Chapters 10 and 20 continued: Mid-latitude Grasslands
These regions are called grasslands because of the predominance of grasses and grasslike plants.
As rainfall levels become low, they take on a scrubbier, more desert-like feel, with sparser vegetation of
sagebrush, grasses, and cacti.
We will focus on the grass-dominated areas in today’s discussion.
Usually grasslands occur in _________ climates, most often _____________________ climates,
which are in the interiors of continents, with __________ versus ___________ patterns.
They are ________ areas.
In many cases, rainfall is widely variable and undependable, and ranges from
8 to 16 inches per year.
These grasslands climates are different from savanna climates in that they typically do not have
such strong extremes between wet and dry periods each year; rainfall is somewhat more evenly
distributed over the year.
Also, being in higher latitudes, they experience _________________ and
greater variability in _____________ and ___________ over the year.
The rainfall is received from
the movement of the ITCZ.
These regions can be very _________ due to their open topography and adjoining mountains,
and spawn ______________________.
The soils are ____________: deep, rich soils that are high in plant nutrients, so they are very
___________. They are crumbly and well aerated, so it is easy for plants to grow deep roots.
some of the richest __________ in the world, and support the great breadbaskets of the world.
The grasses are major contributors to the fertility of the soil.
This is because the majority of the
plant is in the root system:
a 9 foot tall grass can have roots that go down 26 feet deep.
These roots are
In addition, lower rain levels means fewer nutrients are ________________ as compared to more
Also, ashes from fires add _____________________ to the soil.
Fire is an important force on the landscape.
It is ignited by lightning during thunderstorms, and
humans also have a history of spreading fires in grassland systems.
Fire is spread easily by the
These are __________________ fires that do not kill the roots of the grasses or most
Grasses and many flowering ___________ - non-woody plants – dominate the grasslands.
the tropical savannas, the plants are adapted to fire and drought.
Their leaves are ______________ so
that they do not lose moisture.
Also, in many grasses the leaves can ________________ to reduce
Often the plants here, as in the tropical savannas, have ___________________ leaves to
reduce water loss, and they have _____________ to reach water that is farther below the surface.
Grasses are especially adapted to grazing, because they _____________________ (most plants