NATURAL SCIENCE

Human interaction is a complex and diverse constituent. On earth there are a variety of ecosystems.

1. Ecosystem Structure
Judging from the composition and function, an ecosystem made up of the following components.
a. Component autotrof
(Auto = self and trophikos = provides meals).
Autotrophs are organisms that are able to provide / synthesize their own food in the form of organic matter from inorganic materials with the help of energy such as solar and chemical. Autotrof component serves as producer, for example, green plants.
b. Heterotrophic components
(Heteros = different, trophikos = food).
Heterotroph is an organism that utilizes organic materials such as food and material supplied by other organisms. Heterotrophs are classified as humans, animals, fungi, and microbes.
c. Materials nonliving (abiotic)
Nonliving material that is the physical and chemical components consisting of soil, water, air, sunlight. Nonliving material is medium or substrate where the continuity of life, or living environment.
d. Decomposers (decomposers)

Decomposers are heterotrophic organisms that decompose organic matter derived from dead organisms (complex organic material). Decomposing organisms absorb some decomposition and release of simple materials that can be reused by the manufacturer. Including decomposers are bacteria and fungi.
2. Types of Ecosystems
Broadly divided into ecosystems terrestrial ecosystems and aquatic ecosystems. Aquatic ecosystems distinguished on freshwater ecosystems and aquatic ecosystems Sea.
a. Terrestrial ecosystems
Terrestrial ecosystem is the ecosystem that the physical environment is land. Based on geographical location (latitude), terrestrial ecosystems can be divided into several biomes, which are as follows.
1. Desert biome
Some desert biome found in the tropics (along the back), which borders the meadow.
The characteristics of the desert biome is arid and low rainfall (25 cm / year). Slang day high temperature (can mendapai 45 ° C) so that evaporation is high, while the night temperature is very low (it can reach 0 ° C). The temperature difference between day and night is huge. Plant annuals contained in a small desert. In addition, in the desert found also chronic leafy plants like cactus thorns example, or no leaves and roots are long and has a network to store water. Animals that live in the desert, among others Rodentia, snakes, lizards, frogs, and scorpions.
2. Grassland biome
Biomes are located in the area extending from the tropics to the subtropics. Characteristics of rainfall is approximately 25-30 cm per year and irregular rains. Porosity (water absorption) tall and drainage (water flow) is fast. Existing plant consists of herb plants (herbs) and grasses that are both dependent on the moisture. Among other animals: bison, zebras, lions, wild dogs, wolves, elephants, giraffes, kangaroos, insects, rodents and snakes
3. Wet Forest Biomes
Wet Forest Biomes are in the tropics and subtropics.
Characteristics is 200-225 cm of rainfall per year. Relatively many species of trees, species differ from one another depending on geography. The main tree height between 20-40 m, tree branches and leafy tinngi to form a hood (canopy). In the rain forest microclimate changes (climate directly located around the organism). Hood area gets enough sunlight. Variations in temperature and high humidity / large; temperature throughout the day around 25 ° C. In the tropical rain forest plants often are distinctive, the liana (rattan), cacti and orchids as epiphytes. Among other animals, monkeys, birds, rhinos, wild boar, tiger, and owls.
4. Deciduous forest biome
Deciduous forest biome found in temperate regions,
Its features are evenly distributed rainfall throughout the year. There are in areas experiencing the four seasons (winter, spring, summer, and fall). Few tree species (10 s / d 20) and not too tight. Animals such as deer, bears, foxes, squirrels, woodpeckers, and rakoon (countryman mongoose).
5. Taiga biomes
Taiga biomes are in the Northern Hemisphere north and in the mountains of the tropics. Its features are low winter temperatures. Usually taiga forest is composed of a single species such as conifers, pines, dap like. Shrubs and plants little wet. Animals such as moose, black bear, ajag, and the birds that migrate south in the fall.
6. Tundra biome
There tundra biome hemisphere north in the arctic circle and is on a high mountain peaks. Plant growth in this area is only 60 days. Examples of dominant vegetation is Sphagnum, lichen, plants seeds annuals, timber plants are short, and grass. In general, the plant is able to adapt to the cold conditions.
Animals that live in this area was settled and no one came in the summer, all warm-blooded. Animals that live have thick hair or fur, for example muscox, reindeer, polar bears, and insects, especially mosquitoes and black flies.
b. Freshwater Ecosystems
The characteristics of freshwater ecosystems include temperature variations are not flashy, less light penetration, and are affected by climate and weather. Most kinds of plants are species of algae, while other seed plants. Almost all animal phyla found in fresh water. Organisms that live in fresh water generally have to adapt.
Adaptation to freshwater organisms are as follows.
Adaptation of plants
Plants that live in fresh water usually unicellular and cell wall strong as some algae and blue-green algae. Water into the cells to the maximum and will stop on its own. Higher plants, such as lily (Nymphaea gigantea), has roots anchor (root tendrils). Lower plants and animals that live in aquatic habitats, osmotic pressure equal to the osmotic pressure of the environment or isotonic.
Animal Adaptations
Freshwater ecosystems inhabited by nekton. Nekton is actively moving animals using strong muscles. Higher animals that live in freshwater ecosystems, such as fish, to overcome the osmotic pressure did osmoregulation to maintain water balance in the body through excretion system, gills, and digestion.
Freshwater habitats are intermediaries marine habitat and terrestrial habitats. Classification of organisms in the water can be based on the flow of energy and living habits.
1. Based on the flow of energy, organisms are divided into autotrophs (plants), and fagotrof (makrokonsumen), the carnivorous predators, parasites, and saprotrof or organisms that live in the substrate remains of organisms.
2. Based on the habits of life, organisms are distinguished as follows.
a. Plankton;
 base consists of phytoplankton and zooplankton;
 usually hovering (moving passive) to follow the motion of the water flow.
b. Nekton;
 animals that actively swim in the water, such as fish.
c. Neuston;
 organisms that float or swim in the water or
 located on the surface of the water, such as aquatic insects.
d. Periphyton; plant or animal is attached / dependent
 in plants or other objects, such as snails.
e. Bentos; animals and plants that live on base or live in
 sediment. Bentos can sessil (attached) or move freely,
 such as worms and mussels. See Fig.
Freshwater ecosystems fall into the water is calm and the water flowing. Includes a calm water ecosystems are lakes and swamps, including running water is a river ecosystem.
1. Lake
Lake is a body of water that pooled and breadth ranging from a few square meters to hundreds of meters.
FIG. Various Freshwater Organisms
Based on the way Her life
On the lake there is a regional division based on the penetration of sunlight. Areas that can be penetrated by sunlight so that photosynthesis occurs is called photic region. Areas that are not impenetrable sunlight called afotik area. In the lake there are also regions of the drastic changes in temperature or thermocline. Thermocline separates the warm area above the colder regions of the base.
Plant and animal communities scattered in the lake according to depth and distance from the edge. Based on that lake is divided into 4 regions as follows.
a) Regional littoral
This area is a shallow area. The sunlight penetrates to the optimum. The warm water adjacent to the edge. The plant is rooted aquatic plants and leaves nothing sticking to the surface.
Very diverse community of organisms including the types of attached algae (especially diatoms), various snails and mussels, insects, krustacea, fish, amphibians, reptiles such as water and spring water turtles and snakes, ducks and geese, and a few mammals that frequent foraging in the lake.
b. Regional limnetik
 This area is an area of
​​free water away from the edges and still
 sunlight can penetrate. The area is inhabited by a variety of
 phytoplankton, including algae and cyanobacteria. Alga
 photosynthesize and reproduce at high speed during
 summer and spring.
 Including most zooplankton Rotifera and shrimp-
 small crustaceans prey on phytoplankton. Zooplankton are eaten by fish-
 small fish. Small fish eaten by larger fish, then
 big fish eaten snakes, turtles, and fish-eating birds.
c. Profundal area
 This area is an area in, the area of ​​the lake afotik.
 Microbes and other organisms use oxygen for respiration
 cell after decomposing detritus falling from the
 limnetik. The area is inhabited by worms and microbes.
d. Benthic areas
 This area is an area of ​​the lake where the presence of benthos
 and the remains of dead organisms.

FIG. Four Main Areas In Freshwater Lake
Lakes can also be grouped based on its production of organic matter, which is as follows:
a. Lake Oligotropik
 Oligotropik is a term for the deep and
 lack of food, because the phytoplankton in the area limnetik not
 productive. Ciricirinya, crystal clear water, inhabited by a few organisms,
 and in the bottom water oxygen is abundant throughout the year.
b. Lake Eutropik
 Eutropik is a term for a shallow lake and rich
 content of foods, because phytoplankton are very productive. Characteristics
 the water is murky, there are a variety of organisms, and
 oxygen contained in the profundal.
Oligotrofik lake can become eutrophic lakes due to organic materials that enter and sediment. This change can also be accelerated by human activities, such as the remnants of agricultural fertilizers and urban waste piles that enrich the lake with a number of nitrogen and phosphorus discharges. The result is a population explosion of algae or blooming, resulting in excessive production of detritus which eventually spending the supply of oxygen in the lake.
Enrichment of the lake is called "eutrophication". Eutrophication making the water unusable and reduce the value of the beauty of the lake.
2. River
The river is a body of water that flows in one direction. The river water was cold and clear and contain little sediment and food. The flow of water and waves constantly deliver oxygen to the water. The water temperature varies with altitude and latitude.
Communities are different from lakes rivers. River water flowing does not support the existence of the plankton community to remain silent, because it will be swept away. Instead of going on photosynthesis of attached algae and rooted plants, so it can support the food chain.
Animal community composition also differed between the rivers, creeks, and downstream. In the creeks are common freshwater Man. Often encountered in the downstream cat fish and carp. Several major rivers inhabited by a variety of turtles and snakes. Special rivers in tropical regions, inhabited by crocodiles and dolphins.
Stream organisms can survive not drift due to evolutionary adaptation. For example, dorsoventral thin bodied and can be attached to the rock.
Several types of insects that live on the downstream sides inhabit small habitat that is free of the whirlpool.
c. Sea ecosystems
Distinguished marine aquatic ecosystems over the ocean, coastal, estuarine, and coral reefs.
1. Sea
Marine habitats (oceanic) is characterized by the salinity (salt content) with high CI-ion reached 55%, especially in the tropical ocean, because the high temperature and evaporation. In the tropics, the sea temperature is around 25 ° C. The difference in the temperature of the upper and lower height. The boundary between layers of hot water at the top with cold water at the bottom is called the thermocline region.
In cold regions, the temperature of sea water so that the water can be mixed evenly, the region remains fertile sea level and many plankton and fish. The movement of water from the shore to the middle of the water causes the top down to the bottom and vice versa, allowing the formation of the food chain that goes balk. Marine habitats can be distinguished by its depth and surface area horizontally.
1. According to depth, sea ecosystems are divided as follows.
 a. Litoral is an area that borders the land.
 b. Neretik is an area that is permeable to light
 sun to the bottom of it ± 300 meters.
 c. Batial is an area which ranges from 200-2500 m
 d. Abisal an area farther and deeper than
 beach (1500-10000 m).
2. According to the horizontal surface area, respectively, of the
 getting into the middle of the sea, the sea is divided as follows.
 a. Epipelagik is the region between the surface to a depth of
 water about 200 m.
 b. Mesopelagik an area under the epipelagik into
 an 200-1000 m. Animals such as sharks.
 c. Batiopelagik is an area of ​​the continental slope to a depth of
 200-2500 m. Animals that live in this area such as octopus.
 d. Abisalpelagik an area with depths reaching
 4.000m; no plants but animals are still there. Beam
 the sun can not penetrate this area.
 e. Hadal pelagic deepest part (base). Depth
 more than 6,000 m. In this section there is usually a marine catfish and
 Links fish that can emit light. As a manufacturer in
 This place is a bacteria that symbiotically with coral
 particular.
In the sea, plants and animals have low levels of cell osmotic pressure similar to the pressure of osmosis seawater. Higher animals adapt to drinking more water, a little urine output, and the expenditure of water by osmosis through the gills. Excessive salt is actively excreted via the gills.

2. Coastal ecosystems
Coastal ecosystems ecosystem bordering the land, sea and tidal areas.
Coastal ecosystems are affected by ocean tides daily cycle. Organisms that live on the coast have structural adaptations that can be embedded in the substrate.
The area above the beach just submerged at high tide. The area is inhabited by several species of algae, mollusks, and mussels which become food for crabs and shore birds.
Central coastal areas submerged at high tide and low tide. The area is inhabited by algae, sponges, sea anemones, mussels and clams, snails herbivores and carnivores, crabs, sea urchins, sea stars, and small fish.
Deepest coastal areas submerged at high tide and low tide. The area is inhabited by a variety of invertebrates and fish and seaweed.
Plant community succession of tidal areas landward distinguished as follows.

1. Formation pes caprae
So named because the most widely grown on a sand dune plant Ipomoea pes caprae is resistant to the waves and wind; plant spread and leaf thickness. Other plants are Spinifex littorius (wind grass), Vigna, Euphorbia atoto and Canaualia martina. More toward land again overgrown Crinum asiaticum (daffodils), Pandanus tectorius (pandanus), and Scaeuola Fruescens (babakoan).
2. Formation baringtonia
The area is dominated by plants baringtonia, including Wedelia, Thespesia, Terminalia, Guettarda, and Erythrina.
When you land in muddy tidal areas, the forested area of ​​mangrove roots breath. Breathing is an adaptation of plant roots in the muddy areas lacking oxygen. In addition to working to take in oxygen, the roots can also be used as a buffer from tidal waves. That includes plants in mangroves include Nypa, Acathus, Rhizophora, and Cerbera.
If the soil is not too wet tidal, trees often grow are: Heriticra, Lumnitzera, Acgicras, and Cylocarpus.

3. Estuarine
Estuary (estuary) is the union of the river to the sea. Estuarine often lined by extensive intertidal mud slab or salt marsh.
Water salinity changes gradually starting from the fresh water to the ocean. Salinity is also influenced by the tidal cycle with its water daily. Nutrient enrichment of the river estuary.
Plant communities that live in estuaries such as the salt marsh grass, algae, and phytoplankton. Animal communities such as various worms, clams, crabs, and fish. There is even some marine invertebrates and fish that make the estuary as a breeding or migrating towards freshwater habitats. Estuary is also a vertebrate foraging for spring water, ie water fowl.

4. Coral reefs
In tropical seas, the neritik area, there is a special community that consists of stony corals and other organisms. This community is called coral reefs. Regional communities can still be penetrated by sunlight so that photosynthesis can take place.
Coral reefs dominated by coral (coral) which is a group of Cnidaria that secrete calcium carbonate. Framework of calcium carbonate substrate bermacammacam shape and arrange another place to live corals and algae.
The animals that live in the reef eat microscopic organisms and other organic waste. A variety of invertebrates, micro-organisms, and fish live among the coral and the algae. Herbivores such as snails, sea urchins, fish, fall prey to the octopus, starfish, and carnivorous fish.