Plant, animal, microorganism, soil, atmosphere, the whole composed of their interactions
This entry is missingOverview, add relevant content to make the entry more complete, and it can also be upgraded quickly. Hurry upeditCome on!
In nature, any natural living area always includes five parts: plants, animals, microorganisms, soil, atmosphere (and water in the latter two), which interact to form a whole.For example, in a forest section, the chemical composition, water status and physical properties of soil affect the growth, development, results and regeneration of tree species, as well as the growth and development of other vegetation members.All vegetation itself strongly affects the physical and chemical properties of soil.The material "biological cycle" between soil and vegetation is constantly carried out, which causes the redistribution of soil minerals according to soil layers.
At the level of plant community, it was Soviet scholars in 1940Sukachev introduced a concept in science.
living environment
Announce
edit
Vegetation absorbs water from the soil, and then discharges water into the atmosphere through transpiration. Vegetation also affects the evaporation of water on the soil surface, the surface runoff of water and the transfer of water underground.
On the one hand, the growth and development of vegetation are restricted by the temperature and humidity of the air as well as its movement and composition;On the other hand, the composition, height, stratification and density of vegetation also affect these properties of the atmosphere.
Animals affect vegetation in many aspects during their life activities: they not only chew and trample vegetation directly, but also indirectly promote pollination of flowers and dispersal of seeds and fruits.Animals also change the soil, "fertilize" the soil with their own excreta, loosen the soil, and thus change the chemical and physical properties of the soil.Animals also affect the atmosphere to some extent.
The relationship between vegetation and microorganisms is particularly important. In addition to being the parasites of higher plants, microorganisms (bacteria, fungi, viruses, etc.) also participate in the decomposition of soil organic matter and the absorption of certain atmospheric gas substances (such asNitrogen fixing bacteriaAnd the absorption of free nitrogen by nodule bacteria) and the general transformation of substances in the soil, which is sometimes beneficial and sometimes harmful to the growth and development of higher plants.On the other hand, the root exudates of higher plants strongly affect soil microorganisms, so that in the rhizosphere of higher plants, there are differentRhizosphere microorganismform.Microorganisms also directly or indirectly interact with vertebrates andinvertebrateIn interaction.
Sukachev called the most consistent part of the earth's surface formed by the interaction of planting, movement, micro, air and soil of the biosphere "biogeographic community". He believed that biogeographic community was connected with a certain section of the earth's surface;It is composed of living things (plants, animals, microorganisms) and non living things (atmosphere, rocks, soil), which are called components of biogeographic community;The relationship between components is based on the exchange of material and energy between them and the external environment. Biogeographical communities are biological and abiotic unity with internal contradictions and dynamic balance.
In the composition of biogeographic communities, such elements as topography, climate, gravity, time, etc. are not included because they are not physical bodies and do not participate in the exchange of material and energy in biogeographic communities. They are factors that affect this exchange;Human activities are also included in the factors.
Biome
Announce
edit
Biological community refers to all organisms (including microorganisms) living in the same area at the same time
Biogeographic communities are composed of biological and abiotic natural components with very different structures and functions, but they are not their mechanical mixtures, but complex and integral biological abiotic systems.This system moves and develops according to special laws;This special law is different from the laws governing the movement and behavior of its components.
The biogeographical communities in nature are very diverse, including forest, swamp, meadow, tundra, grassland, desert, freshwater, marine, etc.There are only places with permanent snow, newly erupted lava, newly deposited sandbars and citiesOpen pitNo biogeographic community is developed, or it is only shown in fragments and sprouts.
The boundary of biogeographic community is usually determined by the boundary of plant community.Because vegetation occupies a key central position in the biogeographic community.Changes in the composition, structure and nature of vegetation will inevitably lead to corresponding changes in the nature and state of other components of the biogeographic community.
The concept of biogeographic community is not only applicable to natural systems, but also to artificially created productive land: cultivated land, sown grassland, plantation, park, pond, reservoir, etc.Of course, in addition to the laws shared with natural biogeographical communities, this artificially created system also has a series of characteristics that are subject to the characteristics of cultivated plants and human management measures in terms of component structure and material and energy metabolism.They are often distinguished separately, called cultivated biogeographic communities or agricultural biogeographic communities.
From the above introduction, it is easy to see that the concept of biogeographic community is very close to the concept of ecosystem.In 1965, the "Scientific Symposium on Terrestrial Ecosystems" held in Copenhagen, Denmark, decided to use the two as synonyms, which reflected the views of most scholars.However, some representatives of the Sukachev School of the Soviet Union objected that there were differences between the two schools after all.A., the founder of the term ecosystemG. According to Tansley and ecologists from all over the world at present, the concept of ecosystem is applicable to natural objects of different sizes and complexity - from a drop of water in a pond, a fish tank with aquatic plants and fish, to the oceans and even the entire earth's surface, there are ecosystems.
Of course, biogeographic community is also a system, but it is limited to the completely determined plant community and the narrow range of its space.It can neither be distributed in a drop of water nor on a lonely tree.In particular, ecosystems such as cities and industrial and mining areas cannot be included in the concept of biogeographical communities.The relationship between biogeographic communities and ecosystems can be expressed as follows: biogeographic communities are ecosystems within the boundaries of plant communities.Or rather, ecosystem categories and biogeographical communities coincide at the plant community level.There are differences between the above level and the following principles, and even the research methods are qualitatively different.
Biosphere research and biogeographic community research can complement each other in the comprehensive understanding of nature.
