My Research (Plants in Tundra)

Plant Adaptations

Plants, too, must deal with the cold of winter (which most do by going dormant). But they also must adapt to the relatively cool summer, the shortness of the growing season, chilly soils (cooled by permafrost), and frequent winds.

Perennials
Because of the short growing season, most tundra plants are perennials-they spend several years gathering and storing nutrients between each episode of seed production. Many can reproduce by sending runners through the soil, sprouting new plants at the nodes. This is less costly than blooming and producing seeds and fruits

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Heat Efficient
To deal with cool summers, the flowers of Arctic dryad and Arctic poppy revolve slowly throughout the long days catching the sun's rays like tiny satellite dishes.

Protective Covering
Some plants, such as wooly lousewort, protect themselves from wind, desiccation, and cold by growing thick "fur" that is made up of thousands of tiny, curly hairs..

Some tundra plants, such as Labrador tea and Arctic dryad, retain old leaves rather than dropping them. This conserves nutrients and helps protect the plant from cold, windscour, and desiccation. Other plants, such as Kamchatka rhododendron, achieve extra protection by growing in dense mats or cushions.

Evolution for Survival
Some tundra plants, such as arctic birch, are considerably tougher than their non-tundra relatives, and are able to survive in harsher conditions. They have also evolved a prostrate growth form, enjoying the extra warmth trapped in the boundary layer just above the ground surface.

Small and low growing plants are also a characteristic of tundra plants. This is because of the lack of nutrients found in the soil. Also being close to the dark, warmth, absorbent soil helps to keep plants from freezing.

Plants are also dark and hairy. The darkness of their flesh absorbs solar heat, and the hair helps to trap the heat and keep it close to the surface of the plant. The warmer the plant the faster they grow. Some plants also grow in clumps in order to break harsh winds and protect each other from the cold. These plants also stay warmer because more of the plant is exposed to the sun.

Plants in clumps remain 20 degrees warmer than the surrounding air. Some plants even have dish-like flowers that track the sun. The dish allows more sun to be focused on the center of the flower. The warmth that the plant attracts, allows it to grow quicker and healthier than other plants.

Arctic Moss
Genus: Calliergon
Species: giganteum

The Calliergon giganteum grows in the arctic tundra which is a harsh cold environment in the Northern Hemisphere within the arctic circle. There are strong winds, up to 100 miles per hour. In the tundra it is very cold: the average winter temperature is -25° C, and in the summer it is rarely over 10° C. The summertime only lasts six to eight weeks. In the winter it is dark most of the time, and even in the summer it is usually cloudy and overcast; therefore plants get little sunlight. The tundra is also unusually dry; it gets an average of just 30 cm of rainfall per year. The growing season is very short. There is also a major lack of nutrients.

A cool fact about the tundra is that nearly 75 % of it is covered in permafrost. There are many cracks on the surface because of the earth freezing and thawing. This frozen soil prevents water from sinking into the ground, causing many lakes, streams, bogs, and fens (wetlands with a constant high water level) during the summer. Probably the most unique thing about the arctic moss Calliergon giganteum is that it grows in freshwater arctic lakes and in fens.

The Calliergon giganteum is an aquatic plant found growing on the bottom of tundra lake beds and in and around bogs and fens. It is a member of the Siberian tundra biome. Like all mosses, Calliergon giganteum is a bryophyte. They have rhizoids (tiny rootlets) instead of roots. They never have wood stems. They have tiny leaves, usually only one cell thick. There are lots of leaves on the stem. They do not have flowers. They can either reproduce by growing shoots or by sending out spores, which need to be wet to survive. They have two life stages; gametophyte and sporeophyte. There are some ways Calliergon giganteum is unique. It is very slow growing. It grows as slow as one centimeter per year. It also lives a very long time; the shoots live seven to nine years, the leaves live for four. It is brown in color. Its branches are crowded. It is one of the few plants on the tundra. It is "the slowest growing longest living freshwater macrophyte ever recorded" (Amazing Arctic Moss.)

The Calliergon giganteum has adapted well to its cold climate. When it is not growing, it stores nutrients so new leaves can be made quickly next spring. The more leaves the more they can photosynthesize. It is adapted to the incredibly strong winds because it grows near to the ground. Because it can grow under water it is protected from the drying winds and cold, dry air of the frozen tundra. Its long life and slow growth are probably adaptations to the short growing season and the cold.

There are few uses for the Calliergon giganteum. In the arctic, moss covers the ground and warms it up allowing other plants to grow. It is eaten by migrating animals such as birds. Some type of arctic moss was frozen for thousands of years and is helping scientists learn about life on our planet.

The Calliergon giganteum is fairly common. It is one of about 2000 plant species on the tundra, most of which are mosses and lichens.

Arctic Willow
Common Name(s): Rock Willow
Genus: Salix
Species: arctica

Salix arctica whose common name is Arctic willow or rock willow can be found in the North American tundra. The North American tundra consists of Northern Alaska and Northern Canada. It stretches from 52 N to 65 N and from 60 W to 165 W. The Tundra can be described as a treeless plain with uneven ground. Each year

this treeless plain gets 15-35cm (6-14 in) of precipitation. There are two seasons in the tundra. They are winter and summer. Salix arctica prefers to live in dry, cold, open places, hummocks in wet sphagnum bogs, sedge meadows, margins of pools, and muddy salt flats in course sandy soil. The Arctic willow likes cold climates, which makes the tundra a perfect place for it because the average temperatures range from -70 degrees F to 20 degrees F.

Salix arctica is 15-20 cm in height. It has many different shapes, but sometimes has long trailing branches that root where they touch the surface. Rock willows/Arctic willows grow prostrate, shrub, and carpet. The leaves are oval shaped with pointed tips, wedge shaped bottoms, and have little stalks. These leaves are 15-50 mm in length. The leaves are dark green on the bottom and a lighter green on the top. They have net like veins and long hairs that cover their leaves. The flowers of the Salix arctica are upright scaly spikes that are unisexual flowers with no petals. The Salix arctica blooms in the spring. They are 5 cm and are dark brown or sparkling pink. There's no fruit on the plant, only seeds. There are no taproots on this plant. The lateral roots are shallow due to the frozen ground underneath the permafrost.

Salix arctica has made many adaptations to the cold climate of the North American tundra. In its strongest growth season the Salix arctica forms a pesticide to keep insects like the Arctic woolly bear away. It has also adapted to the permafrost by growing a shallow root system. The leaves of the Salix arctica have also adapted to the cold weather by growing long fuzzy hairs.

The Salix arctica is very plentiful in the wild, but is still vulnerable because of the delicate habitat it lives in. It has a shallow root depth, which makes them susceptible to root damage. It also has a short growing season. There is also a limited food supply for herbivorous insects. There is also a low N.P.P. (nitrogen/ phosphorus/ potassium) in the North American tundra. This means that the chemical fertility of the soil is low. There are many studies being done on the Salix arctica. Some of the organizations involved are I.T.E.X. (International Tundra Experiment), S.A.G.E. (Sustainable Arid Grassland Ecosystems). International Tundra Experiment placed open top chambers (O.T.C) in order to raise the average temperature a couple of degrees to find out how it affected the plants, insects, etc. Sustainable Arid Grassland Ecosystems studied the arctic grasslands and plants.

The Tundra is a delicate place where tire tracks can last for years. The Salix arctica has adapted well in these frigid non-fertile conditions. In such conditions small changes could drastically affect the Salix arctica.

Bearberry
Common name: Bearberry, Foxberry, and Kinnikinic
Genus: Arctostaphylos
Species: uva-ursi
Parts used:

Bearberry is a low growing evergreen. It   has a stem that rises 2-8" off the ground and is covered in a thick bark and fine silky hairs. On the stem are many oval-shaped, leathery leaves that are _" to 1" long. The flowers have five petals and are pale pink or white. The petals are only _" long and are curled around the narrow center. They bloom anywhere between March and June. The fruit is a red berry 3/8" in diameter. Bearberry gets its name because bears like to feast on these berries. Bearberry is commonly found in dry, non-nutrient soils such as sand, soils

on rock outcrops and shallow soils. This plant ranges from northern California to Alaska, east from Oregon and Washington to the mountains of west Montana, and from there, south to New Mexico. Other areas of the world include Greenland, Iceland, and northern Eurasia. Bearberry is plentiful in the wild.

Since bearberry is a low growing plant it can stay out of the wind chill. It's fine silky hairs also help to keep it warm. Leathery leaves are also an adaptation to the cold of the tundra.

Bearberry is a very useful plant. All parts of it can be used in some way. The fruit can be eaten and cooked with other foods. The roots can be made into a tea that can treat a constant cough or slow down menstrual bleeding. A tea from the stem is used to prevent miscarriage and to speed up a women's recovery after childbirth. The leaves can be added to tobacco or used as a substitute for it. A tea made from the leaves can be drunk to treat kidney or bladder problems.

Caribou Moss
Common Name: Caribou Moss, Reindeer Lichen
Genus: Cladonia
Species: rangiferina
Parts Used: entire organism

Caribou moss grows in arctic and northern regions around the world. It grows on the ground and on rocks. It looks like a foamy, gray-green spongy mass, and grows to be 1 to 4 inches high. The stems, or stocks, are hollow, and branch out many times. Although it is called caribou moss, it is actually a lichen.

Lichens are two separate organisms. They are made up of fungi and algae, which live and grow together. The spongy   threads of lichens support and protects the algae. The algae has chlorophyll which can make food. Each has something the other needs. This is called a symbiotic relationship. Lichen can make food when the temperature gets very low and there is little light. The tissues of lichens aren't easily damaged by frost. This makes it a great plant for the tundra.

Lichen can survive for long periods of time without water. They just dry out and go dormant when there is little water or light. They can begin to grow again even after very long periods of dormancy.

Animals such as Reindeer and Caribou feed on lichen during the coldest periods of the season. They do this because it is one of the only things that they have for food when the weather is cold and there is little other vegetation left. It has lots of carbohydrates that give the caribou energy to make body heat. Caribou have special microorganisms in their stomachs which let them digest lichen. Very few other animals eat lichens. Some scientists think that the caribou evolved to fill the tundra's food niche that other animals couldn't fill.

People are afraid that the reindeer and the caribou are dying from eating lichens. Lichens absorb moisture and nutrients through their surface cells. Pollutants and deadly radiation can pass easily into their cells. The caribou eat the radiation rich lichen and pass it on to people who can get the radiation from caribou meat.

Lichens are commercially grown in Scandinavia to make a powder that thickens soups and desserts. It is very rich in vitamins A and B. The Dena'ina, Native Americans of the area, boil it until its soft. They use it in all kinds of their foods. They also make a tea out of it as a medicine for diarrhea.

It is also used to tan caribou hides so if you don't boil out the harsh acids, it will give you a very bad stomach ache.

Small and low growing plants are also a characteristic of tundra plants. This is because of the lack of nutrients found in the soil. Also being close to the dark, warmth, absorbent soil helps to keep plants from freezing.

Plants are also dark and hairy. The darkness of their flesh absorbs solar heat, and the hair helps to trap the heat and keep it close to the surface of the plant. The warmer the plant the faster they grow. Some plants also grow in clumps in order to break harsh winds and protect each other from the cold. These plants also stay warmer because more of the plant is exposed to the sun. Extra nutrients and shoots are saved in bulbs or roots for the next growing season. Water is lost through the leaf surface, so small leaves help the plants retain moisture. In the arctic, plants have to be very sturdy. The root, defined as the portion of a plant beneath the soil, brings in essential water and minerals from the soil. It also anchors the plant to the substrate, providing stability.

The shoot includes all aerial plant structures such as stems, leaves, flowers, and fruits. The shoot gathers the carbon dioxide and light energy necessary for photosynthesis, provides surfaces for gas exchange, and contains the plant's reproductive organs. Each of these parts, the root and the shoot, is dependent on the other, for roots cannot perform photosynthesis and shoots cannot take in water and inorganic nutrients.

Prevention of Water Loss

Plants share other structural qualities as well, most of which stem from their adaptation to terrestrial conditions. All plants have reproductive structures that prevent desiccation (drying out) of the gametes. These sex organs, called antheridia (male) and archegonia (female), are themselves covered by a layer of jacket cells that help to retain moisture.

In addition to the protection given to the sex organs, the plant surfaces exposed to air are covered in a waxy layer, called a cuticle, that guards against water loss. Gas exchange in plants is limited to pores in the leaf epidermis called stomata, which can open and close to prevent excessive evaporation of water into the environment.

Autotrophism

Most plants are autotrophs, organisms that synthesize all their own organic nutrients and do not rely on other organisms for food. The reason that plants are autotrophic is that they carry out photosynthesis in their leaves. In the process of photosynthesis, the plant converts water, carbon dioxide, and light energy into oxygen, sugars, and more water. The oxygen is released into the surrounding air through the stomata, and the sugars (organic nutrients) are transported throughout the plant body to areas of growth and storage.

Alternation of Generations

Finally, plants undergo a life cycle that takes them through both haploid and diploid generations. The multicellular diploid plant structure is called the sporophyte, which produces spores through meiotic division. The multicellular haploid plant structure is called the gametophyte, which is formed from the spore and give rise to the haploid gametes. The fluctuation between these diploid and haploid stages that occurs in plants is called the alternation of generations.