Aquatic plants (such as Sargassum), aquatic animals (such as Verticillium and Cirsium), water and sand? Environmental protection bottle

Glass bottles (such as specimen bottles, large test tubes or medical glucose injection bottles) and vaseline In general, the animals and plants you need can be bought at the flower and bird market or similar aquariums, which is not very expensive. For the requirements of color and variety, you can consult the sales staff, and remember not to enlarge the fish, because it will consume more oxygen and make the ecological bottle not last long.

How to edit this paragraph

first step

"Prepare a transparent plastic bottle (or an oil drum collected after cooking oil is used up) and cut off the upper part." There are generally two sources of bottles: one is garbage dumps and trash cans, the other is drinking drinks, and the third is eating at home. In any case, when you use it for the first time, you should clean it first. But you can't wash it with soap or detergent (children often use these things to wash easily). Because after cleaning with these chemicals, there will be soap and other residues in plastic bottles, which will bring harm to the survival of aquatic organisms. It is recommended to wash with hot water and add some baking soda if necessary. Because it is a simulated ecosystem, it is best not to put non-original items such as filters.

Second step

"Put a layer of silt at the bottom of the bottle and pour most of it? Environmental protection bottle

A bottle of water in natural waters "for children in cities," mud at the bottom of the water "and" half a bottle of water in natural waters "can't be obtained. Even in rural areas, it is dangerous for children to find "mud under the water" and "water in natural waters" after class. Moreover, according to the author's experimental results, sludge has a great influence on the water quality of the ecological bottle, and it is easy to make the whole ecological bottle very messy. Many aquatic animals and plants cannot survive in a messy ecological bottle. It is suggested to take some sand and pebbles, then wash them with tap water to remove dust and dirt, and then lay them on the bottom of the bottle to replace sludge, so as to provide a boarding place for bacteria that feed on dead plants and animal excreta. If you can't get water from natural waters, you can put tap water in a sunny place for more than two days, which will breed some microorganisms. After the ecological bottle is filled with water, the exact position of the water surface is marked on the outside of the ecological bottle with adhesive tape. Because when the water in the bottle is constantly evaporating, the mineral concentration in the water will be higher and higher. In order to maintain a balanced environment, it is necessary to replenish water to maintain the water in the bottle.

Third step

"Plant some plants with roots in the bottle and put some duckweeds on the water." It should be noted that plants added to ecological bottles are generally algae, so water should be added first? Environmental protection bottle

Put the plants away, then put them away, to avoid washing them when adding water. One child didn't notice such a detail, but he didn't plant any water plants all afternoon. Eco-bottles filled with water and planted with aquatic plants usually need to wait for several hours to allow some turbidity in the water to settle down before being put into aquatic animals.

Fourth step

"Put snails, small fish, shrimp, loach, etc."? If you use an oil drum, you can put a few small fish in it. Many students will find that fish are easy to die on the first day in an ecological bottle. On the first day, the water quality of the ecological bottle was very good. Why do fish die so easily? Actually, fish can't adapt to the new environment. Most fish are very sensitive to sudden changes in water temperature. When the fish is suddenly replaced by water with different temperature, it is easy to die naturally. Therefore, it is also exquisite to put fish in ecological bottles. You can put a plastic bag in the original fish tank, transfer the fish to this plastic bag, and then transfer the water and fish to the ecological bottle. After about 1.5 hours, you can safely put the fish in its new home. Many students will ask the teacher, how many fish should be put in an ecological bottle? The number of fish preserved in ecological bottles is directly related to the volume of water in ecological bottles and the amount of oxygen available to fish in water. If you keep goldfish, you can put two or three adult goldfish every 4 liters of water. Another way to judge whether there are too many fish in an ecological bottle is to pay attention to whether there are any fish floating on the water and constantly "panting". If this happens, it means that there is not enough dissolved oxygen in the water, or there is something wrong with the water quality or too many fish are put in. Snails, small fish and shrimp are hard to eat by children in the city. We can use water snails instead. Generally, one or two water snails can be put in a 20-liter bottle. Water snails breed quickly. Soon you will find colloidal eggs on the bottle wall or on the water. Within two weeks, you and your students will observe that eggs begin to hatch into small snails. Water snails mainly feed on green algae, which is a green film-like substance growing on the bottle wall. Note that the sunshine amount of ecological bottle is directly related to the growth rate of green algae. In a balanced ecological bottle, the amount of green algae increased every day should be similar to that of water snails. ? Environmental protection bottle

With this eco-bottle, once a week, we can organize students to discuss according to their observation records, so that they can guess the reasons for the observed changes or predict what may happen to this aquatic ecosystem. The whole activity lasts at least two weeks, which is different from the teaching time in the textbook design. It is necessary to adjust the teaching progress. Put a layer of bottom mud at the bottom of the bottle and more than half of the water in natural waters. For children in cities, "bottom mud" and "water in natural waters" are unavailable. Even in rural areas, it is a dangerous behavior for children to look for "mud under the water" and "water in natural waters" after class. Moreover, according to the author's experimental results, sludge has a great influence on the water quality of the ecological bottle, and it is easy to make the whole ecological bottle very messy. Many aquatic animals and plants cannot survive in a messy ecological bottle. It is suggested to take some coarse sand or fine stone, put it on a large filter screen, then rinse it with tap water to remove dust and dirt, and then lay it on the bottom of the bottle to replace sludge, so as to provide a boarding place for bacteria who eat dead plants and animal excreta for a living. If water in natural water is not available, overnight water can be used instead. When making overnight water, tap water should be allowed to stand for at least 24 hours in advance to ensure enough time warp and remove chlorine-containing chemicals. Most aquatic organisms are sensitive to chlorine-containing substances, and contact with these substances is easy to die. After the ecological bottle is filled with water, the exact position of the water surface is marked on the outside of the ecological bottle with adhesive tape. Because when the water in the bottle is constantly evaporating, the mineral concentration in the water will be higher and higher. In order to maintain a balanced environment, it is necessary to replenish water to maintain the water in the bottle. Of course, the supplementary water can only be overnight water. What can be put in the environmental protection bottle? Eco-bottle can simulate the pond ecosystem. From this, we can understand the interaction and influence among various ecological factors in the ecosystem and deepen our understanding of nature.

Edit the experimental principle of this paragraph.

In the ecological bottle, shrimp feed on green algae and absorb oxygen released by photosynthesis of green algae to survive. Green algae rely on their own chlorophyll, and use sunlight, water and carbon dioxide exhaled by shrimp for photosynthesis to synthesize their own glucose and release oxygen at the same time. The excrement discharged by shrimp is decomposed by bacteria, and the decomposed excrement is just the fertilizer of green algae. The two complement each other and exist for a long time. Conclusion Eco-bottle is actually a microcosm of the earth's ecosystem. In the teaching of ecosystem, the interdependence between biology and environment is vividly and intuitively displayed. The ecological bottle is simple to manufacture and can be used for a long time.

Edit this paragraph to change the observation.

Reducing water and adding animals and plants to ecological bottles will cause changes in ecological communities. Reducing the amount of water and increasing the number of animals will increase the number of times fish come out to breathe. ? In an ecosystem similar to the "ecological bottle", survival competition refers to the natural phenomenon that individuals of the same or different species compete with each other to maintain individual survival and racial reproduction. Including intraspecific competition (competition between individuals of the same species), interspecific competition (competition between individuals of different species) and the struggle between biological individuals and ecological environment. The high fecundity of organisms is an important reason for survival competition. All creatures tend to breed at high speed, and the things and living space on the earth are limited, which will inevitably lead to competition. Because individuals of the same species have the most similar needs for things and space, intraspecific competition is often stronger than interspecific competition. The result of survival competition is the survival of the fittest and the elimination of the weak. Creatures that adapt to the environment can not only get a chance to survive, but more importantly, they can reproduce better. The theory of survival competition is the main part of Darwin's theory of evolution with natural selection as its core. All kinds of creatures in nature and all kinds of things in their living space constitute a symbiotic ecosystem. This ecosystem is a harmonious whole, which takes a long time to form. If any link is destroyed, the ecosystem in the ecological bottle may be out of balance.