Question

36. Succession studied on the island of Krakatau, Indonesia, has been done using A) pollen. B) indirect observations. C) chronosequences. D) direct observations, 37. Primary succession beings in A) an area that previously had plant-life. B) an area that never contained plant-life. e water D) an area that already has plants. 38. Secondary succession takes place in habitats that A) are initially devoid of plants and organic soil. B) have some plants following disturbance. C) have some plants following disturbance but do not have organic soil. D) have been disturbed and contain no plants but still contain organic soil. 39. When succession was studied at the Duke Forest in North Carolina, how many years did it take for the agricultural field to revert to deciduous climax forest? A) 500 years B) 200 years 10 years Di Never it will remain a field forever 0 Invasion of cheatgrass (Bromw tectorum) in the wester United States is maintained by Al overgrazing associated with droughts following hurricanes B) periodic fires in combination with grazing C frequent logging in combination with periodic tires D major floods associated with humicanes

Answer 1

Answer 36: Successions studied on the island of Krakatau; Indonesia has been done using:

Correct option is Pollen.

Reason: The colonization patterns observed for Krakatau Islands, Indonesia, suggests that changes in the vines population and communities resulted in the regeneration of tropical rain forest. This pattern has been achieved in some 111 years.

Long back ,71 species of vines showed growth habitat out of large numbers of spermatophytes. Some out of them were dioecious, as well some were monoecious. Some of them were cross pollinated by the insects and via some other forms of agencies. The evidence for pollens gave an important remark in the successions, can also be pointed by the presence of large amounts of pollens or seeds shown close to fruiting plants on the island of Krakatau, Indonesia that may have come there from long distances and escaped from parent plants.

Answer 37: Primary succession begins in:

Correct option is: An area that never contained plant life.

Reason: Primary succession begins with an area where the land is barren or had no organisms or plants present there. For examples: sand dunes, volcanic erupted lava regions etc. Pioneer species when comes in action and works on rocks that ultimately convert it into soil and then begin with some plant growths proceeds it with grass stage, herbs, shrubs and finally into larger trees. It involves usually 4 to 5 stages to reach at its climax.

Answer 38: Secondary succession takes place in habitat that:

Correct option is: have been disturbed and contained no plants but still contain organic soil.

Reason: Secondary succession usually takes place on a previously colonized land area. They usually might have faced some calamity or destruction that damaged the place. It can be due to wildlife fires etc. But, the presence of rich soil can still be left due to previously existing pioneer species or plants or vegetations available there. Although, all plants are destroyed by any kind of calamity, the already existing rich soil can re-establish the ecosystem.

Answer 39: When succession is studied at the duke forest in North Carolina:

Correct option is: it took almost 200 years to revert to deciduous climax forest.

Reason: Almost 900 species can be seen in Duke forest. Majority of them are pines, hardwoods etc. Small natural pines were developed around 110 years and hardwoods nearly took 200 years for the reestablishment to occur as a forest.