Grasses are also early successional species because they reproduce quickly and require minimal diversity of resources to survive. Their quick reproduction and growth also categorizes them as R-selected species.

The correct response is secondary succession. This process occurs following some disturbance when the seedbank is still intact. For example, after an earthquake or fire all the vegetation is removed but there are still seeds in the ground. This would be an example of secondary succession because the vegetation can still recover. This is different from primary succession - primary succession occurs when there is no prior vegetation on the landscape and there is no seedbank. Tertiary and quaternary succession are made up terms.

Ecological succession is the change of the structure of an environment overtime. The environment can be changed due to a sudden disruption or small changes overtime. These changes can take place over a few decades or millions of years. 

Primary succession is, by definition, the establishment of living communities in areas where life had not previously existed. A waterfront that is barren rock does not initially have the potential to support life until mineral and soil deposits allow new plant communities to establish themselves. The other answers are not correct because plant communities already exist in these examples, which is not characteristic of primary succession. 

Lichens are able to survive on bare rocks, with very few nutrients available. As a result, they are one of the first organisms to colonize an area of primary succession, where they usually break down rocks over time to form the base of soil in the new habitat.

Market-based, hierarchical, sectarian, and rational methods are all risk management strategies. Conservative method is not a risk management strategy.

Many Rocky Mountain and Western conifer species are adapted to germinate only after being exposed to temperatures typical of a wildfire. Pioneer species and shrubs typically have no problem generating after a clear-cut, but often foresters have to plant pine saplings in a clear-cut area, because remaining seeds will not germinate.

Although human activites are reducing the extent of many biomes, they are causing the spread of deserts, a process called desertification. Rain forests are being felled for lumber or burned down for ranching or agriculture. Africa's rapidly expanding human population threatens the wildlife of the savanna. The tallgrass prairie has been converted to agricutural land. Clearing for lumber, agriculture, and housing has dramatically reduced America's deciduous forests.

Composting is a process in which purely organic waste is converted into a rich soil conditioner commonly known as 'compost'. The process usually begins with household food and plant scraps, which are broken down over time and added to soil to fertilize the soil and help it retain moisture.

"Habitat connectivity" is the only term that describes something positive that increases the quality of biodiversity. It is defined as the degree to which landscape facilitates movement and ecological flows important for the survival of other species. Every other term describes things that decrease habitat and negatively impact biodiversity.