8 public questions tagged with this topic.
In aquatic ecosystems, the biomass pyramid is often inverted because the biomass of phytoplankton (producers) is lower than that of zooplankton.
Ref: NCERT Class 12 Biology Chapter 12: Ecosystem Ecological Pyramids - Number Biomass Energy
In a pond ecosystem, the biomass of phytoplankton (producers) is lower than that of zooplankton (consumers), creating an inverted pyramid of biomass.
Ref: NCERT Class 12 Biology Chapter 12: Ecosystem Ecological Pyramids - Number Biomass Energy
Optimal diet theory ranks prey by profitability, commonly energy obtained per unit handling time, E/h. A lower-ranked prey type should be accepted only when its profitability exceeds the expected rate of gain from rejecting it and searching for the preferred prey. The expression E2/h2 > E1/(h1 + S1) states precisely that condition: prey 2 yields energy fast enough to outperform the combined search and handling return associated with prey 1. As preferred prey becomes scarce, S1 rises and the right-hand rate falls, making prey 2 more acceptable. Energy alone or handling time alone cannot determi
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 10
A plant, an insect herbivore, and the herbivore's parasitoid occupy three linked feeding levels, forming a tritrophic interaction. Plant chemistry and structure influence herbivore performance, and those changes can affect parasitoid host location or development. Damaged plants may release volatile compounds that attract parasitoids, creating an indirect defense, while parasitoid suppression of herbivores can indirectly improve plant fitness. This framework therefore includes both direct consumption and indirect effects across trophic levels. Commensalism is only a two-species outcome category
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 8-13
Under the inhibition model, established early colonists suppress recruitment or growth of later arrivals through preemption of space, resource capture, allelopathy, or other antagonistic effects. Replacement occurs chiefly when residents die or are damaged, releasing occupied sites rather than because they prepare the habitat for successors. 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 disturb
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 20
Biogenic succession attributes a temporary directional change to living agents such as herbivores, pathogens, or ecosystem engineers. Their population activity changes mortality, recruitment, or habitat structure, producing community replacement even though the driver is not the plants' own progressive modification of the site. Classical succession terminology divides community development into site exposure, arrival, establishment, interaction, environmental reaction, and relative stabilization. Modern ecology treats these as useful descriptions rather than a rigid deterministic program. Loca
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 20
Ecesis is a process rather than a seral community: it is the successful germination, establishment, and growth of immigrants after their arrival. Pioneer, intermediate, and climax communities describe recognizable positions or assemblages in a successional sequence, whereas ecesis describes what colonists do. Classical succession terminology divides community development into site exposure, arrival, establishment, interaction, environmental reaction, and relative stabilization. Modern ecology treats these as useful descriptions rather than a rigid deterministic program. Local resource conditio
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 20
The ratio NPP/biomass compares how much new producer material an ecosystem generates relative to its existing standing biomass during a specified time. It is closely related to production-to-biomass ratio and biomass turnover rate. A grassland may have modest standing biomass yet replace a large fraction annually, producing a high ratio, whereas a mature forest stores enormous amounts of wood but adds a smaller fraction each year, producing a lower ratio. Normalizing production by biomass therefore enables comparison among biomes that differ greatly in size and growth form. NPP alone measures
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 17
