What does ecological disaster mean?

Ecological disasters include climate change, soil erosion, destruction of forest vegetation and extinction of wild animals. Ecological disaster refers to the disaster brought to society and human beings by the destruction of ecosystem balance.

There are two main factors that destroy the ecological balance, natural factors and human factors. Among them, human factors are the main reason for the imbalance of ecological balance. Natural factors such as floods, droughts, earthquakes, typhoons, landslides and tsunamis. The destruction of ecological balance caused by natural factors is called the first environmental problem.

Extended data

First, natural factors.

Natural factors such as floods, droughts, earthquakes, typhoons, landslides and tsunamis. The destruction of ecological balance caused by natural factors is called the first environmental problem. The destruction of ecological balance caused by human factors is called the second environmental problem.

Second, human factors.

Human factors are the main cause of ecological imbalance. Human factors mainly include the following three aspects:

(1) changed the environmental factors. For example, human production and life activities produce a lot of waste gas, waste water, garbage and so on. , continuously discharged into the environment; Unreasonable or predatory use of natural resources by human beings, such as blind land reclamation, deforestation, excessive reclamation of water surface, overloading of grassland, etc., will worsen environmental quality, have short-term or long-term effects, and make the ecological balance unbalanced.

(2) changing biological species. In the ecosystem, blindly adding a species may destroy the ecological balance. For example, the Welland Canal, which was dug by the United States in 1929, connected the internal drainage with the ocean, causing octopus to enter the internal drainage, reducing the annual output of trout from 20 million kilograms to 5,000 kilograms, seriously damaging the inland aquatic resources.

Reducing one species in the ecosystem may also destroy the ecological balance. In 1950s, China killed a large number of sparrows, which caused serious pests in some areas. The reason is that sparrows, the natural enemies of pests, have been killed, and pests have lost their natural inhibitors.

For example, in 1859, a farmer brought 25 rabbits from England to Australia, which caused serious damage to the Australian ecosystem because there were no natural enemies. For another example, 1906, Kaba forest in Arizona, USA, killed carnivores to protect deer, which led to a large number of deer breeding, and finally there was no food and it was on the verge of extinction.

(3) Damage to the biological information system. Only through mutual information contact can organisms maintain their own clusters and reproduce normally. Man-made release of a substance into the environment interferes with or destroys the information connection between organisms, which may lead to imbalance or destruction of ecological balance.

For example, many insects in nature induce male adults of the same species to mate by secreting and releasing sex pheromones. If the pollutants discharged into the atmosphere can react with them, the sex pheromones of female insects will lose their physiological activity of attracting male insects, which will inevitably affect the mating and reproduction of insects and eventually lead to the decline or even disappearance of the population.