Week 9: Assessing and Monitoring Biodiversity

Question 1

what do environmental impacts assessments do?

Answer 1

Helps decide which developments go ahead

Question 2

how are impacts assessed?

Answer 2

Biodiversity inventory - what species and vegetation communities are present at the site? Is any of the biodiversity there of conservation concern?
Is the biodiversity at the site in good condition?
Surveys of flora and fauna present are examined

Question 3

what are the four choices for environmental assessments?

Answer 3

Application rejected
Conditions imposed on the development (modified) - implement mitigation measures
Approved
Approved but an offset is required

Question 4

reducing the impact of development

Answer 4

Compensation for loss of biodiversity as a result of development
Generally protects high quality habitat or improves condition of existing habitat
Usually swap like for like - same species, same ecosystems
If there is no match we need to calculate equivalent offset

Question 5

biodiversity banking

Answer 5

A biodiversity offset scheme in NSW
Developers buy credits to offset destruction of biodiversity
Biodiversity credits created from protecting or restoring habitat
Offsets focus on vegetation so some biodiversity can fall through the cracks

Species credits - for threatened species that may not be covered by habitat surrogates

Ecosystem credits - ecological communities and threatened species but predicted by vegetation type

Question 6

calculating credits

Answer 6

Habitat area
Landscape value - connectivity
Site value - condition (structure, function, composition)

Question 7

defining condition

Answer 7

Aesthetic - naturalness (human perception)
Production - provision of ecosystem services
Biodiversity - supports plant and animal populations

Question 8

condition assessment and challenges

Answer 8

he definition of condition determines what gets measured

Challenges:
What to measure
How to calculate the metric
Accuracy
Precision
To solve accuracy and precision take more samples and average scores across multiple observations

Question 9

condition parameters

Answer 9

Vegetation condition can be separated into 3 components:
Structure - ground, mid, canopy
Function - ecosystem services like hollows, litter
Composition - the species present

Question 10

approach to condition assessments

Answer 10

Condition parameters are measured
Measurements are compared against benchmark
Scores are combined into an index of condition

Question 11

habitat hectares

Answer 11

A site-based score of quality and quantity of native vegetation:
Attributes compared to benchmark
Each attribute given specific weight
Sum weighted scores = index
Habitat ha = index*area

Question 12

biometric approach

Answer 12

Uses benchmarks for condition
Based on standardised quadrants not area of vegetation
Measures condition parameters - similar to habitat hectares
Structure
Function
Composition
Parameters scored against benchmark and then combined using a weighted average of the scores

Question 13

habitat hectares vs biometric approach

Answer 13

HH: used a defined patch, 7 components measure, doesn’t measure species diversity, measured large trees, not tree hollows - combined into a metric using an additive approach (assumes that condition elements can be substituted)
BM: used quadrants and transects, 9 components, doesn’t measure species diversity, measured tree hollows not large trees, doesn’t measure organic litter - combined into a metric using multiplicative metric (requires a much larger increase in other attributes to compensate for loss in one)

Question 14

how do we know management actions are working?

Answer 14

Condition assessments can be used to evaluate how close we are to our management goals
Quantitative condition assessments - eg. Good if there is over 75% coral cover

Question 15

monitoring

Answer 15

What is the current status of biodiversity and how has it changed over time?
Population - is it large enough? Is it stable or increasing or decreasing?
Ecosystem - is it in good condition?

Question 16

indicators should be

Answer 16

Should be:
Unambiguous: clear relationship to objective
Comprehensive: should cover the range of possible consequences for the objective
Direct: should directly describe the attribute of interest
Operational: information that is able to be collected in practice
Understandable: easily understood and communicated
Ecologically relevant
Sensitive to change: able to provide early warnings of change
Widely applicable: can be broadly distributed and represents multiple species
Capable of providing continuous assessment: available all year round
Able to distinguish between disturbance and natural cycles
Relatively independent of sample size
Easy to measure
cost-effective

Question 17

conceptual models of ecosystems

Answer 17

Key ecological attributes - influence multiple aspects of the system such as vegetation structure
Conceptual models represent links between attributes and drivers, identify possible management actions and select the most important thing to monitor

Question 18

range of natural variability

Answer 18

What is the benchmark against which we are measuring change against?
What should we consider normal?
What sort of change would trigger a management response?

Question 19

monitoring design

Answer 19

Power to detect an effect - robust sampling, collect data that will alert us to a problem, take enough samples, account for detectability
Type I (false alarm) and Type II error (don’t want to miss real change)

Question 20

indicators vs index

Answer 20

Single indicators do not always give a broad perspective of change
Index is a combination of indicators
Attempt to provide more comprehensive picture across a range of related indicators
Often trade of depth for breadth

Question 21

when should we intervene?

Answer 21

Thresholds should identify when
Thresholds can represent tipping points or small changes leading to large responses
There may be more than one stable state (alternative stable states); product of disturbance and a process that maintains biodiversity; some changes are permanent but some return via a different path (hysteresis)