Biosphere (3) Flashcards
What are the distinctive biomes where the ocean interfaces with land or with fresh water?
-Intertidal zones are where the ocean meets the land and the shore is pounded by waves during high tide and exposed to the sun and drying winds during low tide.
-Estuaries are productive areas where a freshwater stream or river merges with the ocean.
-Wetlands are transitional between aquatic and terrestrial ecosystems.
What are the 2 categories of freshwater biomes?
- Standing water biomes (lakes and ponds)
- Flowing water biomes (rivers and streams)
What determines the amount of phytoplankton growth in a lake or pond?
The mineral nutrients nitrogen and phosphorus typically determine the amount of phytoplankton growth in a lake or pond.
How do lakes and ponds receive large inputs of nitrogen and phosphorus?
Many lakes and ponds receive large inputs of nitrogen and phosphorus from sewage and runoff from fertilized lawns and farms.
Explain how the nutrients may produce a heavy growth of algae. What happens when the algae dies?
These nutrients may produce a heavy growth (“bloom”) of algae, which reduces light penetration.
When the algae die and decompose, a pond or lake can suffer severe oxygen depletion, killing fish that are adapted to high oxygen conditions.
Explain how the water of a river is when it’s near the source.
Near the source, the water is usually clear, cold, and oxygen-rich, with a swift current
Explain the organisms in rivers and streams.
-Inhibits the growth of phytoplankton
-Most of the organisms found here are supported by the photosynthesis of algae attached to rocks or by organic material, such as leaves, carried into the stream from the surrounding land
How is the composition of rivers downstream?
Downstream, a river or stream generally widens and slows. The water is usually warmer, lower in oxygen, and may be murkier because of sediments and phytoplankton suspended in it.
What are freshwater wetlands and what are their advantages?
Freshwater wetlands range from swamps to marshes and bogs.
They provide water storage areas that reduce flooding and improve water quality by filtering pollutants
The same type of biome cannot occur in geographically distant places even if the climate is similar. True or false?
False. The same type of biome may occur in geographically distant places if the climate is similar.
What are the features of tropical forests?
Tropical forests
-occur in equatorial areas,
-experience warm temperatures and days that are 11–12 hours long year-round, and
-have variable rainfall.
-Tropical rainforests harbor enormous numbers of species.
What are the features of Savannahs?
Savannas
-are warm year-round,
-have 30–50 cm annual rainfall,
-experience dramatic seasonal variation,
are dominated by grasses and scattered trees
-have insects as the dominant herbivores
What are the features of deserts?
Deserts
-are the driest of all terrestrial biomes.
-They typically have low and unpredictable rainfall.
-The cycles of growth and reproduction in the desert are keyed to rainfall.
-Deserts can be very hot or very cold.
-Desertification, the conversion of semi-arid regions to deserts, is a significant environmental problem
What are the features of chapparals?
The chaparral is characterized by dense, spiny shrubs with tough, evergreen leaves.
-Chaparral experiences mild, rainy winters, and hot, dry summers
-with vegetation adapted to periodic fires.
-Firestorms that race through the densely populated canyons of Southern California can be devastating.
What are the features of temperate grasslands?
Temperate grasslands
-are mostly treeless, except along rivers or streams
-are found in regions of relatively cold winter temperatures
-experience precipitation of about 25–75 cm per year, with periodic droughts, and
in North America have historically been grazed by large bison and pronghorn.
