The vital activity of organisms has a significant impact on the environment and changes its composition and properties. The content of oxygen and carbon dioxide in the air, the amount of humus and minerals in the soil, and even the climate of individual parts of the earth’s surface depend on living organisms.
The simplest effect of life on the environment is manifested in its mechanical change.
Example: building burrows, making passages, animals greatly change the properties of the soil. The soil also changes under the influence of the roots of higher plants: it strengthens, becoming less susceptible to destruction by streams of water or wind.
Small crustaceans, insect larvae, molluscs, and many fish species living in the water column have a peculiar type of nutrition called filtration. Passing water through themselves, these animals continuously filter out food particles contained in solid suspensions from it. This activity can be compared to the work of a giant filter that constantly purifies natural waters.
The mechanical effect, however, is much weaker in comparison with the effect of organisms on the physicochemical properties of the environment.
Example: the greatest role here belongs to green plants, which form the chemical composition of the atmosphere. Photosynthesis is the main mechanism for supplying oxygen to the atmosphere, thereby providing life for a huge number of organisms, including humans.
Largely due to the activity of living beings, the formation of gases such as nitrogen, carbon monoxide (carbon dioxide), ammonia occurs.
Plants constantly absorb water from the soil and evaporate it, maintaining the water regime of the environment at a certain level. The presence of green plants contributes to constant air humidification. Plants smooth out temperature drops over the soil, changes in moisture. All this creates a certain, comfortable microclimate that has a beneficial effect on the organisms living here.
Living matter also changes the physical properties of the medium, its thermal, electrical and mechanical characteristics.
Organisms have a decisive influence on the composition and fertility of soils.
Example: due to their activity, in particular as a result of the processing of dead roots, fallen leaves, and other dead tissues by organisms, humus is formed in the soil – a light porous substance of brown or brown color, containing the main elements of plant nutrition. Many living organisms are involved in the formation of humus: bacteria, fungi, protozoa, ticks, millipedes, earthworms, insects and their larvae, spiders, mollusks, moles, etc. In the process of life, they convert the remains of living organisms into humus and thereby increase soil fertility …
Living organisms move huge amounts of different substances on the Earth.
According to the law of universal gravitation, inanimate matter can only move from top to bottom. Rain and snow fall from top to bottom, water flows in streams and rivers, avalanches move. In the opposite direction, substances move on Earth thanks to living organisms.
Example: migratory fish move huge masses of organic matter upstream during spawning. Birds that feed on marine animals, together with excrement, return to land those chemical elements that rivers carry from land to sea. Plants absorb water and mineral salts from the soil and lift them up to the ground organs.
Thus, living organisms turn out to be the most important link in the global transfer of chemical elements – the constant circulation of substances in the biosphere.