Biodiversity or biological diversity is the quantity and variety of both life forms and ecosystems that there is on the planet of which they are part.
Biological diversity is constantly changing, as genes, organisms and ecosystems evolve to adapt to the environment. An example is the fact that there are dog breeds that no longer exist or that have been adapted to become domestic animals. Another example is human activity influencing the habitat of animals, so that some species migrate to survive.
Importance of biodiversity
Bees are essential in the pollination process, which in turn maintains biological balance.
Biodiversity is responsible for generating the balance of the ecosystems of the entire planet. This is vital, as all species depend on this delicate balance to survive.
Biodiversity is important for the generation and maintenance of life on Earth, including the human species. Without it, the absence of interactions between species would lead to the disappearance of a large part of them. Species need each other to feed, produce or provide necessary nutrients, and even reproduce.
Imbalances in ecosystems alter biological cycles, food chains, climatic conditions, etc. This threatens the existence of species and ideal conditions that allow life.
For example, bees play an essential role in pollinating flowers, which allows them to reproduce and generate flowers, fruits and various foods. If bees become extinct due to climate change or pollution, this process would be drastically altered, putting flowers at risk. As a result, other species would be affected by the absence of flowers as a food source.
Therefore, it is crucial to safeguard biodiversity on our planet. Biological diversity is divided into three types: genetic diversity, species diversity and ecosystem diversity.
Types of biodiversity
There are three types of biological diversity according to variety of genes of a species, the variety of species and the variety of existing ecosystems. Below, we describe each type of biodiversity.
1. Genetic diversity
It refers to the variety of genetic information that exists in organisms of the same species. This allows species to evolve and adapt to their environment.
An example of genetic diversity is that of the “Darwin finches” of the Galapagos Islands. There, naturalist Charles Darwin realized that the beaks of finches were different depending on the food source available in the area of the island where they were found.
These anatomical differences meant that only those finch species whose beaks were adapted to eat local seeds could survive and transmit that genetic information.
2. Species diversity
It refers to the variety and number of species that exist on the planet. When we talk about species we are referring to the basic unit of biological classification that groups organisms with similar characteristics that can generate offspring.
There is no exact figure for the number of existing species because new groups of organisms are constantly being discovered. But it is estimated that it could reach 10 million species. For example, there are 37 different species of dolphins known (Delphinidae).
The diversity of species is greater in tropical or warm areas. This is because its conditions are more favorable for the emergence of life than in the temperate or cold zones of the planet.
3. Diversity of ecosystems
It is the variety of organisms that interrelate in ecosystems, whether aquatic or terrestrial. In turn, ecosystem biodiversity is divided into three types:
Alpha diversity: is the variety of organisms that exist in an ecosystem. For example, when studying the number of species that live in a certain river, which is an aquatic ecosystem.
Beta Diversity: refers to the variety of organisms that exist in interrelated ecosystems. For example, at the mouth of a river that goes to the sea, two aquatic ecosystems interact: that of the river, which is freshwater, and that of the ocean, which is saltwater. In each of them there are animal and plant species that relate to each other in order to live.
Gamma diversity: is the variety of organisms that exist in a given geographic area, including all its ecosystems. For example, in the Amazon rainforest there are terrestrial ecosystems such as tropical forests and freshwater aquatic ecosystems such as rivers and lakes, to name a few.
See also Diversity and Natural Selection.
Causes of biodiversity loss
Planet Earth has lost its biological diversity at different periods. For example, 12,000 years ago a drop in temperatures known as glaciation occurred, which extinct most of the species at that time.
But now, biodiversity loss is largely driven by human actions, such as climate change, animal hunting, and environmental pollution.
Climate change
Over time, the planet’s climate has changed naturally due to cataclysms or volcanic eruptions. However, the accelerated technological evolution of the last hundred years brought with it an increase in temperature. The cause of this is the use of fossil fuels such as oil, which generates a concentration of gases in the atmosphere.
This phenomenon artificially alters the planet’s temperature, causing extreme heat waves, increasingly colder winters, more frequent formation of storms and hurricanes, etc. These changes impact biodiversity by changing the conditions that make life possible.
For example, El Niño is a climate event related to the warming of ocean currents in the Pacific Ocean. This generates intense rains, floods and the appearance of pests in agricultural areas.
poaching
Poaching is the illegal capture of animal or plant species. Hunting species in danger of extinction or those found in protected areas harms biodiversity by reducing the number and variety of living species.
Poaching can cause the extinction of a species. This is the case of the glaucous macaw (Anodorhynchus glaucus), a species that existed in Paraguay, Uruguay, Bolivia and Argentina, and that disappeared due to indiscriminate hunting.
Environmental pollution
Forest fires pollute the air and alter ecosystems, affecting biodiversity.
An environment becomes contaminated when elements or substances are introduced that alter its original conditions. These alterations generate changes in the quality of air, water and soil that impact the natural cycles of ecosystems and their biodiversity.
Some polluting agents are:
Organic waste: such as fruit peels, tea bags, food remains or animal excrement, among others. Many times this type of waste goes directly to the ground or water, contaminating them.
Urban solid waste: such as paper, cardboard, plastic or glass. In many countries there are policies for the separation and recycling of solid waste, but in places where this does not occur, this waste ends up in sanitary landfills that contaminate the environment.
Petroleum: This hydrocarbon is composed of chemicals such as benzene, which is toxic to humans and contaminates water. Furthermore, when oil is extracted, the use of chemicals that contaminate the soil is required.
Radiation: a radioactive element is one that has an imbalance between the number of protons and neutrons; therefore, it is unstable. High-dose radiation causes harm to humans and the environment. An example is what happened at the Chernobyl nuclear plant in 1986, in which several people died and the biodiversity of the area was destroyed.
Forest fires: The fire of a vegetal area can be generated spontaneously with the impact of lightning or with a very intense drought. However, the majority are caused by human action, such as those generated to expand livestock or agricultural areas. This pollutes the air and destroys the biodiversity of the place.
The overexploitation of natural resources
The overexploitation of natural resources consists of taking advantage of water, soil, animal or plant species at a speed that prevents them from being generated or reproduced again.
An example would be logging in the Amazon rainforest for the wood and paper industry. If new trees are not planted, or if trees that take decades to grow again are cut down, an imbalance is generated that destroys the fauna and flora of the area, decreasing biodiversity.
Another common example is mining. In this case, the indiscriminate extraction of minerals can not only destroy these resources, but also the processes to obtain them contaminate water and soil, since they require the use of chemical substances. In this way, the ecosystem in which they are found is altered.
The introduction of exotic species
The introduction of species consists of moving a species from its natural location to a new ecosystem of which it is not part. When this occurs, there is the possibility that the cycles of said ecosystem are altered, endangering its biodiversity.
When the introduced species damages the ecosystem it is called an invasive species. This is the case of the tiger salamander (Ambystoma tigrinum), which was introduced to the United States as fishing bait and is now a threat to the native salamander (Ambystoma californiense).
The arrival of exotic species to new ecosystems can be of two types:
Intentional: a new species is introduced in order to obtain a benefit. This is the case of the introduction of a new species of tree to obtain better quality wood.
Accidental: occurs when animals in captivity manage to escape to a new area, or when species of animals and plants are transported on ships or planes without any type of health control.
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