The ecosystem is a dynamic thing. Both abiotic and biotic factors are constantly undergoing an evolution in response to changing forms of life.
These changes have made many ecologists develop interests to understand how biological communities are formed and undergo evolution over time.
Ecological succession is a progressive process where the structure of a biological community change over time. Ecological succession is classified into primary and secondary succession.
So, what is the main difference between primary and secondary succession? The former occurs in a lifeless or barren area while the latter occurs in an area that was previously inhabited.
Keep in mind that ecological succession involves progression from communities with lower species diversity to communities with higher species diversity. But this is not a universal rule.
We have provided a comprehensive explanation of some of the crucial differences between primary succession and secondary succession in this article. Keep reading to find out more!
You May Also Like: Difference between Microevolution and Macroevolution
Comparison Table (Primary Succession Vs Secondary Succession)
|Basic Terms||Primary Succession||Secondary Succession|
|Meaning||It is a type of ecological succession where plants and animals first colonize a barren area.||It is a type of ecological succession where living things re-colonize an area that was previously occupied due to a disturbance.|
|Occurrence||Lifeless or barren habitat.||An area that got deprive of life and previously inhabited.|
|Time Taken for Completion of the Process||1000 years and more.||50-200 years.|
|Soil||There was no soil at the beginning that created a condition that does not sustain life.||There is soil and some living organism.|
|Humus||Lack of humus due to soil absence.||The presence of humus due to soil.|
|Seral Community||Numerous intermediary seral communities.||Fewer intermediary seral communities.|
|Pioneer Community||Present and come from the outside.||Develop from the migrants and previous occupants.|
|Favorable Environment||The unfavorable environment at the beginning.||Favorable environment since the beginning.|
|Reproductive Structure||Absent from any previous community.||Present from the previous community.|
|Solubility||Dissolves in warm water.||Does not dissolve in water.|
|Previous Community||No previous community.||Previous community present.|
|Examples||Desert, bare rocks, ponds, and more.||Natural calamities such as deforestation.|
You May Also Like: Difference between Homologous and Analogous Structures
What Is Primary Succession?
It is a kind of ecological succession that takes place in a barren or lifeless environment. But it is later colonized by plants and animals for the first time.
The succession of events results in a stable ecosystem. The new habitat is formed due to the eruption of volcanoes or glaciers. The natural events cause soil and living organisms absence.
The pioneer organisms that occupy such a new environment are fungi, lichens, and algae. This group of organisms develops due to weathering of rocks to form soil.
Research shows that primary succession is initiated by biological and external factors. Besides that, the emergency of pioneer organisms also helps to facilitate weathering of rocks to form soil.
The growth, reproduction, death, and decomposition of pioneer organisms add organic content to the soil. The organic matter further contributes to the growth of vegetation that covers the land.
These fast-growing vegetations happen due to bird and wind dispersal of seeds. These new vegetations attract other groups of animals.
The arrival of new species of organisms in the ecosystem leads to a more stable environment. Keep in mind that the climax community is less volatile than the preceding ecosystems.
According to ecologists, primary succession is a long process that takes many years to be complete. Examples of primary succession are deserts, ponds, bare rocks, and more.
What Is Secondary Succession?
It is a kind of ecological succession that takes place in an environment with an already established ecosystem. But the ecosystem got a disruption due to natural calamities like floods or volcanoes.
The environment has pre-existing soil that enhances re-colonization by other living organisms. The ecological succession is initiated by some external factors.
The pioneer species of secondary succession are low-lying plants and other annual plants like grass. These pioneer species arise from the pre-existing organisms of the previous community.
The environmental changes fostered the growth of intermediate species. Examples of these species are shrubs and herbs that help to enhance further changes in the environment.
Some of the external factors that facilitate secondary succession are seed dispersal and seed production. The composition of the environment is influenced by climate, pH, and soil texture.
Secondary succession takes less time when compared to primary succession. It approximately takes between 150 and 200 years.
Examples of secondary succession include succession after volcanic fires, harvesting, disforestation or abandon land due to human activities and outbreak of diseases.
You May Also Enjoy: Difference between Natural and Artificial Selection
Main Differences between Primary and Secondary Succession
- Primary succession starts from a barren habitat. Secondary succession occurs in areas that were previously occupied.
- Primary succession takes 1000 years and more to be complete. Secondary succession takes 150-200 years to be complete.
- Secondary succession has organic matter that improves soil fertility. Primary succession lacks organic matter due to soil absence.
- Secondary succession has fewer seral communities. Primary succession has numerous seral communities.
- Primary succession has an unfavorable environment. Secondary succession has a favorable environment.
- Secondary succession has soil in the initial stages. Primary succession lack soil during the initial stages.
- Primary succession dissolves in warm water. Secondary succession does not dissolve in water.
- Primary succession is initiated by both biological and external agents. Secondary succession is initiated by some external factors.
- Secondary succession uses reproductive structures of previous occupants. Primary succession lacks reproductive structures.
- Examples of primary succession are bare rocks, ponds, and deserts. Examples of secondary succession include succession after deforestation, volcanic fire, human activities, and outbreak of diseases.
Frequently Asked Questions
What Is Ecological Succession?
It is an evolutionary process that results in a change of species structure of a community within an ecosystem over a given period of time. It is grouped into primary and secondary succession.
What Is a Pioneer Community?
It is a group of organisms that occupy the habitat that is undergoing primary succession. These are lower living species that can tolerate bare rocks and extreme conditions.
Is a Volcanic Eruption Secondary Succession?
Yes. It is a disturbance the destroys the existing living organisms in a certain habitat. Both plants and animals are destroyed but the soil remains. Keep in mind that this succession begins on existing soil.
Is Primary Succession Faster than Secondary?
Not really. Primary succession takes over 1000 years to be complete and secondary succession take between 150-200 years to be complete. Hence, secondary succession is faster than primary succession.
You May Also Like: Difference between Convergent and Divergent Evolution
Does Secondary Succession Have Pioneer Species?
Absolutely. Pioneer species can also be found in secondary succession after the occurrence of fire, deforestation, and outbreak of diseases. These species quickly colonize the space previously occupied by vegetation.
Does Ecological Succession Ever Stop?
No. The random and potential natural events are inevitable. These factors are responsible for ecological succession. But climax community represents the stable end product of successional sequence.
What is Microbial Succession?
It is a succession where the complexity of the ecosystem is increased by changes in environmental parameters like nutrient levels and coexisting microorganisms that vary over time with the degradation of organic matter.
Ecological succession is a progressive sequence that fosters the evolution of new species. These changes result in a stable community at the climax stage.
The main difference between primary and secondary succession is based upon the habitat of occurrence. These two types of ecological succession help to maintain ecological balance.
Keep in mind that stable climax communities are uncommon in the environment. It happens since the environment usually experiences frequent disturbances that prevent communities from reaching an equilibrium state.
More Sources and References