In the last half-century, firefighters in North America have developed

In the last half-century, firefighters in
North America have developed a powerful system for
fighting wildfires using modern technology. But at the
same time, foresters and ecologists are increasingly
(5) aware that too much firefighting can be worse than
none at all. Over the millennia, many forest ecosystems
have evolved in such a way that they are dependent on
periodic fires for renewal and for limiting damage
when fires do occur. Ancient ponderosa forests, for
(10) example, were stable in part because low-intensity
fires maintained open forests with low levels of fuel
for future fires. These fires burned lightly around the
bases of mature trees, leaving these trees alive and
clearing the understory of brush and young trees.
(15) Scientists can easily count the regular recurrence of
fires in these forests over the centuries by examining
the scars left on trunks the typical interval between
fires could be as short as 5 years and rarely extended
beyond 25 years.

(20) If fires are kept out of forests, however, deadwood
and other fuels build up then, when fire is sparked by
lightning or some other cause, what results is a fire so
large that it leaves total devastation. Such fires often
kill off wildlife that might escape low-intensity fires,
(25) and they also reach the crowns of centuries-old trees,
destroying them and ultimately enabling rains to erode
the unprotected topsoil. Because of the relative success
of fire-suppression efforts, many forests, including
ponderosa forests, have now been free of fire for
(30) 50 years or longer, leaving them vulnerable to these
devastating crown fires. It is therefore increasingly
necessary for land managers in North America to
strive to manage rather than eliminate fires land
management policies should recognize the essential
(35) role that fire plays in many ecosystems.

Fire behavior depends on the complex interaction
of three factors—topography, weather, and fuel—and
since topography is fixed and weather is unpredictable,
fuel is the only element that land managers can
(40) control. Land managers should therefore focus their
efforts on fuel. A new kind of wildfire management
that is designed to simulate the natural role of fire
through a combination of selective harvesting and
prescribed fires is the most promising method for
(45) controlling fuel. Selective timber harvesting focuses
on smaller trees—markets for this smaller material
do exist—leaving the larger, fire-tolerant trees on the
land and thinning the forest, thereby re-creating the
conditions that allow for low-intensity burns.
(50) Prescribed fire management includes both the
intentional lighting of controlled burns and the policy
of allowing fires set by lightning to burn when the
weather is damp enough to reduce the risk of extensive
damage. Once fuels are reduced by these fires,
(55) maintenance burns at 15- to 20-year intervals will be
needed. When wildfires inevitably occur, they will be
more easily controlled and do much less damage.

1. The primary purpose of the passage is to

(A) claim that ideological dogma may be impeding the enactment of a fundamental and necessary policy change
(B) compare the actual effects that have resulted from two different policies designed to have the same effect
(C) contend that a recently implemented policy requires a substantial increase in funding
(D) recommend a fundamental policy change in light of evidence that current policy has created undesirable conditions
(E) argue that two seemingly contradictory goals of a policy are actually compatible in a fundamental way

2. By “maintenance burns” (line 55) the author most clearly refers to

(A) the low-intensity fires that regularly occurred in ancient forests
(B) fires that reduce the population density of mature trees
(C) the types of fires that are likely to occur in North American forest ecosystems today
(D) a type of fire that used to occur at intervals greater than 50 years
(E) naturally or intentionally set fires that are allowed to burn to eliminate fuel

3. Which one of the following sentences would most logically complete the last paragraph of the passage?

(A) However, if homes were not built in such close proximity to forests, the damage to developed property would be limited substantially.
(B) Unfortunately, until foresters recognize the dangers posed by excess fuel in forests, these proposals are likely to meet with resistance in the forestry community.
(C) But even with these policies, which require some years to achieve their intended effects, large, devastating fires will remain a threat in the near term.
(D) Yet, because smaller trees will likely yield less profit for timber companies, the ecological benefits of the new plans must be weighed carefully against their economic impact.
(E) But given the large financial resources needed to operate a prescribed fire management system, the chances of such policies being implemented are quite small.

4. The author cites the factors of topography, weather, and fuel in the last paragraph primarily as part of

(A) the support provided for the contention that land managers must focus on fuel to reduce the risk of crown fires
(B) an argument that, given the interaction among these factors, land managers’ efforts to control wildfires will always be somewhat ineffective
(C) an attempt to provide a clearer understanding of why forest fires have become unnaturally devastating
(D) an argument that specific fuel types and forest densities are dependent on topographic and weather conditions
(E) the suggestion that fires started by lightning will continue to be a factor in wildfire suppression efforts

5. The passage provides the most support for inferring that which one of the following is true of ancient ponderosa forests?

(A) Ponderosas that thrived in these forests probably differed genetically from modern ponderosas in subtle, though significant, ways.
(B) The population density of trees in these forests was generally lower than it is in many ponderosa forests today.
(C) Weather patterns in these forests were substantially different from weather patterns in ponderosa forests today.
(D) The diversity of plant species was greater in these forests than it is in ponderosa forests today.
(E) In addition to clearing out excess fuel, periodic low-intensity fires helped to control wildlife populations in these forests.

6. It can be inferred from the passage that the author would be most likely to regard a policy in which all forest fires that were started by lightning were allowed to burn until they died out naturally as

(A) a viable means of restoring forests currently vulnerable to catastrophic fires to a cycle of periodic low-intensity fires
(B) an essential component of a new wildfire management plan that would also involve the regulation of timber harvests
(C) beneficial to forests that have centuries-old trees, though harmful to younger forests
(D) currently too extreme and likely to cause the destruction land managers are seeking to avoid
(E) politically infeasible given the public perception of the consequences of such fires