Human Impacts on Biogeography

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Biologists, who commonly study the distribution of plant and animal species in different environments—their biogeography— strive to develop interpretations or explanations of the patterns of species distribution, but these may be incorrect if the effects of human beings are not taken into consideration. In some cases, these effects may be accidental; for example, some species of rat were unintentionally transported aboard ships from Europe to the islands of the South Pacific. In other cases, species distributions may have been deliberately modified by human beings. The Polynesians in the South Pacific intentionally moved the kumara (sweet potato) to islands in that region to provide the population with a new food crop.

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The relocation of species by humans (and more recently the imposition of restrictions on movement by way of national controls and world conventions) has been primarily for economic reasons and for environmental protection. For example, humans introduced Sitka spruce trees into Scotland and England from North America to use them as a timber crop. Similarly, the Monterey pine tree was introduced into New Zealand in the nineteenth century from California and has become the most widely used species in the timber production industry in that country. The potato has been carried from its native home in the high Andes of South America, modified and developed into many varieties, and transported around the world because it can be used as a food crop. The plant formerly known as the Chinese gooseberry was relocated from its native China to New

Zealand where an industry was established around the renamed kiwifruit.

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We have extended the distribution of some species because of certain useful traits that make the species desirable beyond their former known range. For example, willows have extensive root systems, can grow relatively quickly, and are now used in several countries worldwide to stabilize river margins as a flood protection measure. The distribution of willows has therefore been influenced considerably by human use in river bank management.

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The effects of introduced species can be many and varied and can include effects on the distribution of other species. For example, the North American gray squirrel was introduced into England and has now largely displaced the native red squirrel.

The accidental introduction of organisms to new areas may have major pest implications. The South African bronze butterfly, the larva (immature insect forms) of which feed on buds and other parts of geraniums and similar flowers, was accidentally introduced into the Balearic Islands via imported geraniums. In its native South Africa, the distribution and abundance of the butterfly are affected in part by a native wasp that parasitizes (feeds on) the larvae. In the absence of the parasite wasp on the Balearic Islands off the coast of Spain, the butterfly has now spread to mainland Spain where its rapid spread has been accentuated by trade in garden plants and modern transport. The species has become a major pest due to the lack of a natural predator and is now causing great problems for the horticultural industry in Spain.

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Human-driven changes in the distribution of some species may result in hybridization (interbreeding) with other species and so have a genetic effect. For example, the North American cord grass was accidentally introduced to the south coast of England in the early nineteenth century. It hybridized with the European cord grass and resulted in the production of a new species, which in this case is also a major pest plant of estuaries in England where it became dominant and extensive.

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Information about a species distribution (prior to human modification) maybe applied in pest control programs for the introduced species. Studies of the species in its native habitat may yield information about the factors that limit or influence its distribution and population dynamics. That information may then be applied in the development of strategies to contain and control the spread of pest species. For example, information about the role of the parasitic wasp in the ecology of the bronze butterfly may be utilized in the process of finding control strategies for that species on mainland Spain.

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【Paragraph 1】

Biologists, who commonly study the distribution of plant and animal species in different environments — their biogeography — strive to develop interpretations or explanations of the patterns of species distribution, but these may be incorrect if the effects of human beings are not taken into consideration.?In some cases, these effects may be accidental; for example, some species of rat were unintentionally transported aboard ships from Europe to the islands of the South Pacific. In other cases, species distributions may have been deliberately modified by human beings. The Polynesians

in the South Pacific intentionally moved the kumara (sweet potato) to islands in that region to provide the population with a new food crop.

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1. Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect

choices change the meaning in important ways or leave out essential information.

A. In biogeography it is common to consider and study the effects of plant and animal species as they are distributed within environments where humans live.

B. Biologists who study environments in which plants and animals are distributed have arrived at interpretations or explanations for how species succeed, but these may not be correct.

C. To understand plant and animal distribution patterns correctly, biologists must consider the role of hum an beings in the biogeography of species

D. It is common for biologists who try to understand the effects of humans on their environments to be incorrect in their explanations of certain distribution patterns of plants and animals.

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2. In paragraph 1, the author makes the point that the relocations of rats and the kumara to new environments differed in

A. whether or not humans planned to transfer these species to a new environment

B. how far these species had to be transported to arrive at the new environment

C. how difficult it was for these species to become established in the new environment

D. whether or not these species succeeded in the new environment

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【Paragraph 2】

The relocation of species by humans (and more recently the imposition of restrictions on movement by way of national controls and world conventions) has been primarily for economic reasons and for environmental protection. For example, humans introduced Sitka spruce trees into Scotland and England from North America to use them as a timber crop. Similarly, the Monterey pine tree was introduced into New Zealand in the nineteenth century from California and has become the most widely used species in the timber production industry in that country. The potato has been carried from its native

home in the high Andes of South America, modified and developed into many varieties, and transported around the world because it can be used as a food crop. The plant formerly known as the Chinese gooseberry was relocated from its native China to New Zealand where an industry was established around the renamed kiwifruit.

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3. In paragraph 2, the author mentions Chinese gooseberries and the Monterey pine in order to

A. contrast two plant species transplanted for different reasons

B. demonstrate how two extremely different species adapt to a similar environment in New Zealand

C. offer evidence that newly introduced species can have unintended positive effects on the environment

D. provide examples of species moved for economic purposes

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【Paragraph 3】

We have extended the distribution of some species because of certain useful traits that make the species desirable beyond their former known range. For example, willows have extensive root systems, can grow relatively quickly, and are now used in several countries worldwide to stabilize river margins as a flood protection measure. The distribution of

willows has therefore been influenced considerably by human use in river bank management.

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4. According to paragraph 3. why are willows a species that are now found in different countries worldwide?

A. They adapt easily to a variety of environments.

B. They have characteristics that make them useful in preserving river banks during floods.

C. They have a root system that allows them to reproduce easily and live long.

D. They require little care or management from humans.

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【Paragraph 4】

The effects of introduced species can be many and varied and can include effects on the distribution of other species. For example, the North American gray squirrel was introduced into England and has now largely displaced the native red squirrel. The accidental introduction of organisms to new areas may have major pest implications. The South African bronze butterfly, the larva (immature insect forms) of which feed on buds and other parts of geraniums and similar flowers, was accidentally introduced into the Balearic Islands via imported geraniums. In its native South Africa, the distribution and

abundance of the butterfly are affected in part by a native wasp that parasitizes (feeds on) the larvae. In the absence of the parasite wasp on the Balearic Islands off the coast of Spain, the butterfly has now spread to mainland Spain where its rapid spread has been accentuated by trade in garden plants and modern transport. The species has become a major pest due to the lack of a natural predator and is now causing great problems for the horticultural industry in Spain.

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5. What can be inferred from paragraph 4 about geraniums in South Africa as compared to geraniums in Spain and the Balearic Islands?

A. The structural parts and buds of geraniums in South Africa differ from those of geraniums in Spain and the Balearic Islands.

B. Compared to the geraniums in Spain, the ones in South Africa are less likely to have bronze butterfly larvae as a pest.

C. Geraniums are less important to the horticulture industry in South Africa than they are to the horticultural industries tries of Spain and the Balearic Islands.

D. Geraniums in South Africa are traded more than the geraniums in Spain and the Balearic Islands are.

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6. According to paragraph 4, why did the South African bronze butterfly become a major pest in Spain?

A. Spain has a greater number of flowers for the butterflies to feed on

B. The butterfly’s larvae reach maturity more quickly in Spain than they do elsewhere.

C. There are no natural predators of bronze butterfly larvae in Spain

D. The species of geranium that is found in Spain is a more delicate garden plant and easier for pests to consume

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7. Paragraph 4 supports which of the following statement about the South African bronze butterfly?

A. It was deliberately introduced into two new environments at the same time.

B. Its spread on mainland Spain had a significant economic impact.

C. It changed its parasitizing behavior when it adapted to new environments.

D. Its presence on mainland Spain and the Balearic Islands caused other insect populations to increase.

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【Paragraph 6】

Information about a species distribution (prior to human modification) maybe applied in pest control programs for the introduced species. Studies of the species in its native habitat may yield information about the factors that limit or influence its distribution and population dynamics. That information may then be applied in the development of strategies to contain and control the spread of pest species. For example, information about the role of the parasitic wasp in the ecology of the bronze butterfly may be utilized in the process of finding control strategies for that species on mainland Spain.

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8. Paragraph 6 returns to a discussion of the bronze buttery in order to

A. demonstrate that information about species in their native habitat can be applied to controlling their spread in new habitats

B. emphasize the negative effects of parasitic wasps on butterflies in general

C. further support the claim that the bronze butterfly was accidentally introduced to mainland Spain

D. conclude by recommending the development of careful pest control strategies so that the ecology is not damaged

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【Paragraph 2】

The effects of introduced species can be many and varied and can include effects on the distribution of other species. For example, the North American gray squirrel was introduced into England and has now largely displaced the native red squirrel. The accidental introduction of organisms to new areas may have major pest implications. ■The South African bronze butterfly, the larva (immature insect forms) of which feed on buds and other parts of geraniums and similar flowers, was accidentally introduced into the Balearic Islands via imported geraniums. ■In its native South Africa, the distribution and abundance of the butterfly are affected in part by a native wasp that parasitizes (feeds on) the larvae.■ In the absence of the parasite wasp on the Balearic Islands off the coast of Spain, the butterfly has now spread to mainland Spain where its rapid

spread has been accentuated by trade in garden plants and modem transport. ■The species has become a major pest due to the lack of a natural predator and is now causing great problems for the horticultural industry in Spain.

9. Look at the four squares [■] that indicate where the following sentence could be added to the passage.

Its presence there helps control the bronze butterfly population.

Where would the sentence best fit?

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10.【Directions】An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.

A variety of factors, including human activity, can affect the distribution of species.

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Answer Choices

A. Research has shown that the biogeography of species can change even without human interference as can be seen in the wide distribution of willows along a wide range of river banks.

B. Introducing a species to a new environment can have unintended consequences such as those that occurred when a butterfly was relocated to an environment that lacked its natural predator.

C. The success of relocating two species together depends on how they help each other survive in a new environment as demonstrated by the South African bronze butterfly and geraniums.

D. The study of the relocations of certain species to new habitats has been difficult because it is not always clear if the relocations were natural or caused by humans.

E. Humans have relocated species for a variety of reasons, including obtaining new food sources, creating new industries, and taking advantage of the characteristics of certain species.

F. Understanding the distribution of a species in its native habitat can be useful in controlling Its spread as a pest in Its new habitat.

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