Prelims tit-bits- Environment and Ecology part 2

1. Ecotone v/s Ecocline

  • Ecotone describes a variation in species prevalence and is often not strictly dependent on a major physical factor separating an ecosystem from another, with resulting habitat variability
  • Ecocline is a variation of the physicochemical environment dependent of one or two physico-chemical factors of life, and thus presence/absence of certain species

2. Keystone species and Ecosystem engineer

Keystone species is a species that has a disproportionately large effect on its environment relative to its abundance <think of keystone of an arch>

Ecosystem engineer is any organism that creates, significantly modifies, maintains or destroys a habitat.

Discuss– Flagship and Foundation species

3. Indicator species 

  • An indicator species is any species that defines a trait or characteristic of the environment.
  • are also known as sentinel organisms, i.e. organisms which are ideal for bio monitoring
  • Eg. Some species of lichens are very sensitive to air pollution. Their presence thus indicates low air pollution

4. Ecological interaction

  • Mutualism is an interaction between species that is beneficial to both. <+ +> <eg. Flowering plants and pollinators>
  • Commensalism is an interaction in which one species benefits and the other species is unaffected <+ 0> <eh. Epiphytes and host plants>
  • Parasitism relationship is one in which one member of the association benefits while the other is harmed <+ ->
  • Amensalism is the type of relationship that exists where one species is inhibited or completely obliterated and one is unaffected by the other. <- 0> <competition and antibiosis>

Discuss- What is symbiosis?

Discuss- Difference b/w competition and antibiosis

5. biodiversity hotspot 

  • A biogeographic region with significant levels of  that is under threat from humans
  • Norman Myers described the concept

2 Criterias –

  • it must contain at least 0.5% or 1,500 species of vascular plants as endemics <species richness and endemicity>
  • it has to have lost at least 70% of its primary vegetation <threat perception>

Discuss- Hotspots of India

By Dr V

Doctor by Training | AIIMSONIAN | Factually correct, Politically not so much | Opinionated? Yes!