Later, some naturalists believed that ecology was different from ordinary natural history and had quantitative and dynamic characteristics. They believe that ecology is a theoretical science of natural history. Ecologists who hold physiological views believe that ecology is a branch of general physiology, which is different from the general organ system physiology and focuses on the relationship between life processes and environmental conditions on the whole level. Scholars engaged in plant community and animal behavior understand ecology as the science of biological community and the science of animal behavior under the influence of environmental conditions respectively. Scholars who focus on evolution interpret ecology as a science that studies the relationship between environment and biological evolution.
Later, the viewpoint of ecosystem was added to the definition of ecology, and the relationship between biology and environment was summarized as material flow and energy exchange. Since 1970s, it has been further summarized as material flow, mass flow, energy flow and information flow. The development of ecology can be roughly divided into three stages: germination, formation and development.
In the embryonic stage, the ancients accumulated simple ecological knowledge in the long-term production of agriculture, animal husbandry, fishing and cats, such as the relationship between crop growth and seasonal climate and soil moisture, and the phenological habits of common animals. For example, Aristotle, a Greek scholar in the 4th century BC, roughly described the different types of animal habitats, which were divided into terrestrial and aquatic types according to the environmental types of animal activities, and carnivorous, herbivorous, omnivorous and special feeding types according to their feeding habits.
Theophrastus, a student of Aristotle and the leader of Athens School in the 3rd century BC, put forward a concept similar to that of today's plant community in his works on plant geography. Monographs about agriculture, animal husbandry, fishing and hunting, such as Natural History by Pliny the Elder in ancient Rome in 1 th century and Qi Shu by Jia Sixie, an agronomist in China in the 6th century, all described simple ecological views.
The formation period is 15 century to 1940s.
/kloc-after the 0/5th century, many scientists have accumulated a lot of macro-ecological data through scientific investigation. /kloc-At the beginning of the 9th century, the outline of modern ecology began to appear. For example, there are many descriptions of insect ecology in Reaumur's six volumes of entomology. Swedish naturalist Linnaeus combined phenology, ecology and geography for the first time. This paper comprehensively describes the influence of external environmental conditions on animals and plants. French naturalist Buffon emphasized the influence of biological variation based on environment. Humboldt, a German plant geographer, creatively combined the influence of climate and geographical factors to describe the distribution law of species.
/kloc-in the 0/9th century, ecology developed further. On the one hand, the development of agriculture and animal husbandry has prompted people to carry out experimental research on the physiological effects of environmental factors on crops and livestock. For example, in this period, five degrees Celsius was determined as the initial temperature of general plant development, the temperature development curve of animals was drawn, and the product of illumination time and average temperature was put forward as the "luminosity" index of comparative photochemical action, as well as the influence of the minimum law of plant nutrition and spectral structure on the development of animals and plants.
On the other hand, Malthus' book Population Theory published in 1798 has a wide influence. Verhulst described the relationship between population growth rate and population density with his famous logistic curve in 1833. Introduce mathematical analysis methods into ecology. The quantitative description of plant communities in the late19th century is also based on statistical principles. In 2008+085 1 Darwin put forward the theory of natural selection in the Origin of Species, emphasizing that biological evolution is the product of the interaction between biology and environment, which aroused people's concern about the relationship between biology and environment and promoted the development of ecology.
/kloc-From the middle of 0/9th century to the beginning of 20th century, people's concern about agriculture, fishing cats and environmental sanitation directly related to human health promoted the research on agricultural ecology, wildlife population ecology and vector insect behavior. Because the marine expedition organized at that time paid attention to the investigation of biological resources, it also enriched the contents of aquatic organisms and aquatic ecology.
By 1930s, many ecological books and textbooks had expounded some basic concepts and arguments of ecology, such as food chain, niche, biomass and ecosystem. So far, ecology has basically become an independent discipline with specific research objects, research methods and theoretical systems.
Development period Since the 1950s, ecology has absorbed the research results of mathematics, physics and chemical engineering technology, advanced in a precise and quantitative direction, and formed its own theoretical system:
With the application of mathematical methods, precise and sensitive instruments and computers, ecologists may explore the material basis of the interaction between biology and environment more extensively and deeply, and make quantitative analysis of complex ecological phenomena. With the development of the whole concept, new branches such as system ecology have emerged, and the theoretical system of ecology has been initially established.
Because most ecosystems in the world are influenced by human activities, socio-economic production systems and ecosystems are intertwined, actually forming a huge composite system. With the rapid development of social economy and modern industrialization, a series of problems affecting social production and life, such as natural resources, population, food and environment, have become increasingly prominent.
In order to find the scientific basis and effective measures to solve these problems, the International Union of Biological Sciences (IUBS) formulated the International Biological Plan (IBP) to conduct ecological research on terrestrial and aquatic biota. Following IBP, UNESCO and others established the International Man and Biosphere Organization (MAB), and formulated the "Man and Biosphere" plan to organize participating countries to develop forests and grasslands.
Like many natural sciences, the development trend of ecology is: from qualitative research to quantitative research, from static description to dynamic analysis; Gradually develop into multi-level comprehensive research; Cross-research with other disciplines is becoming more and more obvious.
Judging from the impact of human activities on the environment, ecology is the intersection of natural science and social science; Methodologically, the study of the mechanism of environmental factors can not be separated from physiological methods, physical and chemical techniques, and group investigation and systematic analysis can not be separated from mathematical methods and techniques; Theoretically speaking, the concepts of metabolism and steady state of ecosystem basically come from physiology, and studying the interaction between biology and environment from the perspectives of material flow, energy flow and information flow can be said to be a research system developed by physics, chemistry, physiology, ecology and socio-economics. The basic contents of ecology are divided into microbial ecology, plant ecology, animal ecology and human ecology. It can also be subdivided, such as insect ecology and fish ecology.
According to the structural level of biological system, there are individual ecology, population ecology, community ecology and ecosystem ecology.
According to the types of living environment, there are land ecology and water ecology; The former can be divided into forest ecology, grassland ecology and desert ecology. And the latter can be divided into marine ecology, lake ecology, river ecology and so on. There are also finer divisions, such as plant rhizosphere ecology and intestinal ecology.
The combination of ecology and non-life science includes mathematical ecology, chemical ecology, physical ecology, geographical ecology and economic ecology. Combined with other branches of life science are physiological ecology, behavioral ecology, genetic ecology, evolutionary ecology and paleoecology.
Application branches include: agricultural ecology, medical ecology, industrial resource ecology, environmental protection ecology, urban ecology and so on.
The general law of ecology can be roughly explained from four aspects: population, community, ecosystem and the relationship between man and environment.
In the case of no obvious change in the environment, the population tends to be stable. The space and resources of a population's living environment are limited, and it can only carry a certain number of creatures. When the carrying capacity is close to saturation, if the population (density) increases again, the growth rate will be reduced, or even negative, which will reduce the population. When the population (density) decreases to a certain limit, the growth rate will rise again, and finally the population will reach a stable level allowed by the environment. Studying the natural laws of population can guide production practice. For example, making reasonable catch and forestry harvesting can not only ensure the best yield, but also do not harm the regeneration ability of biological resources.
Any species in a biological community depends on and restricts other species. Common ones are:
In the food chain, the proportion of two species living in adjacent links tends to remain relatively stable. For example, the survival of predators depends on prey, and their number is also limited by prey; The survival and quantity of prey are also restricted by predators, and the quantity between them remains relatively stable;
Competition, species often compete for the same resources: for example, plants compete for glory, space, water and soil nutrients; Animals compete for food, habitat and so on. In the long-term evolution, competition has promoted the differentiation of species' ecological characteristics, eased the competitive relationship and produced a certain biological community structure. For example, there are trees with high exultation and shrubs with low shade tolerance in the forest. Animals in the forest may be different day and night, or have different diets and do not interfere with each other;
Mutually beneficial growth For example, fungi and algae in lichens depend on each other for survival, large herbivores rely on parasitic microorganisms in the gastrointestinal tract to help digestion, and the relationship between ants and aphids shows interdependence among species. The above relationship makes the biological community present a complex and stable structure, that is, ecological balance. The destruction of balance often leads to the permanent loss of some biological resources.
The metabolic function of an ecosystem is to keep the substances needed for life constantly circulating and regenerating. The energy provided by sunlight drives the continuous circulation of substances in the ecosystem, including not only the material circulation in the environment, the nutrient transfer between organisms and the material exchange between organisms and the environment, but also the transformation of material forms such as the synthesis and decomposition of biological substances.
The normal operation of material circulation needs a certain ecosystem structure. With the evolution and diffusion of living things, a large number of inorganic substances in the environment are synthesized into living things, forming vast forests, grasslands and birds and animals living in them. Generally speaking, the material metabolism of developing biological communities is more in and less out, but when the community matures, the metabolism tends to be balanced, and the in and out are roughly the same.
People should pay attention to the law of material metabolism in the process of transforming nature. On the one hand, we can only make use of the situation in production and rationally develop biological resources, but we can't make a quick profit by making use of the situation. At present, due to the lack of timely compensation for fertility decline, a large area of farmland in the world has decreased. On the other hand, we should also control environmental pollution. Because a large number of toxic industrial wastes enter the environment, which exceeds the degradation and self-purification ability of ecosystems and biospheres, causing toxic accumulation and endangering human beings and others.
Biological evolution is the product of the interaction between biology and environment. In the course of life, organisms constantly import and export substances from the environment, and the changed material environment in turn affects or selects organisms. They always develop in the direction of mutual adaptation and coordination, which is usually called normal natural succession. With the expansion of human activities, the impact on the environment is becoming more and more obvious.
In the process of transforming nature, human beings have done many things that violate the laws of nature consciously or unconsciously, damaging their own interests. For example, the long-term deforestation, overfishing and indiscriminate exploitation of some natural resources have caused the shortage and exhaustion of resources, which cannot meet the needs of mankind; A large number of industrial pollution directly harms human health. These are all the results of the interaction between man and the environment, and they are a reaction after the destruction of nature. The general law of ecology The three laws of ecology summarized by American scientist Little Miller are as follows:
The first law of ecology: any action we take is not isolated, and any action against nature has countless effects.
Many of them are unpredictable. This law was put forward by G.Hardin and can be called the multi-effect principle.
The second law of ecology: everything is interrelated and blended with other things. This law is also called interconnection principle.
The third law of ecology: nothing we produce should interfere with the natural biogeochemical cycle on the earth. This law can be called non-interference principle.
Text:
It can be roughly explained from four aspects: population, community, ecosystem and the relationship between man and environment.
● Natural adjustment of population In the absence of obvious changes in the environment, the population tends to remain stable. The space and resources of a population's living environment are limited, and it can only carry a certain number of creatures. When the carrying capacity is close to saturation, if the population (density) increases again, the growth rate will decrease, or even appear negative, which will reduce the population. When the population (density) decreases to a certain limit, the growth rate will rise again, and finally the population will reach a stable level allowed by the environment. Studying the natural laws of population can guide production practice. For example, making reasonable catch and forestry harvesting can not only ensure the best yield, but also do not harm the regeneration ability of biological resources.
● Interdependence and mutual restriction among species. Any species in the biological community is interdependent and restrictive with other species. Common ones are: ① food chain. In the food chain, the proportion of two species living in adjacent links tends to remain relatively stable. For example, the survival of predators depends on prey, and their number is also limited by prey; The survival and quantity of prey are also restricted by predators. The number between them remains relatively stable. 2 competition. Species often compete for the same resources: for example, plants compete for glory, space, water and soil nutrients; Animals compete for food, habitat and so on. In the long-term evolution, competition has promoted the differentiation of species' ecological characteristics, eased the competitive relationship and produced a certain biological community structure. For example, there are trees with high exultation and shrubs with low shade tolerance in the forest. Animals in the forest either come out during the day or at night, or they have different diets and do not interfere with each other. 3 mutual benefit. For example, fungi and algae in lichens depend on each other for survival, large herbivores rely on parasitic microorganisms in the gastrointestinal tract to help digestion, and the relationship between ants and aphids. , all show the interdependence between species. The above relationship makes the biological community present a complex and stable structure, that is, ecological balance, and the destruction of balance may often lead to some kind of.
● Recycling of substances The metabolic function of an ecosystem is to keep the substances needed for life continuously recycled. The energy provided by sunlight drives the continuous circulation of substances in the ecosystem, including the material circulation in the environment, the nutrient transfer between organisms, the material exchange between organisms and the environment, and the transformation of material forms such as the synthesis and decomposition of biological substances. The normal operation of material circulation needs a certain ecosystem structure. With the evolution and diffusion of organisms, a large number of inorganic substances in the environment are synthesized into living substances, forming vast forests, grasslands and birds and animals living in them. Generally speaking, the material metabolism of developing biological communities is more in and less out, but when the community matures, the metabolism tends to be balanced, and the import and export are roughly the same. People should pay attention to the law of material metabolism in the process of transforming nature. On the one hand, they can only make use of the situation in production. We should rationally develop biological resources instead of short-term fishing. At present, due to the lack of timely compensation for fertility decline, a large area of farmland in the world has decreased. On the other hand, we should also control environmental pollution. A large number of toxic industrial wastes enter the environment, which exceeds the degradation and self-purification capacity of ecosystems and biospheres, resulting in toxic accumulation and destroying the living environment of human beings and other organisms.
● Interaction between biology and environment Biological evolution is the product of interaction between biology and environment. In the course of life, organisms constantly input and output substances from the environment, and the changed material environment of organisms in turn affects or selects organisms. They always develop in the direction of mutual adaptation and coordination, which is usually called normal natural succession. With the expansion of human activities, the impact on the environment is becoming more and more obvious. In the process of transforming nature, human beings have done many things that violate the laws of nature consciously or unconsciously, and have harmed their own interests. For example, the long-term logging, overfishing and indiscriminate exploitation of some natural resources have caused the shortage and exhaustion of resources, which can not meet the needs of mankind; A large amount of industrial pollution directly harms human health, which is the result of the interaction between man and the environment and a reaction after nature is destroyed. Branches ① are divided into microbial ecology, plant ecology, animal ecology, human ecology, etc. It can also be subdivided, such as insect ecology and fish ecology. ② According to the structural level of biological system, there are individual ecology, population ecology, community ecology and ecosystem ecology. ③ According to the living environment, there are terrestrial ecology and aquatic ecology. The former can be divided into forest ecology, grassland ecology and desert ecology. And the latter can be divided into marine ecology, lake ecology, river ecology and so on. There are more detailed divisions, such as plant rhizosphere ecology and intestinal ecology. ④ The combination of ecology and non-life science includes mathematical ecology, chemical ecology, physical ecology, geographical ecology and economic ecology. Combined with other branches of life science, there are physiological ecology, behavioral ecology, genetic ecology, evolutionary ecology, paleoecology and so on. ⑤ Application branches include: agricultural ecology, medical ecology, industrial resource ecology, pollution ecology (environmental ecology), urban ecology, etc. Basic principles The basic principles of applied thinking ecology usually include four aspects: individual ecology, population ecology, community ecology and ecosystem ecology.
A healthy ecosystem is stable and sustainable: it can maintain its organizational structure and autonomy in time, and it can also maintain its resilience to stress. A healthy ecosystem can maintain its complexity and meet human needs.
The application of the basic principles of ecology, I think, is a human social organization established by imitating the biological production, energy flow, material circulation and information transmission of the natural ecosystem, focusing on the natural energy flow, minimizing the artificial additional energy, seeking to produce the maximum comprehensive benefits with the minimum consumption, and solving various environmental crises facing mankind at present.
Several popular views are as follows:
1, implementing sustainable development
1987 the world commission on environment and development put forward that "it can meet the needs of contemporary people without threatening the development of future generations' ability to meet their development needs" The concept of sustainable development coordinates the relationship between society and human development, including the sustainable development of ecological environment, economy and society, but the most fundamental thing is the sustainable development of ecological environment.
2. Pay attention to the harmonious development between man and nature.
In fact, the important reason why the contemporary world is facing an unprecedented serious ecological crisis is the misunderstanding of nature in the past. Since industrial civilization, mankind has tried to dominate and conquer nature with its advanced "high technology". Although this seriously wrong concept and behavior has brought about an economic leap, the environmental problems caused by it are irreversible. As a member of the biological world, human beings must live in harmony with nature and develop together.
3. Ecological ethics
The development path that destroys the environment and consumes resources at will is an irresponsible and immoral development model for future generations and other creatures. The new ecological ethics should not only develop the economy, but also consider these behaviors of human beings, which should not only be conducive to the survival and development of contemporary human beings, but also leave enough space for future generations.
Industrial ecology, restoration ecology, ecological engineering and urban ecological construction. It is differentiated from ecology and is the result of the promotion of the basic principles of ecology.
When calculating economic output, we should not think that natural resources are worthless or infinite, but should use the concept of ecological value. We should consider the destructive impact of economic development on the environment, minimize the damage by using the progress of science and technology, and advocate a consumption mode that is conducive to a virtuous cycle of materials, that is, the concept of moderation, sustainability and health. There are many other definitions of ecology:
Ecology is a science that studies how organisms (including animals and plants) live and why they live according to their own way of life. (Elton, 1927)
Ecology is a science that studies the distribution and abundance of living things. (Andreas, 1954)
Ecology is a science that studies the structure and function of ecosystem. (European Patent Office, 1956)
Ecology is a science that studies the interaction and mechanism between living systems. (Ma Shijun, 1980)
Ecology is a comprehensive study of biology, physical environment and human society. (European Patent Office, 1997)
Some supplementary points about ecology Ecology is a young science, so it should have a very promising side, but it is often despised by other biologists and regarded as "false, big and empty". In fact, this idea is completely incorrect.
Ecology comes into being because it is closely related to our life, and it is a science used to study the relationship between biology and environment. Therefore, for an ecologist, the knowledge that ecology requires people to master is quite comprehensive, at least they should have a certain understanding of biology, environment, water temperature, geography and so on, especially the biology and environment should have a solid foundation, so an ecologist should know a lot.
It is difficult to be ecological. It is inevitable to collect samples everywhere, investigate the reasons and come back for experimental analysis.
Here I also want to talk about some reference books on ecology. First of all, as a beginner of ecology, Ecology written by Academician Li Bo of Inner Mongolia University is an excellent reference book, which is a classic in both content and layout. In fact, Yang Zhi introduced above is only his previous works (Academician Li Bo has passed away, alas). There is also Basic Ecology written by Academician Sun Ruyong of Beijing Normal University, which is also a good book. Academician Sun is still alive.
There are many branches of ecology, such as grassland ecology, and plants in Beijing are very powerful; Those engaged in water ecology are among the best in the country. I have to mention an extremely powerful person here, Academician Liu Jiankang, who is one of the founders of freshwater ecology. Now he is 93 years old and still goes to work every day. He is in good spirits and can be called a veteran.
Does ecology have a future? This is a question that many people will doubt. Personally, if you regard the future as a way of "money", I advise you not to engage in ecological research. If you really want to do something to improve the deteriorating ecological environment, you can consider it.