8 public questions tagged with this topic.
Standing crop refers to the total biomass of living organisms in a particular trophic level at a given time.
Ref: NCERT Class 12 Biology Chapter 12: Ecosystem Ecosystem - Structure Components Stratification
“Abiotic factors and nutrient supply” for biomass of primary producers in bottom-up ecosystems is controlled by. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Ecosystem processes are constrained by energy conservation and by the cycling of matter. Energy enters mainly through primary production, is lost as metabolic heat at every transfer, and therefore cannot be recycled in the way that carbon, nitrogen, phosphorus, or water can. The remaining alternatives—“Predator abundance”, “Competition”, “
Ref: Fundamentals of Ecology, Odum & Barrett, 5th Ed., Ch. 4
“Increased primary producers and subsequent trophic levels” for increased nutrient supply in bottom-up ecosystems results in. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Rates depend on temperature, moisture, substrate quality, consumer physiology, and the elemental balance between organisms and their food. These controls explain why the same process can differ among terrestrial, freshwater, and marine systems without changing its definition. The remaining alternatives—“Increased predators onl
Ref: Fundamentals of Ecology, Odum & Barrett, 5th Ed., Ch. 4
Species richness often rises during succession as soil development, structural complexity, and habitat heterogeneity create additional niches and more species reach the site. The trend is a broad expectation rather than an inviolable rule, because strong dominance or late disturbance can produce plateaus or declines. 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 disturbance. Facilitation, toler
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 20
Productivity is a rate of biomass or carbon production and therefore requires dimensions of mass per area per time. Grams per square metre per day includes the essential time denominator, whereas grams per square metre, kilograms per hectare, and grams dry weight describe standing amount rather than production rate. Carbon accounting separates gross fixation from respiratory expenditure. Gross primary productivity records all photosynthetic carbon fixation; net primary productivity subtracts autotrophic respiration, while net community productivity subtracts total ecosystem respiration. Keepin
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 17
Trees usually contain the greatest biomass in forests because they accumulate woody tissue over decades or centuries. Their large trunks, branches, and roots store carbon far longer than the bodies of herbivores, carnivores, or parasites. Biomass is standing mass, not productivity: a forest can retain a massive producer stock even when annual net production is modest. Consumers may have rapid turnover, but respiratory losses and incomplete transfer prevent their standing biomass from approaching the long-lived plant reservoir. Energy and matter should not be conflated: nutrients can cycle amon
Ref: Fundamentals of Ecology, Odum & Barrett, 5th Ed., Ch. 3
The width of an energy-pyramid tier represents energy flow or production at that trophic level, normally standardized per unit area and time, such as kilojoules per square metre per year. Including time distinguishes energy flux from standing biomass. Tier width narrows because only a fraction of lower-level production becomes higher-level production. Joules alone describe an amount, but rigorous ecological pyramids specify both spatial and temporal denominators so ecosystems of different size or observation period can be compared. Turnover explains many apparent paradoxes: a small, fast-renew
Ref: Fundamentals of Ecology, Odum & Barrett, 5th Ed., Ch. 3
A pyramid of energy is always upright when it expresses production or energy flux per unit area per unit time. Each trophic level receives only part of the energy processed by the level below, while respiration irreversibly disperses usable energy as heat. Biomass pyramids can invert because standing stock combines production and turnover: rapidly renewed phytoplankton may support a larger instantaneous consumer biomass. Energy flux incorporates time, so fast producer turnover cannot produce an inverted energy pyramid under consistent accounting. Pyramid shape is an accounting result with biol
Ref: Fundamentals of Ecology, Odum & Barrett, 5th Ed., Ch. 3
