This document discusses ecological concepts such as mortality, r-selected species, habitat, ecological niche, and carrying capacity. It defines mortality as the rate at which individuals die in a population. R-selected species are those that live in environments below carrying capacity and can grow rapidly when conditions are favorable. Habitat refers to where an organism lives, while ecological niche describes its role in an ecosystem. Niche can be defined by variables like temperature and resources. Carrying capacity is the maximum population size an environment can sustain indefinitely.

1. Banu .S and Nayana .P
Jr . M.F.Sc
College of Fisheries
Mangalore

2. Overviews
Ecological concepts
 Mortality
 Risk selected species
Habitat concepts
 Ecological niche
 Carrying capacity

3. Mortality
 Mortality is the condition of being mortal , or
susceptible to death .
 Rate at which individuals are lost by death ( death
rate)
 Mortality is a measure of the no. of deaths ( in general
, or due to a specific cause ) in a populations .

4. R- selected species
 These organisms live in setting, where population level
below the maximum no. that environment can support
the carrying capacity.
 Their nos are going exponentially high at the
maximum rate
 Organism tend to be small, short lived and
opportunistic .
 They grow through irregular boom and bust in a
population cycle

5.  R- selected species like insect, bacteria and largest
species such as frog, rats
 They are capable of rapid growth.
 They need favorable condition for their growth.
 These r- selected species mature later in life and have
fewer offspring with longer gestation times.

6. Habitat in an ecosystem
 Ecologist use the term habitat to mean the role that
the organism live and term ecological niche to mean
that the role of organism plays in the ecosystem
 Habitat is the “address” and Niche is the “profession”

7. Ecological niche
 Different species interact in different ways.
 Interaction can have positive, negative and neutral
impact on the species involved.
 Each species in an ecosystem occupies a niche
 Niche can be defined as interaction of all the ranges of
tolerance, under which an organisms can live.

8.  Niche can be easier to quantify and analyze.
 It can be described as specific ranges of variables like
temperature, latitude and altitude.
 For example: African fisheagle occupies very similar
ecological niche to the American bald eagle.
 The full range of habitat types in which the species can
exist and reproduce without any competition from
other species is called fundamental niche.

9. Carrying capacity
 Carrying capacity of environment varies from region to
region depending on population pressure.
 Their dependences on food, water, energy, raw
material requirement, waste production.
 Carrying capacity of environment is the threshold
limit of use of that ecosystem without damaging the
systems.

10.  Every ecosystems has its resources that are used for
economic development for survival and for the habitat
creation.
 Regenerating them over the period of time that are
temporary and not exceeding threshold damage limit.