1. Explain what an ecologist studies. Does this have any impact on you? Explain!

An ecologist studies the relationship of the environment to the organisms. Symbiosis would be an example of ecology. Ecologists need to be trained and know something. Environmentalists can be anybody and protest something. Ecologists need to study the environment and be college graduates and understands the relationship while an environmentalist has less information and no thinking is required to be one. An example of ecology would be how the Salt Lake Valley was polluted from coal burning and then ecologists came along and people used natural gas which helped a lot.

The interaction between an organism’s biochemistry or general physiology and its environment is called physiological ecology; in our exploration of ecology, we shall often stress the relationship between an organism’s physiological systems and its interactions with its environment. Ecology is also concerned with three higher levels of organization: populations, which are groups of individuals belonging to the same species; communities, which are units composed of all the populations living in a given area; and ecosystems, which are communities and their physical environments considered together. Each of these designations may be applied to a small local entity or to a large widespread one. Thus the sycamore trees in an isolated patch of forest may be regarded as a population, and so may all the sycamore trees in the eastern United States. Similarly, a small pond and its inhabitants, or the forest in which the pond is located, may be treated as an ecosystem.

The various ecosystems are linked to one another by biological, chemical, and physical processes. Inputs and outputs of energy, gases, inorganic chemicals, and organic compounds can cross ecosystem boundaries through meteorological factors such as wind and precipitation, geological ones such as running water and gravity, and biological ones such as the movement of animals and the dispersal of pollen and seeds. Thus the entire earth is itself a true ecosystem, in that no part is fully isolated from the rest. The global ecosystem is ordinarily called the biosphere.

No organism - no rhinoceros, duck, or oak tree, or bacterium - exists alone. Each is a part of an intricately linked system of living and nonliving elements. The study of the relationship between organisms and their environment is called ecology. Ecologists study not only how organisms act together but also how they are adapted to their environments. Adaptation, which results from evolution by natural selection, is a factor that unifies the structure, physiology, and behavior of all organisms throughout the biosphere.

The biosphere is that area of the earth where life exists. Insects and spores of microorganisms and plants have been found 8 km high in the atmosphere. Other organisms such as sea urchins and brittle stars live 8 km below the surface of the ocean. Almost all life, however, exists on or within a few meters of the earth’s surface. The biosphere is so thin that if the earth were the size of a basketball, the biosphere would be much thinner than this page.

Ecologists learn about the biosphere by studying smaller and simpler ecological units within it. These simpler levels serve as models for the larger, more complex biosphere. Large ecological units in the atmosphere are called biomes. A smaller ecological unit is a population, all the members of a species that live in the same area and make up a breeding group. For example, the moose on Isle Royale, a national park in Lake Superior, constitute a population. They interact with each other and with other species on the island, including the timber wolves that kill and eat moose. The moose population, the wolf population, and all the other living things on the island form a community. A community includes all the populations in an area.

Ecologists also study ecosystems. An ecosystem is an ecological unit that includes all the interacting parts of an environment in an area. A lake, a prairie, and a cave are all examples of ecosystems. The nonliving components of an ecosystem are called abiotic factors, and the living components are called biotic factors.

Abiotic factors in an ecosystem include sunlight, precipitation, temperature, the slope and drainage of the land, and the chemistry of soils and of the atmosphere. These physical factors interact with one another. For example, a season of heavy rains can cause a river to flood its banks, depositing sediments on nearby land. When the flood recedes, the sediments will have changed the soil composition. Other interactions of abiotic factors can produce more dramatic results. A river can completely change course, volcanic activity can suddenly create a mountain or an island.

Biotic factors in an ecosystem include plants, animals, protists, and all other living organisms. Like abiotic factors, biotic factors also interact in many ways. All organisms compete for food, water, space, and other resources. One type of competition occurs between members of the same species, and another type of competition occurs between different species. For example, two different species in the same community may eat the same plants.

Two other forms of interaction of biotic factors are predation and symbiosis. In predation one animal, the predator, kills and eats another animal, the prey. In the Isle Royale community wolves are the predators and moose are the prey. Symbiosis is a close relationship between two organisms of different species. Usually at least one of the species benefits from the relationship.

Abiotic and biotic factors in ecosystem also interact with each other. For example, climate and soil conditions determine which plants will live in a certain area. Plant life in turn affects the distribution of animals. For example, the grass that grows in Siberia must withstand that region’s cold, dry climate. The teeth and digestive system of the saiga antelope are adapted for eating this grass. In contrast, deer that reside in the wetter forests of the eastern United States are adapted for browsing on the leaves of the trees that are found there.

Living organisms also affect abiotic factors. For example, plants replenish oxygen in the atmosphere by the process of photosynthesis. The interaction of biotic and abiotic factors results in the great diversity of ecosystems in the biosphere.

Abiotic factors such as temperature, rainfall, and soil determine which organisms will thrive in a certain area. A biome is a large area identified by the presence of characteristic plants and animals. Biomes are commonly identified by their dominant plant life in the deciduous forest biome.

Because abiotic factors change gradually, biomes seldom have distinct boundaries. As climate varies over the earth’s surface, deserts tend to grade into grassland, and cold-climate forests grade into warmer-climate forests. Ecologists separate biomes into two very broad classifications: terrestrial biomes, or those on land, and aquatic biomes, or those of water

The biomes found at the earth’s coldest extremes are the polar biomes. They surround the North and South poles. Similar conditions exist on the tops of the highest mountains. The poles receive almost no precipitation, so although ice is abundant, fresh water is scarce. The sun barely rises in the winter months, and fierce winds sweep over the land. Despite the harsh conditions, however, life does exist in the polar biomes.

In the Arctic polar biome an ice cap lies over the Arctic Ocean, where the latent heat of water keeps the ice no thicker than 5 to 30 m. During the summer months, when temperatures can rise to 25ºC, some of the ice melts, revealing scattered patches of soil. More than 100 species of flowering plants, along with mosses and lichens, live there. Animals such as gulls, walruses, and polar bears also inhabit the Arctic coast.

In the Antarctic polar biome an ice cap lies over a large landmass; therefore the icecap is not warmed by water’s latent heat. Only a few species of lichens and mosses live along the coast. Three types of flowering plants also grow on the rocky tip of the Antarctic peninsula. Only bacteria and some small insects inhabit the vast Antarctic interior. Seals, whales, and penguins, are found on or near the Antarctic coast. Penguins breed in winter so their young will hatch in the spring.

The Tundra, a treeless biome blanketed by snow in the winter, forms a continuous belt across northern North America, Europe and Asia. Tundralike areas also exist on mountains above the tree line, the highest point at which trees can grow. Permafrost, a permanently frozen layer of ground over 500 m thick, characterizes the northern tundra. Even the surface soil above the permafrost remains frozen for all but eight weeks of the year.

In the brief summer the tundra landscape explodes with life, becoming a patchwork of ponds, bogs, and soggy soil. Tundra plants, which are short and often woody, appear as do swarms of mosquitoes and blackflies. Ducks, geese, and predatory birds arrive in great numbers. By mid-September the cold returns.

Many plants and animals have adapted to the cold and snowy tundra environment. Dwarf willows are only about 0.3 m tall, an adaptation to the cold winds that sweep across the tundra. The large size of caribou creates a low surface to volume ratio that helps prevent heat loss. Caribou are also swift runners with great stamina, adaptations that allow them to avoid predators and migrate long distances.

The coniferous forest is a biome that is dominated by conifers, cone-bearing evergreen trees such as pines, firs, spruces, and cedars. In the northern hemisphere this biome lies south of the tundra. Plants are adapted for long, cold winters; short summers; nutrient-poor soil; and frequent droughts. Their waxy needles remain on the trees all winter. The shape of their needles is an adaptation that reduces water loss. In addition, their stomata are recessed in the body of the leaf, which helps conserve water.

Typical mammals of this biome include moose, bears, and lynx. Many of these animals rely on stored body fat during the cold months. Although some animals reside in the forest year round, others migrate to warmer climates in the fall and return in the spring. Most invertebrate species hibernate six to eight months of the year, taking advantage of the insulating snow cover.

Large tracts of coniferous forest cover northern parts of Europe, Asia, and North America. Ecologists subdivide the coniferous forest in North America into three areas:

• The taiga, the northernmost band, occupies northern Canada and Alaska. The widely spaced trees include pruce, and balsam fir, whose cone-shaped crowns shed heavy snows.

• The coniferous belt is found south of the taiga and extends across much of Canada as well as northern parts of the United States. Ecologists call this the "spruce-moose" belt, named for two prominent resident species.

• The southern pine forests cover much of the southeastern United States. In addition to conifers, oaks and other broadleaf trees are found in this more temperate zone. In areas with frequent forest fires, southern pines dominate. The pitchy bark of these trees scorches, but does not burn, protecting the cells in the sapwood beneath it. Fires clear the land. Pine seedlings that germinate after a fire grow well on the unshaded land.

The deciduous forest is a biome characterized by the presence of trees that loose their leaves in the fall. Deciduous forests stretch across the eastern United States, much of Europe, and parts of Asia, South America, Africa, and Australia. These regions have pronounced seasons, with precipitation evenly distributed throughout the year. The moderate rainfall and rich soil in this biome support vast numbers of plant and animal species.

Deciduous trees have broad, thin leaves with large surface area that permits maximum light absorption. Dominant species include birches, beeches, maples, oaks, hickories, sycamores, elms, willows, and cottonwoods. White-tailed deer, foxes, raccoons, and squirrels are typical mammals. Black bears live in some less populated regions. Some animals of the deciduous forest biome hibernate during the cold winters. Others, like hundreds of bird species such as warblers, spend the warm months in the deciduous forest and migrate to warmer climates in the winter. About one-fourth of the bird species that live in the deciduous forest, including the cardinal and bluejay, remain in the forest throughout the winter.

The grassland is a biome dominated by grasses. This biome covers about one-fourth of the land surface of the earth. Grassland areas vary greatly in their temperature range. They occur at about the same latitude as deciduous forests, but do not receive enough rainfall to support trees. Grasslands are known by various names in different regions of the world - prairie in North America, steppes in Asia, pampas in South America, and veldt in South Africa. The savanna is a grassland with scattered trees found in tropical and subtropical areas.

Some grasslands produce much food and support large numbers of animals. Dominant grazing mammals include bison and antelope in North America; antelope, elephants, and giraffes in Africa; and kangaroos in Australia. In South America the rhea, a huge flightless bird similar to the ostrich, is a major grazing animal. Billions of grass-eating insects also inhabit this biome, including numerous species of grasshoppers. Grasses can survive not only the grazing of animals but also the occasional fires that sweep across the plains.

Deserts are dry areas where rainfall averages less than 25 cm per year. Rain may fall on Africa’s Sahara desert only once every few years. Yet most desserts are not barren, and harbor many species of plants and animals. Many deserts are not hot year round. In the desert of Idaho and Northern Nevada, winter temperatures often plunge below freezing.

Organisms are adapted to the desert climates. Some desert plants absorb water through deep root systems, while cactuses and other succulents have shallow, diffuse roots. The saguaro cactus of Arizona and Mexico stores water and carries out photosynthesis in thickened stems and branches. A single saguaro can take up and store as much as a ton of water. A thick, waxy cuticle covering the stem helps prevent water loss. The leaves of the saguaro have evolved into sharp protective spines, an adaptation that protect against thirsty predators.

Within a few days or even hours of the infrequent rains, a desert becomes awash with color. Plants have little time to exploit the sudden moisture for photosynthesis and cell growth. Thus they are adapted to quick growth, flowering, and seed production.

Like plants, desert animals are also adapted to their environment. The camel absorbs water from food and produces dung so dry that it can be used to fuel a fire hours after it is excreted. Many dessert animals also show behavioral or physiological adaptations. For instance, the Kalahari ground squirrel uses its bushy tail as an umbrella, holding it over its body for shade.

There are two types of rain forest biomes - the tropical rain forest and the temperate rain forest. The tropical rain forest biome is found near the equator where rainfall and sunlight abound. These rain forests may get as much rain as some grasslands do in a year. One small area may support 100 species of plants, all of which compete for sunlight. Thus evolution has resulted in a distinct stratification of vegetation in rain forests. The tallest trees, which reach heights of 30 to 45 m, form the canopy. Lower levels of growth make up the understory. The bottom vegetative layer is the forest floor, also called the ground layer. Though you may think of the tropical rain forest as an impenetrable jungle, much of the forest is surprisingly cool and free of vegetation since little sunlight reaches it. The very dense growth known as jungle is actually a specific kind of community found only along riverbanks where sunlight breaks through to the forest floor.

Animal life is also rich and diverse, with hundreds of thousands of insect species; colorful birds such as parrots and toucans; apes, monkeys, and predatory cats in South America; and the clouded leopard in Asia. Animals of the tropical rain forest inhabit various levels of the forest. Some are adapted to tree-dwelling life. Primates, for example, use their hands and tail to grasp branches and vines. Stereoscopic vision improves their ability to judge distances. Some animals, such as the flying lizard, glide from tree to tree. Brilliant plumage helps distinguish a tropical bird from its thousands of competitors.

Moderate temperatures and high humidity characterize the temperate rain forest. This biome extends along the west coast of North America from central California to southern Alaska. Plant life includes conifers such as the redwood and the Sitka spruce. Unlike mammals of the tropical rain forest, deer, elk, rodents, and most other temperate rain forest species live on the ground.

Aquatic biomes occupy the majority of the earth’s surface. As with land biomes, organisms are evolutionarily adapted to the various abiotic and biotic factors. For example, algae are adapted to the intensity of sunlight that penetrates the water and determines the rate of photosynthesis.

The marine biome is the earth’s ocean and its associated areas. Ecologists have subdivided marine biomes into three areas: ocean, intertidal zones, and estuaries.

The ocean covers about 70 percent of the earth and has an average depth of 3.7 km. In some places the ocean is 11.5 km, about 7 miles deep. The water contains about 3.5 percent salt, mostly NaCl, a fact that profoundly effects the biology of organisms living there. Ecologists divide the ocean into two zones: the open ocean, or pelagic zone, and the ocean bottom, or benthic zone. The oceans further divided into photic zone, where light penetrates and the aphotic zone, where no light penetrates. The photic zone extends to a depth of about 200 m; photosynthesis occurs most efficiently above this depth.

The pelagic zone is divided into two sub-areas. The first subarea, the neritic zone, extends over the continental shelf. Since light penetrates these waters and strong currents called, called upwellings, carry minerals from the ocean bottom, the neritic zone supports the greatest amount of marine life. These waters are rich in plankton - the protozoa, algae, and invertebrates on which larger animals feed. Numerous fish, squid, sea turtles and other animals live in these waters.

The second subarea, the oceanic zone, the deep water of the open sea, is less populated. Even in photic areas, mineral levels are too low to support much life. Animals of the oceanic zone feed primarily on sinking plankton and dead organisms.

Organisms living below 2000 m are called abyssal organisms and are some of the strangest on earth. Deep-sea fish have slow metabolic rates and reduced skeletal systems that are adaptations to near-freezing temperatures and tremendous pressure. Their large jaws and teeth and expandable stomach can accommodate the rare prey that they can catch at these depths. Even more unusual organisms inhabit thermal vent communities. Near these areas seawater and sulfur gases seep through vents in the earth’s crust. These hot springs, rich in minerals and often exceeding 700ºC, support about 200 species of bacteria in the surrounding area. The bacteria are chemosynthetic - that is, they manufacture food with chemical energy, rather than light energy. Most convert sulfur compounds to useable energy. An assortment of unique clams, crabs, and worms feed on these bacteria.

Along ocean shores, the tides produce a rhythmic rise and fall of water in an area called the intertidal zone. Organisms in this zone are adapted to periodic exposure to air. Crabs prevent dehydration by burrowing into sand or mud. Clams, mussels and oysters filter plankton from the water during high tide, then retreat into their shells at low tide. At low tide, shorebirds descend on the beaches to snatch this abundant food. One bird, the oystercatcher, uses its long beak to pry open clam shells.

These animals are also adapted to the force of waves crashing onto the shore. Sea anemones cling to rocks with a muscular disk. Sea stars gain footing with aid of tube feet. The streamlined shape of most chitons and bivalves helps protect these mollusks from the pounding waves.

An estuary is a biome found throughout the world where freshwater rivers and streams flow into the sea. Examples of estuarine communities include bays, mud flats, and salt marshes. The shallow waters ensure plenty of light, and rivers deposit large amounts of mineral nutrients. However, the interplay between fresh and salt water causes great variation in temperature and salinity. In addition, like the intertidal zone, much of the estuary is exposed to the air during low tide.

Estuarine life is adapted to the frequent change. For example, some mangrove trees have special glands on their leaves that eliminate excess salt water taken up by the roots. Soft-shell clams lie buried in the mud, with only their long siphons protruding above the surface. The siphon filters plankton from the water at high tide and also detects predators at low tide, contracting whenever it senses danger.

Low levels of dissolved salts characterize the freshwater biome. The salt content of fresh water is about 0.005 percent, compared with 3.5 percent in oceans. The freshwater biome includes bodies of water as huge as Lake Superior and as small as half-acre pond. They include clear mountain streams in the Himalayas or the Rockies and slow, turbid rivers like the lower Mississippi or the Mekong River of southeast Asia.

Ecologists divide lakes and ponds into two categories. Eutrophic lakes are rich in organic matter and vegetation, making the waters relatively murky. Oligotrophic lakes contain little organic matter. The water is much clearer, and the bottom is usually sandy or rocky.

Fishes inhabit both eutrophic and oligotrophic lakes. Carp and catfish are typical of murky eutrophic waters. Largemouth bass and pike survive in more moderately eutrophic waters. Lake trout are found in oligotrophic lakes. Freshwater lakes and ponds also support mammals such as the otter and muskrat, and birds such as ducks and loons.

A river is a body of water that flows down a gradient, or slope, toward its mouth. A river can be as short as a few kilometers or as long as the Nile, which runs from eats Africa to the Mediterranean, a distance of 6738 km.

Gradient is a key abiotic factor in river. Water flows swiftly down steep gradients, and organisms here are adapted to withstand powerful currents. These include the larvae of caddis flies and the nymphs of mayflies, stoneflies, and dobson flies, which cling to the rocky bottom. Brook trout and other fishes are strong enough to face upstream while feeding on drifting invertebrates. Slow-moving rivers and their backwaters are richer in nutrients than fast waters are and therefore support a greater diversity of life. Rooted plants and the fishes that feed on them are adapted to the weak currents.

1. Biosphere

2. Realm - environmentally different parts of the world

3. Biome (a smaller part of realm) - that is created by factors such as : (1. precipitation, 2. land forms, 3. elevation, 4. latitude )

Salt Lake Biomes:

1. grassland

2. shrubs

3. deciduous forest

4.Aspens

5. Pine, spruce, etc ...

6. Trees get shorter, timberline

7. Tundra

10,000 feet is the timberline in Salt Lake City

going up is the same as going toward the pole, temperatures fall and with them change the biomes

4. Ecosystem - an area within a biome

5. Community - biology classroom ( with aquarium representing pond, plants representing forests, and students animals)

6. Population - a group of organisms of the same species

7. Organisms - (predator, producer, etc ..)

8. Niches - the way of a life of species. An organism’s niche includes its habitat, feeding habits, reproductive behavior and all aspects of its biology.

Ecology has a great impact on me. If the ecology was not studied, then the biomes would be wiped out. I would have less to eat and I would be hungry as would everybody else. There might be less oxygen in the air which would bring my life-span down due to the lack of grasslands and forests which produce oxygen. I would not be able to go into the nature and hunt for animals if there were no there and if there was no nature then I would not be able to go to the nature at all. Ecology has that great impact on me. If it were not for ecology then I would be living in a polluted valley and my life-span would also be shorter. Ecology in a way lengthens my life since it is the study of the interaction between the environment and the organisms which would be me.

2. Explain the concept of ecological succession. Describe the succession of plants and animals in different areas.

1. beaches
2. bare rock
3. receding glacier
4. alpine lake
5. Forest fire in Yellowstone
6. Clear cutting a forest
7. Fires put out in Utah
8. Control of fires in Long leaf pine forests

Just as biologists can often predict the periodic responses of organisms, they can also often predict specific patterns of change in plant and animal populations. The gradual, sequential replacement of populations in an area is called succession.

The table above illustrates the process of succession. The grasses shown are the pioneer species, or the first species to colonize a new habitat. All the pioneer species in an area make up a pioneer community. Each set of species in the community changes the environment in ways that ultimately make it unfavorable for the survival and reproduction of those species. Yet these changes allow other species to survive and reproduce. As a result the pioneer community will be replaced by a new community, which will later be replaced by another. Each intermediate community that arises through thus process is called a seral community. The repeated replacement of seral communities eventually leads to the establishment of a climax community, a community that will remain stable as long as the area is undisturbed.

The soil, climate, and other abiotic factors in a region determine the organisms that will make up a climax community. The forest in the table is a typical climax community in temperate areas of the eastern United States.

Primary succession is the sequential replacement of populations in an area that has not previously supported life, such as bare rock or a sand dune. The transformation of a barren environment into a climax community may require a thousand years or more. When glaciers retreated from eastern Canada about 12,000 years ago, they left a huge stretch of barren bedrock from which all the soil had been scraped. This geologic formation, called the Canadian Shield, was inhospitable to plants and to most animals.

Succession on bare rocks is primary succession. In the Galapagos Islands primary succession also occurred on new islands form volcanic eruptions.

Secondary succession is the sequential replacement of populations in disrupted habitats that have not been totally stripped of soil and vegetation. The disruption may stem from a natural disaster, such as a forest fire or volcanic eruption, or from human activity, such as farming, logging, or mining. After a forest fire, for example, succession might follow the pattern in the table above.

Old field succession is the replacement of populations in abandoned farm fields. It commonly takes about 100 years to produce a stable community of trees, such as beech and maple, in an old field. Secondary succession in an abandoned field in the eastern United States begins with annual grasses, mustards, and dandelions. The succession proceeds with perennial grasses and shrubs, continues wit trees such as aspen and dogwoods, and ends with a climax deciduous forest of beech and maples.

In many area environmental conditions are such that a true climax community never forms. For example, the natural climax community in many grassland biomes would be a forest, but periodic fires prevent forests from developing These grasslands are celled fire-controlled climax communities.

Succession will depend on the 4 aspects of physical environment. These aspects determine what type of biome there will be and what will the climax community become.

1. Precipitation- makes a difference whether it is a forest, grassland, desert, etc. Precipitation determines the environment. Because of the precipitation, we have a semi-arid climate in Utah and there are the desserts
2. Latitude- the farther north you go, it is as if you were going higher in elevation. Alaska contains a tundra for this reason. There are Alpine’s in Utah at 10,000 feet but if you were to go to Colombia, you would find them there at 24,000-25,000 feet.
3. Elevation- the higher the elevation, the colder it gets and there is less o oxygen. Elevation determines the type of species of plants that live there, which in turn determines the species of animals. Elevation increase would be ecological succession.
4. Landform- If you increase the amount of area, you increase the amount you can do. Grass produces more oxygen than trees on a land. Landform is different for different biomes such as a mountain where water runs of or a lake where water runs down to. Certain landforms support certain biomes

1. In beach succession, it starts with a body of water which brings sand in and forms a beach. The middle beach is where the water does not reach and it is dry, this is where ecological succession occurs. The pioneering grasses start to get a hold of the beach. Only the best plants get on the beach. Then the dunes form and soon enough the grasshopper, and lizard start to find protection on the beach. Roots, leaves, and animals decay on the beach and form Humus, an organic material. Then the Cottonwood stage starts to begin. The plants start to create a new climate making new forms of life possible. Each stage is characterized by different animals called index animals. The cherry tree is a characteristic of the cottonwood stage. The pine trees are replaced by oak. The shade provides the environment for a new environment. When a tree dies, the event of succession begins. The humus and moisture then increase the ant population. Fungus plants start to thrive eventually. There are many varieties of beetles there, and such carnivores as the fox snake. The Oak forest provides food and shelter for the animals, as the shade and humidity increase growth. Oak is then replaced by beeches and maples. This is the climax community which remains the same over time. Fire can disturb the climax community. The pioneer plants play an important role in ecological succession at the very beginning of it or you would not be able to start succession. Different climate and different soil has different successions.
2. The first colonists on bare rock are algae, which are the pioneer species. Later different types of algae replace the first algae. Eventually lichens colonize the bare rock. Acids in the lichens leach out nutrient minerals from the rock. Eventually the necromass, or dead organic matter, from the lichens and minerals from the rock begins to form a thin layer of soil in which few herbaceous plants can grow. These plants the die, building the thickness of the soil by decaying and forming humus. Soon shrubs are able to grow followed by trees. Then other trees can cling to the soil which can be only a few inches deep. Ecological succession can also happen on a newly formed volcano, like Krakatoa in the 1920’s. Rainfall weathers the volcanic material into tiny material particles. Marine organisms and sea birds are the first to reach the islands. Bird droppings (guano) provide a habitat for bacterial spores deposited by the wind. In time other organisms arrive, blown by winds or carried onto the island by ocean currents. Some of these organisms thrive and establish new communities and as new species arrive, new seral communities are formed and the process of primary succession is continued.
3. A receding glacier is continually being exposed as the face of the glacier moves back. So imagine that you have traveled to the glacier that dominates the head of Glacier Bay, Alaska. The face of the glacier has been melted and receding for the last 200 years, and has moved back some 100km (62 miles). A walk across the ground exposed by the receding glacier is in sense a walk through time—the farther one walks away from the glacier face, the longer the land has been exposed. The most recently exposed area, at the face of the receding wall of ice, are piles of bare rock and gravel that lack the usable nitrogen essential to plant and animal life. For about 10 yeas the piles remain devoid of life. The seeds and spores of the first pioneering plants to colonize this barren landscape – mosses, fireweed, willows, cottonwood, and Dryas, a sturdy plant with clumps about 30 cm(1 feet) across—are carried in by the wind. At first all of these plants grow close to the ground, severely stunned by mineral deficiency. But Dryas has myccorrhizae on its roots that supply the nutrients it needs. After a few years, Dryas uses this competitive advantage to crowd out the other plants. What remains is a dense mat of Dryas. After about 10 years, seeds of alder arrive, blown in from distant sites. It is a matter of chance when they come, but inevitably some finally make their way to the site, landing on the mat of Dryas. Alder roots have nitrogen-fixing nodules, so they are able to grow even more rapidly than Dryas. Dead leaves and fallen branches from the alder trees add even more usable nitrogen to the soil, in time allowing the willows and cottonwood to invade and grow with vigor. After about 30 years, there are dense thickets of alder, willow, and cottonwood that shade and eventually kill the pioneering Dryas. The alder thicket matures until, some 80 years after the glacier first exposed the land, Sitka spruce invades the thickets. Spruce trees cannot fix nitrogen, but the nitrogen released by the alders enables them to form a dense forest that shades out the alders and willows. In the competition for light needed to carry out photosynthesis, the alders lose, just as Dryas did before them. After the spruce forest is established, hemlock trees arrive at the site. They are very shade-tolerant and have a root system that competes well against spruce for soil nitrogen. Hemlock trees soon become dominant in the forest. This last community of spruce and hemlock proves to be a very stable ecosystem—a climax community. Similar communities are found over broad areas of Alaska, Canada, and Russia. Climax communities are not permanent creations of nature, fixed and unchangeable. As local climates change, the distribution of particular species within the forest ecosystem may change too. Whatever these fluctuations, it remains true that climax communities are among the most stable of ecosystems, remaining relatively unchanged for long periods of time.
4. Lakes undergo succession that slowly transforms them from crystal clear bodies of water into dry land. A tiny prairie pond may be transformed into dry land in a few dozen years. Changes in the largest lakes take place over millions of years. The process of lake succession, involves eutrophication. Eutrophication is the increase in nutrients in the environment. Early in its existence a lake may be so low in nutrients that relatively few organisms can survive in it. Such a lake is termed oligotrophic. As nutrients such as nitrogen and phosphorous flow into the lake from surrounding land and from the atmosphere, the biomass in the lake gradually increases and the lake becomes murkier. Meanwhile, sediment accumulated around the roots of the cattails and rushes that have begun growing along the shore of the lake. Also, an increasing number of aquatic arthropods and fish begin to populate the lake. In time the accumulated soil from the surrounding watershed along with the necromass begins to fill in the lake. The lake has then gone from an oligotrophic condition to a eutrophic condition, one in which there are many nutrients. Eventually the lake may become so full of rich sediment that it becomes a marsh, then a swamp, and finally dry land—which may then proceed through successional stages to become a dense forest.
5. The Yellowstone fire was a form of ecological succession. The fires burnt trees to disrupt ecological succession since the trees were a climax community. The result was then a seral community, which was the grasslands. The fire controls the climax community and every so often it makes a grassland out of it. Trees are not important to animals and produce less oxygen than grass. The grazing animals need grass lands and animals need more space, which trees lessen. Yellowstone should have been allowed to let burn since that was the right thing, and 165,000,000 dollars was wasted on trying to extinguish it which still did not work. At places where they took bulldozers and pushed in the landscape, ecological succession will take the longest and it damaged the environment. The Yellowstone fires were important for the seral communities. The fires maintain seral communities, which are as mentioned above the most important for grazing animals. The seral communities are the biomes leading up to the climax community, the forest.
6. Clear cutting a forest removes all the trees from the forest and it burns the remains of it, You eventually end up with bare rock and dirt. Fallen logs are good for succession since they produce humus or soil which is a vital component for ecological succession in all cases whether it be beach succession or succession in receding glaciers. When you clear cut you get rid of all of it and ecological succession has to start all over at the pioneering plants, and not the seral communities. And let’s just say your going to be waiting for a long time before you have trees in the forest again, maybe decades.
7. The climax community in the shrub and grassland biomes in Utah would be shrubs. Fires in Utah maintain the seral community and since the deer eat the shrubbery on the climax community. Because of this, the fires make sure that there is not an overpopulation of deer and deer are not in that biome if fires sweep through regularly and eliminate the shrubbery. Because of the fires that are put out, there is an increased number of deer. Also there are less grasslands which are more important for grazing animals such as Bison. If there are only shrubs, then the land cannot support Bison, and they go to, well you know what I mean. The fires need to be let burn to as in Yellowstone occasionally to eliminate shrubs and overpopulation of deer.
8. Turpentine is token form long leaf pine forests. Long leaf pine forests are climax community to jack pines and the fires there have to be stopped. You allow the fires to go through if you want to have the jack pines. In this forest, fire is a limiting factor. If you want certain things, then the fires can maintain it. Allow only fires that are cause by nature to burn through the forest to maintain the proper number of fires within the biome.