Agrocenosis and agrosystems synopsis on ecology. Topic: Agrocenoses. Agroecosystems Objectives: To characterize ecosystems created as a result of human economic activity. Fundamentals of ecology. Ecosystems. Air in the soil

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If every person on a piece of his land would do everything he can, how beautiful our land would be. (A.P. Chekhov)

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Agrocenoses

Biocenoses that arise on agricultural land.

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Agrocenosis

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"Agrocenosis and agroecosystem" GBPOU RO "RKRIPT" Biology teacher Petrikina OB

Agrocenosis (from the Greek. Agros - field) is a biocenosis that occurs on agricultural lands. Examples of agrocenoses include:

Potato field Buckwheat field

Cotton field rice field

Garden Garden

The similarity of agrocenosis and biocenosis: The presence of producers The presence of consumers The presence of decomposers Plants are the initial link in the food chain Food connections between organisms The cycle of substances Daily and seasonal changes

Differences between agrocenosis and biocenosis: Reduced species diversity Short food chains The cycle of substances is incomplete (primary production is the harvest, taken by humans) Species cultivated by humans cannot compete with wild species without human support Unstable system Significant use of additional energy (muscle strength of humans, animals ; agricultural machinery) to maintain crop yields

Ideal agrocenosis plant - human plant - animal Ideal food chain of agrocenosis Consists of one single species

In agrocenoses, diverse communities of species are formed that can survive under conditions of constant anthropogenic impact Food chains of 3 - 4 links are formed, competitive interactions and other types of relationships arise between species

Inhabitants of the potato field Wireworm Potato aphid

Inhabitants of the potato field Golden potato nematode Colorado potato beetle

Inhabitants of the wheat field Cornflower Osot Ovsyug Kukol sowing

Inhabitants of a wheat field Mouse vole Ground squirrel Field slug Grain moth

Viper Wheat field inhabitants Hedgehog Quail Viper Harrier

Biological method of control Riders and egg-eaters are human helpers in the fight against agricultural pests: on the left above and below - female egg-eaters on the eggs of the host insect; top right - aphid rider; bottom right - dead aphids after the development of riders in them

Food chain in the agrocenosis Harrier Wheat Meadow mint Bread gnat Cereal moth

Agroecosystem is a territory deliberately planned by a person, where the receipt of agricultural products and the return of its components to the fields are balanced.Created by a person to obtain a high yield - pure products of autotrophs (producers)

Properly planned agroecosystems include: 1) arable land 3) livestock complexes 2) pastures (or meadows)

Peculiarities of agroecosystems: Plant nutrients taken from the fields along with the harvest are returned to the biological cycle together with organic and mineral fertilizers. Biodiversity is maintained through special landscape planning: alternation of fields, meadows, forests, copses, forest belts, water bodies, etc. The variety of species in the fields is supported by the alternation of crops, not only in time but also in space. A person controls the work of agroecosystems, introducing a significant amount of additional energy into them (tillage, irrigation, fertilizers, pesticides, etc.)

Describe the proverbs by linking them to the studied topic What you sow - so you reap It is not a problem that there is quinoa in the rye, otherwise it’s a trouble, no matter how rye or quinoa

Build food chains using the suggested organisms: wheat mouse vole quail kite ferret (ferret) already grain moth chisel meadow viper fox hedgehog

Answer the questions: Explain why crops cannot compete with weeds. Indicate the ways of returning nutrients to the soil. Why is the soil rapidly depleting in agrocenoses?

Homework Lecture notes Answer the questions: Indicate the importance of agrocenoses for providing the population with food, the development of the national economy. What are the ways to increase the productivity of agrocenoses?

Agrocenosis (from the Greek. agros –Field) -

biocenosis that occurs on agricultural land.

Examples of agrocenoses include:

• Buckwheat field

• Potato field

• Cotton field

• Rice field

• Garden

Similarities between agrocenosis and biocenosis:

• Availability of producers
• Availability of consumers
• The presence of reducers
• Plants are the first link in the food chain
• Food connections between organisms
• Cycle of substances
• Daily and seasonal changes

Differences between agrocenosis and biocenosis:

• Reduced species diversity
• Short food chains
• The cycle of substances is incomplete (primary production is the harvest, taken by man)
• Human cultivated species cannot compete with wild species without human support
• Unstable system
• Significant use of additional energy (muscular strength of humans, animals; agricultural machinery) to maintain crop yields

Ideal agrocenosis

Consists of one single species

Ideal food chain of agrocenosis

• plant - human
• plant - animal

In agrocenoses, diverse communities of species are formed that can survive in conditions of constant anthropogenic impact

Food chains of 3 - 4 links are formed, competitive interactions and other types of relationships between species arise

Inhabitants of the potato field

Wireworm

Common potato aphid

Inhabitants of the potato field

Golden potato nematode

Colorado beetle

Inhabitants of the wheat field

cornflower

Cockle

Sow thistle

Wild oats

Inhabitants of the wheat field

Field slug

Grain moth

Mouse vole

Gopher

Inhabitants of the wheat field

Viper

Harrier

Viper

Quail

Boomerang effect

In agriculture, a variety of plant protection chemicals are used in abundance - pesticides.

So regulatory links arising in agrocenoses are disrupted.

The rest of the pests gives a new, even higher outbreak.

Biological control method

Biological control method

Riders and egg-eaters are human helpers in the fight against agricultural pests: top left and bottom - female egg-eaters on the eggs of the host insect; top right - aphid rider; bottom right - dead aphids after the development of riders in them

Food chain in agrocenosis

Bread gnat

Grain moth

Wheat

Harrier

Meadow mint

Agroecosystem -

a territory deliberately planned by man, in which the receipt of agricultural products and the return of its components to the fields are balanced

Created by man to obtain a high yield - pure products of autotrophs (producers)

Properly planned agroecosystems include:

1) arable land

2) pastures (or meadows)

3) livestock complexes

Features of agroecosystems:

• Plant nutrients removed from the fields along with the harvest are returned to the biological cycle along with organic and mineral fertilizers.

• Biodiversity is maintained through special landscape planning: alternation of fields, meadows, forests, copses, forest belts, water bodies, etc.

• The variety of species in the fields is supported by the alternation of crops, not only in time but also in space.

• A person controls the work of agroecosystems, introducing a significant amount of additional energy into them (tillage, irrigation, fertilizers, pesticides, etc.)

Describe the proverbs by linking them to the topic studied

• What goes around comes around

• It’s not a problem that there is quinoa in the rye, but it’s a trouble, no matter how rye or quinoa

Build food chains using the suggested organisms:

• wheat
• mouse vole
• quail
• kite
• ferret (ferret)

• grain moth
• meadow mint
• viper
• fox

Answer the questions:

• Explain why crop plants cannot compete with weeds.

• Indicate the ways of returning nutrients to the soil.
• Why is the soil rapidly depleting in agrocenoses?

Homework

• Lecture notes
• Answer the questions:

• Indicate the importance of agrocenoses for providing the population with food, development of the national economy.
• What are the ways to increase the productivity of agrocenoses?

Agrocenoses Biocenoses that arise on agricultural lands are called agrocenoses. Gardens, parks, crops of agricultural plants are called agrocenoses. 1. Power source? Not only sunlight, but the energy of applied organic fertilizers, the energy of human labor, the energy of combustible fuel.

Agrocenoses 2. What is typical for producers? The biocenosis is distinguished by a lesser variety of species; one plant culture (monoculture), wheat, rye, and corn, is often cultivated. 3. What is typical for consumers? Fewer species, but larger numbers. The rule of the German ecologist Tienemann is fulfilled: "The poorer in species the community, the higher the number of each individual species can be."

Agrocenoses 6. In natural biogeocenoses, natural selection plays a leading role, but in agrocenoses? A significant difference is that in agrocenoses the effect of natural selection is weakened, the guiding factor is artificial selection, selection in favor of the most productive varieties of plants. 7. How does the productivity of an agrocenosis differ from the productivity of natural ecosystems in the same zone? Usually somewhat lower. The fields are empty for part of the year, the monoculture is not able to use all available resources.

Increasing the productivity of agrocenoses In 2000, 6 billion people lived on Earth. The annual net increase is 78 million people - almost the same number currently live in all of Germany. For a day, the number of earthlings increases by almost a quarter of a million people, in an hour - by 10 thousand. This leads to many problems, one of which is an increase in the productivity of ecosystems. 1. Creation of highly productive varieties of plants, resistant to diseases and adapted to different climatic zones.

Increasing the productivity of agrocenoses It is economically more profitable to create drought-resistant plants than to organize irrigation of large areas. In addition, irrigation causes secondary soil salinization, so it is more expedient to pay attention to dry farming. Cultivated plants require a high culture of farming. Without human intervention, agrocenoses of grain and vegetable crops exist for no more than a year, fruit crops for 2030 years.

Increasing the productivity of agrocenoses 2. The main resource of agrocenosis is soil. Proper and timely soil cultivation, spring and autumn plowing, loosening, additional watering is necessary. To preserve humus (soil organic matter), in many places, moldboard plowing is replaced by non-moldboard loosening of the soil; it is necessary to use organo-mineral fertilizers. The application of fertilizers should be fractional in different periods of the growing season, the plant requires various fertilizers, which must be applied in certain combinations strictly according to the norm.

Increasing the productivity of agrocenoses Examples: 1. The rabbits were dealt with by infecting them with a virus found in South American rabbits. 2.The prickly pear was dealt with with the help of a moth butterfly brought from Argentina. 3. In the last century, the Australian scale insect came from Australia to North America and then to Europe. It was possible to destroy it only after the introduction in Europe and America of a natural enemy - the ladybug.

Increasing the productivity of agrocenoses To increase biodiversity - the basis for self-regulation of biogeocenoses - it is necessary to create agroecosystems - planned territories where, in addition to agrocenoses, high biological diversity is maintained due to the alternation of fields, meadows, forests, coppices, forest belts, water bodies.

Increasing the productivity of agrocenoses The most advanced direction of modern agriculture is the transition from the principles of confrontation with nature to the principles of cooperation with it. This means maximum adherence to environmental laws in agricultural practice.