Systematic process for determining field-sampling effort required to know vegetation changes in large, disturbed rangelands where management treatments have been applied

Rangeland Ecology and Management
By:  and 

Links

Abstract

Adequate numbers of replicated, dispersed, and random samples are the basis for reliable sampling inference on resources of concern, particularly vegetation cover across large and heterogenous areas such as rangelands. Tools are needed to predict and assess data precision, specifically the sampling effort required to attain acceptable levels of precision, before and after sampling. We describe and evaluate a flexible and scalable process for assessing the sampling effort requirement for a common monitoring context (responses of rangeland vegetation cover to post-fire restoration treatments), using a custom R script called “SampleRange.” In SampleRange, vegetation cover is estimated from available digital-gridded or field data (e.g., using the satellite-derived cover from the Rangeland Assessment Platform). Next, the sampling effort required to estimate cover with 20% relative standard error (RSE) or to saturate sampling effort is determined using simulations across the environmental gradients in areas of interest to estimate the number of needed plots (“SampleRange quota”). Finally, the SampleRange quota are randomly identified for actual sampling. A 2022 full-cycle trial of SampleRange using the best available digital and prior field data for areas treated after a 2017 wildfire in sagebrush-steppe rangelands revealed that differences in the predicted compared with realized RSEs are inevitable. Future efforts to account for uncertainty in remotely sensed−based vegetative products will enhance tool utility.

Publication type Article
Publication Subtype Journal Article
Title Systematic process for determining field-sampling effort required to know vegetation changes in large, disturbed rangelands where management treatments have been applied
Series title Rangeland Ecology and Management
DOI 10.1016/j.rama.2023.09.009
Volume 92
Year Published 2024
Language English
Publisher Elsevier
Contributing office(s) Forest and Rangeland Ecosystem Science Center
Description 5 p.
First page 68
Last page 72
Google Analytic Metrics Metrics page
Additional publication details