This article answers common questions about how Terraware assigns and manages monitoring plots for Assigned Plot Observations. For step-by-step instructions on scheduling and conducting Observations, see Scheduling and Managing Observations and Conducting Observations in the Field.
How are monitoring plot locations chosen?
Terraware randomly assigns monitoring plot locations within each Stratum that has had plants allocated to it. Locations are not determined until the Observation starts — this prevents any bias in how planting areas are treated during the planting season, and ensures plot locations reflect the most up-to-date withdrawal data.
Because plots are distributed across Strata rather than Substrata, it's not guaranteed that every Substratum will have at least one monitoring plot assigned to it.
How many plots will I need to monitor?
The number of plots assigned per Stratum is calculated by Terraware using a formula based on the Common Stand Examination protocol developed by the United States Forest Service. The formula determines the minimum number of plots needed to draw statistically significant conclusions about the entire Stratum.
The main factor affecting the number of plots is the variance in planting density within the Stratum — the higher the variance, the more plots are needed to achieve a statistically significant result. Most projects will find the number of plots manageable. If the number seems unexpectedly high, it may indicate high variance in how plants were distributed across the Stratum.
When will I know where my plots are?
Plot locations are not assigned until the Observation's start date arrives and its status changes to In Progress. There are two reasons for this: first, it prevents any biases in how plots are treated during the planting season; and second, it ensures plot locations reflect the most up-to-date plant withdrawal information at the time the Observation starts. Once the Observation is In Progress, you can download a CSV file of the plot coordinates from the web app, and the coordinates will be visible in the mobile app after you claim your plots.
What is the difference between permanent and temporary plots?
Permanent plots are monitored in every Observation cycle for the life of the project. Their locations stay consistent across all Observations, making them useful for tracking long-term changes in the land. Corner stakes should be left in place at permanent plots after each Observation so they can be found again in future cycles.
Temporary plots are assigned fresh for each Observation cycle. Their locations change with every Observation, which helps build a broader picture of site health across the whole Planting Site over time. All stakes and markers should be removed from temporary plots after each Observation.
Two different observations for the same site shown side by side. Note how the permanent plots (pink) don't change between the observations, but the temporary plots (yellow) do.
What if a plot is in an inaccessible location?
If an assigned plot is in a location that can't be safely or practically reached — for example, due to terrain, water, or restricted access — you can request that it be reassigned.
- In the monitoring plot table in the Observations page, click the More menu for the plot you want to reassign.
- Click Request Reassignment.
- Terraware will assign a new location for the plot.
Can multiple people monitor plots at the same time?
Yes. Multiple users can claim and monitor different plots simultaneously, even within the same Planting Site. Each user claims the specific plots they plan to monitor, and once a plot is claimed it cannot be claimed or monitored by anyone else. This makes it practical for larger teams to divide up monitoring work across a site on the same day.
What happens if an Observation isn't completed before the end date?
If the Observation's end date passes before all plots have been monitored, the Observation status changes to Overdue. You can continue monitoring and uploading data after the end date has passed. If you need to close the Observation before all plots are complete, an Admin or Manager can end it manually from the web app. The Observation status will then show as Completed (Ended).
Note: Observation data will not appear in the Plants Dashboard until the Observation has been either completed or ended.
Why isn't my Survival Rate being calculated?
Survival Rates cannot be calculated if any of the following are true:
- T0 data has not been set for all permanent plots.
- Temporary plots are included in calculations but t0 data has not been set for all Strata.
- The Planting Site geometry has changed and no subsequent Observation has been completed yet.
For more information about setting up t0 data, see Survival Rate Calculations.