weed
a plant growing in the wrong place
- many grow rapidly & provide cover for foxes, rabbits, or other introduced species
- may degrade native animal habitats
- ornamental (garden) species can become weeds if they spread into native bush
can displace native fungal species
cane toads
- the poster child of introduction failure
- introduced into Australia in 1935 to control the cane beetle population
- but they do not eat cane beetles at the to p of the sugar cane because they cannot climb well
- animals would eat the cane toads & became a significant challenge to native Australian animals today
some introductions are unintentional
e.g. Ballast water from ships = at least 70 varieties of fish, worms, molluscs, seaweed, and toxic algae
microbes as well - through industrial shipped good
Indigenous land management practices
- shaped the Australian environment
- e.g. fire-based land management
- fish traps at Lake Condah
As a consequence of natural and long-term Indigenous fire use, many Australian plants are
specifically adapted for fire
Controlled, cool, patchy burns
- patchwork burning in early fire seasons thins out young shrubs and trees while preserving the canopy and encouraging growth of new grass
- contrast to the effect of intense late season fires, or even prescribed burns
When did changes start?
with the birth of agriculture and the associated urban populations
domestication of plants and animals occurs in multiple sites worldwide beginning 10,000 years ago
what is domestication?
involves one species controlling the reproduction and breeding of a 2nd species, generally to its own benefit
e.g. 6 closely related species of great economic importance worldwide (cauliflower, broccoli)
In plants, domestication is often associated with. . .
hybridization and / or increased numbers of chromosomes (tetraploid vs hexaploid for example)
domestication causes. . .
morphological + behavioural changes
