Forest Biometrics Exam Questions
And Correct Answer
This course will concentrate on two areas: - Answer -✔✔Sampling and Estimation
Growth and Yield
Sampling is - Answer -✔✔a method or process that allows an estimation to be
generated to describe a population
why dont we measure all the trees in an area? - Answer -✔✔Measuring an entire
population is time consuming and in most cases cost prohibitive
Sampling, if done correctly, can provide a - Answer -✔✔cost effective and accurate
method for effective decision making for natural resource managers
there is a direct correlation between costs and - Answer -✔✔information quality
To determine the quality of sampling and estimation we will use - Answer -✔✔statistics
for validation
For a forester, the sampling and estimation process is called - Answer -✔✔forest
inventory
2 most common reasons to do a forest inventory - Answer -✔✔gather info for
-management
-timber sales
The intensity of a forest inventory results in an estimation of the - Answer -✔✔-whats
out there
-how much is out there
-where is it
the higher the intensity of an inventory, the greater the - Answer -✔✔accuracy
Inventory Objectives can include - Answer -✔✔Volume or value or both of timber in a
defined spatial extent
Number of deer per spatial unit
Habitat quality for a wildlife species
Occurrences of other species (vegetative or animal)
Fuel Load Modeling
Road characteristics and integrity
Soil analysis
, Two types of Sampling: - Answer -✔✔Subjective and Probability
subjective sampling - Answer -✔✔can be implemented with or without preconceived
bias
what does biased sampling mean - Answer -✔✔conscious avoidance of forest stand
nonconformities i.e. only pick plots that seem to represent the entire stand that can
leave out nonaverage characteristics
what does non-biased sampling mean - Answer -✔✔inclusion of forest conditions that
include areas considered extremes (min/max) of the population i.e. small/large DBH
Subjective sampling Can be justified when: - Answer -✔✔• Extreme high cost of
sampling and large variations between sample variables i.e. inaccessible spatial extents
with large ranges for DBH and # Trees
• Estimations are time sensitive and decisions are not related to bias estimates
• Low funding to complete inventory
• Precision estimates are not needed
• Results are not going to be contested
probabilty sampling - Answer -✔✔covers sampling techniques needed to serve multiple
decisions for the long term and where statistical validation is needed
what is the preferred sampling method? - Answer -✔✔probability
Two levels of numerical results: - Answer -✔✔computation and final reported values
main difference between computation and final reported values: - Answer -✔✔number
of decimal places. Computation has many decimal places, final has rounded number of
decimal places
Size and shape of sampling field plots are determined based on - Answer -✔✔customs,
traditions and experience.
Fixed plots are best for measuring - Answer -✔✔change
what do you use to help determine appropriate plot size for an area - Answer -✔✔size
of area, density of trees, types of trees
Inventories are collected and results used for varied - Answer -✔✔temporal decision
making i.e. current or future or both
And Correct Answer
This course will concentrate on two areas: - Answer -✔✔Sampling and Estimation
Growth and Yield
Sampling is - Answer -✔✔a method or process that allows an estimation to be
generated to describe a population
why dont we measure all the trees in an area? - Answer -✔✔Measuring an entire
population is time consuming and in most cases cost prohibitive
Sampling, if done correctly, can provide a - Answer -✔✔cost effective and accurate
method for effective decision making for natural resource managers
there is a direct correlation between costs and - Answer -✔✔information quality
To determine the quality of sampling and estimation we will use - Answer -✔✔statistics
for validation
For a forester, the sampling and estimation process is called - Answer -✔✔forest
inventory
2 most common reasons to do a forest inventory - Answer -✔✔gather info for
-management
-timber sales
The intensity of a forest inventory results in an estimation of the - Answer -✔✔-whats
out there
-how much is out there
-where is it
the higher the intensity of an inventory, the greater the - Answer -✔✔accuracy
Inventory Objectives can include - Answer -✔✔Volume or value or both of timber in a
defined spatial extent
Number of deer per spatial unit
Habitat quality for a wildlife species
Occurrences of other species (vegetative or animal)
Fuel Load Modeling
Road characteristics and integrity
Soil analysis
, Two types of Sampling: - Answer -✔✔Subjective and Probability
subjective sampling - Answer -✔✔can be implemented with or without preconceived
bias
what does biased sampling mean - Answer -✔✔conscious avoidance of forest stand
nonconformities i.e. only pick plots that seem to represent the entire stand that can
leave out nonaverage characteristics
what does non-biased sampling mean - Answer -✔✔inclusion of forest conditions that
include areas considered extremes (min/max) of the population i.e. small/large DBH
Subjective sampling Can be justified when: - Answer -✔✔• Extreme high cost of
sampling and large variations between sample variables i.e. inaccessible spatial extents
with large ranges for DBH and # Trees
• Estimations are time sensitive and decisions are not related to bias estimates
• Low funding to complete inventory
• Precision estimates are not needed
• Results are not going to be contested
probabilty sampling - Answer -✔✔covers sampling techniques needed to serve multiple
decisions for the long term and where statistical validation is needed
what is the preferred sampling method? - Answer -✔✔probability
Two levels of numerical results: - Answer -✔✔computation and final reported values
main difference between computation and final reported values: - Answer -✔✔number
of decimal places. Computation has many decimal places, final has rounded number of
decimal places
Size and shape of sampling field plots are determined based on - Answer -✔✔customs,
traditions and experience.
Fixed plots are best for measuring - Answer -✔✔change
what do you use to help determine appropriate plot size for an area - Answer -✔✔size
of area, density of trees, types of trees
Inventories are collected and results used for varied - Answer -✔✔temporal decision
making i.e. current or future or both
