Interesting course indeed, fascinating I really enjoy it. fabulous to study nature
Why there is no text Version? it is more easy to make notes.
Hi!!! I can't answer the question.... How can I answer the questions?
It's a really great ecology course because you can integrated all fundamental concepts and improve your hability of understanding ecology. I think so it's a really wonderful discipline but its really fussy. Greeting to all members of ecology course!
Environmentalism can simply be considered as a social movement that mainly concerns for environmental conservation and improving the state of the environment. Green color often represents environmentalism and environmental concerns. In simple words, it is just a social movement that strives to persuade or induce the political process by lobbying, activism as well as education for protecting natural resources & eco-systems
Hello, i can't downloadable pdf, why.??
How i can answer the questions.??
I love this course, thanks a lot.!!
its ok more informative that when i did it in college
¿como contesto las preguntas ?
The Scope of Ecology
Ecology is the study of the interactions of living organisms with their environment.
One core goal of ecology is to understand the distribution and abundance of living things in the physical environment. Attainment of this goal requires the integration of scientific disciplines inside and outside of biology, such as biochemistry, physiology, evolution, biodiversity, molecular biology, geology, and climatology. Some ecological research also applies aspects of chemistry and physics, and frequently uses mathematical models.
When a discipline such as biology is studied, it is often helpful to subdivide it into smaller, related areas. Within the discipline of ecology, researchers work at four specific levels, sometimes discretely and sometimes with overlap:
Cell biologists interested in cell signaling need to understand the chemistry of the signal molecules (which are usually proteins) as well as the result of cell signaling.
Ecologists interested in the factors that influence the survival of an endangered species might use mathematical models to predict how current conservation efforts affect endangered organisms.
To produce a sound set of management options, a conservation biologist needs to collect accurate data, including current population size, factors affecting reproduction (like physiology and behavior), habitat requirements (such as plants and soils), and potential human influences on the endangered population and its habitat (which might be derived through studies in sociology and urban ecology).
Researchers studying ecology at the organismal level are interested in the adaptations that enable individuals to live in specific habitats. These adaptations can be morphological, physiological, and behavioral.
For instance, the Karner blue butterfly (Lycaeides melissa samuelis) is considered a specialist because the females preferentially oviposit (that is, lay eggs) on wild lupine. This preferential adaptation means that the Karner blue butterfly is highly dependent on the presence of wild lupine plants for its continued survival.
After hatching, the larval caterpillars emerge
and spend four to six weeks feeding solely
on wild lupine. The caterpillars pupate
(undergo metamorphosis) and emerge as
butterflies after about four weeks.
The adult butterflies feed on the nectar of
flowers of wild lupine and other plant species.
A researcher interested in studying Karner blue butterflies at the organismal level might, in addition to asking questions about egg laying, ask questions about the butterflies’ preferred temperature (a physiological question) or the behavior of the caterpillars when they are at different larval stages (a behavioral question).
A population is a group of interbreeding organisms that are members of the same species living in the same area at the same time, (Organisms that are all members of the same species are called conspecifics.)
A population is identified, in part, by where it lives, and its area of population may have natural or artificial boundaries: natural boundaries might be rivers, mountains, or deserts, while examples of artificial boundaries include manmade structures, or roads.
The study of population ecology focuses on the number of individuals in an area and how and why population size changes over time.
Wild Lupine Example
Population ecologists are particularly interested in counting the Karner blue butterfly, because in the US it is classified as federally endangered. However, the distribution and density of this species is highly influenced by the distribution and abundance of wild lupine. Researchers might ask questions about the factors leading to the decline of wild lupine and how these affect Karner blue butterflies.
For example, ecologists know that wild lupine thrives in open areas where trees and shrubs are largely absent. In natural settings, intermittent wildfires regularly remove trees and shrubs, helping to maintain the open areas that wild lupine requires.
Mathematical models can be used to understand how wildfire suppression by humans has led to the decline of this important plant for the Karner blue butterfly.
A biological community consists of the different species within an area and the interactions within and among these species.
Community ecologists are interested in the processes driving these interactions and their consequences. Questions often focus on competition among members of the same species for a limited resource. Ecologists also study interactions among various species; members of different species are called heterospecific. Examples of heterospecific interactions include predation, parasitism, herbivory, competition, and pollination. These interactions can have regulating effects on population sizes and can impact ecological and evolutionary processes affecting diversity.
Karner blue butterfly larvae form mutualistic relationships with ants. Mutualism is a form of a long-term relationship that has co-evolved between two species and from which each species benefits.
For mutualism to exist between individual organisms, each species must receive some benefit from the other as a consequence of the relationship. Researchers have shown that there is an increase in the probability of survival when Karner blue butterfly larvae (caterpillars) are tended by ants. This might be because the larvae spend less time in each life stage when tended by ants, which provides an advantage for the larvae.
Meanwhile, the Karner blue butterfly larvae secrete a carbohydrate-rich substance that is an important energy source for the ants. Both the Karner blue larvae and the ants benefit from their interaction.
This is an extension of organismal, population, and community ecology. The ecosystem is composed of all the biotic components (living things) in an area along with the abiotic components (non-living things) of that area.
Some of the abiotic components include air, water, and soil. Ecosystem biologists ask questions about how nutrients and energy are stored and how they move among organisms and the surrounding atmosphere, soil, and water.
The Karner blue butterflies and the wild lupine live in an oak-pine barren habitat. This habitat is characterized by natural disturbance and nutrient-poor soils that are low in nitrogen. The availability of nutrients is an important factor in the distribution of the plants that live in this habitat. Researchers interested in ecosystem ecology could ask questions about the importance of limited resources and the movement of resources, such as nutrients, though the biotic and abiotic portions of the ecosystem.
Biogeography is the study of the geographic distribution of living things and the abiotic factors that affect their distribution.
Species distribution patterns are based on biotic and abiotic factors and their influences during the very long periods of time required for species evolution.
Some of the most distinctive assemblages of plants and animals occur in regions that have been physically separated for millions of years by geographic barriers, such as Australia.
If you were to begin a journey at the equator and walk north, you would notice gradual changes in plant communities.
At the beginning you would see tropical wet forests with broad-leaved evergreen trees, Further north, you would see these broad-leaved evergreen plants give rise to seasonally dry forests with scattered trees and you would begin to notice changes in temperature and moisture. At about 30 degrees north, these forests would give way to deserts, which are characterized by high daytime temperatures with low precipitation.
Moving farther north, you would see that deserts are replaced by grasslands or prairies. Eventually, these are replaced by deciduous temperate forests which give way to the boreal forests found in the subarctic, finally, you would reach the Arctic tundra.
This trek north reveals gradual changes in both climate and the types of organisms that have adapted to environmental factors found at different latitudes.
Energy from the sun is captured by green plants, algae, cyanobacteria, and photosynthetic protists.
These organisms convert solar energy into the chemical energy needed by all living things. Light availability can be an important force directly affecting the evolution of adaptations in photosynthesizers.
In aquatic ecosystems, the availability of light may be limited because sunlight is absorbed by water, plants, suspended particles, and resident microorganisms.
Toward the bottom of a lake, pond, or ocean, there is a zone that light cannot reach. Photosynthesis cannot take place there, and, as a result, a number of adaptations have evolved that enable living things to survive. For instance, aquatic plants have photosynthetic tissue near the surface of the water; think of the broad, floating leaves of a water lily-water lilies cannot survive without light. In environments such as hydrothermal vents, some bacteria extract energy from inorganic chemicals because there is no light for photosynthesis.
The availability of nutrients in aquatic systems is also an important aspect of energy or photosynthesis. Many organisms sink to the bottom of the ocean when they die in the open water; when this occurs, the energy found in that living organism is sequestered for some time unless ocean upwelling occurs.
Ocean upwelling is the rising of deep ocean waters
that occurs when prevailing winds blow along
surface waters near a coastline. As the wind
pushes ocean waters offshore, water from the
bottom of the ocean moves up to replace this water.
As a result, the nutrients once contained in dead
organisms become available for reuse by other
In freshwater systems, the recycling of nutrients occurs in response to air temperature changes. The spring and fall turnover is a seasonal process that recycles nutrients and oxygen from the bottom of a freshwater ecosystem to the top of a body of water. These turnovers are caused by the formation of a thermocline: a layer of water with a temperature that is different from that of the surrounding layers. In wintertime, the surface of lakes in many northern regions is frozen. However, the water under the ice is slightly warmer, at 4 °C to 5 °C.
The deepest water is oxygen poor because the decomposition of organic material at the bottom of the lake uses up available oxygen that cannot be replaced by means of oxygen diffusion due to the surface ice layer.
As air temperatures drop in the fall, the temperature of the lake water cools to 4 °C; therefore, this causes fall turnover as the heavy cold water sinks and displaces the water at the bottom.
The oxygen-rich water at the surface of the lake
then moves to the bottom of the lake, while the
nutrients at the bottom of the lake rise to the surface.
During the winter, the oxygen at the bottom of the
lake is used by decomposers and other organisms
requiring oxygen, such as fish.
Temperature exerts an important influence on living things because few living things can survive at temperatures below 0 °C due to metabolic constraints.
It is also rare for living things to survive at temperatures exceeding 45 °C; this is a reflection of evolutionary response to typical temperatures. Enzymes are most efficient within a narrow and specific range of temperatures; enzyme degradation can occur at higher temperatures. Therefore, organisms either must maintain an internal temperature or they must inhabit an environment that will keep the body within a temperature range that supports metabolism.
Temperature can limit the distribution of living things. Animals faced with temperature fluctuations may respond with adaptations, such as migration, in order to survive.
Migration, the movement from one place to another, is an adaptation found in many animals, including many that inhabit seasonally cold climates. Migration solves problems related to temperature, locating food, and finding a mate. In migration, for instance, the Arctic Tern (Sterna paradisaea) makes a 40,000 km round trip flight each year between its feeding grounds in the southern hemisphere and its breeding grounds in the Arctic Ocean.
Not all animals that can migrate do so: migration carries risk and a high energy cost.
Some animals hibernate or estivate to survive hostile temperatures. Hibernation enables animals to survive cold conditions, and estivation allows animals to survive the hostile conditions of a hot, dry climate.
Animals that hibernate or estivate enter a state known as torpor: a condition in which their metabolic rate is significantly lowered. This enables the animal to wait until its environment better supports its survival.
Some amphibians, such as the wood frog (Rana sylvatica), have an antifreeze-like chemical in their cells, which retains the cells’ integrity and prevents the frogs cells’
Water is required by all living things because it is critical for cellular processes. Since terrestrial organisms lose water to the environment by simple diffusion, they have evolved many adaptations to retain water.
Plants have a number of interesting features on their leaves, such as leaf hairs and a waxy cuticle, that serve to decrease the rate of water loss via transpiration.
Freshwater organisms are surrounded by water and are constantly in danger of having water rush into their cells because of osmosis. Many adaptations of organisms living in freshwater environments have evolved to ensure that solute concentrations in their bodies remain within appropriate levels.
Marine organisms are surrounded by water with a higher solute concentration than the organism, these organisms have morphological and physiological adaptations to retain water and release solutes into the environment.
Inorganic nutrients, such as nitrogen and phosphorus, are important in the distribution and the abundance of living things.
Plants obtain these inorganic nutrients from the soil when water moves into the plant through the roots. Therefore, soil structure (particle size of soil components), soil pH, and soil nutrient content play an important role in the distribution of plants. Animals obtain inorganic nutrients from the food they consume.
Therefore, animal distributions are related to the distribution of what they eat. In some cases, animals will follow their food resource as it moves through the environment.
Some abiotic factors, such as oxygen, are important in
aquatic ecosystems as well as terrestrial environments.
Terrestrial animals obtain oxygen from the air they breathe.
Oxygen availability can be an issue for organisms living at
very high elevations, however, where there are fewer
molecules of oxygen in the air. In aquatic systems, the
concentration of dissolved oxygen is related to water
temperature and the speed at which the water moves.
Cold water has more dissolved oxygen than warmer water. In addition, salinity, current, and tide can be important abiotic factors in aquatic ecosystems.
Wind can be an important abiotic factor because it influences the rate of evaporation and transpiration. The physical force of wind is also important because it can move soil, water, or other abiotic factors, as well as an ecosystem’s organisms. Fire is another terrestrial factor that can be an important
agent of disturbance in terrestrial ecosystems. Some
organisms are adapted to fire and, thus, require the
high heat associated with fire to complete a part of
their life cycle.
For example, the jack pine, a coniferous tree-requires heat from fire for its seed cones to open.
abiotic nonliving components of the environment
algal bloom rapid increase of algae in an aquatic system
aphotic zone part of the ocean where no light penetrates
benthic realm (benthic zone) part of the ocean that extends along the ocean bottom from the shoreline to the deepest parts of the ocean floor
biogeography study of the geographic distribution of living things and the abiotic factors that affect their distribution
biome ecological community of plants, animals, and other organisms that is adapted to a characteristic set of environmental conditions
biotic living components of the environment
canopy branches and foliage of trees that form a layer of overhead coverage in a forest
cryptofauna invertebrates found within the calcium carbonate substrate of coral reefs
ecology study of interaction between living things and their environment
ecosystem services human benefits and services provided by natural ecosystems
emergent vegetation wetland plants that are rooted in the soil but have portions of leaves, stems, and flowers extending above the water’s surface
endemic species found only in a specific geographic area that is usually restricted in size fall and spring turnover seasonal process that recycles nutrients and oxygen from the bottom of a freshwater ecosystem to the top
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