5 public questions tagged with this topic.
Keystone species play a crucial role in ecosystem structure, and their removal can have cascading effects on the ecosystem.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Attributes - Birth Death Sex Ratio Age Distribution
“Species are top predators and hence rare” for high trophic status implies. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Extinction risk rises when abundance, geographic range, or genetic variation becomes small because demographic chance, environmental fluctuations, inbreeding, and rare catastrophes then have disproportionate effects. Correlated losses among subpopulations further weaken regional persistence. The remaining alternatives—“Species consume only plants”, “Organisms are decomposers”
Ref: Conservation Biology, Primack & Sher, 6th Ed., Ch. 7
Broad overlap in ecological roles is the central premise of functional redundancy. Species within a functional group can use similar resources or perform comparable processes, so loss of one may be compensated by others and initially cause little change in aggregate function. Ecosystem function can respond to diversity through niche partitioning, facilitation, insurance, or a sampling effect. Niche differences allow more complete resource use, asynchronous responses stabilize aggregate output, and high richness increases the chance of including a strongly productive species. Functional redunda
Ref: NCERT Biology Class 12, Ch. 15 Biodiversity and Conservation
Complementarity raises ecosystem function when species differ in resource use, timing, rooting depth, microhabitat, or facilitative effects. As richness increases, these distinct contributions accumulate, enabling more complete resource capture or mutually beneficial interactions than a single species could achieve. Species richness counts taxa but does not show their abundance, traits, or interaction strengths. Dominant species may control bulk process rates, rare species may provide specialized functions or future insurance, and predators can restructure whole food webs through indirect effe
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 20
Fungi and bacteria initiate biochemical decomposition by colonizing dead material and secreting extracellular enzymes. These enzymes depolymerize proteins, polysaccharides, lipids, and, in specialized taxa, lignin into compounds small enough for cellular uptake. Fungal hyphae penetrate litter and transport resources across microsites, while bacteria exploit soluble products and newly exposed surfaces. Detritivores and scavengers accelerate the process through fragmentation, but they do not replace microbial mineralization; their feeding increases surface area and redistributes inoculum. Carbon
Ref: Fundamentals of Ecology, Odum & Barrett, 5th Ed., Ch. 3
