Muskan Shafi Education Content Expert
Education Content Expert
Pioneer Species are those species who invade the barren area and initiate the ecological succession. These species invade those areas which are totally barren, lacking any nutrition and are inhabitable. They are solid and hardy. Best example of Pioneer Species is Lyme Grass which is found on the barren land of sand.
- Pioneer species occupy a region and alter the ecology as they develop, procreate, use resources, and eventually die.
- By producing soil and other debris as part of their daily lives, pioneer species provide space for other creatures to settle in and begin their own colonisation of the environment.
- Succession is a process where other entities evolve, change themselves and start their own livelihood in the ecosystem.
- Ecological Succession is of two types namely Primary and Secondary Succession.
Read More: NCERT Solutions for class 12 Biology Ecosystem
| Table of Content |
Key Terms: Pioneer Species, Ecological Succession, Primary Succession, Secondary Succession, Species, Ecological Community, Ecology, Soil stability, Nutrient enrichment
What are Pioneer Species?
[Click Here for Sample Questions]
Pioneer Species are those who start the development of an ecological community in a particular area where there at that moment no life form was existing. They can provide much-needed chances for any life to evolve.
- Pioneer species are the first ones to start development.
- This species evolves barren lands, areas where there is no life and starts a whole new ecological community.
- Pioneer species start the ecosystem's recovery by making it more favourable to later species. Typically, this is done by soil stability, nutrient enrichment, reduced light availability and wind exposure, and temperature control.
- Pioneer species include lichens, fungus, bacteria, fireweed, grasses, alder, and willow.
Pioneer Species
Pioneer Flora
- Pioneer plant species are photosynthetic because the new habitat would likely have soil with fewer nutrients and would not be exposed to any energy source other than light energy on a large scale.
- Pioneer plant species mostly use wind pollination. Also, the mode of reproduction is usually asexual rather than sexual.
- Pioneer species eventually die, producing plant litter that will eventually decompose as "leaf mould," creating new soil for secondary succession and releasing nutrients for smaller fish and aquatic plants in nearby bodies of water.
- Example of a pioneer plant species is Lyme grass which is found in barren land covered by sand.
Pioneer Fauna
- Only when flora and fungi have settled in a region, pioneer fauna begin to populate it.
- Soil fauna, which includes tiny protists as well as invertebrates, plays an essential role in soil formation and nutrient cycling.
- Bacteria and fungi are the most significant organisms in the degradation of organic detritus left behind by primary producers such as skeletal soil, moss, and algae.
- There are certain exceptions to the rule that vertebrates are not pioneer species. Natterjack toads are one example of it.
Read More:
| Relevant Concepts | ||
|---|---|---|
| Hydrarch Succession | Difference between Primary and Secondary Succession | Extinction |
| Endemic Species | Keystone Species | Endangered Species |
Pioneer Species Examples
[Click Here for Previous Year Questions]
Given below are a few examples of Pioneer Species:
- Pioneer Fauna: snails, worms, some toads etc
- Cyanobacteria: Anabaena, Rhizobium
- Bryophytes: Hyophila involuta
- Lichens: Placopsis gelada
- Bacteria: Thiobacillus spp.
- Angiosperms: Lupinus lepidus
Habitat and Reproduction in Pioneer Species
[Click Here for Sample Questions]
In order to exist, survive, and provide the conditions for other entities to move in and establish a way of life in the area, such individuals change the environment around them. As a result, it influences other entities. Along with changes in the biotic state, some of these changes may also affect the abiotic state, such as temperature, soil, etc.
- Lichens, which can grow on rocks even in the absence of soil, may be among the earliest life forms to change rocks into the soil for plants.
- Pioneer species are often strong plants with adaptations such as expanded roots, root nodules with nitrogen-fixing bacteria, and transpiring leaves.
- They are often photosynthetic plants since during the early phases of succession, no alternative energy source is usually available. It is therefore less likely that pioneer species won't have photosynthesis.
- The plants that make up these pioneer species usually prefer wind pollination because insects are less likely to be seen in the arid environment that they live in.
- Pioneer species have a tendency to perform asexual reproduction due to the presence of hard or barren settings that make it more favourable to not improve reproductive success than sexual reproduction.
- It is possible for these species to go extinct, leaving behind plant debris that eventually turns into leaf mould
- Pioneer species leave fresh soil for secondary succession and supply nutrients for tiny fish and aquatic plants in the nearby water bodies.
Characteristics of Pioneer Species
[Click Here for Previous Year Questions]
Listed below are the features of Pioneer Species that help them evolve:
Hardy in Nature
These entities are really strong, they can stand undamaged and can bear the hardest environmental situations.
Short Life Span
Bearing such hard conditions of environment and presence in barren land offers limited options for an entity to survive long, thus this also tells us Pioneer Species learn reproductive lessons in their early stage of life be it sexual or asexual. This is the reason Pioneer Species have a short presence.
Small Size of Propagule
Small propagule sizes make it simple to disperse plants and achieve successional objectives. Additionally, a small seed or propagule's size improves the likelihood of hatching because it can get "stuck" in tight spaces during hostile conditions.
Asexual Mode of Reproduction
The sexual mode of reproduction is not really a good option for pioneer species because it requires more time and energy. Despite the fact that sexually active species have also been discovered. In contrast, because of its benefits, the asexual mode is more common.
High Rates of Seed Production and Dispersal
Pioneer species generate their seeds in extremely huge numbers in a geometric pattern, and they have extremely high dispersal rates. Such dispersal rates are necessary in a nutrient-deficient area to support colonization.
Wind Helps in Pollination and Seed Dispersal
Because hostile environments are terrible for many species, they are also bad for pollinators. Wind pollination is the only solution. Wind pollinates the majority of pioneer species that reproduce sexually, for which pollination is an essential stage in the fertilization of gametes. Furthermore, even their seeds are spread by wind.
Light’s Inclusion in Seed Germination
- Seeds of pioneer species are naturally photo blastic in nature. Light serves as the trigger for its germination, and they have strong light requirements.
- The seeds of pioneer species do not have much need considering the conditions they inhabit because a seed normally germinates under the availability of ideal conditions.
- They claim that "light stimulation" is the only requirement for germination.
Seeds are Orthodox and Easy to Generate
- Exceptional seeds, defined as "seeds with 5% total moisture content and still live and possessing extraordinary lifespan," are present in pioneer species.
- This characteristic enables pioneer organisms to reproduce even after a prolonged hibernation.
- They can produce new plants after germination and resist desiccation easily.
- These seeds are not adversely impacted by low moisture content.
Read More: Important Questions on Ecosystem
Ecological Succession
[Click Here for Sample Questions]
Ecological systems feature biological interactions and interrelationships between various components of natural systems. Their interactions and connections determine how the ecological system will function, their sustainability, the requirements and rate of survival, and other associated factors. Ecological communities are area-specific and are based on how "common" species coexist.
- Ecological succession refers to all of the processes, conditions, and interrelationships in a community that regulates its evolution across time.
- It encompasses the structural behaviour and changes of a biological community across time.
Types of Succession
[Click Here for Previous Year Questions]
Ecological succession is started by the emergence of new, vacant habitats, such as from a lava flow or a major landslide, or by some type of community disruption, such as a wildfire, strong windthrow, or logging, which may wipe out the whole species. As a result, there are two types of succession:
Primary Succession
Primary succession is a form of ecological succession that begins in barren places. It is the stage during which plants and animals first colonise a dead, barren ecosystem, such as regions devoid of soil or locations where the earth is incapable of supporting life.
- The pioneer species or the first species establishes a simpler biological community. With the introduction of additional species, this community gradually grows more complicated.
- Due to the amount of time it takes natural calamities to strike, which is already a rare occurrence, the process might be drawn out. As a result, the procedure is slightly lengthier and more variable over time.
- Only "blue-green algae/Cyanobacteria" and plants are considered to be photo-auto-lithotrophs. They are the only pioneer species known to have contributed to primary succession.
- Major landslides, fires, volcanic eruptions, and flooding cause horrific habitat loss in certain areas.
Primary Succession
Secondary Succession
Secondary ecological succession happens when the original ecosystem is destroyed. Thus, it is the sort of succession in which plants and animals recolonize a habitat following a large disturbance such as a landslide, lava flow, wildfire, or another natural disaster.
- It takes place when an apex community is destroyed. Secondary succession occurs in an ecosystem when the disturbance did not remove all living forms and nutrients.
- We can consider angiosperm trees and shrubs as examples of pioneer species in secondary succession.
- These have some incredibly rapid rates of population expansion and community development. It's not necessary for the pioneer species in secondary succession to be photo-auto-lithotrophic.
- Microbial and invertebrate taxa have just recently been added to the list of pioneer species. These species can be litho/organography, auto/heterotrophs, or photo/chemotrophs.
- This emphasizes the crucial idea that secondary succession happens in areas where some food sources already exist in the substrate.
Secondary Succession
Check More:
| Related Topics | ||
|---|---|---|
| Heredity and Evolution | Importance of Ecosystem | Tundra Ecosystem |
| Terrestrial Ecosystem | Energy Flow in Ecosystem | Components of Ecosystem |
Things to Remember
- Pioneer Species are the organisms who start the ecological community's development in an unfavourable region.
- These species are hardy in nature and reproduce by pollination.
- All elements, procedures, and interactions that affect when a community changes over time are included in ecological succession.
- There are two types of Ecological succession namely Primary Succession and Secondary Succession.
- The earliest life forms to transform rocks into the soil for plants are lichens.
- Insects and bigger vertebrates can occupy the region as the primary habitat shifts from lichen-covered rock to grasses.
- Pioneer species alter the environment as they develop, reproduce, consume resources, and die.
Previous Year Questions
- The pioneer species in Xerarch and Hydrarch succession are… (KCET - 2015)
- Lichen is the pioneer vegetation on which succession… (BHU UET - 2006)
- During ecological succession… (NEET - 2015)
- Pioneers in the secondary succession of previously burnt forest are…
- The primary succession refers to the development of communities on a…
- Name the term used to describe a single non-dominant species… (KEAM)
- Association between mycobiont and phycobiont are found in…
- During the process of ecological succession, the changes that take place…
- In ecological succession, the climax community is best recognized… (AMUEEE - 2010)
- Secondary succession takes place on/in… (AIPMT 2 - 2015)
Sample Questions
Ques. What are Pioneer Species? (3 Marks)
Ans. Pioneer Species refers to any organism in ecosystems that is the first to settle in a barren region. These species can survive in hostile environments with few resources. Many bacteria can thrive on rock, in water, and in the sand, making them good examples.
- Microbes may proliferate and colonise desolate settings because they require minimal space and can consume minerals and other elemental elements.
- Pioneer species alter the environment as they develop, reproduce, consume resources, and die.
- Pioneer species' usual life activities generate soil and other debris, allowing other creatures to move in and begin their own
- Small microbes make up this group. Common examples of pioneer species are bacteria, lichen, mosses, and fungi.
Ques. What are the features of Pioneer Species? (3 Marks)
Ans. The following listed are the features of Pioneer Species:
- They are hardy in nature, and they can bear any natural phenomena caused by nature.
- Due to hard conditions to survive these entities have a short life span.
- For achieving successional objectives they have a small size of propagule.
- They reproduce by asexual mode known as pollination as it is very easy for them.
- Pioneer species have high rates of seed production and high dispersal rate.
- For getting help in primary succession they have a wide range of Ecological and Geographical.
Ques. What does Ecological Succession mean? Explain with an example. (3 Marks)
Ans. Ecological succession is a phenomenon that is guided by the community, in which the composition and structure of the community change in a systematic and ordered fashion, ultimately leading to the establishment of a climax community.
- This is a progressive process that can occur in a previously barren environment (as in the case of primary succession) or in a cleared area as a result of a major disturbance (as with secondary succession).
- Pioneer species are important in these processes because they prepare new or recently damaged habitats for more complex populations.
- For instance, after a forest fire that destroys all the big trees in certain terrain, grasses may develop, following shrubs and other tree species, until finally, the pre-fire community is once more present.
Ques. What is the Importance of Pioneer Species? (5 Marks)
Ans. Pioneer species play a vital role in ecosystem development. The existence of barren terrain shows that the area cannot be converted into soil without the life activities of pioneer species.
- This is why lichens are such good pioneers. Lichens release acids that progressively break down rock when they colonise bare rock. Because lichens do not require soil, they can colonise bare regions and begin the soil-creation process.
- As lichens, bacteria, and mosses invade, a little number of organic matter forms as these creatures die.
- This early debris serves as the foundation for soil, in which windblown seeds can take root. Organisms move into the changing region throughout time, which might take years, decades, or more.
- Early pioneer species will provide food, shelter, and resources for subsequent species. As time passes, larger species tend to enter the evolving ecosystem: lichen gives place to moss, which introduces grass, which can generate soil for larger shrubs and trees.
Ques. Mention how Primary Succession on rocks is influenced by pioneer species. (2 Marks)
Ans. In primary succession on rocks, the pioneer community is the lichen stage, which causes the gradual weathering of rocks and the development of soil, leading to the production of lichen acids. Lichen acids slowly erode the rock's surface and produce minerals necessary for lichens to proliferate properly. This is how primary succession is influenced by pioneer species.
Ques. What is eco-succession? What kinds of eco-succession are there? (3 Marks)
Ans. The term "Eco-succession" refers to a continuous transformation in a biotic community. The two main categories of succession are primary and secondary. The pattern of succession of a community is determined by the pre-existing characteristics of a location. The following three types of patterns have been noticed:
- Hydrosere
- Merosere
- Xerosere
Ques. Describe how Primary Succession and Secondary Succession are different. (5 Marks)
Ans. Primary succession occurs when newly exposed or newly created rock is inhabited for the first time by living beings. Secondary succession occurs when an area formerly populated by living organisms is disrupted and subsequently re-colonized.
- A set of events that occur in order to build a stable ecosystem is referred to as primary succession. Secondary succession, as opposed to primary succession, begins in an environment with pre-existing soil.
- Natural phenomena such as a volcano or glacier eruptions are commonly responsible for the formation of new habitats. Secondary succession occurs in environments where the primary succession has been interrupted, yet certain plants and animals may still remain.
- Secondary succession generally occurs after a calamity, such as a forest fire, hurricane, or harvesting, which destroys the previous ecology. The onset of primary succession is generally caused by either a biological or an external stimulus.
- Secondary succession can occur as a result of a fire, harvesting, logging, or abandonment of land, or as a result of a disease epidemic. Examples of primary succession include the creation of a new ecosystem following a volcano eruption, glacier outbursts, or a nuclear explosion.
Ques. When does Secondary succession happen? (3 Marks)
Ans. Secondary succession begins in a pre-existing soil environment. Secondary succession occurs in environments where the primary succession has been interrupted, yet certain plants and animals may still remain.
- This sort of succession generally occurs after a calamity, such as a forest fire, hurricane, or harvesting, which destroys the previous ecology.
- Secondary succession is always initiated as a result of some external factor. Following a forest fire, towering trees are burned, and the first plants to sprout in such regions are generally annuals.
- Secondary succession sometimes takes less time than primary succession; for example, the secondary succession of an area following a forest fire takes roughly 150 years to complete.
- Secondary succession can occur as a result of a fire, harvesting, logging, or abandonment of land, or as a result of a disease epidemic.
Ques. What factors affect the growth of the community during secondary succession? (3 Marks)
Ans. The following factors can have an influence on the growth of a community during secondary succession:
- Soil Quality: After a disturbance, the general quality of the soil that remains can have a significant influence on secondary succession. This might encompass everything from soil pH to soil density and composition.
- Residual Organic Matter: The quantity of organic matter that remains in the soil following disturbance also influences the rate of success and the sorts of pioneer plants. The more organic matter there is in the soil, the faster secondary succession will occur.
- Existing Seed Banks: Seeds may stay in the soil depending on how the community was disrupted. This is also influenced by how near the location is to outside seed sources, which might result in a larger abundance of some pioneer species.
Ques. Pioneer species are either autotrophs or heterotrophs. Explain whether the given statement is True or False. (3 Marks)
Ans. They can be either. The whole process of succession as well as its features tends to vary depending on whether the pioneer species is an autotroph or heterotroph.
Process of Autotrophic Succession
This occurs when plants, blue-green algae, or planktons are the pioneer species (in the case of aquatic environments). It is distinguished by autotrophic dominance throughout the ecological succession process. The community's energy and biomass content stay high and continue to rise until the peak community is attained.
Process of Heterotrophic Succession
This occurs when the pioneer species are bacteria or fungi, for example. The community is initially dominated by heterotrophs, but autotrophs catch up in later successional stages. The energy and biomass content of the resultant communities diminish steadily until the climax community is attained.
For Latest Updates on Upcoming Board Exams, Click Here: https://t.me/class_10_12_board_updates
Check-Out:
Comments