Ecology on the whole is all about relationship and function of biological things and environment. Primarily ecology has different level of hierarchy for better understanding of its own, which are as follows:
- Global ecology: Deals with Biosphere, ecosystem and ecology of the planet
- Landscape ecology: Deals with ecology at terrestrial level and its related ecosystem
- Ecosystem ecology: Deals with the ecology of community ecosystem with emphasis to environment.
- Community ecology: Deals with ecology of group of population of different species within an area.
- Population ecology: Branching out from Community ecology this deals with a group of population of same species within an area.
- Organismal ecology: Deals with physiological, evolutionary, and behavioural ecology, and the challenges posed by its environment.
Though environment is a part of any ecological study, it plays a vital role in its nature and function, with relation to origin, development and destruction of any biological activity. On the environment aspect, climate is prominent which is supported by earth’s set up and the natural phenomenon. The impact of sunlight is considered to be very important, as the intensity is very high at tropics towards equator than the rest. This initiates the air circulation and precipitation process in which warm and wet air, rise and flow towards the poles. During this process the abundant precipitation left over the tropics resulting in high moisture and humid condition and chill air descending to poles resulting in rainless and cold climate. Such conditions roots the existence of climate for a particular area.
Any weather condition prevailing in a given area is known as climate, which is of two types viz., Macroclimate and Microclimate. Temperature, Precipitation, Sunlight and Wind are the four important physical components of Climate.
The macroclimate deals climatic pattern at global, regional and community (local) level. Global climate patterns are determined largely by the input of solar energy and Earth’s movement in space. The sun warms the atmosphere, land, and water. This warming establishes the temperature variations, cycles of air and water movement, and evaporation of water that causes dramatic latitudinal variations in climate. At Regional and local level, climatic patterns are modified by variation in season, water bodies and mountains, which are in a way interconnected. The occurrence in variation of season is largely effected by the tilted axis of rotation by earth and the amount of sunlight it receives consequently upon day length, solar radiation and temperature. So as for the water bodies also, the angle of inclination of earth, influence and drag the ocean currents setting up the temperature and environment at coastal region of the continents. Due the high specific heat of water, oceans and large lakes tend to moderate the climate of nearby land. During a hot day, when land is warmer than the water, air over the land heats up and rises, drawing a cool breeze from the water across the land. In contrast, because temperatures drop more quickly over land than over water at night, air over the now warmer water rises, drawing cooler air from the land back out over the water and replacing it with warmer air from offshore. This local moderation of climate can be limited to the coast itself, however. Likewise, mountains too influence air flow over land. When warm, moist air approaches a mountain, the air rises and cools, releasing moisture on the windward side of the peak. On the leeward side, cooler, dry air descends, absorbing moisture and producing a “rain shadow.” This leeward rain shadow determines where many deserts are found, including the Great Basin and the Mojave Desert of western North America and the Gobi Desert of Asia. Additionally Mountains also affect the amount of sunlight reaching an area and thus the local temperature and rainfall. Southfacing slopes in the Northern Hemisphere receive more sunlight than north-facing slopes and are therefore warmer and drier. These physical differences influence species distributions locally. In addition, every 1,000-m increase in elevation produces an average temperature drop of 6°C, equivalent to that produced by an 880-km increase in latitude. This is one reason that high-elevation communities at one latitude can be similar to those at lower elevations much farther from the equator.
In microclimate, the features like casting shade, altering evaporation from soil, or changing wind patterns were influential. Forest trees often moderate the microclimate below them. Cleared areas therefore typically experience greater temperature extremes than the forest interior because of greater solar radiation and wind currents that arise from the rapid heating and cooling of open land. Within a forest, low-lying ground is usually wetter than higher ground and tends to be occupied by different tree species. A log or large stone can shelter organisms such as salamanders, worms, and insects, buffering them from the extremes of temperature and moisture. And this is where abiotic factors like temperature, light, water and nutrients along with biotic factors tend to blend in for a microcosm.
On the global climate change scenario, climatic variables affect the geographic ranges of most plants and animals, any large-scale change in Earth’s climate profoundly affects the biosphere. The burning of fossil fuels and deforestation are increasing the concentrations of carbon dioxide and other greenhouse gases in the atmosphere. As a result, Earth is warming and is projected to warm upto eight times by the year 2100 than it was in 1900. As the climate warmed and the glaciers retreated, tree distributions expanded northward. A detailed record of these changes is captured in fossil pollen deposited in lakes and ponds, shows that species with winged seeds that disperse relatively far from a parent tree, such as the sugar maple (Acer saccharum), expanded rapidly northward after the last ice age ended. In contrast, the northward range expansion of the American beech (Fagus grandifolia), whose seeds lack wings, was delayed for thousands of years compared with the shift in suitable habitat. Changes in the distributions of species are already evident in many well-studied groups of terrestrial, marine, and freshwater organisms, consistent with the signature of a warmer world.