Espm 114: Overpopulation, Invasives And Control

Front 1

What are invasive species?

Back 1

They're exotics that displace natives

Front 2

What is the invasives rule of tens?

Back 2

- 10% of imported species will escape
- 10% of escaped species will establish
- 10% of established species will become invasive pests

Front 3

How do species invade?

Back 3

- may be natural of by humans
- via humans may be accidental escapees or hitchhikers
- may be deliberate, for ornaments, pets, agriculture, fisheries, conservation or sport

Front 4

What are the stages of invasion?

Back 4

-transport
-introduction
-establishment
-spread and displacement

Front 5

How does disturbance aid invasion?

Back 5

Disturbance of an ecosystem increases the chance of species invasion.

fire can enhance invasion of non-native, fire tolerant species

Front 6

How does overgrazing aid invasion?

Back 6

Import non native plant propagules into native vegetation

provide microsites for invasion

Front 7

What factors help invasion?

Back 7

disturbance and overgrazing

Front 8

What are traits of successful invaders?

Back 8

-widespread
-abundant
-dietary generalist
-short generation time
-tolerant of extremes

Front 9

What happened with the cane toad in relation to invasion?

Back 9

They were introduced to Autralia to help control beetle pests on sugar cane but they did not control the beetles. They actually had a negative effect on native fauna.

Front 10

What are the population control methods?

Back 10

- corrective
- removal of individuals identified perpetrating problem
- preventative
- removal of problem species or lowering of density prior to potential problem

Front 11

What is the key factor behind action of population control methods?

Back 11

Public perception

Front 12

What is lethal control?

Back 12

- Shooting or overdose tranquilizing
- Poisons
- Pesticides

Front 13

What are the qualities of the most commonly used control methods?

Back 13

- effective
- cheap
- non-discriminatory

Front 14

What is the problem with contraception?

Back 14

- slow to impact population if implemented when density close to K
- effective when population at low density
- expensive

Front 15

How is translocation as control?

Back 15

- non-lethal
- expensive and success rate varies