In our article we will tell you what biogeography is. This is a separate science located at the intersection of geography and biology. What does biogeography do? The first thing this science pays attention to is the interconnection of geographical distribution from the distribution of animals, microorganisms, and plants.
Subjects of study of biogeography:
- Distribution of aggregates of organisms (i.e. biocenoses).
- Fauna.
- Flora.
The object of study, it is not difficult to guess, is our planet Earth, or rather, the biosphere. The latter is represented by the space on which all living organisms live.
Sections of biogeography
First, we highlight the sections existing in science:
- Geography of organisms.
- Geography of vegetation and animals.
- Synthetic biogeography.
These sections are also divided into several categories. So, in the geography of organisms, one can distinguish the geography of microorganisms, phytogeography and zoogeography. The second section distinguishes: the geography of microbiocenoses, phytocenoses, and zoocenoses.
The whole organic world that surrounds us can be viewed from two perspectives. From biology and geography. The first helps us understand how our world is organized. The second answers the question of how it is distributed.
Geography of microorganisms
The importance of biogeography is very great in our life. But not all of its disciplines are well developed. For example, the geography of microorganisms, which will be discussed now, is in its infancy. What is the reason for this? The whole reason lies in the difficulties with the study of the object itself.
This industry is underdeveloped, since the study of microorganisms began only in the twentieth century. So, in 1914, the tasks of this particular section of biogeography were announced, in 1957 P. Dancero published a number of his works, and in 1963 the Soviet scientist A. G. Voronov. In 1963, the scientist L. A. Zenkevich conducted a series of studies of the oceans, which made a huge contribution to the development of the geography of microorganisms.
Now a little explanation of the term "microorganism". This name was given to the smallest plant organisms, which we can see only under a microscope. They are common in the atmosphere, hydrosphere and biosphere. To make it clearer, we list the types of microorganisms:
- Bacteria.
- Mushrooms (yeast or mold).
- Unicellular protozoa (ciliates).
- Viruses.
It is thanks to microorganisms that we have a number of minerals: coal, peat and oil. They are the main component of the geographical landscape, form the humus necessary for plants, and so on. Microorganisms are constantly evolving, so they are widely used.
Phytogeography
We continue our story about what biogeography is studying. Another section of it is the geography of the distribution of plants. Phytogeography considers the relationship between environmental conditions and vegetation. It can also be called geobotany. The object of study is the type of vegetation (phytocenoses). It's no secret that the vegetation is largely dependent on the climate of the area. So, phytogeography is able to give an answer to the question of why the tundra, jungle or desert are formed specifically in this place.
However, not only climate affects vegetation, but also plants are able to influence the environment. Under tall trees creates its own special microclimate, which differs in the microclimate of an open area. In addition, the vegetation does not allow the soil to collapse under the influence of water, wind and temperature changes. That is, it prevents erosion. Thus, it is possible to find a whole interconnected complex in absolutely any territory, which includes:
- Plants.
- Animals.
- Climate.
- The soil.
In another way, this system can be called biogeocenosis or ecosystem.
Zoogeography
The basics of biogeography include science that studies the distribution of animals on the planet. As it has already become clear, we are talking about zoogeography. This science studies the principle of the spread of animals.
The objects in this case are fauna and habitats. That is, zoogeography is engaged in studying the distribution of animals over the entire surface of the globe, studying the distribution of fauna, the process of extinction and resettlement of animals (in another language, it studies the expansion or reduction of habitats).
The tasks of science include:
- Exploring areas of the planet that are populated by animal populations.
- Clarification of the reasons for the nature of the settlement of animals.
- Identification of the relationship between factors (natural and man-made) and the distribution of animal organisms.
- Making a forecast of changes concerning the animal world (combining the species composition and so on).
The zoogeography section also has a division into several subsections. These include:
- Registration
- Comparative.
- Causal.
It is not difficult to guess that such a division is caused by the stages of studying the fauna. First, the composition and structure of the fauna are described, then it is compared with other territories of the regions. And only in the last turn conclusions are made - according to what patterns faunistic complexes are formed and developed.
Zoogeography is divided into the following components:
- Arealogy.
- Geographical Zoology.
- Geozoology.
- Historical zoogeography.
- Landscape zoogeography.
- Paleozoology.
- Systematic zoogeography.
- Factor zoogeography.
- Faunistics.
- Ecological zoogeography.
Geography of microbiocenoses
Biogeography is a whole complex of sciences, another component of which is the geography of microbiocenoses.
Let's start with an explanation of the term “biocenosis”. This is a collection of living organisms that inhabit approximately homogeneous living space. Biocenoses are formed historically, and it includes:
- Animals.
- Plants.
- Mushrooms.
- Microorganisms.
All elements of the biocenosis are interconnected by the environment. This system is capable of self-regulation, that is, it is dynamic. All components are interconnected. The constituent parts of the biocenosis are producers, consumers and reducers.
This system has several important quantitative indicators:
- Biodiversity (how many species are included in the biocenosis).
- Biomass (weight of all organisms living in the biocenosis).
Geography of phytocenoses
We in the article have already answered the question of what biogeography is studying. However, no mention was made of phytocenoses. What is it? This is a community of plants that germinate within a single biotope. The phytocenosis is characterized by relative uniformity of composition, which is distinguished by a system of relationships between both plants and plants with the environment.
A very important zone-forming factor is climate. Its role in the geographical distribution of phytocenoses is extremely large. This can be traced on the example of the occurrence of zonal vegetation. The latter refers to the totality of some plants that meet the features of the climate (first of all, heat and moisture should be included here).
Geography of zoocenoses
Again, biogeography is a science that borders on biology and geography. Another section of it is the geography of zoocenoses. Zoocenosis refers to the totality of animal organisms that make up the biocenosis. It is also important to note that it is a structural element of the ecosystem. It is understood that the animals that make up the zoocenosis are in any relationship with each other.
The functions of zoocenosis include:
- Conservation of ecosystem productivity.
- Performance as a backbone factor.
- Preservation of phytocenosis structure.
- Ensuring the efficient use of ecological space.
- Influence on the species diversity of phytocenosis.
Synthetic Biogeography
Synthetic biogeography is a complex that includes the geography of ecosystems and biocenoses. Characteristic: the use of integrated methods of geographical and biological disciplines. Synthetic geography allows you to give a comprehensive assessment of the biogeographic features and originality of territories. In addition, this science compares natural areas using standard indicators and characteristics.
Initially, the composition of synthetic biogeography included zoo- and phytogeography. Why did these sciences come together? They are capable of mutually enriching each other, which is necessary in comparative geographical studies. It is also important to say here that it was zoogeographic studies that made a very large contribution to synthetic biogeography.
A bit of history
Who is the founder of biogeography? The scientist A. Humboldt, whose travels and scientific works laid the foundations of science. The history of biogeography has gone through the following periods (M. A. Menzbir):
- Belief in the biblical version of the origin of life on Earth.
- The superiority of catastrophe theory.
- Rejection of previous theories.
- Darwinism.
But L. Stuart believes that three periods can be distinguished in the history of science:
- The taxonomy of Carl Linnaeus.
- The evolutionary teachings of Charles Darwin.
- Discovery of genetics.
There are merits and Russian scientists. A striking example is A.P. Kuzyakin, thanks to whom we got a new direction in biogeography - landscape zoogeography.
Methods
I would like to say a little more about the methods of study. It is not difficult to guess, they are characteristic of such sciences as biology and geography. Among the geographical methods, we distinguish: comparative-geographical and cartographic (they play a more important role).
General scientific methods (modeling, system analysis, mathematical) and specific (comparative, cartographic, historical) are used.