Have you ever thought about how it is possible that volcanic areas like Hawaii are full of life? Or how long does it take a forest to recover after a great fire? Or what would happen if we stopped taking care of the crops? Like living beings, ecological communities also grow, change and develop. These changes are due to a natural process called ecological succession. If you want to learn more about it, keep reading, then, in ecology, we are going to talk to you about the ecological succession, its definition, stages and examples.
What is ecological succession
The ecological succession It is a natural process in which a sequence of Changes in the ecological community which are observable in time and space. It is due to local colonizations and extinctions of species.
During ecological succession the level of complexity of ecosystems evolves. The early stages represent communities with simple trophic chains and little biodiversity, but that over time goes transforming complex ecosystems where there are more interactions and greater wealth and diversity of living beings.
The ecosystem formed at the end of the succession is called climax or climate community. This stage represents the maturity of the community, that is, when it remains for many years and is well developed. In relation to these two concepts, climax and maturity, some controversy has risen because there are immature communities (in primary stages) in climax, that is, without changes, such as the vegetation of the dunes or the deserts.
Depending on the starting point of the ecological community, ecologists differentiate two types of ecological succession:
- Primary succession.
- Secondary succession.
Primary succession
The primary succession It is the one that develops in a Virgin Biotypethat is, an area devoid of a pre -existing community, as occurs in dunes, new volcanic islands, glacier setback, etc. It is rare.
The process begins with soil formation, understanding, as the layer of the biologically active earth’s surface that contains roots, microorganisms, invertebrate and nutrient communities. Normally, the primary succession occurs in areas where the mother rock is exposed to the surface, but this cannot be directly colonized. First suffers the action of erosion and weathering, a set of physical and chemical processes that fragment, degrade and dissolve the rock. In this way the land colonization by lichens and mossesthey can grow in substrates with shallow and little amount of organic matter. The biological action of these organisms contributes to the degradation of the rock and the release of nutrients, also provide organic matter when they die. Thus, the arrival of other species such as annual plants, herbs that have one year of life, and subsequently perennial annual ones that endure more time are favored. If the community continues to evolve, the seeds of shrub species forming thickets could germinate and the trees would finally grow to forests.
The same goes for animals, then, The first to settle will be insects and other invertebrates and small reptiles that can hide between rocks and feed on invertebrates. Small birds could also arrive whose diet is based on seeds, or even in invertebrates and reptiles. As the plant community becomes more complex, small mammals would appear, such as rodents and other birds. Finally, the large mammals and other predators would arrive in the community, as the ecosystem will provide enough food and den.
Secondary succession
Secondary succession appears when there has been a Regressive succession in the ecosystem. This means that destroyed the ecosystem that existed and, therefore, The ecological succession process must be initiated. This ecosystem has been able to be eliminated by fires, floods, diseases, tals, crops, etc.
The Secondary succession It occurs in places whose characteristics depend on the previous communities or the situation prior to the disturbance. The waste or legacies are those organisms, sometimes living, that come from the previous community. The greater the amount of waste greater speed of succession or recovery.
The presence and abundance of waste cushions the difference between the conditions prior to disturbance. They function as Source of new speciesThey increase the heterogeneity of the environment and also decrease the loss of soil and nutrients.
Ecological Succession Mechanisms
Ecologists have studied for a long time How ecological succession occurs and have found a series of mechanisms that favor the succession of species in communities.
One of these mechanisms is facilitationwhereby species with great colonization capacity favor the arrival and survival of the species that appear in the latest stages of succession. It is especially important in the primary succession. If stress increases in the physical environment, it increases facilitation. Although, if the environmental conditions become extreme, it is imposed The competition Faced with facilitation, that is, the species become selfish and fight for the resources available to survive.
Ecological succession occurs thanks to The pioneer speciesthose that first reach inhospitable sites. They have a great colonization capacity, but a low capacity to compete when resources are scarce. Some pioneer species are lichens and mosses They were mentioned before.
In addition, pioneer species have tissues with high concentrations of nitrogen and phosphorus, becoming the preferred food of herbivores. In this way the ecological succession is accelerated, since these plants will suffer high mortality and will be replaced by the latest stages of stages.
Some examples of ecological succession
These are some clear Examples of ecological succession.
The Michigan Lake Dunes
After finishing the last glaciation, the glaciers that covered the great lakes were withdrawn and exposed large dunes. These dunes are large sand formations that accumulate on the banks of the lakes.
Over the years, plant species have been happening. First, drought tolerant species were established that, in addition, allowed the fixation of the dunes, preventing the wind from eroding and transporting. After twenty years the grasses appeared, shrubs such as the cherry of sands and trees such as the willows and poppies, who continued to stabilize the substrate. After another 50 or 100 years the pine forests began to grow that were finally replaced by the oaks, being able to stay for millennia.
Currently, this sequence of plants can be observed, as the lakes have lower level and the process continues over time.
The groove of a lake
An oligotrophic lake (with a small amount of nutrients) begins to receive nutrients and sediments by the streams and rivers that flow into it. Thanks to the increase in nutrients, algae begins to proliferate. If nutrients increase floating water plants and others that begin to root. The death and decomposition of organisms make remains accumulate at the bottom of the lake and the mob is created, while losing depth. In this way the lake begins to transform into a swamp. The soil is acidified and begins to proliferate typical plants of the banks such as the reeds. Terrestrial animals such as earthworms and some insects may appear. Trees that tolerate high humidity such as straightenings or birch grow on the turbounds. Over time they will be replaced by other trees that will form a more mature forest. The fauna of the place also evolves, disappearing the amphibians due to the lack of moisture and appearing poultry and mammals typical of forests. In the event that there is a lot of peat, a lot of moss would grow that would acidify both the soils that trees would die.
This process has originated the current peat bogs of the planet after the glaciations and could happen within thousands of years in Lagos such as those of Geneva or Leman, the largest lake of Western Europe and located in the Alps, and in Lake Constanza, which borders Germany, Switzerland and Austria.
If you want to read more articles similar to Ecological Succession: Definition, stages and exampleswe recommend that you enter our category of ecosystems.
