Food chain hazel thrush hawk. Family: Ipidae = Bark beetles. Food chains in deciduous and mixed forests

Family Bark beetles (Scolytidae).

Very close to elephants, differing mainly in the shape of the head, not extended into the rostrum. An adult bark beetle has an elongated cylindrical body, 1-8 mm long, articulated bark beetle antennae with a clearly demarcated large club, and short legs with thin paws, the segments of which, as a rule, do not bear pads on the underside. Bark beetle larvae are white, legless, thick and short, with a C-shaped body and a large brown head.

Unlike elephants, female bark beetles, when laying eggs, drill into plant tissues with their whole body and lay special uterine passages in them. If elephants very rarely develop under the bark and in the wood of dying trees, then bark beetles, with rare exceptions, lead just such a way of life. Only a few bark beetles live in the stems of herbaceous plants, inside fruits and seeds. In the forest, one can often find standing or fallen trees, the bark of which is covered with small heaps of sawdust. If the sawdust is swept away, a round inlet opens in the bark, and soon the host himself appears - a small bark beetle, which, moving backwards, pushes out another portion of ground wood or bark.

The biology of the bark beetle is very interesting. During the breeding season, they form families. Some species of bark beetle form a monogamous family, consisting of a male and a female, some - a polygamous family, which consists of a male and several females. In the first case, the uterine passage in the bark is gnawed out by the female, to which the male bark beetle then flies. In polygamous families, the beginning of work falls on the lot of the male, who gnaws out a fairly large marriage chamber. When the chamber is ready, several female bark beetles enter there, each of which, after mating, begins to gnaw its own uterine passage. The elytra of many species of bark beetles are specially adapted for throwing sawdust out of the passages: their tops are depressed, forming a recess, along the edges of which there are teeth. The entire device as a whole is called "cars". When several passages depart from the marriage chamber of the bark beetle, some of them are laid up, and some - down the trunk. From the upper passages, the gnawed drilling flour is poured out without much effort, while it must be specially taken out of the downward passages. Therefore, the female bark beetle, making a move, pushes the gnawed sawdust to the rear end of the body, where they fall into the "wheelbarrow". Backing back, the beetle carries this portion of drilling flour out of the way out. Sometimes the male helps the female.

Some bark beetles do not build their own uterine passages, but climb into the passages of other bark beetles, using their walls to lay eggs. Even without peeling off the bark, you can determine where the bark beetle passes: if the sawdust is brown, the beetle gnaws under the bark; if they are white, the course is laid in the depths of the wood. From the eggs of the bark beetle laid in the walls of the uterine passages, larvae hatch, which lay their own larval passages. As a result, a “bark beetle nest” appears, the system of moves of which is characteristic of certain species of bark beetles. Therefore, knowing the type of tree and having a sample of the nest in front of you, you can accurately name the species of bark beetle pest. Some bark beetles, laying the uterine passage, gnaw several holes along it - vents. With an increase in the moisture content of wood, the number of vents increases. If the vents are closed, the female gnaws them out again. These holes are often used for repeated mating of the bark beetle. The direction of the uterine passages often makes it possible to determine when the tree was populated - before or after it fell to the ground. Bark beetles that attack standing trees usually lay their mother passages up, which makes it easier to push out the dust. Moves on fallen trees are laid more randomly.

When choosing breeds, bark beetles are guided by their sense of smell. It is by smell that they can not only accurately select the forage species they need, but also distinguish a weakened tree from a healthy one. The smell of a tree favorable for the development of offspring is caught by bark beetles at a distance of 500 - 1000 m. The ability to perceive odors in males is less pronounced, and usually several times more females than males fly to the populated trunk. It is not easy for bark beetles to populate the tree. As soon as the bark beetle has time to drill an inlet, sap begins to flow from there, and resin in coniferous trees. The first settlers often die. But a weakened tree, having exhausted its small reserves of protective agents, eventually ceases to resist and becomes the prey of bark beetles. The first successfully introduced bark beetles begin to build uterine passages and throw out the spent dust. The smell of this dust, testifying to the defenselessness of the tree, is especially subtly perceived by bark beetles.

It is from this moment that the mass settlement of the defeated trunk by whole hordes of bark beetles begins. But there won't be enough space for everyone who comes. In obedience to instinct, bark beetles lay moves no closer than a certain distance from each other; soon the entire useful surface of the trunk is divided, and late females fly away with nothing. When, during periods of mass reproduction of bark beetles, there are not enough weakened trees, many of the most common species attack healthy trees as well. The first groups of settlers perish, drowning in resin or sap, but weaken the tree so much that the bark beetles following them can easily populate the trunk. Many species of bark beetle weaken trees even earlier, when young bark beetles feed by gnawing on crown branches. These bark beetles are aptly named "forest gardeners" - after all, after their attack, tree crowns look trimmed. Such a "haircut" of trees greatly reduces their resistance to colonization by bark beetles.

Bark beetle larvae develop relatively quickly. For most species, this is natural, since their food - fresh bark - contains a sufficient amount of sugars and protein compounds. There are no such readily available substances in the thickness of the wood, however, some bark beetles successfully develop here. How do these larvae feed? Symbiotic mushrooms come to their aid. It turned out that female bark beetles, and sometimes males of such bark beetles, have devices for storing fungal spores in the form of recesses at the base of the legs or mandibles or in the form of cuticular tubules in the prothorax. When the bark beetles leave the mother's passage, these pockets fill with fungal germs. Gnawing a gallery in the wood for their offspring, females scatter fungal spores from their pockets. These spores give rise to mycelium, which covers the walls of the passages. It feeds on the larvae of woodworms. Bark beetles are massive forest pests. Attacking weakened trees, bark beetles quickly cause their death and prepare the conditions for the settlement of the next set of pests, which finally render the wood unusable.

Therefore, the fight against bark beetles is one of the central issues of the forest protection service. In this case, the main attention should be paid to preventive measures - the timely removal or destruction of diseased trees, logging residues, deadwood. The littering of the forest is always accompanied by the reproduction of pests, a clean and healthy forest can suffer from pests only in exceptionally rare cases. Each tree species has its own characteristic set of bark beetle species. The species composition of bark beetles that damage spruce is very diverse. Bark beetles (Dryocoetes) - short beetles with a wide massive body, yellow or dark brown, in dense long hairs. These bark beetles do not have a typical "wheelbarrow", but the posterior edge of their elytra is oblique, flattened and covered with strong bristles, so that it can serve to throw out the dust from the passages. The listed species are far from exhausting the entire diversity of the complex of spruce bark beetles.

A food chain is the transfer of energy from its source through a series of organisms. All living beings are connected, as they serve as food objects for other organisms. All food chains consist of three to five links. The first are usually producers - organisms that themselves are able to produce organic substances from inorganic ones. These are plants that obtain nutrients through photosynthesis. Next come the consumers - these are heterotrophic organisms that receive ready-made organic substances. These will be animals: both herbivores and carnivores. The closing link of the food chain is usually decomposers - microorganisms that decompose organic matter.

The food chain cannot consist of six or more links, since each new link receives only 10% of the energy of the previous link, another 90% is lost in the form of heat.

What are food chains?

There are two types: pasture and detritus. The former are more common in nature. In such chains, the first link is always the producers (plants). They are followed by consumers of the first order - herbivorous animals. Further - consumers of the second order - small predators. Behind them - consumers of the third order - large predators. Further, there may also be fourth-order consumers, such long food chains are usually found in the oceans. The last link is the decomposers.

The second type of power circuits - detritus- more common in forests and savannahs. They arise due to the fact that most of the plant energy is not consumed by herbivorous organisms, but dies off, then being decomposed by decomposers and mineralized.

Food chains of this type start from detritus - organic residues of plant and animal origin. First-order consumers in such food chains are insects, such as dung beetles, or scavengers, such as hyenas, wolves, vultures. In addition, bacteria that feed on plant residues can be first-order consumers in such chains.

In biogeocenoses, everything is connected in such a way that most types of living organisms can become participants in both types of food chains.

Food chains in deciduous and mixed forests

Deciduous forests are mostly distributed in the Northern Hemisphere of the planet. They are found in Western and Central Europe, in Southern Scandinavia, in the Urals, in Western Siberia, East Asia, North Florida.

Deciduous forests are divided into broad-leaved and small-leaved. The former are characterized by such trees as oak, linden, ash, maple, elm. For the second - birch, alder, aspen.

Mixed forests are those in which both coniferous and deciduous trees grow. Mixed forests are characteristic of the temperate climate zone. They are found in the south of Scandinavia, in the Caucasus, in the Carpathians, in the Far East, in Siberia, in California, in the Appalachians, near the Great Lakes.

Mixed forests consist of trees such as spruce, pine, oak, linden, maple, elm, apple, fir, beech, hornbeam.

Very common in deciduous and mixed forests pasture food chains. The first link in the food chain in the forests are usually numerous types of herbs, berries such as raspberries, blueberries, strawberries. elderberry, tree bark, nuts, cones.

First-order consumers will most often be such herbivores as roe deer, elk, deer, rodents, for example, squirrels, mice, shrews, and also hares.

Second order consumers are predators. Usually it is a fox, wolf, weasel, ermine, lynx, owl and others. A vivid example of the fact that the same species participates in both pasture and detrital food chains will be the wolf: it can both hunt small mammals and eat carrion.

Second-order consumers can themselves become prey to larger predators, especially birds: for example, small owls can be eaten by hawks.

The closing link will be decomposers(decay bacteria).

Examples of food chains in a deciduous-coniferous forest:

• birch bark - hare - wolf - decomposers;
• wood - Maybug larva - woodpecker - hawk - decomposers;
• leaf litter (detritus) - worms - shrews - owl - decomposers.

Features of food chains in coniferous forests

Such forests are located in the north of Eurasia and North America. They consist of trees such as pine, spruce, fir, cedar, larch and others.

Here everything is very different from mixed and deciduous forests.

The first link in this case will not be grass, but moss, shrubs or lichens. This is due to the fact that in coniferous forests there is not enough light for a dense grass cover to exist.

Accordingly, the animals that will become consumers of the first order will be different - they should not eat grass, but moss, lichens or shrubs. It can be some types of deer.

Despite the fact that shrubs and mosses are more common, herbaceous plants and bushes are still found in coniferous forests. These are nettle, celandine, strawberry, elderberry. Hares, moose, squirrels usually eat such food, which can also become first-order consumers.

The consumers of the second order will be, like mixed forests, predators. These are mink, bear, wolverine, lynx and others.

Small predators such as mink can become prey for third order consumers.

The closing link will be the microorganisms of decay.

In addition, in coniferous forests are very common detrital food chains. Here, the first link will most often be plant humus, which is fed by soil bacteria, becoming, in turn, food for unicellular animals that are eaten by fungi. Such chains are usually long and may consist of more than five links.

Examples of food chains in a coniferous forest:

• pine nuts - squirrel - mink - decomposers;
• plant humus (detritus) - bacteria - protozoa - fungi - bear - decomposers.

For me, nature is a kind of well-oiled mechanism, in which everything is provided for to the smallest detail. It's amazing how everything is thought out, and it is unlikely that a person will ever be able to create something like this.

What does the term food chain mean?

According to the scientific definition, this concept includes the transfer of energy through a number of organisms, where the first link is the producers. This group includes plants that absorb inorganic substances, from which they synthesize nutritious organic compounds. Consumers feed on them - such organisms that are not capable of independent synthesis, which means that they are forced to eat ready-made organic matter. These are herbivores and insects, which act as a "lunch" for other consumers - predators. As a rule, the chain contains about 4-6 levels, where the closing link is represented by decomposers - organisms that decompose organic matter. In principle, there can be much more links, but there is a natural "limiter": on average, each link receives little energy from the previous one - up to 10%.

Examples of food chains in a forest community

Forests have their own characteristics, depending on their type. Coniferous forests do not have rich herbaceous vegetation, which means that food chains will have a certain set of animals. For example, a deer enjoys eating elderberry, and he himself becomes the prey of a bear or lynx. For a broad-leaved forest there will be a set. For example:

• bark - bark beetles - titmouse - falcon;
• fly - reptile - ferret - fox;
• seeds and fruits - squirrel - owl;
• plant - beetle - frog - already - hawk.

It is worth mentioning the scavengers who "recycle" organic remains. There are a great many of them in the forests: from the simplest unicellular to vertebrates. Their contribution to nature is enormous, because, otherwise, the planet would be covered with the remains of animals. They also convert dead bodies into inorganic compounds that plants need, and everything starts anew. In general, nature is perfection itself!

Target: expand knowledge of biotic environmental factors.

Equipment: herbarium plants, stuffed chordates (fish, amphibians, reptiles, birds, mammals), insect collections, animal wet preparations, illustrations of various plants and animals.

Working process:

1. Use the equipment and make up two power circuits. Remember that a chain always starts with a producer and ends with a decomposer.

________________ →________________→_______________→_____________

2. Recall your observations in nature and make two food chains. Sign producers, consumers (1st and 2nd orders), decomposers.

________________ →________________→_______________→_____________

_______________ →________________→_______________→_____________

What is a food chain and what underlies it? What determines the stability of the biocenosis? Formulate a conclusion.

Conclusion: ______________________________________________________________________________________________________________________________________________________________________________________________________________________________

3. Name the organisms that should be in the missing place of the following food chains

1. From the proposed list of living organisms, make a food web:

2. grass, berry bush, fly, titmouse, frog, snake, hare, wolf, decay bacteria, mosquito, grasshopper. Indicate the amount of energy that passes from one level to another.

3. Knowing the rule of energy transfer from one trophic level to another (about 10%), build a biomass pyramid of the third food chain (task 1). Plant biomass is 40 tons.

4. Conclusion: what do the rules of ecological pyramids reflect?

1. Wheat → mouse → snake → saprophytic bacteria

Algae → fish → seagull → bacteria

2. Grass (producer) - grasshopper (consumer of the 1st order) - birds (consumer of the 2nd order) - bacteria.

Grass (producers) - elk (consumer of the 1st order) - wolf (consumer of the 2nd order) - bacteria.

Conclusion: A food chain is a series of organisms that feed on each other in succession. Food chains begin with autotrophs - green plants.

3. flower nectar → fly → spider → tit → hawk

wood → bark beetle → woodpecker

grass → grasshopper → frog → snake → serpent eater

leaves → mouse → cuckoo

seeds → sparrow → viper → stork

4. From the proposed list of living organisms, make a food web:

grass→grasshopper→frog→snake→rot bacteria

bush→hare→wolf→fly→decay bacteria

These are chains, the network consists of the interaction of chains, but they cannot be indicated in the text, well, something like this, the main thing is that the chain always begins with producers (plants), and always ends with decomposers.

The amount of energy always goes according to the rules of 10%, only 10% of all energy goes to each next level.

Trophic (food) chain - a sequence of species of organisms, reflecting the movement in the ecosystem of organic substances and the biochemical energy contained in them in the process of feeding organisms. The term comes from the Greek trophy - nutrition, food.

Conclusion: Therefore, the first food chain is pasture, because begins with producers, the second - detrital, because. starts with dead organics.

All components of food chains are distributed into trophic levels. The trophic level is a link in the food chain.

Spike, plants of the grass family, monocots.

There are a great variety of plants and animals on earth. All of them are forced to ensure their livelihoods, eating and processing vital energy. Thus, their interaction always unites beings in whose links energy also passes from one to another.

Food chains

These sequences, of course, have their own characteristics. But in general, absorption and interaction occurs according to general laws and rules that are characteristic of almost any habitat. After all, what is By and large, this is a situation where nutrients and energy are transferred from one living organism to another in a sequential manner. Links, as a rule, are formed from producers and consumers (of various levels). The first in the chain feed on non-organic matter, extracting food for their livelihoods directly from the soil, air and water. For example, most plants use the phenomenon of photosynthesis. And bacteria living in almost any environment feed on minerals and gases. Consumers continue the sequence. The first level - they eat plant foods (producers) and are called herbivores (herbivores). The second, third, fourth levels of consumers eat animal food - they are carnivores, or predators.

A large predator closes the food chain, becoming the head. Usually there are not so many such representatives in a certain environment. Nature assigns a special role to scavengers, microorganisms that process dead flesh, turning it into inanimate matter. After all, if not for them, the whole earth would be strewn with the corpses of plants and animals!

Food chains in deciduous forests. Examples

After a few words about the theory, let's move on to the practice of compilation. Any food chain for broad-leaved forests is provided by the rich species diversity of plants and animals that live here. Rough vegetation feeds such herbivorous mammals as small rodents, hares, deer, elk, roe deer. They mainly feed on dense grasses in glades, bark and branches of trees and shrubs, berries, mushrooms, nuts. All these types of food can be found in abundance - animals will always have something to profit from, even in the cold winter. Predators also live here, serving as links in the food chain in broad-leaved forests. Their way of life is fundamentally different from herbivores. Foxes and wolves, weasels and weasels, lynxes and martens, birds of prey. Basically, they prey on other animals. The inhabitants of the forest are also characterized by smaller predators (amphibians, for example), which can also become prey for large carnivores. Accordingly, food chains are formed in broad-leaved forests. They are sometimes multi-level and intertwined with each other in the middle links.

Here are some of them:

1. Birch bark - hare - fox.
2. Tree (bark) - bark beetle - titmouse - hawk.
3. Grass (seeds) - forest mouse - owl.
4. Grass - insect - frog - already - a bird of prey.
5. Insect - reptile - ferret - lynx.
6. Leaves - earthworm - thrush.
7. Fruits and seeds of trees - squirrel - owl.
8. Leaves - caterpillar - beetle - titmouse - falcon.

Conservation and loss of energy

Creatures of the previous link in the food chain in deciduous forests serve as a food base for the next link. Thus, the transfer of energy from one organism to another and the circulation of substances in nature are carried out. But at the same time, a huge part of this energy is lost (up to 90%). This is probably why the number of links in the food chain in broad-leaved forests, as a rule, is no more than five or six at the maximum.