Chapter 55 Conservation Biology and Restoration Ecology
What Factors Can Affect Survival of a Species or Community?
1. Making decisions to preserve communities requires an understanding and integration of many
factors. Assume you work for the U.S. Government and manage a large national forest. You are
told that to maintain the economy in the area, the government has agreed to allow foresters to
remove half a million acres of trees from a million acre parcel. This parcel is almost square in
shape.
You have asked your staff to do an analysis of two possible methods for removing the half million
acres.
Proposal I: Split the million acres into two parcels of a half million acres each and allow the
foresters to harvest one all trees on one of these parcels.
Proposal II: Designate 50 parcels (of 10,000 acres each) within the million acre tract and allow
the foresters to cut trees in these 50 parcels.
List some of the ecological advantages and disadvantages of each proposal.
Proposal I
Advantages
Disadvantages
Proposal II
Advantages
Disadvantages
Chapter 55 Conservation Biology and Restoration Ecology
What Factors Can Affect Survival of a Species or Community?
1. Making decisions to preserve communities requires an understanding and integration of many
factors. Assume you work for the U.S. Government and manage a large national forest. You are
told that to maintain the economy in the area, the government has agreed to allow foresters to
remove half a million acres of trees from a million acre parcel. This parcel is almost square in
shape.
You have asked your staff to do an analysis of two possible methods for removing the half million
acres.
Proposal I: Split the million acres into two parcels of a half million acres each and allow the
foresters to harvest one all trees on one of these parcels.
Proposal II: Designate 50 parcels (of 10,000 acres each) within the million acre tract and allow
the foresters to cut trees in these 50 parcels.
List some of the ecological advantages and disadvantages of each proposal.
Proposal I
Advantages
Disadvantages
Proposal II
Advantages
Disadvantages
2. Given the following characteristics of various animal species, which of the forestry cutting
proposals would be more likely to insure continued success of the animal species described?
Explain your answers.
a. C. arnivora is a secondary and occasionally a tertiary consumer or carnivore. Behaviorally, it roams
over about 20 square miles of “home range”, in search of food, e.g. rabbits (herbivores) and foxes
(carnivores).
b. R. odentia is a small rodent-like herbivore. Currently it occurs in small numbers in the forest. Its
preferred food and habitat are found along the edges of the forest and are composed primarily of
herbaceous (nonwoody) annual plants which produce tender shoots in the spring and plentiful seeds
later in the year.
c. P. redatoria is a predatory bird which feeds on small rodents and occasionally on snakes and other
reptiles. It can range over large distances looking for food. It nests in hollows that occur naturally in
a particular species of tree. These hollows are not found in trees under 20 years of age but are
commonly found in trees 40 years and older.
2. Given the following characteristics of various animal species, which of the forestry cutting
proposals would be more likely to insure continued success of the animal species described?
Explain your answers.
a. C. arnivora is a secondary and occasionally a tertiary consumer or carnivore. Behaviorally, it roams
over about 20 square miles of “home range”, in search of food, e.g. rabbits (herbivores) and foxes
(carnivores).
b. R. odentia is a small rodent-like herbivore. Currently it occurs in small numbers in the forest. Its
preferred food and habitat are found along the edges of the forest and are composed primarily of
herbaceous (nonwoody) annual plants which produce tender shoots in the spring and plentiful seeds
later in the year.
c. P. redatoria is a predatory bird which feeds on small rodents and occasionally on snakes and other
reptiles. It can range over large distances looking for food. It nests in hollows that occur naturally in
a particular species of tree. These hollows are not found in trees under 20 years of age but are
commonly found in trees 40 years and older.
3. Conservation biologists have debated extensively which is better: many, small reserves or a few
large ones.
a. What types of factors should be considered in making judgments about size and location of
reserves?
b. Some ecologists argue that we should we be concerned about preserving the largest number of
species. Others argue that we should be most concerned with saving those species judged to be of
unusual importance. Develop an argument to support one of these viewpoints. Your argument
should be based on our existing understanding of biology, in general, and ecology in particular.
4. Based on your answers to questions 1 to 3 above, which of the proposals for removing half a million
acres from the national forest (question 1) would you recommend? Explain the reasoning behind your
recommendation.