In which of the following instances would an ecological succession regarded as secondary?
1. Newly cooled lava
2. Bare rock
3. Newly created pond
4. Abandoned farmland
Identify the correct statements regarding ecological succession:
I: | Usually, secondary succession is faster than primary succession. |
II: | Ecological succession involves a change over time in vegetation only. |
III: | Natural or human disturbance can convert a particular seral stage of succession to an earlier stage. |
1. Only I and II
2. Only I and III
3. Only II and III
4. I, II and III
Ecological succession leads to mesic conditions in:
I: | Hydrarch succession |
II: | Xerarch succession |
1. Both I and II
2. Only I
3. Only II
4. Neither I nor II
The correct sequence of seral stages in primary hydrarch succession [pioneer to climax] would be:
1. | Phytoplankton, Submerged plant stage, Submerged free floating plant stage, Reed swamp stage, Marsh-meadow stage, Scrub stage, Forest |
2. | Phytoplankton, Submerged free floating plant stage, Submerged plant stage, Reed swamp stage, Marsh-meadow stage, Scrub stage, Forest |
3. | Phytoplankton, Submerged plant stage, Submerged free floating plant stage, Marsh-meadow stage, Reed swamp stage, Scrub stage, Forest |
4. | Phytoplankton, Reed swamp stage, Marsh-meadow stage, Submerged plant stage, Submerged free floating plant stage, Scrub stage, Forest |
The amount of nutrients present in the soil, at any given time, is referred to as:
1. Standing state
2. Standing crop
3. Primary productivity
4. Secondary productivity
The reservoir is located in the Earth’s crust for:
I. Gaseous type of nutrient cycle
II. Sedimentary nutrient cycle
1. Only I
2. Only II
3. Both I and II
4. Neither I nor II
The function of a reservoir of nutrient cycle is to:
1. synthesize minerals
2. transfer minerals to other ecosystems
3. meet any deficit
4. destroy the unwanted minerals
The dry weight of living organisms is mainly made up of:
1. | Water | 2. | Calcium |
3. | Nitrogen | 4. | Carbon |
The maximum percent of total global carbon is found:
1. in fossil fuels
2. in atmosphere
3. dissolved in oceans
4. in biomass of microbes
The amount of carbon dioxide in the atmosphere is regulated mainly by:
1. the atmosphere itself
2. human activities
3. decomposition by microbes
4. the oceanic reservoir