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
Carbon dioxide is returned to the atmosphere by all the following except:
1. photosynthesis by the primary producers
2. respiratory activities of producers and consumers
3. decomposers
4. volcanic activity