low growing vegetation. Decomposition takes a long time, especially due to permafrost. Permafrost is a layer of soil that is always freezing and has consistent freeze/thaw cycles. It also makes it so plants cannot have deep roots. Arctic tundra are in the Arctic Circle and have more extreme temperature differences. Alpine tundra occur at very high elevations, above the tree line, and has characteristics of tundra while being at a lower latitude and not having permafrost. Tundra covers about 10% of the Earth's surface.

(Sources: Encyclopedia Britannica, National Geographic)

Global Distribution of Tundra

24mautnermazlens — 2023-12-21 13:41:17 UTC

Tundra can occur above 60°N in North America and above 70°N in Europe. Tundra mostly occurs in northern areas and not southern areas because Antarctica's large ice sheets make it less conducive to tundra.

(Sources: Encyclopedia Britannica, NASA, Wikimedia (image))

Climate

24mautnermazlens — 2023-12-21 13:45:53 UTC

The temperature range in Arctic tundra is between 4℃ and -32°C. In alpine tundra, temperature is usually between 12℃ and -18°C, overall more moderate than Arctic. Tundras have long cold winters, with periods of no sunlight. The amount of snow varies based on proximity to water, and when there is snow it is usually dry snow. Winds can be very strong in tundras. Mild summers are a key characteristic of tundra, preserving the freeze/thaw cycles and delicate permafrost balance. In summers, there are days with sun all day. These solar extremes are due to tundra being very close to the poles. The cool climate of tundra lead to shorter growing seasons and slower rates of decomposition.

(Source: Encyclopedia Britannica, NASA)

Dominant Vegetation

24liangh — 2023-12-21 13:58:45 UTC

Because the tundra gets less than 25 cm of annual precipitation, and the frozen permafrost is difficult for roots to penetrate, Tundra is largely treeless. Vegetation that can persist is low to the ground and can withstand tundra conditions: shrubs, grasses, mosses, and lichens. Tundra plants are adapted to carry out photosynthesis in cold temperatures with low light levels; with scarce populations of pollinators, plants have also adapted to reproduce asexually through budding and division.

(Sources: National Geographic, United States Forest Service (image))

Climatograph of Aklavik, Canada

24mautnermazlens — 2023-12-21 13:59:14 UTC

68°N

(Source: NASA)

Climatograph of Murmansk, Russia

24mautnermazlens — 2023-12-21 13:59:51 UTC

68°N

(Source: NASA)

Climatograph of Nome, Alaska

24mautnermazlens — 2023-12-21 14:00:41 UTC

64°N

(Source: NASA)

Crustose Lichen

24liangh — 2023-12-21 14:15:35 UTC

Crustose lichen are abundant in tundra biomes and form a crust over surfaces like boulders or soil. Instead of transporting nutrients through plant tissue and veins, lichens get nutrients from the surrounding air and rain.

(Sources: United States Forest Service (image))

Reindeer Moss

24liangh — 2023-12-22 04:56:33 UTC

Like other lichens, Reindeer Moss is formed from a mutualism between blue-green algae and fungus. It's called reindeer moss because this lichen acts as an important food source for reindeer in the tundra.

(Sources: United States Forest Service (image))

Soil Characteristics

24liangh — 2023-12-22 05:19:21 UTC

Often called Cryosols (by Canadian classification) or Gelisols (by US taxonomy), soil in the tundra has two components: an active surface layer with freeze-thaw cycles and a permafrost layer. The surface layer is where biological activity such as root growth, animal burrowing, and decomposition occur. Due to the harsh temperatures, decomposition is a slow process in the tundra, and soils generally have high levels of organic matter.

Permafrost, which is ground that stays frozen year-round, is an integral part of the tundra biome - containing rocks, ice, soil, and organic matter. Permafrost is also one of climate change's first victims, and the loss of this carbon sink will promote decomposition and more carbon release. Gelisols are easily erodible and often scarce in plant nutrients - hence why most plants obtain nutrients through other methods.

(Sources: University of Idaho, Britannica, Simon Fraser University (image))

Animal Life

24liangh — 2023-12-22 05:41:22 UTC

Because of the cold temperatures, the Tundra's diverse fauna are adapted to both handle cold winters and subsequently reproduce early on in the summer so young can prepare for winter. Common adaptations include: thick coats of fur for insulation in the cold, layer of fat as insulation, winter hibernation, and migration patterns sound during cold seasons. It is unlikely to find amphibians or reptiles in the tundra, and as result of temperature, most of the animal life is warm-blooded.

Caribou (reindeer) are one example of tundra wildlife. They are herbivorous mammals that feed on lichen, have fur that insulates and sheds water or snow, and their coats turn from brown to grey in the winter.

The Arctic Fox is one of the Tundra's main carnivores, often trailing behind polar bears to eat the remainder of what they've killed. Its diet changes with the season, and even though the average adult is only 50-60 cm in length, they are known to hunt animals as large as caribou.

(Sources: National Geographic, UC Berkeley, Animal Corner (image))

24liangh — 2023-12-22 05:43:01 UTC

Source: Britannica