Question

Spartina is a group of grasses that dominates communities of salt marshes in many coastal areas. Many of the insects, snails, birds, mice, and other animals found in these communities rely on Spartina for food, nest building materials, protection for their young, etc. The roots of Spartina also form dense mats that hold together soil in these ecosystems. Many species that live in Spartina salt marshes cannot survive outside of these unique ecosystems. Because living near the ocean is desirable to many humans, many Spartina marshes have been drained & cleared for human development. Analysis of the destruction that came when Hurricane Katrina hit Louisiana in 2005, however, showed that the reduction of salt marshes in coastal Louisiana was a contributing factor to the storm surge penetrating further inland.

1. The value of Spartina salt marshes in protecting coastal areas from storm surge would be classified as which type?
A. Extrinsic.
B. Intrinsic.
C. Neither.
2. The value of Spartina salt marshes in holding soil together would be classified as which type?
A. Extrinsic.
B. Intrinsic.
C. Neither.
3. In general, you would expect species that only live in Spartina salt marshes to have a higher extinction risk than species that can survive in urban areas.
A. True
B. False
4. Based only on the information included in this scenario, extinction risk for species that only live in Spartina salt marshes would be most influenced by which factor?
A. Restricted geographic range.
B. Narrow habitat requirements.
C. Small population size.

Answer 1

1)a. Extrinsic

2) b. Intrinsic

3) a. True

4) a. Restricted geographic range

Step-by-step explanation:

1. Spartina Salt marshes are important to the coastal areas as they protect them from storm surge as affecting the erosion of salt marsh edges and it is classified as extrinsic.

2) b. Intrinsic

Intrinsic factors such as vegetation and soil affect the erosion of salt marsh edges. It is determined by characteristics of soil and root biomass found under the ground.

3) a. True

Species that could survive in urban areas are less prone to extinction than the species that only survive in spartina salt marshes.

4) a. Restricted geographic range

A restricted geographic range is a factor that leads and affects the extinction in endemic species more.