Invasive Species Lecture Notes

Flashcards to review key concepts related to invasive species, their impacts, management strategies, and specific examples from the lecture notes.

What is an invasive species?

An invasive species is one that arrives in a habitat it had not previously occupied, establishes a population, and spreads autonomously.

What is one of the main conservation threats today?

Species invasions are one of the main conservation threats today.

In which environments are introduced species especially prevalent?

Introduced species comprise a large proportion of all species, especially in islands.

What percentage of plant species in the Hawaiian islands are introduced?

Almost half of the plant species in the Hawaiian islands are introduced.

What is an example of a native species that has become invasive due to human activity?

Common reed (Phragmites australis) is an example of a native species that became invasive.

What event caused common reed to spread widely in the mid-nineteenth century?

The introduction of Old World genotypes in soil ballast caused common reed to spread.

How did the introduction of European genotypes affect reed canarygrass?

Reed canarygrass, which was native but uncommon, became invasive due to introduced European genotypes.

What caused the grass Elymus athericus to invade more habitats in western Europe?

Increased nitrogen in aerial deposition and runoff allowed Elymus athericus to spread.

What role did fire suppression play in the invasion of Douglas fir in the western United States?

Fire suppression enabled Douglas fir and other tree species to invade grasslands and shrublands.

What was the impact of introduced mammals in New Zealand?

Introduced mammals, such as brushtail possums and rats, have damaged native fauna and flora.

How does the Australian brushtail possum affect local ecosystems in New Zealand?

It destroys native trees and eats bird eggs and chicks, causing significant ecological damage.

What are the two categories of native invasive species?

(1) Native species with new genotypes becoming invasive, and (2) native species invading due to environmental modifications.

What impact have introduced carnivores had on native species in New Zealand?

Introduced carnivores prey on various native birds, insects, and reptiles, significantly harming local biodiversity.

What is the effect of feral pigs in New Zealand?

Feral pigs cause erosion, damage native vegetation, and change nutrient cycling.

What are the impacts of invasive species on ecosystems?

Invasive species can modify habitat structure, change nutrient cycles, and disrupt native species interactions.

What alteration did North American beavers cause in Tierra del Fuego?

They converted forests of southern beech to grass- and sedge-dominated meadows.

What are the effects of Australian paperbark trees in the Florida Everglades?

They transformed grass- and sedge-dominated prairies into nearly mono-specific paperbark forests.

How did invasive species affect the animal community in the Mediterranean Sea?

Caulerpa taxifolia replaced seagrass meadows, greatly changing the animal community.

What is a 'changed fire regime' in relation to invasive species?

Invasive species can alter the frequency and intensity of fires in an ecosystem.

How do introduced nitrogen-fixing species like firetree influence native plants?

By fertilizing low-nutrient soils, they allow other exotics to establish while outcompeting natives.

What pathogen eliminated the American chestnut, and what was its ecological impact?

Asian chestnut blight eliminated chestnut, affecting forest structure and nutrient cycling.

What is the impact of the North American gray squirrel on native squirrels in Britain?

The gray squirrel forages for nuts more efficiently, leading to the decline of the native red squirrel.

How did the red imported fire ant affect native ant populations?

It aggressively attacks other ant species, causing significant population declines of natives.

What impact has European brown trout had on local fish species in introduced areas?

They have caused the local extirpation of a number of native fish species.

What phenomenon describes when two or more introduced species enhance each other's survival?

Invasional meltdown describes the phenomenon where introduced species interact to increase each other's effects.

What are key methods for managing invasive species?

Prevention, early detection, monitoring, and eradication are key management strategies.

What is a 'white list' in the context of invasive species management?

A white list is a list of species approved for introduction after conducting risk assessments.

What is a 'black list' in invasive species management?

A black list is a list of species that cannot be admitted under any circumstances.

How can citizens contribute to invasive species management?

Through public education and monitoring for unusual plants or animals.

What are some successful methods for controlling invasive species populations?

Mechanical control, chemical control, and biological control are common methods.

What is a significant challenge in the use of biological control agents?

Introduced biological control agents can sometimes attack non-target native species.

What is meant by 'lag times' in the context of introduced species?

Lag times refer to periods when introduced species remain innocuous before suddenly increasing in numbers.

What is the goal of the Biosecurity Act of 1993 in New Zealand?

To address the entire issue of biological invasions comprehensively.

What was a notable case of successful eradication of an invasive species?

The successful eradication of the giant African snail in parts of Florida.

What role does public opposition play in the management of invasive species?

Public objections can halt eradication campaigns and complicate management efforts.