strata

-1 rows


Description

Regions within planting sites that have a consistent set of conditions such that survey results from any part of the stratum can be extrapolated to the entire stratum. strata are subdivided into plots. Every stratum has at least one plot.

Columns

Column Type Size Nulls Auto Default Children Parents Comments
id int8 19 √ null
observed_stratum_species_totals.stratum_id observed_stratum_species_totals_stratum_id_fkey C
stratum_histories.stratum_id stratum_histories_stratum_id_fkey N
stratum_populations.stratum_id stratum_populations_stratum_id_fkey C
stratum_t0_temp_densities.stratum_id stratum_t0_temp_densities_stratum_id_fkey C
substrata.stratum_id substrata_stratum_id_fkey C
planting_site_id int8 19 null
substrata.planting_site_id substrata_planting_site_id_stratum_id_fkey R
planting_sites.id strata_planting_site_id_fkey C

Which planting site this stratum is part of.
name text 2147483647 null

Short name of this stratum. This is often just a single letter. Must be unique within a planting site.
boundary geometry 2147483647 null

Boundary of the stratum. This area is further subdivided into plots. This will typically be a single polygon but may be multiple polygons if a stratum has several disjoint areas. Coordinates always use SRID 4326 (WGS 84 latitude/longitude).
created_by int8 19 null
users.id strata_created_by_fkey R

Which user created the stratum.
created_time timestamptz 35,6 null

When the stratum was originally created.
modified_by int8 19 null
users.id strata_modified_by_fkey R

Which user most recently modified the stratum.
modified_time timestamptz 35,6 null

When the stratum was most recently modified.
variance numeric 0 null
students_t numeric 0 null
error_margin numeric 0 null
num_permanent_plots int4 10 null

Number of permanent plots to assign to the next observation. This is typically derived from a statistical formula.
num_temporary_plots int4 10 null
area_ha numeric 0 null
target_planting_density numeric 0 1500
boundary_modified_by int8 19 null
users.id strata_boundary_modified_by_fkey R

Which user most recently edited the stratum’s boundary.
boundary_modified_time timestamptz 35,6 null

When the stratum’s boundary was most recently modified.
stable_id text 2147483647 null

Stratum identifier that doesn’t change even if the stratum is renamed or edited. Defaults to the stratum name.

Indexes

Constraint Name Type Sort Column(s)
strata_pkey Primary key Asc id
strata_planting_site_id_id_key Must be unique Asc/Asc planting_site_id + id
strata_planting_site_id_name_key Must be unique Asc/Asc planting_site_id + name
strata_planting_site_id_stable_id_key Must be unique Asc/Asc planting_site_id + stable_id

Check Constraints

Constraint Name Constraint
area_positive (area_ha > (0)::numeric)
must_have_permanent_clusters (num_permanent_plots > 0)
positive_target_density (target_planting_density > (0)::numeric)
no_negative_temporary_plots (num_temporary_plots >= 0)

Relationships

Close relationships within degrees of separation