The main local temperature fluctuations are caused by the sun's energy not uniformly reaching all parts of the earth's surface. Both factors cause a wide variation in the exposure of the Earth's surface to the energy provided by sunlight. For example, the solar energy that reaches the poles is less concentrated and the temperature is lower. a) Seasonal Variations in Solar Energy: Seasons are determined by the following two main factors: .. the inclination of the Earth's axis and .. the distance from the Earth to the Sun, which varies throughout the year.
The tilt of the earth's axis remains the same as it moves around the sun. The atmospheric circulation also leads to variations in the solar energy that reaches the surface of the earth. This atmospheric circulation of air helps to create a moderate temperature on the surface of the earth.
With an increase in height from the Earth's surface, there is a steady decrease in troposphere temperature. Eggs, embryos, larvae and seedlings have a limited tolerance range for most factors. From top to bottom, a clear density gradient is established, with ice floating on the surface of the lake.
The layer of the atmosphere near the Earth's surface is the troposphere, which can be differentiated into the lower (0 to 8 km) and upper (8 to 13 km) troposphere.
Endotherms or Homeotherms These animals can maintain their constant internal body temperature , which is independent of outside temperature( “homeo” means same)
Aquatic poikilotherms maintain no appreciable difference between their bodies and the temperature and surrounding water. Cod fish that hatch at a temperature of 4o to 80oC have 56 vertebrae, while when they hatch at 100 to 110oC they have 54 vertebrae (Clarke, G.L vii). Poikilotherms do not have the problem of losing metabolic heat, they can occupy the habitat that homeotherms cannot. . viii). They produce more energy anaerobically. . ix) Animals living in the colder region are smaller in size compared to their closely related species in the warmer region to reduce heat loss from the body surface.
Endotherms or Homeotherms These animals can maintain their constant internal body temperature, which is independent of outside temperature ("homeo" means the same). Seasonal changes in the insulation such as the type and thickness of fur, structure of feather and a layer of fat. v) Birds and mammals have shorter limbs like legs, tail and ear in the colder climate to avoid the excessive loss of heat by them. As explained by Allen's rule that warm-blooded animals lose their body heat through the limbs.
They tend to be shorter in the colder regions compared to their relative species in the warmer climatic regions. In all homeotherms, the enzyme systems in their body exhibit the maximum activity at a constant temperature, which is called the optimum temperature. For example, all mammalian enzymes have their maximum activity at 37o C, which is the constant temperature of their body. . vii) Some of the mammals can hibernate during extreme cold.
They reduce their body temperature, but unlike poikilotherms, they keep it higher than the ambient temperature, e.g. They do not eat, drink or urinate during hibernation, but maintain an almost normal metabolism. They do this by recycling urea, which is completely converted into amino acids, which in turn are converted into proteins, and energy is conserved to carry out essential life processes at a minimum rate.
Heterotherms They are between ectotherms and endotherms as they regulate their body temperature by ectothermy at times and endothermy at other times.
Heterotherms They are in between ectotherms and endotherms as they regulate their body temperature by ectothermy sometimes and by endothermy at other times. The
Factors involved in the formation of soil
It is important in determining the chemical composition of soil according to whether it is derived from igneous, sedimentary or metamorphic rock. ii) Climate:. Temperature and precipitation determine the weathering of rocks, the breakdown of minerals, organic matter and the leaching of materials. iii) Biotic factors: Plants, animals, bacteria and fungi contribute to soil formation. Animals, bacteria and fungi break down organic matter, mix it with mineral matter and help aerate the soil and percolate water. . iv) Topography: Soil formation also depends on the topography of the place.
The contour of the land determines the amount of water that enters the soil.
The process of formation of soil
Because of the slope, climate and native vegetation, different soils can develop from the same parent material. In some of the soils all the horizons are very clear, but in others they appear to form a continuum as the boundaries are not clear. Soil texture: Soil texture is partly due to the parent material and partly the result of soil formation processes.
Based on the particle size, the soils are classified into four main types as shown in table 5. Depletion of the top layers of the land's soil is called soil erosion. Topographical factors are concerned with the geography of the earth of a particular area that area as it shows various irregularities.
For example, south-facing slopes of the mountains receive the most solar energy, which is maximum when the degree of inclination is equal to the angle of the sun from the zenith point. This results in increased soil organic matter at high altitude and causes an increase in soil nitrogen content with a decrease in pH. Shelford's Law of Tolerance: An organism's presence and success depend on the completeness of the complex state.
Bergmann's rule: It states that "birds and mammals of the same species attain a larger body size in cold regions than in warmer regions, and among the closely related species live larger in the colder climate. Photoperiodism: Responses of plants and animals to changes in light and the relative duration of darkness.Periodicity: These rhythms are driven by daily rotation of the earth on its axis and its.
Phototaxis: This is the orientation of the moving organisms towards (positive) or away (negative) from the direction of light. Photokinesis: Increase or decrease in the locomotor activity of the motile organisms in response to light is called phototaxis. Soil Erosion: Depletion of the top layers of soil from the ground is called soil erosion.
