Biogeochemical Cycle or Nutrient cycle is a pathway by which a chemical element or molecule moves through both biotic (biosphere) and abiotic (lithosphere, atmosphere, and hydrosphere) compartments of Earth.
the element is recycled, although in some cycles there may be places (called reservoirs) where the element is accumulated orheld for a long period of time (such as an ocean or lake for water). Water, for
example, is always recycled through the water cycle, as shown in the diagram.The water undergoes evaporation, condensation, and precipitation,falling back to Earth clean and fresh. Elements, chemical compounds, and otherforms of matter are passed from one organism to another and from one part of the biosphere to another through the biogeochemical cycles.
All the nutrients—such as carbon, nitrogen, oxygen, phosphorus, and sulfur—used in ecosystems by living organisms operate on a closed system; therefore, these chemicals are recycled instead of being lost and replenished constantly such as in an open system.
Open System; the sun constantly gives the planet energy in the form of light while it is eventually used and lost in
the form of heat throughout the trophic levels of a food web. Carbon is used to make carbohydrates, fats, and proteins, the major sources of food energy.
The most well-known and important biogeochemical cycles, for example, include the carbon cycle, the nitrogen cycle, the oxygen cycle, the phosphorus cycle, the sulfur cycle, and the water cycle
Biogeochemical cycles always involve equilibrium states: a balance in the cycling of the element between compartments. However, overall balance may involve compartments distributed on a global scale. As
biogeochemical cycles describe the movements of substances on the entire globe, The study of these is inherently multidiciplinary. The carbon cycle may be related to research in ecology and atmospheric sciences. Biochemical dynamics would also be related to the fields of geology and pedology (soil study).
Biodiversity is the variation of life forms within a given ecosystem, biome, or for the entire Earth. Biodiversity is often used as a measure of the health of biological systems. The biodiversity found on Earth today consists of many millions of distinct biological species, which is the product of nearly 3.5
billion years of evolution. "totality of genes, species, and ecosystems of a region".
Biodiversity also supports a number of natural ecosystem processes and services . Some ecosystem services that benefit society are air quality , climate (both global CO2 sequestration and local), water purification pollination, and prevention of erosion.
Cybernetics is the interdisciplinary study of the structure of regulatory systems.Cybernetics is closely related to control theory and systems theory. Both in its origins and in its evolution in the second-half of the 20th century, cybernetics is equally applicable to physical and social (that is, language-based) systems. Cybernetics
is preeminent when the system under scrutiny is involved in a closed signal loop, where action by the system in an environment causes some change in the environment and that change is manifest to the system via information, or
feedback, that causes the system to adapt to new conditions: the system changes its behaviour. This "circular causal" relationship is necessary and sufficient for a cybernetic perspective.
Contemporary cybernetics began as an interdisciplinary study connecting the fields of control systems,
electrical network theory, mechanical engineering, logic modeling,evolutionary biology, neuroscience, anthropology, and psychology in the 1940s, often attributed to the Macy Conferences.
Other fields of study which have influenced or been influenced by cybernetics include game theory, system theory (a mathematical counterpart to cybernetics), sociology, psychology (especially neuropsychology, behavioral psychology, cognitive psychology), philosophy, and architecture
Ecological succession, a fundamental concept in ecology, refers to more or less predictable and orderly changes in the composition or structure of an ecological community. Succession may be initiated either by formation of new, unoccupied habitat (e.g.,a lava flow or a severe landslide) or by some form of disturbance (e.g. fire, severe windthrow, logging) of an existing community. Succession that begins in areas where no soil is initially present is called primary succession, whereas succession that begins in areas where soil is already present is called secondary succession.
Clement's theory of succession/Mechanisms of succession
F.E.Clement (1916) developed a descriptive theory of succession and advanced it as a general ecological concept. His theory of succession had a powerful influence on ecological thought. Clement's concept is usually termed classical ecological theory. According to Clement, succession is a process involving several phases:
1. Nudation: Succession begins with the development of a bare site,
called Nudation (disturbance).
2. Migration: It refers to arrival of propagules.
3. Ecesis: It involves establishment and initial growth ofvegetation.
4. Competition: As vegetation became well established, grew, and spread,various species began to compete for space, light and nutrients. This phase iscalled competition.
5. Reaction: During this phase autogenic changes affect the habitatresulting in replacement of one plant community by another.
6. Stabilization: Reaction phase leads to development of a climax community. Ecological succession was formerly seen as having astable end-stage called the climax (see Frederic Clements), sometimes referred to as
the 'potential vegetation' of a site, shaped primarily by the local climate.This idea has been largely abandoned by modern ecologists in favor ofnonequilibrium ideas of how ecosystems function. Most natural ecosystems
experience disturbance at a rate that makes a "climax" communityunattainable. Climate change often occurs at a rate and frequency sufficient to prevent arrival at a climax state. Additions to available species pools through range expansions and introductions can also continually reshape communities.
The Animal Kingdom
The animal kingdom is huge. It contains more than a million species. Most are small - much smaller than your eyes can see. But afew, like elephants and whales, are giants. All animals have one thing in common. They cannot make food. They need to eat plants or other animals to survive. All animals also need oxygen to survive. Animals include everything from ants, spiders, and worms to fish,lizards, bears,dogs, birds,cats, and humans.
Those with Backbones and Those Without
When you think of living things, you probably think first of animals. Animals have their own Kingdom, Animalia, which is a scientific classification. Because the animal kingdom is so big, scientists begin by dividing it into two general groups, vertebrates and invertebrates. Vertebrates are animals with backbones such as humans, horses, elephants, bears, birds, fish, and frogs. Invertebrates are animals without backbones such as butterflies, ants, clams, and worms.
Zebra lionfish have sharp venomous spines. This makes them powerful predators.
Humans have more in common with eagles, snakes, and rhinoceroses than you might think. This is because we’re
all vertebrates, and all vertebrates share a common design in the way they are built. Vertebrates all have a collection of bones or cartilage called the vertebral column, or backbone. They also have skeletons inside their bodies that protect their soft inner organs.
All vertebrate bodies are covered with skin. The skin may be smooth, rough, slimy, or scaly, but it's still skin. Vertebrate skin has a covering of hair, feathers, or scales. There are about 45,000 different kinds of vertebrates
living on Earth. Scientists have classified vertebrates into five smallergroups, based on characteristics they share. These groups are the mammals, birds, reptiles, amphibians, and fish.
Invertebrates A newly emerged red-stripe butterfly rests while its wings dry.
Animals without backbones are called invertebrates. Invertebrates are the largest group of animals. Scientists have identified nearly 1 million different species. Insects are one of the biggest groups. Many invertebrates have a hard or rigid outer covering. Beetles, for example, have a hard outer covering called an exoskeleton. Snails are covered by a hard shell.
Invertebrates that live in water, such as octopuses and sea anemones, are called aquatic invertebrates. Some aquatic invertebrates do not have a hard covering. They have a flexible skin wrapping their bodies. Aquatic
invertebrates range in size from plankton, which are too small to see without a microscope, to giant squid that grow to be over 20 m long!
The Champions of the Animal Kingdom
People are good at a lot of things, but if animals could enter the Olympics as one team they would probably win almost all the medals! Animals can outrun, outswim, and outjump all humans.
Young cheetahs learn to hunt by watching their mother. Later, they start taking part in the hunt. Cheetahs are the fastest land animal and can reach speeds of 113kph in short bursts.
Fastest Mammal on Land
Cheetahs can run up to 113 kph.
Fastest Mammal in Water
Dall porpoises can swim up to 56 kph.
Fastest Flying Bird
Peregrine falcons can dive toward the ground at more than 320 kph.
Fastest Flightless Bird
North African ostriches are the fastest birds on land. They can run at speeds
up to 72 kph. They are also the biggest bird. They can weigh 155 kg.
Sailfish can swim up to 109 kph.
The blue whale’s low-frequency pulses are as loud as 188 decibels. This is louder than a jet engine. A blue whale’s call can be detected more than 805 km away. On land, the loudest animals are howler monkeys.
Their howls can be heard 4.8 km away.
Arctic terns have the longest annual migration of any animal. In its life, the average Arctic tern will travel a distance equal to going to the Moon and back.
Arctic terns migrate to and from the Antarctic - about 35,405 km round trip - each year. Among mammals, gray whales and northern elephant seals are the migration champions. They travel up to 20,900 km round trip each year.
Female Anopheles mosquitoes, which carry and transmit malaria, play a role in the deaths of more than a million people each year.
Most Venomous Animal
A single sea wasp (a kind of jellyfish with 60 tentacles, each 4 m
long) has enough venom to kill 60 adult humans.
The rhinoceros beetle can lift 850 times its own weight.
Asian elephants are born after a gestation period of 19 to 22 months.
Blue whales are the largest mammals of all time and the largest living animal. Females grow to a length of about 27 m. They may weigh well over 100 metric tons. The heaviest blue whale weighed more than 190 metric tons. The longest ever measured was more than 33 m.
African elephant bulls are the heaviest land animal. Large males may weigh as much as 5,895kg.
Despite their power and size, elephants are vegetarians, or herbivores.
Largest Living Animal on Land
African elephants are the heaviest land animal. They are also the second tallest land animal. Large bulls (males) weigh more than 5,895 kg and are 3.5 m tall at the shoulder. Giraffes, which can grow to a height of 5 m,
are the tallest land animals. Large males weigh more than 1,800 kg.
Australia's stout infantfish, slightly smaller than the better-known dwarf goby, is less than 1 cm long.
Adult bee hummingbirds, found in Cuba, weigh about 2 g.
Adult bumblebee bats, which live in Thailand, weigh about 2 g.
In the 1770s, British explorer Captain James Cook presented a Madagascar radiated tortoise to the royal family of Tonga. The tortoise lived until 1965. It was at least 188 years old when it died! Several Galápagos tortoises have
lived past age 150.
amphibian - cold-blooded animal that hatches from an egg in the waterand lives on land as it grows up
reptile - cold-blooded, scaly animals
mammal - warm-blooded animals that have hair or fur and carry their babies in their womb
bird - warm-blooded animals that have feathers, lay eggs, and fly
insect - small animal that hatches from eggs and grows up to have sectioned bodies and jointed legs
fish - cold-blooded animals that live in water and have fins and gills
species - a category scientists use to group animals together that are alike
breed - to give birth
vertebrate - animal that has a backbone or spinal cord
backbone - spine made of bone in animals
invertebrate - animal that has no backbone or spinal cord
adapt - animals that change so that they can live in their habitat comfortably
coloration - markings and patterns on an animal
exoskeleton - hard outer structure such as a shell
burrow - a hole or tunnel dug in the ground by a small animal, such as a rabbit or mole
habitat - the area or environment where an animal normally lives
arachnid - invertebrate that has two body sections and eight legs and includes spiders, ticks, mites, and scorpions
arachnophobia - fear of spiders