Presentation of the influence of the environment on plants. Basic environmental factors and ecological groups of plants, presentation for a biology lesson (6th grade) on the topic. Questions and tasks
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Lesson 61. Basics environmental factors and ecological groups of plants MAOU Secondary School “Finist” No. 30, Rostov-on-Don
Lesson Objectives: Find out what environmental factors are? Get to know the main factors environment. Identify the main ecological groups of plants.
What branch of biology deals with the study of these organisms?
Let's remember What is ecology? Does the environment influence the growth and development of a living organism? Give a reasoned answer. Give examples.
VOCABULARY Environmental factors are environmental factors that affect a living organism
Classification of environmental factors
Abiotic factors Factors inanimate nature: light, temperature, air humidity, water, air composition, soil, terrain
Biotic factors Factors of living nature: plants, animals, bacteria, fungi
Anthropogenic factor Influence economic activity humans to living organisms
Abiotic factors Groups of plants in relation to light birch fern meadow plants
Pubescence of leaves (reflects rays, protects from overheating) Different intensity of evaporation and different number of stomata on a leaf Reduction (or increase) of the leaf surface, which increases (or reduces) cooling evaporation of the monstera episcia Abiotic factors Plant adaptations to temperature changes
Ecological groups of plants Light-loving plants Shape - low, branched, with a wide crown; The leaves are small, dense, with shiny thick skin and numerous stomata; covered with a waxy coating or hairs; M.B. turned edge towards the sun; The root system is well developed.
Ecological groups of plants 2. Shade-loving plants Shape – herbaceous, fragile and tender; Leaves are large, thin with a large number there are many chloroplasts and stomata on both sides of the leaf; The root system is poorly developed.
Ecological groups of plants Plants of aquatic and excessively moist places Form – herbaceous; The leaves are large, with a large number of chloroplasts, there are many stomata on the upper side of the leaf, a system of intercellular spaces is developed; The root system is poorly developed or completely absent.
Ecological groups of plants 4. Plants of dry habitats Form – herbs, trees, shrubs; Leaves – thick dense skin, pubescence or spines, few stomata, waxy coating; The root system is very well developed.
Homework Textbook § 54, 55 RT No. 182, 183
We do not live in a vacuum. Every time we have to interact with the environment. We interact with the atmosphere, temperature, humidity, other people, animals. And all this cannot but affect us. When it's too hot, you can get heatstroke if you're near standing man If you are sick with the flu, then we also have a high chance of getting infected. Also life appearance plants are directly dependent on the environment. We will learn how exactly in this lesson.
Ecology is the science of the relationships of living organisms and their communities with each other and with the environment.
An environmental factor is a phenomenon or object that affects the body.
Environmental factors:
An ecological niche is a set of conditions necessary for the existence of a certain species. Any living organism is capable of existing only at certain values of environmental factors.
Sunlight serves as a source of energy for plants, as it is necessary for photosynthesis (see Fig. 1). Light also has a regulatory effect on plant growth, flowering, and fruiting.
Rice. 1. Photosynthesis
For timothy and strawberries, light is necessary for seed germination.
Plants in relation to light:
- Photophilous (heliophytes). Able to grow only on brightly lit surfaces (feather grass, wheat, pine, black locust).
- Shade-loving (sciophytes). They can only grow in shaded areas. Burns may occur in bright sunshine ( raven eye, anemone).
Shade-tolerant. They grow well in lighted places, but can also tolerate slight shading (linden, oak, ash).
Both overheating and too low temperatures are harmful to any plant. Too high temperatures lead to loss of moisture, burns, and destruction of chlorophyll.
Action high temperatures heliophytes are susceptible, and therefore they have a number of adaptations: they can turn leaves, shed the leaf blade, leaving only the petiole, the leaves are turned into spines (cacti). Reducing the area of the leaf blade helps heliophytes avoid excessive evaporation of water. Thick white pubescence or silvery coloring of the leaves helps the plant reflect most of the rays falling on it.
When water freezes, ice crystals form in cells, damaging them. When the temperature drops to sub-zero values, the chemical processes in the cell slow down, creating an imbalance that can lead to death.
Appearance of plants in cold habitats: evergreen, with small, hard foliage, low (does not exceed the height of the snow cover) ( dwarf birch, willow).
During dry and cold periods, many plants can go into a state of dormancy, when all life processes are slowed down. In woody plants, the shoots of this year become woody and the thickness of the cork layer increases. Herbaceous plants lose all above-ground organs. Shrubs and trees are shedding their leaves. Aquatic plants sink to the bottom (duckweed), retaining only bottom leaves (water lily).
Sclerophytes are plants of arid habitats (false spotted cornflower (see Fig. 2)). They have hard leaves.
Rice. 2. False-spotted cornflower
Succulents are plants of arid habitats that are capable of storing moisture in the fleshy structures of the body - stems, leaves (aloe (see Fig. 3), cacti).
Rice. 3. Aloe
Plants in relation to humidity
- Aquatic plants and plants living in conditions of excess moisture
- Plants of dry habitats
- Plants in habitats with normal moisture
Soil chemical composition
Plants get from soil minerals. Most of all they need compounds of phosphorus, nitrogen, and potassium. They also need compounds of boron, manganese and iron.
Animals feed on plants, so plants have protective devices: needles, thorns (acacia), hard foliage (steppe plants), poisons (nightshade plants).
Other animals enter into mutualistic relationships with plants: bees, butterflies, pollinate plants. Birds spread their seeds by eating delicious berries.
Mutualism is a mutually beneficial relationship between 2 organisms.
Large plants shade smaller ones, thus creating a division into tiers. Epiphytic plants (orchids) can use others as support.
Plants participate in maintaining a constant air composition (they release oxygen and absorb carbon dioxide).
They take part in the formation of soils (root systems absorb some substances and release others). After the death of the plant most substances are returned back to the soil.
Plant roots anchor the slopes of hills and ravines and protect the soil from erosion (destruction).
Forest plantations (see Fig. 4) are used to protect fields from dry winds and fires.
Rice. 4. Forest plantings
Large woody plants evaporating large amounts of moisture. Can be used to drain wetlands (eucalyptus trees).
People cut down forests, drain swamps, and irrigate dry lands. This destroys natural habitats and creates conditions for agricultural crops. New plant varieties are being developed.
Deforestation can lead to loss of fertile soil and the formation of deserts. If irrigation is not carried out properly, soil waterlogging can occur.
Plant 3 coleus in 3 identical pots with the same soil. Grow them for a month different conditions: alone in bright light and with additional lighting, the second - in normal daylight, the third - in partial shade - 3 meters from the window. Observe the growth and development of plants. Try to draw conclusions.
Schematically sketch the shape of the crowns of trees (birch, linden, pine) grown in different light conditions. Draw conclusions.
An extreme form of plant adaptation to extreme conditions environment (cold, dry, hot) - this is suspended animation.
Anabiosis is a state of the body in which traces of vital activity are so small that there are no visible signs of life.
Thus, mosses endure winter freezing or complete drying out in a state of suspended animation, from which they return to normal activity after thawing or rain.
References
- Biology. Bacteria, fungi, plants. 6th grade: textbook. for general education institutions / V.V. Beekeeper. - 14th ed., stereotype. - M.: Bustard, 2011. - 304 p.: ill.
- Tikhonova E.T., Romanova N.I. Biology, 6. - M.: Russian Word.
- Isaeva T.A., Romanova N.I. Biology, 6. - M.: Russian Word.
- biolicey2vrn.ucoz.ru ().
- Rae.ru ().
- Travinushka.ru ().
Homework
- Biology. Bacteria, fungi, plants. 6th grade: textbook. for general education institutions / V.V. Beekeeper. - 14th ed., stereotype. - M.: Bustard, 2011. - 304 p.: ill. - With. 263, tasks and question 5, 6, 7 ( .
- What groups of plants exist in relation to light. Describe them.
- What are the environmental factors? Describe them.
- * Choose 2 plants different types and classify them into environmental groups in relation to light, humidity, temperature.
Environmental factors and their influence on plants
While studying botany, you learned that plants tropical forest and tundras, forests and meadows are different, even if they belong to the same species. While caring for cultivated plants, you noticed that some crops are especially demanding of moisture, while others need bright lighting. You know that weeds are difficult to control because they produce many seeds, which ripen before the seeds cultivated plants. Many weeds have long rhizomes, which they use to quickly reproduce. Plants are adapted to certain conditions, environmental conditions.
Let's remember what ecology and environmental factors are.
Habitat and environmental factors. All nature surrounding the plant, is his habitat . It has all the conditions necessary for growth and development of this plant, but in different quantities and ratios. Factors (conditions) external environment can directly affect the plant, they are necessary for the existence of the organism, but are not necessary for the plant. The plant is affected by factors such as light, moisture in the air and soil, temperature, the presence and concentration of salts in the soil, wind and some others.
Environmental factors name any element of the environment that can have a direct or indirect effect on the body.
Let's find out how environmental factors can affect plants. Environmental factors can limit plant growth. For example, if the soil contains a small amount of mineral salts, and a crop is cultivated on it from year to year, then the reserves of salts are exhausted and plant growth stops. If an environmental factor is below a critical level or, conversely, exceeds the maximum possible level, it becomes a limiter for plant growth, even if other factors are present. required quantity. This environmental factor is called limiting factor . IN aquatic environment Oxygen is most often the limiting factor. For plants, sun lovers(sunflower), - light. Moreover, not only the intensity of lighting is important, but also the duration.
At different stages of development, the plant reacts differently to environmental factors. It is known that the most resistant to too high or too high low temperatures are the kidneys higher plants, seeds, spores.
All factors together determine the conditions for the existence of plants, orliving conditions . It is clear that living conditions in the Far North and in the steppe zone, in the forest and in the meadow are different. But living conditions change with the seasons and even during the day. Plants, like all living organisms, have an amazing ability to respond to changes and adapt to their living conditions.
Adaptation of plants to dry and hot habitats. In arid and hot habitats, plants must be able to obtain water, retain it, avoid excessive evaporation, but also not “overheat” in the sun.
Semi-deserts and deserts are inhabited by plants with powerful root systems. Some root systems are very deep, which gives them the ability to use groundwater. So in the bushesclan Juzgun the roots go 30 m deep. In other plants (cacti) The root system is shallow but widespread, so during rare rains they quickly absorb moisture from large areas.
The third group of plants (for example, Tatar rhubarb ) does not have a highly developed root system, but they are able to absorb morning dew with their large leaves spread above the surface of the earth.
These plants tend to have thick skin and very few stomata. Their metabolic process and, as a result, growth are slowed down.
Shrubs with a deep root system do not accumulate water, but retain it. To reduce evaporation, their small leaves are densely pubescent. Often there are no leaves at all, and photosynthesis occurs in shoots that look like twigs or thorns(saxaul). When there is a lack of water, the few stomatal fissures close.
In addition to adaptations for absorbing and storing water, desert plants have the ability to tolerate even long-term drought. Among them - ephemera - plants completing their life cycle from seed to seed within a few days. Their seeds germinate and the plants bloom and bear fruit immediately after rain falls. At this time, the desert is transformed - it blooms.
These plants survive long periods of drought in the seed stage.
Perennial bulbous or rhizomatous plants survive drought in the form of underground storage organs.
Lichens survive long-term drought in the most amazing way; many lower plants, some species of mosses and ferns, even a few flowering plants: They lose all moisture and, being completely dehydrated, remain dormant until rain falls.
Adaptation of plants to cold and wet living conditions.The living conditions for plants in the tundra are very harsh. First of all, it's temperature. Average monthly summer temperatures rarely exceed +10 °C. Summer is very short - about two months, but even in summer frosts can occur.
There is little precipitation in the tundra, and accordingly the snow cover is small - up to 50 cm. Therefore, strong winds are dangerous - they can blow away the snow that protects plants. Why is there quite a lot of moisture in the tundra? Firstly, it does not evaporate as intensely as in warmer zones. Secondly, water does not go deep into the soil, as it is retained by a layer of permafrost. Therefore, there are many small lakes and swamps here.
Plants in this zone are usually stunted and covered in snow in winter, which protects them from cold and wind. Root systems- superficial. On the one hand, their development is hampered by permafrost, on the other - high humidity soil and, as a result, lack of oxygen in the soil. It is interesting that the structural features of the shoots are reminiscent of plants in hot climates, only they protect not from heat, but from cold. This is a thick skin, a waxy coating, a plug on the stem. The plants must have time to bloom and produce seeds in a short summer.
Tundra trees produce seeds that can germinate only once every century. The seeds fully ripen only when the summer for the tundra is warm for two years in a row. As a rule, tree seeds find themselves in conditions unsuitable for germination. Many tundra plants reproduce vegetatively, such as mosses and lichens.
Light as an environmental factor. The amount of light that a plant receives affects both its external appearance and internal structure. Trees grown in the forest have taller trunks and a less spreading crown. If they grew under the canopy of other trees, then they are oppressed and much less developed than their peers in open space.
Shade and light plants can also differ in the arrangement of leaf blades in space. In the shade, the leaves are arranged horizontally to catch as much sunlight as possible. In the light, where there is enough light - vertically to avoid overheating.
Plants grown in the shade have more large leaves and longer internodes than plants of the same or similar species grown in the sun.
The leaves are not the same internal structure: In light leaves, columnar tissue is better developed than in shadow leaves. In the stems of light plants it is more powerful mechanical fabric and wood.
Interactive training lesson. (Complete all lesson tasks)
Audio fragment "Environmental factors" (4:33)
ABOUTnature surrounding the body -this is his habitat. Science, studyingunderstanding the relationships between organismswith each other and with the environment,called ecology. Apply water to the plantThere are environmental environmental factors:light, temperature, humidity, wind,soil composition, etc. All factors requiredplants needed for life, defineddetermine living conditions. Excess ordeficiency of one or more ecological factors affectstructure of the body. Plants are suitableadapt to living conditions incertain boundaries.
An environmental factor thatis below critical levelor, conversely, exceeds the maxithe lowest possible level for a plantvein is called limitingfactor
The influence of anthropogenic factors on the environment The work was carried out by 1st year student of group 173 Kuzmin Yuri
The influence of anthropogenic factors on the environment. Anthropogenic factors are the result of human impact on the environment in the process of economic and other activities. They can be divided into 3 groups.
The first are factors that have a direct impact on the environment as a result of sudden, intense and short-term activities. For example: automotive gasket or railway through the taiga, seasonal commercial hunting in a certain area, etc.
Second Indirect impact through economic activities of a long-term nature and low intensity. For example: environmental pollution with gaseous and liquid emissions from a plant built near a railroad without the necessary treatment facilities, leading to gradual drying out of trees and slow poisoning heavy metals animals inhabiting the surrounding taiga.
The complex impact of the above factors, leading to a slow but significant change in the environment (population growth, increase in the number of domestic animals and animals accompanying human settlements - crows, rats, mice, etc., transformation of land, the appearance of impurities in water, etc. .p.). As a result, only plants and animals that have managed to adapt to the new state of life remain in the changed landscape. For example: coniferous trees are replaced in the taiga by small-leaved species. The place of large ungulates and predators is taken by taiga rodents and small mustelids that hunt them, etc. Third
In the 20th century anthropogenic factors began to play a significant role in changes in climate, the composition of the atmosphere and soil, fresh and sea water bodies, in the reduction of forest area, and the disappearance of many species of plants and animals.
Human influence on the environment Currently, changes are occurring in the human environment associated with the influence of the scientific and technological revolution and human economic activity. This is, first of all, pollution of the air, water bodies, mismanagement of the land, etc.
Atmospheric pollution The gas shell of the Earth is one of the important special environmental problems Today. It is known how important air is for any living organism: a person can live for a month without food, a week without water, and a few seconds without air. At the same time, what we breathe is strongly influenced by a number of factors - the results of the intensive development of industries such as fuel and energy, metallurgical, petrochemical, etc.
The fuel and energy complex includes the activities of thermal power plants, the operation of which is associated with the release into the atmosphere of sulfur oxide and nitrogen formed during the combustion of raw coal.
An equally dangerous air pollutant is the metallurgical industry, which emits various chemical compounds especially heavy but rare metals. Processed products from the petrochemical industry, especially hydrocarbon compounds (methane, etc.), have also become a dangerous source of air pollution.
A dangerous air pollutant is tobacco smoke, from which, in addition to nicotine, a large amount (about 200) of toxic substances such as carbon monoxide, benzoperine and others enter the air.
As a result of atmospheric pollution, phenomena such as the greenhouse effect have arisen - an increase in the overall temperature on Earth; ozone hole, formed as a result of the destruction of the ozone layer in the atmosphere by nitrogen oxides emitted by the engines of ballistic and space rockets. Smog is the accumulation of harmful gases in the lower layers of the atmosphere as a result of increased operation of boilers operating on coal, fuel oil, diesel fuel, as well as as a result of air pollution from vehicles. Acid rain is a combination of sulfur and nitrogen in the air with water and falling to the Earth in the form of rain (acid). Such “rain” negatively affects the skin, hair, as well as the development of plants, accelerates the corrosion of metals, destroys gypsum, marble, acidifies water bodies and soils, which leads to the death of fish, forests, and animals living in them.
The main organizational and technological methods of combating air pollution are as follows: Reducing the number of power plants (thermal power plants) through the construction of more powerful, equipped the latest systems purification and disposal of gas and dust emissions; Cleaning coal before it reaches thermal power plants; Replacing coal and fuel oil at thermal power plants with environmentally friendly fuel - gas; Engine regulation internal combustion in cars, installing special catalysts on them to neutralize carbon monoxide, replacing harmful ethyl gasoline, which pollutes the air with lead, which is less environmentally harmful. Of particular importance in purifying the atmospheric air is landscaping in cities and villages, in industrial zones.
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