question_answer

All successions proceed to a similar climax community, the mesic. Explain.

Or

Write differences between the following terms

(i) Immigration and emigration

(ii) Ectomycorrhizae and endomycorrhizae

(iii) Population and community

(iv) Natality and mortality

(v) Predation and competition

Answer:

All successions proceed to a similar climax community, i.e. the mesic. It can be explained in following way
? Succession of plants occurs as hydrach or xerarch.
· Hydrach succession occurs in water bodies and the successional series progresses from hydric to mesic conditions.
· Xerarch succession takes place in dry areas and the series progresses from xeric to mesic conditions.
· Hence, both xerarch and hydrach conditions lead to medium water conditions (mesic).
Hydrach succession \[\downarrow \] Phytoplanktons (Pioneer species aquatic habitat) \[\downarrow \] Free - floating angiosperms \[\downarrow \] Grasses (serial communities) \[\downarrow \] Trees (mesic conditions) Xerarch succession \[\downarrow \] Lichens (pioneer species xerophitic habitat) \[\downarrow \] Bryophytes \[\downarrow \] Herbaceous plants \[\downarrow \] Shrubs (bushes) \[\downarrow \] Trees (mesio conditions)
Or
(i) Difference between immigration and emigration is as follows
Immigration	Emigration
It is the number of individuals of the same species that have come into the habitat from elsewhere during the time period under consideration.	It is the number of individuals of the population who left the habitat and gone elsewhere during the time period under consideration.
(ii) Difference between ectomycorrhizae and endomycorrhizae is as follows
Ectomycorrhizae	Endomycorrhizae
In this, the fungal mycelium forms a net outside the roots.	In this, the fungal mycelium dwells inside the roots.
(iii) Differences between population and community are as follows
Population	Community
It is a group of individuals of a single species found in an area.	It is a group of individuals of different species found in an area.
All the individuals are morphologically and behaviourally similar.	Different individuals are morphologically and behaviourally dissimilar.
(iv) Difference between natality and mortality is as follows
Natality	Mortality
It is the rate of production of new individuals per unit of population per unit time.	It is the rate of loss of individuals per unit time due to death or due to the different environmental changes, competition, predation, etc.
(v) Difference between predation and competition is as follows
Predation	Competition
It is an interspecific interaction, where an animal, called predator, kills and consumes the other weaker animals called prey	It occurs when closely related species compete for the same resources that are limited.