APES- Unit 4

Removal of which of the following will result in the greatest change(s) in an ecosystem?

• indicator species
• keystone species
• foundation species
• threatened species

Clear-cutting:

• restricts timber harvesting to mountaintops
• removes all trees from a widespread area
• involves elimination of subsidies to logging companies
• is a form of violent protest favored by radical environmental organizations

Bottom dwellers (barnacles, oysters, sea cucumbers).

• plankton
• nekton
• benthos
• pelagic

Free-swimming macroscopic organisms such as fish, whales, and turtles

• plankton
• nekton
• benthos
• pelagic

Lower layer in deep water habitats: sunlight does not penetrate

• aphotic zone
• bathyal zone
• euphotic zone
• pelagic zone

Dimly lit middle layer. No photosynthesis, zooplankton and fish live there; migrate to feed

• aphotic zone
• bathyal zone
• euphotic zone
• abyssal zone 

River mouths, inlets, bays, sounds, temperate salt marshes and tropical mangrove forests

• estuaries
• intertidal zone
• coral reefs
• open ocean

Develop specialized niches to deal with daily changes in temperature, salinity, and wave action

• estuaries
• intertidal zones
• coral reefs
• coastal zone

Main body of a watershed or drainage basin; lotic system

• estuary
• river
• wetland
• lake

Lake area near shore; shallow, with rooted plants

• littoral
• profundal
• limnetic
• benthic