Forest Biometrics Detailed Version Exam 1 2025

This course will concentrate on two areas: - Correct Answer-Sampling and Estimation Growth and Yield Sampling is - Correct 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? - Correct Answer-Measuring an entire population is time consuming and in most cases cost prohibitive Sampling, if done correctly, can provide a - Correct Answer-cost effective and accurate method for effective decision making for natural resource managers there is a direct correlation between costs and - Correct Answer-information quality To determine the quality of sampling and estimation we will use - Correct Answer-statistics for validation For a forester, the sampling and estimation process is called - Correct Answer-forest inventory 2 most common reasons to do a forest inventory - Correct Answer-gather info for -management -timber sales The intensity of a forest inventory results in an estimation of the - Correct Answer--whats out there -how much is out there -where is it the higher the intensity of an inventory, the greater the - Correct Answer-accuracy Inventory Objectives can include - Correct 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: - Correct Answer-Subjective and Probability subjective sampling - Correct Answer-can be implemented with or without preconceived bias what does biased sampling mean - Correct 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 - Correct 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: - Correct 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 - Correct 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? - Correct Answer-probability Two levels of numerical results: - Correct Answer-computation and final reported values main difference between computation and final reported values: - Correct 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 - Correct Answer-customs, traditions and experience. Fixed plots are best for measuring - Correct Answer-change what do you use to help determine appropriate plot size for an area - Correct Answer-size of area, density of trees, types of trees Inventories are collected and results used for varied - Correct Answer-temporal decision making i.e. current or future or both in order to estimate what an inventoried forest will look like in several years, you make - Correct Answer-models These models allow foresters the ability to track changes in - Correct Answer-growth, mortality and ingrowth over time Future predictions of these characteristics from models can mold - Correct Answer-decisions and management objectives Forest stand dynamics and techniques used to forecast them are classified as - Correct Answer-growth and yield models These growth and yield models are complex mathematical functions designed to - Correct Answer-simulate biological growth from sampled characteristics Early forms of growth and yield models resulted in - Correct Answer-tables or graphs Current models have derived a level of complexity that dictates execution by - Correct Answer-computers