Question

1. Choose one Biome to describe. Include a description of the Ecosystem found within that biome. Include specific information (plant AND animals AND climate AND location).

How do humans impact the biogeochemical cycles within this Biome? You should include mention to 3 biogeochemical cycles.

Answer 1

A biome is an area on the planet that can classified according to the plants and animals that live in it.

The biome I have chosen is- Tundra Biome.

The Tundra Biome

• Tundra is the coldest of all biomes.
• The word Tundra comes from a finnish word, tunturi, which means a treeless plain.
• In the biome, the tree growth is limited by low temperatures, short seasons and scarcity of nutrients.
• The nutrient pool is mainly formed by dead organic material. Two major nutrients found are- Nitrogen and Phosphorous. Nitrogen through biological fixation and phosphorous through precipitation.
• Precipitation in these regions is low leading to lesser growth of tress.
• The trees have a shallow root system and are not fit to survive high winds.

Location

• Tundra regions are found in the north pole, at very high elevations, atop mountains.
• They are mostly found in the Arctic, Alaska, Canada, Greenland, Iceland, Russia and Northern Scandinavia.

Precipitation

• Tundra regions get less than 10 inches (25 centimeters) of rain annually making them close to a desert.
• The low precipitation is responsible for lack of flora and fauna.

Classification

Tundra is broadly classified into two types:

A. Arctic Tundra

• Arctic tundra is located in the northern hemisphere, around the north pole and extending south to the coniferous forests of the taiga.

• The growing season ranges from 50 to 60 days. The average winter temperature is -34° C , and the average summer temperature is 3-12° C.

• Rainfall varies in different regions of the arctic. Yearly precipitation is 15 to 25 cm (6 to 10 inches).

• Soil is formed slowly. A layer of permanently frozen subsoil called permafrost exists, consisting mostly of gravel and finer material. When water saturates the upper surface, bogs and ponds may form, providing moisture for plants.

• There are no deep root systems in the vegetation of the arctic tundra because of the snow and frost. There are about 1,700 kinds of plants in the arctic and subarctic, and these include:- low shrubs, sedges, reindeer mosses, liverworts, and grasses, 400 varieties of flowers, crustose and foliose lichen

• All of the plants are adapted to high winds and disturbances of the soil. Plants are short rooted and group together to resist the cold temperatures and are protected by the snow during the winter. They can carry out photosynthesis at low temperatures and low light intensities. The growing seasons are short and most plants reproduce by budding and division rather than sexually by flowering.

• The fauna in the arctic is also diverse: Herbivorous mammals: lemmings, voles, caribou, arctic hares and squirrels, Carnivorous mammals: arctic foxes, wolves, and polar bears, Migratory birds: ravens, snow buntings, falcons, loons, sandpipers, terns, snow birds, and various species of gulls, Insects: mosquitoes, flies, moths, grasshoppers, blackflies and arctic bumble bees, Fish: cod, flatfish, salmon, and trout

• Animals are adapted to the cold winters and to breed quickly in the summer. Animals such as mammals and birds also have additional insulation in the form of fat. Many animals hibernate during the winter because food is not abundant.

B. Alpine Tundra

• Alpine tundra is located on mountains throughout the world at high altitude.
• The growing season is approximately 180 days.
• The nighttime temperature is usually below freezing.
• The soil in the alpine is well drained. The plants are very similar to those of the arctic ones and include: tussock grasses, dwarf trees, small-leafed shrubs, and heaths.
• Animals living in the alpine tundra are also well adapted:- Mammals: pikas, marmots, mountain goats, sheep, elk, Birds: grouselike birds, Insects: springtails, beetles, grasshoppers, butterflies.

Biogeochemical cycles

1. Nitrogen cycle

In the tundra, the nitrogen cycle is used by the snow and ice. The snow is created in the atmosphere which is made up of 79% nitrogen. This means that snow can absorb a fair amount of nitrogen. First nitrogen goes from the atmosphere into the ground. Then bacteria converts the nitrogen into ammonia and that is when the plants can use it to help them grow. When the animal eats a plant, the nitrogen gets transferred from one organism to the other. When a plant or animal dies, they will decompose into the ground, releasing the nitrogen from their bodies.

2. Water cycle

Runoff - when water hits the surface of earth. The water in our biome will either freeze or go to a near by lake or ocean.
Precipitation - when it snow, hails, or rains.
Transpiration - evaporation of water from a plant.
Infiltration - when soil is absorbing water that is trapped underground. In the tundra, there is several feet of snow and ice covering the ground/soil. Then a layer of permafrost making it hard for water to be absorbed by the soil. But as temperatures rise, the tundra gets hotter and that creates a problem because it makes the snow, ice and permafrost melt at a faster rate than it should.
Evaporation - the process of water turning into a gas from a liquid. As global warming goes on, there will be more water evaporating from the tundra.
Groundwater/Groundwater Storage - water that is deep underground with a layer of unsaturated soil. Once the permafrost melts, then the water can sink through and become groundwater.

3. Carbon cycle

Aquatic arctic moss gets carbon from the water. The plants take the tiny particles of carbon in the water and use it for photosynthesis. They produce oxygen and glucose. When the lemmings eat the moss, they take in the energy. When the plant or the animal dies, decomposers will start to break down the plant or animal to produce carbon.    

-It is important to note that Tundra is one of the biggest carbon dioxide sinks on Earth. In other words, the biomass, which is biodegradable, takes more carbon dioxide than it gives back to the atmosphere when it decomposes. This is because plants absorb CO2 along with with sunlight and water when they carry out photosynthesis. They give it back to the atmosphere when their life cycle is over, and their remains decompose. But in the Arctic, these natural processes are significantly slowed down because of the cold climate. Short summers and long winters slow the decomposition of organic matter. Plant remains, which as a result of continuous freezing and thawing of the soil, remain trapped in a layer of permafrost for several thousand years. This is why tundra is a carbon sink, trapping carbon dioxide and and keeping it from returning to the atmosphere

Human impact on the biome

There is very low to negligible human involvement in the Tundra because of it's harsh living conditions. It is one of the least lived biomes out of all biomes. Thus, humans have little to no direct impact on the Tundra biome.