13 public questions tagged with this topic.
Primary succession occurs in areas without previous life, while secondary succession happens where life existed before.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Interactions - Competition - Competitive Exclusion
Secondary succession occurs in areas where life existed before but was disturbed, such as after a forest fire.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Life History Variations and Population Interactions - Overview
Ecological succession is the gradual process of change in species composition within an ecosystem over time.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Attributes - Birth Death Sex Ratio Age Distribution
Secondary succession occurs after disturbances like wildfires, where the soil remains intact, allowing for faster recovery.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Adaptations - Morphological Physiological Behavioural
Primary succession begins on newly formed or exposed surfaces, such as volcanic rock, where no previous life existed.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Responses to Abiotic Factors - Regulate Conform Migrate Suspend
Secondary succession occurs in areas where life existed before, such as abandoned farmland.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Responses to Abiotic Factors - Regulate Conform Migrate Suspend
Primary succession is slower because it starts on bare surfaces, requiring soil formation before larger plants can establish.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Organism and Environment - Major Biomes Abiotic Factors
Secondary succession occurs when an existing ecosystem is disturbed but soil remains, such as after a wildfire.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Organism and Environment - Major Biomes Abiotic Factors
Nudation first creates a bare or newly available site, migration then brings propagules into that site, and ecesis follows when those immigrants establish and grow. Later processes include aggregation, competition, reaction, and stabilization, so the stated sequence correctly captures the opening phases. Organisms can drive succession autogenically by changing their own habitat, while floods, erosion, sedimentation, or climate can drive allogenic change. Biological agents such as grazers and pathogens may also redirect succession by altering competitive relationships. Distinguishing the driver
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 20
Secondary succession is generally faster because soil, nutrients, propagules, decomposer communities, and sometimes resprouting plants survive the disturbance. Primary succession must begin with substrate weathering and soil formation, processes that can delay the establishment of larger and more resource-demanding species for decades or centuries. Successional trajectories emerge from dispersal, establishment, species interactions, and organism-driven environmental change. Priority effects can make arrival order important, while retained soil and propagules strongly accelerate recovery after
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 20
Secondary succession retains preexisting soil, often together with seeds, roots, spores, organic matter, microbes, and surviving organisms. These biological and edaphic legacies distinguish it from primary succession and permit vegetation and nutrient cycling to recover without first constructing soil from bare substrate. Organisms can drive succession autogenically by changing their own habitat, while floods, erosion, sedimentation, or climate can drive allogenic change. Biological agents such as grazers and pathogens may also redirect succession by altering competitive relationships. Disting
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 20
Secondary succession occurs where a community previously existed and a disturbance removes organisms without eliminating all soil and biological legacies. Forest regrowth after fire, abandoned agriculture, storm damage, or logging are common examples. Remaining seed banks, roots, spores, microbes, soil structure, and nutrients accelerate recovery compared with primary succession. Primary succession starts on newly exposed or sterilized substrate with little or no developed soil, as on fresh lava, glacial till, or bare rock. “Autogenic” and “allogenic” describe causes of successional change rat
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 20
