What is the difference between Simple and Detailed planting sites?
When creating a planting site within Terraware you will be asked whether you want a "Simple" or "Detailed" site. Terraware considers a simple site to be one with only a single zone and a single subzone. Any site that contains multiple zones or subzones is a detailed site. Simple sites tend to be smaller than detailed sites.
What is a stratum? What is a zone?
In general terms, stratification is the process by which a habitat can be divided into areas that display similar characteristics (homogeneity). More specifically, for large scale forestry projects, a planting site may be divided into multiple strata based on a number of attributes that will determine the plant growth patterns each area will support.
Within Terraware, we refer to Strata as Zones. Each zone of a planting site is an area where the growing habitat will be relatively consistent throughout.
How many zones should my planting site have?
Most projects within Terraware will only contain a single zone. That is, the entirety of the planting site will be a similar enough habitat that it can all be grouped together into a single homogeneous area. However, some very large projects may need multiple zones in order to properly plan restoration activities according to differences in growing conditions.
Some factors that might mean your site should be divided into multiple zones:
- Elevation will vary greatly within your planting site
- The distribution of species will vary greatly from one area of your site to another
- Meteorological conditions (rainfall, hours of sunlight, average temperature, etc) will vary greatly within your planting site
- Soil conditions vary greatly from one area of your site to another
- Target planting density will be different from one area of your site to another
As you can imagine, these conditions are related to one another. For example, if your site has a large spread of elevation, you will likely be planting different species at different elevations due to the differences in meteorological and soil conditions. In this case, it would make sense for your site to have one zone for the higher elevation area and one zone for the lower elevation area where habitats are more consistent.
Terraware does not require that zones are geographically contiguous.
Almost all projects will contain 3 or fewer zones. If you think your planting site requires 4 or more zones, it is likely that your site is either very large (10K+ hectares) or you are over-stratifying.
What are subzones?
Terraware uses subzones to break up larger zones into smaller sections. There are no rules about how large a subzone can be or how many make up a zone. To make the best use out of Terraware's plant monitoring feature, each subzone should be sized such that it can be fully planted within a single planting season at your site, though this is not strictly required.
Many zones may be comprised of a single subzone. Others may have many subzones. Both are acceptable.
How do I record planting in zones and subzones?
When you withdraw plants from the nursery for the purpose of planting at your site, you will be asked to provide the zone and subzone in which those plants will be planted. This is how Terraware knows which sections of your site have been planted and which haven't. The plant monitoring feature uses this information to know how to assign plots for observations. Keep this in mind as you divide up your subzones and make plant withdrawals to your site.
How are the locations of monitoring plots chosen?
Monitoring plots are randomly located by Terraware within each zone that has had plants planted in it. Since each zone may contain multiple sub-zones, it is not guaranteed that every sub-zone will have at least one monitoring plot in it. The locations are truly random within each zone.
How many monitoring plots will I need to monitor?
The number of monitoring plots is determined per zone and depends on a number of factors. Terraware uses a formula to determine the minimum number of monitoring plots necessary to draw statistically significant conclusions about the entire zone. This formula is based on the Common Stand Examination protocol developed by the United States Forestry Service, and uses standard methods in statistics and forestry science.
The main factor that will affect the number of monitoring plots you'll need to monitor per zone is the variance of planting density. The higher the variance, the more plots are necessary to achieve a statistical significant result.
When will I know where the plots are that I need to monitor?
The locations of the monitoring plots are not determined until the observation starts. There are a couple of reasons behind this. First, this prevents any biases in the treatment of plots during planting. Second, this allows the plot locations to be located with the most up-to-date plant withdrawal information. Once the observation starts, you will be able to download a CSV file of the coordinates of the plots to use to plan your monitoring activities. You will also be able to view the coordinates within the observations in the mobile app.