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Ecology

M. Saadatian

Ecological factor in ecosystem

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Temperature

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• optimum temperature: an optimum temperature at which growth proceeds with greatest rapidity. (0-50 degree)

• Cardinal temperature : Minimum and maximum temperatures that define limits of growth and development of an organism

Vernalization:is the acquisition of a plant's ability to flower in the spring by exposure to the prolonged cold of winter, or by an artificial equivalent. After vernalization, plants have acquired the ability to flower, but they may require additional seasonal cues or weeks of growth before they will actually flower.

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• Thermoperiodism• The effect on an organism of the rhythmic

fluctuation of temperature, including responses associated with thermal changes accompanying the alternation of day and night.

• Flowering : 8-13 in cool day

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• Warm blooded• The term warm-blooded is a colloquial term to describe

animal species which have a relatively higher blood temperature, and maintain thermal homeostasis primarily through internal metabolic processes. These are characteristics of mammals and birds.

• Cold bloodedCold-blooded creatures take on the temperature of their

surroundings. They are hot when their environment is hot and cold when their environment is cold.

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• Bergmann's rule is an ecogeographic principle that states that within a broadly distributed taxonomic clade, populations and species of larger size are found in colder environments, and species of smaller size are found in warmer regions.

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Humidity

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Aquatic plantAquatic plants are plants that have adapted to living in aquatic environments (saltwater or freshwater). They are also referred to as hydrophytes or macrophytes. These plants require special adaptations for living submerged in water, or at the water's surface. The most common adaptation is aerenchyma, but floating leaves and finely dissected leaves are also common. Aquatic plants can only grow in water or in soil that is permanently saturated with water. They are therefore a common component of wetlands

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Xerophytes

• A xerophyte is a species of plant that has adapted to survive in an environment with little water, such as a desert or an ice- or snow-covered region in the Alps or the Arctic.

• The morphology and physiology of xerophytes are variously adapted to conserve water, and commonly also to store large quantities of water, during dry periods. Other species may be adapted to survive long periods of desiccation of their tissues, during which their metabolic activity may effectively shut down. Plants with such morphological and physiological adaptations are called xeromorphic.

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Mesophyte

• Mesophytes are terrestrial plants which are adapted to neither a particularly dry nor particularly wet environment. An example of a mesophytic habitat would be a rural temperate meadow, which might contain Goldenrod, Clover, Oxeye Daisy, and Rosa multiflora.

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Halophyte• A halophyte is a plant that grows in waters of high

salinity, coming into contact with saline water through its roots or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs, and seashores. An example of a halophyte is the salt marsh grass Spartina alterniflora (smooth cordgrass). Relatively few plant species are halophytes - perhaps only 2% of all plant species. The large majority of plant species are glycophytes, plants which are not salt-tolerant, and are damaged fairly easily by high salinity.

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CLOUD TYPES

LENS CLOUDS

The shape and depth of clouds depend on the

temperature and humidity of the air, and the degree of

uplift to which it is subjected.

CONVECTIONAL UPLIFT results in cumulus clouds. If uplift is continued, then they develop vertically to become storm clouds; cumulo-nimbus which only spread out laterally at the tropopause (about 12km).

CUMULO-NIMBUS

CUMULUS DEVELOPS INTO CUMULO-NIMBUS

CUMULUS WITH LIMITED VERTICAL DEVELOPMENT

CIRRUS clouds are thin, wispy clouds formed from ice crystals at high level, usually near the tropopause at 10-12km.CIRRUS CLOUDS

CONTRAILS are the trails of jet aircraft whose water vapour condenses into ice crystals.

Lens clouds develop as air streams oscillate

above and below the condensation level. Stratus clouds

Stratus clouds from above

STRATUS clouds are layerclouds that develop with whole air masses rising gently, with limited vertical development