Lecture 3 Flashcards
Why is monitoring important for goals and objectives in ER? What should monitoring and G/A be?
- Monitoring is required to assess the success of restoration in terms of ecological values (species composition, structure, function)
o Objectives are useless if they can’t be measured - Monitoring and objectives should be dynamic, and change with eachother
Criteria for selecting which objectives to monitor
o Easy to measure
o Strongly linked to ecological health
o Most important to funders/stakeholders (where relevant)
Indicators that are correlated with ecosystem health
o Diversity of native species
o Abundance of focal native species (keystone, indicator, …)
o Presence/abundance of over abundant species
o WQ
o Hydrology
o Soil characteristics
o Toxicants
Herrick et al. 2006 (monitoring)
o Vegetation monitoring is good but not on its own
Most monitoring for plants is based on composition
Doesn’t predict long term success and should be paired with other indicators
o Indicators should improve soil and site stability, hydrologic function, or biotic integrity
Control vs reference sites
- Control sites – degraded sites that aren’t restored
- Reference sites – non-degraded sites
2 types of baseline data
- Before degradation
- Before restoration
Why is pre-impact baseline data rarely available
o Most sites were degraded before regulations for documentation of conditions
What is BACI?
Before-After control-intervention design
3 factors that make selecting a reference site difficult
o Un-impacted sites can vary greatly among stages of ecological succession
Define successional stage
Use multiple reference sites
o Un-impacted sites can vary within a ‘natural range of variability
Define a range of values to achieve
o Pervasiveness of human impacts means that finding an unimpacted site is really difficult
Define reference type
How to minimize complications of choosing a reference site?
o Have reference site close to restoration site
Fewer differences in site conditions
Alternative to using reference sites
o Using reference conditions from the literature
Provides defensible estimates of important conditions
* E.g., LWD, DO levels
Important aspects of sampling
o Measuring a subset of the population to make inferences about the population as a whole
o Individual measurements in sampling are sampling units, number of these = sample size
Sometimes sampling units occurs within replicates
o Sampling units should be representative of the range of values within the population to ensure inferences are accurate
Achieved by selecting sampling units in a(n):
* Unbiased manner
* Way that ensures reasonable coverage of site and time period
Contrast systematic and random sampling
- Systematic sampling
o Sampling units selected at regular intervals
o Biased, representative
o Drawback: linear features
o Most sampling designs use both this and random - Random sampling:
o Every sampling unit has an equal chance of being selected
o Unbiased
o Not representative
Identifying appropriate sampling size
o Increasing sample size = more cost, greater precision
o Estimate number of sampling units and periods you can afford
o Sample sizes are suitable if they allow you to:
Accurately estimate variables of interest
Detect differences among sites or time periods
o Avoid over sampling
Contrast the different types of abundance
- Presence/not-detected
o Whether or not a species is detected in a given area - Relative abundance
o Number or proportion of individuals without specifying an area
o 30% cover of HBB - Density
o Number of individuals per unit area or volume - Total abundance
o Total number of individuals in a given area
