Week 3: Threatening processes

Question 1

australia’s level of threats

Answer 1

Australia’s species are often more threatened by different factors than species are at a global level

Question 2

indirect drivers of threats

Answer 2

Economic
Demographic
Sociopolitical
Cultural and religious
Science and technology
These things feed into: consumption per capita, population and resource intensity which feed into demand for food and demand for energy

Question 3

direct drivers: fed by demand for food and demand for energy

Answer 3

Over-exploitation
Habitat change
Nutrient loading and pollution
Invasive species
Climate change
These lead to: loss of biodiversity

Question 4

Pressure-State-Response model

Answer 4

A cycle

Pressure: human activities change the environment
Can provide information and lead to a response
Can provide pressures on the state

State: the environment and natural resources; prompts institutional response
Can provide resources for human activities
Can provide information for a response

Response: policies and action; affects human activities
Can lead to decisions and actions that change the state
Can have social responses that worsen pressure

Indicators:
Monitor pressures: pesticide use….
Monitor state: levels of active residues in dung, dead dung beetles, reduced nutrient cycling…
Monitor response: research, improved techniques, better control of overuse

Question 5

DPSIR - invasive species

Answer 5

Pressure: Dynamics of pathways and instability factors; propagule and individual pressure

State: abundance and distribution; effects on ecosystem services

Response: adaption, mitigation, do nothing

Question 6

extinct and threatened in Australia

Answer 6

> 10% endemics extinct
Further 21% threatened

Question 7

ultimate threat factors

Answer 7

Transformation of indigenous land management to pastoralism
Non-native species

Question 8

intermediary mechanisms

Answer 8

Change in fire regime
Livestock and feral stock
Exotic pasture grasses and weeds
Native predators interact with non-native predators
Cane toads
Black rats

Question 9

proximate factors threats

Answer 9

Habitat change
Increased predation
Poisoning
Novel disease

Question 10

pastoralism causes

Answer 10

Over grazing
Tree removal
Water points
Dingoes targeted
Introduced pasture plants

Question 11

exotic meso-predators

Answer 11

Cat and fox introduction and spread correlates with declines across the continent
Mammals in decline are between 35g and 5.5kg

Question 12

changed fire regime

Answer 12

Aboriginal regime - regular, fine-scale, patchwork burning
Current regime - fire suppression, exotic plants changed regime, infrequent severe fires, reduced habitat mosaics, loss of fire-tolerant plants

Question 13

major threats in Australia

Answer 13

Other exotics
Land cleaning
Altered water regimes
Climate change

Question 14

consequences of change in Australia

Answer 14

Soil compaction
Reduced resources
Competition with introduced species
Reduced cover and exotic plant spread
Reduced recruitment of many native trees and shrubs
Meso-predator release

Question 15

PSR model in australia

Answer 15

Pressure: pastoralism, exotic predators, changed fire regimes
State: mammal declines and extinctions
Response: fox baiting, sensing, translocation, cat culling, research

Question 16

what are the interactions with predators?

Answer 16

Habitat-mediated pathways
Community-mediated pathways

Question 17

how do we increase resilience?

Answer 17

Strategic burning can increase habitat complexity
Dingoes reduce predation pressure

Question 18

prioritising threat management description

Answer 18

What threats and where to manage?
Maximise the overall benefit
Efficient as possible
Avoid catastrophic outcomes
Maximise opportunities

Question 19

assumptions of prioritising threat management description

Answer 19

Management of threats is successful
All sites are independent
Distributions are known
Costs are known

Question 20

cost-benefit approach for threats

Answer 20

Benefit depends on:
Number of species affected by threat
Proportion of available habitat treated
Number of threats
Cost:
Grazing - loss of profits
Fox baiting - cost of implementation

Question 21

functional groups, types of guilds

Answer 21

A group of species that exploit the same class of environment resources in a similar way

Question 22

methods of defining functional groups

Answer 22

Similarity in structure or function: growth form, feeding guild, traits
Response to disturbance: fire, grazing, gap loving/shade tolerant, successional role
Data-driven: use broader range of characteristics

Question 23

why use functional groups?

Answer 23

Species problem -too many to study or manage
Generalise findings - to different species or conditions
Management activities - monitoring change and predicting change, both require transferring results and simplicity, shift from species to ecosystem focus

Question 24

grazier functional group

Answer 24

Time horizon: 1-10 years
Concerns: condition suitable for grazing and profit
Cool/warm season growth
C3 and C4
Palatable/unpalatable
Grasses/forbs/woody
Annual/perennial
Grazing response
Noxious weeds

Question 25

functional group regional natural resources planner

Answer 25

5-20 years
Concerns: fire hazard, remnant vegetation, biodiversity, salinity, ecosystem services
Woody/non-woody
Fuel accumulation
Root depth
Invasive species
Rare or threatened species
Fire and grazing response
Habitat quality

Question 26

climate policy maker/modeller

Answer 26

50+ years
Concerns: climate change, biomass, land use, disturbances
Carbon metabolism (for CO2 increase)
Woody/non-woody
Evergreen/deciduous
Grazing response
Fire response
Nutrient cycling/uptake
Litter decomposition rate

Question 27

functional response types

Answer 27

Groups that respond in similar ways to the abiotic and biotic environment
Gap vs understory, fire tolerant vs intolerant, drought or frost resistant

Question 28

functional effect types

Answer 28

Groups that have similar effects on ecosystem processes such as productivity, nutrient cycling and trophic transfer
Nitrogen fixers, ecosystem engineers, fire promoting species

Question 29

are traits functional?

Answer 29

Global trait distributions are constrained
Plants face consistent trade-offs
This reflects traits having function

Question 30

how hard do we need to look when a species is absent?

Answer 30

Detectability:
The probability that you will detect an individual if it is present at a site per unit search effort
Critical to appropriate survey design
Specific to the species in question

Time to detection:
Observed experience
Weather
Time of day
Grass cover interaction
Search for a long time!