Ecology and Ecosystem Dynamics, High school final essays of Chemistry

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Ecology

Homeostasis

 The ecosystem , by itself, tries to resist the

change and maintain itself in equilibrium.

 Positive feedback

 Negative feedback

 An established species and impact of external natural forces,

which try to alter the environmental condition of that area. Ex.

Hardwood tree replacing red pine

 Ecosystem is continuously changing and reorganizing as well

as ecological succession refers to orderly that changes

happening in composition or structure of ecosystem

Succession

Types of Succession

 Primary succession

 Primary succession refers to a series of community changes

which occur on an entirely new habitat which has never

been colonized before. For example, a newly quarried rock

face or sand dunes. (pioneer and climax community).

 Secondary succession

 Secondary succession refers to a series of community

changes which take place on a previously colonized, but

disturbed or damaged habitat. For example, land obtained

after felling trees in a woodland, land clearance, or fire.

Process of ecological succession

 Nudation

 Invasion

 Migration (dispersal)

 Ecesis (establishment)

 Aggregation

 Competition

 Reaction

 Stabilization

Forest ecosystem

 (^) Abiotic Components  (^) Inorganic and organic substances found in soil  (^) Temperature, humidity, rainfall, light  (^) Biogenic gases (CO 2 , O 2 )  (^) Biotic components  (^) Producers: Large trees, herbs, lianas (climbers), Orchids  (^) Primary consumer: Deer, Elephant, moles etc.  (^) Secondary consumer: Snake, Lizards etc.  (^) Tertiary consumers: Tiger, Lion etc.  (^) Decomposers The forest type mainly depends on abiotic factors such as the climate and soil characteristics of a region. It also depends on the nature of the tree species whether they are evergreen forest, deciduous, xerophytes or mangroves.

Tropical deciduous forest

 (^) Notable features:  (^) Tropical deciduous forests form a natural cover almost all over India.  (^) They are of two types-moist and dry. Moist forests are found on the eastern slopes of Western Ghats, North eastern parts of the Peninsular Chhota Nagpur plateau and along the Shiwaliks.  (^) They shed there leaves for a particular period of time.  (^) They are economically very important because of timber like sal and teak.  (^) The animals found here are tiger, wolves, rabbit etc.

Sub-tropical forest

 Notable features:

 (^) Subtropical forests are within or bordering the tropical zone.  (^) temperatures may vary only slightly over a year  (^) Subtropical rainforests occur in Central America, the West Indies, India, Madagascar, mainland Southeast Asia, and the Philippines.  (^) Small deciduous trees and shrubs are found.

Temperate deciduous forest

 Notable features:

 Located in the mid-latitude areas

(between the polar regions and the

tropics).

 The temperature varies widely

from season to season with cold

winters and hot, wet summers.

 During the fall, trees change color

and then lose their leaves.

 Most of the trees are broadleaf

trees such as oak, maple, beech,

hickory and chestnut.

 Animals: toad, chipmunk, gray

squirrel, Yellow-breasted chat etc.

Evergreen coniferous forest

 (^) Notable features:  (^) They are found just in south of arctic tundra  (^) Winters are long, cold and dry  (^) Sunlight is available for few hours only  (^) Soil has less nutrient and acidic  (^) Major trees are Pine, Fir, Cedar etc.  (^) Animals: moose, deer, reindeer, squirrels, wolves, bears, foxes, owls, woodpeckers hawks etc. Coniferous forests grow in the Himalayan mountain region. It requires low temperature. Forests dominated by conifers such as pine, hemlock, spruce and fir. Wildlife such as snow leopards, Himalayan tahrs and musk deer’s are found in this region.

Grassland ecosystem

 Abiotic components:

 Inorganic elements (C, H, O, N, P, S)

 Temperature, humidity, rainfall, light

 Biotic components:

 Producers: Some scattered trees, Grass

 Primary consumers: Grazing animals,

Tropical grassland

 (^) Notable features:  (^) Located near the equator, between the Tropic of Cancer and the Tropic of Capricorn.  (^) Although these areas are overall very dry, they do have a season of heavy rain.  (^) Dominated by grasses  (^) May have some drought-resistant, fire- resistant trees  (^) Animals: giraffes, zebras, buffaloes, kangaroos, mice, moles, gophers, ground squirrels, snakes, worms, termites, beetles, lions, leopards, hyenas, and elephants.  (^) Examples:  (^) Savannas

Polar grassland

 (^) Notable features:  (^) Severe cold and strong wind  (^) Arctic wolf, arctic fox, reindeer, migratory birds and insects are found.  (^) Examples:  (^) Arctic Tundra  (^) Permafrost: Permafrost is soil, rock or sediment that is frozen for more than two consecutive years. In areas not overlain by ice, it exists beneath a layer of soil, rock or sediment.

Desert ecosystem

 (^) About 1/3rd^ of the worlds’ land area is covered with desert  (^) Tropical desert  (^) Notable features:  (^) It is the driest and hottest place on earth.  (^) Rainfall is sporadic and in some years no measurable precipitation falls at all.  (^) Examples: Sahara, Kalahari, Thar, Mexican deserts, Great Australian desert.  (^) Temperate desert  (^) Notable features:  (^) Temperate deserts can be much colder than tropical deserts  (^) The floor of the temperate desert is often covered by rocks and small pebbles  (^) Examples: Mojave, Sonoran Deserts  (^) Cold desert  (^) Notable features:  (^) cold deserts occur in temperate regions at higher latitudes  (^) hot summers but extremely cold winters.  (^) Examples: Atacama,  (^) Gobi, Great Basin, Namib, Iranian, Takla Makan, and Turkestan