If large carnivores are extinct, will the ecosystem crash?

Or because of its huge body, or the human beings itself is at the top of the food chain, we will pay more attention to large carnivial animals at a higher food chain. Therefore, compared to small and grassy animals, we subconsciously believe that large carnivorous animals will be more important in the ecosystem. People can't help but think that if large carnivores are extinct, will ecological balance be broken, and will the ecosystem eventually fail to fix and collapse?

Image source: veer gallery

1. It can be replaced between the same nutritional species

In the ecosystem, between the biology and the creature, the biological and the inorganic environment can make it dynamic balance through energy flow, material circulation, and information transmission. At the same time, the ecosystem has the ability to maintain its own stability. It is generally believed that the more complicated its food network, the stronger its ability to recover.

In a more stable ecosystem, the extinction of a certain species can be replaced by other similar species. For example, in the grassland ecosystem, when large carnivores are extinct, the number of herbivores stares will increase sharply in a short time. The number of grass will also decrease sharply; if there are another kind of carnivores (such as wolf) in addition to cheetah, once the cheetah will increase the predation pressure on the deer, it will not cause the deer to develop too much. Large, it is possible to prevent the collapse of the ecosystem.

Wolf and cheetah are hunting (picture source: Veer gallery)

In fact, wolves and cheetahs can be at the same nutrition level in the food network. Different species of the same nutrition level have the same "role". Therefore, the extinction of cheetahs can be "replaced" by the wolf. For details, different species located in the same nutrition level can complete the material circulation, energy flow, and information transmission function in the ecosystem of the same degree.

Back to the initial assumption, if we can find other things that can complete the same degree of material circulation, energy flow, and information transmission function in the ecosystem in the ecosystem, or the extinction of large carnivorous animals will not affect these three major functions through these three major functions To destroy the ecological balance, then we believe that the ecosystem will not collapse due to the extinction of large carnivores.

2. Can be replaced during energy flowing

Therefore, in terms of energy flow, energy flow is one -way. It can only flow from the first nutrition level to the second nutrition level. Subscribed step by step, the transmission efficiency between the two adjacent nutrition levels is about 10%to 20%.

Therefore, there are very few energy obtained by large carnivorous animals. Most energy is concentrated at the bottom of the species, that is, between green plants and herbivores. In other words, even if large carnivorous animals are extinct one after another, the process of energy flow is almost unaffected. Large carnivores can be replaced during energy flow.

Almost all the energy on the earth comes from the sun (picture source: Veer gallery)

At the same time, the material cycle of the ecosystem refers to the cycle of C, H, O, N, P and other elements that constitute organisms, and constantly carry out cycle from the inorganic environment to biological communities to the inorganic environment. For example, carbon elements are mainly used in the form of green plants from the inorganic environment in the form of carbon dioxide, and then transmitted by the food chain and the food network between the organisms. Enter the atmosphere.

If large carnivorous animals are extinct one after another, the breathing effect of creatures will be affected to some extent (such as the extinction of cheetahs on the grassland ecosystem, the increase in the number of gazelles will increase the corresponding increase in respiratory effects). The material cycle of the ecosystem has basically no effect, and large carnivores can be replaced in the material cycle.

Material cycle (picture source: panoramic network)

Third, the impact on ecosystem information is very small

Finally, as far as information is concerned, after the extinction of large carnivores, the information transmission pattern of the ecosystem will change, but the overall will not be too affected, because the predator is not available. The alertness of herbivorous animals will decline, but the decline in the alertness will not threaten their own survival. system breakdown.

For the flood of the number of other animals such as herbivorous animals that may be worried about, predation is only one of the factors restricting its number. The increase in the number of aggressive populations includes endogenous and exogenous factors, predation is only one of the exogenous factors, and the exogenous factors include diseases, parasites, natural disasters, food restrictions, etc. Endocrine regulation, etc., these behaviors will not change within a short period of time because the predators are disappearing in a short period of time. These factors will limit the growth of the number of other species.

Death deer (picture source: Veer gallery)

In summary, from the perspective of "collapse", even if all large carnivorous animals are extinct, the ecosystem will not completely collapse. After a long evolution, the ecology can be restored to one. Look. Even if all the animals and plants are gone, the bacteria can continue to maintain the activity of the earth's biosphere. Moreover, "large carnivores" will not cause much animal extinction. The number of herbivores as food can be controlled Essence

Produced: Popular Science China

Author: Jia Wei Supervision: China Science Popularization Expo

references:

[1] Justine L. Atks, Ryan A. Long, Johan Pansu, Joshua H. Daskin, Arjun B. Potter, Marc E. Stalmans, Corina E. Tarnita, Robert M. Privele. Cascading IMPACTS OF LARENINININININT IPINT IPINT IPINT IPINT IPINT IPINT IpAFrican Ecosystem [J]. Science, 2019,364 (6436).

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