Lecture 09: Evolutionary Ecology Of Invasive Species (Linstädter)

Question 1

Invasive species def.

Answer 1

„Invasive alien species are plants, animals, pathogens and other organisms that are non-native to an ecosystem, and which may cause economic or environmental harm or adversely affect human health“

-> Have affected native biodiversity in almost ever ecosystem type on earth
-> Are one of the greatest threats to biodiversity
-> re found in all classes and orders

Question 2

Naturalized versus Invasive Species

Answer 2

Naturalized species: a non-native species reproduces and spreads without human assistance

Invasive species: a naturalized species that causes negative impacts on other species, ecosystems or human health

-> Naturalized species can become invasive, but most of them (ca. 90%) do not inflict ecological/economic harm
-> All invasive species have started as naturalized species

Question 3

Impacts caused by invasive species

Answer 3

Natural habitats
* Species declines
* Degradation
* Changes of ecosystem functions (nutrient cycles,
microclimate)
* Changes of soil properties

Agriculture, forestry
* Yield loss due to pest organisms
* Losses in quality

Human health
* Spread of toxic plants
* Allergenic pollen
* Nuisance by weeds and feral animals