Both hydrach and xerarch successions:
1. Take same time
2. Have similar sere
3. Lead to mesic conditions
4. Have same pioneer species
Which of the following organisms will be the first to colonize a bare rock?
1. Annual plants
2. Lichens
3. Perennail plants
4. Herbs and shrubs
During ecological succession
(1) the gradual and predictable change in species composition occurs in a given area
(2) the establishment of a new biotic community is very fast in its primary phase
(3) the numbers and types of animals remain constant
(4) the changes lead to a community that is in near equilibrium with the environment and is called pioneer community
Which of the following would appear as the pioneer organisms on bare rocks?
(1) Liverworts
(2) Mosses
(3) Green algae
(4) Lichens
Secondary succession takes place on/in
(1) bara rock
(2) degraded forest
(3) newly created pond
(4) newly cooled lava
During the stages of succession in a given ecosystem the following changes in characteristics may be observed:
Characteristic | Stages in ecosystem development | |
Early | Late | |
A. Total matter | Low | High |
B. Species diversity | Low | High |
C. Size of organism | Small | Large |
D. Productivity | Low | High |
E. Food chains | Short | Long |
Which one of the characteristics, A, B, C, D or E is responsible for the apparent high degree of stability associated with a climax ecosystem?
(1) B
(2) D
(3) A
(4) E
Some of the stages in the hydrarch are labelled as:
A. Marsh meadow stage
B. Reed swamp stage
C. Submerged plant stage
D. Phytoplankton stage
E. Submerged free floating plant stage
Identify the choice that represents the correct sequence of these stages:
(1) D, C, E, B and A
(2) C, E, A, B and D
(3) B, D, C, A and E
(4) D, E, C, B and A
Read the following statements carefully.
(i) Primary succession is a very slow process taking thousands of years for the climax to reach.
(ii) Energy at a higher trophic level is always more than that at a lower level.
(iii) Bacterial and fungal enzymes degrade detritus into simpler inorganic substances. This process is called fragmentation.
(iv) All succession, whether taking place in water or on land, proceeds to a similar climax community - the mesic.
Which of the two above statements are correct?
1. (i) and (ii)
2. (ii) and (iii)
3. (i) and (iv)
4. (iii) and (iv)
In response to the changing environmental conditions, composition and structure of a community-
1. Remains constant
2. Constantly changes
3. Changes sometime
4. Never changes
What do you mean by ecological succession?
1. One community is succeeded by another
2. One community is dominant over another
3. The gradual and fairly predictable change in the species composition of a given area
4. Success of the ecological community.