SB5d - Human Impact

Forests throughout the U.S. are under increasing development pressure. Habitat fragmentation occurs when the natural habitat is interrupted and partially removed. This occurs when houses, lawns, driveways, and other infrastructure are constructed. This can have consequences for the forest biodiversity. Losing forested land impacts life on Earth in many ways as well as having consequences for Earth's climate. Evaluate the potential solutions below and select those that can reduce the impacts of habitat fragmentation. Select ALL that apply

• Replant trees in gaps to eliminate the space between fragmented landscapes.

• Use carefully controlled burns as a management tool to maintain plant communities.

• Put land in a conservation easement to ensure that it will not be fragmented in the future.

• Reduce the rate of conversion of forestland to alternative uses through zoning and comprehensive planning.

• Create corridors of trees along fencerows or streams as natural pathways for wildlife connecting forest fragments.

European frog's-bit is a free-floating plant with clustered heart-shaped leaves. Resembling small water lilies, frog's bit has white flowers with three petals and yellow centers that bloom in the summer. European Frog's-bit is native to Europe but was introduced to North America in the 1930s as an ornamental pond plant. It is one of eleven invasive aquatic species identified in Maine law as illegal to import, sell, and transport. What is the BEST way to prevent its spread in Maine lakes and ponds?

• treating infestations with aquatic herbicides

• Banning the sale and distribution of the plant

• Limit boaters to only one local waterway to prevent the spread of invasive species from one environment to another.

• Educational outreach and watercraft inspections at boat ramps to keep infestation from migrating from one water body to another.

80% of Australia’s land area is managed by farmers, indigenous communities, and other private land managers. As a result, effectively protecting Australia's environmental resources requires managing environmental assets on private land, and engaging landowners in this effort. Australian dairy farmers have taken the lead in environmental self-assessments and restoration and preservation of the land and water resources. Efforts have been made in the last several decades to preserve and restore Australian lands by dairy farmers. Efforts have included all but one the following techniques. Identify the technique that does not help with restoration or preservation.

• Irrigating pasture land during times of water stress and drought.

• Planting trees, shrubs and grasses to increase river bank stability.

• Fertilizer use on an as-needed basis to reduce nitrous oxide emissions.

• Diverting murky run-off from farms into settling ponds to let nature clean it.

The graph illustrates what has happened over an 8 year period, when non-native Nile perch were introduced to Lake Malawi in Africa. Environmental factors remained the same during this period (i.e., temperature, pH, water levels, etc.) Based on the data, what recommendation would you make to African biologists?

• Remove or reduce the Nile perch as quickly as possible, as it is clearly out-competing the pike cichlid.

• Remove the remaining pike cichlids, as they are competing with the Nile perch.

• Reduce both fish populations, or they will starve one another out.

• There is no competition between these species of fish.

This chart shows the annual catch statistics for the red grouper for the state of North Carolina during the 1990’s. Red grouper begin their lives as females, and the largest fish change sexes to become male during mating season. Only large females' mate with these males and lay eggs. You are a fisheries biologist for the state of North Carolina. You are charged with protecting the fish population, while also keeping professional fishermen from losing their jobs. Based on the chart above, what would you conclude and what would your solution be?

• There is a serious problem with overfishing of red grouper, so there must be a problem with other fish as well. All fishing for any species should be banned.

• There is not a very serious problem. The smaller size and population are probably just due to some bad years. Do nothing and monitor the situation.

• There is a problem with overfishing. Ban fishing for large fish so their size and population can recover, but allow the fishermen to take smaller fish.

• There is a problem with overfishing of red grouper, but the fishermen need to stay in business. Bring in another species of grouper from Australia, so that there are more fish to catch.