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What Is This Indicator, and Why Is It Important?
This indicator reports the production of food and fiber and
the withdrawals of water, using an index with 1980 as the
base year. Values above 1.0 indicate that production or withdrawals
were greater than in 1980; values below 1.0 indicate that
production or withdrawals were lower than in 1980. Products
from U.S. ecosystems meet much of the nation’s food,
fiber, and water needs. Changes in the quantities of these
goods signal fundamental changes in the direct benefits we
receive from ecosystems.
What Do The Data Show? Over the past half-century
or so, agricultural and forest production and freshwater withdrawals
have all increased. But the rates of increase—and in
some cases, periods of decline—vary from system to system.
Agricultural production has grown the fastest. Except for
a few periodic downturns, growth in agricultural production
has generally been faster than the growth in U.S. population.
Forest production has generally grown more slowly than population
growth, except for a decade of more rapid growth during the
late 1970s to 1980s. Forest production has declined since
the mid-1980s. Freshwater use increased faster than population
through 1980, declined by about 10% by the mid-1980s, and
has grown slowly since then. Marine fish landings grew by about 10% from the mid-1970s to the mid-1990s. Recent declines mean that current levels are about equal to those of the late 1970s. Estimates of catches before the late 1970s are uncertain because of the presence then of large foreign fleets, which are no longer permitted to fish in U.S. waters. Most of
the regional patterns of food and fiber production and water
withdrawals match the national patterns above, with a few
notable exceptions:
- Regional agricultural production generally follows the
national growth trends (regardless of regional population
growth).
- The recent modest decline in forest production nationally
is the result of large declines in the Pacific Coast and
Rocky Mountain regions being partially offset by increases
in forest production in the Southeast.
- Total water withdrawals have increased slightly following a 10% decline in the mid-1980s, although trends show water withdrawals have tracked increasing population in the Southeast, Southwest, and to a lesser extent the Midwest regions, while not keeping pace with increasing population in the Northeast/Mid-Atlantic, Pacific Coast, and Rocky Mountain regions.
- Since the late 1970s, marine fish landings have increased in the Pacific Coast region (due to an expanding U.S. fleet—see Fish Landings Indicator) and decreased in the Northeast/Mid-Atlantic and Southeast regions. Landings for all U.S. waters combined have decreased since the mid 1990s.
Discussion This indicator allows comparison
between the amounts of a single good produced in two time
periods. So, for example, an index value for agricultural
products that is greater in 1994 than in any other year means
that the nationwide harvest in 1994 was greater than at any
other time in this 50-year series. The index value for 1994
is approximately 1.25, which means that the harvest in 1994
was about 25% greater than the 1980 harvest.
The index also allows comparison of the rate of growth or
decline in production of two different goods. This can be
seen, for example, by comparing agricultural production to
marine fish landings since 1980. A steadily increasing line,
such as in agricultural products, indicates that the amount
of products we obtain from that ecosystem continues to grow.
In contrast, marine fish landings grew until the mid-1990s,
but have since declined to about 1980 levels.
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