Permanent Sample Plots (PSP)

Understand how the forest grows

ATLAS PSP enables the forest manager to ensure reliable data is available about permanent sample plots (PSPs). PSPs are periodically assessed to record changes in growth over time and in relation to silviculture and other events. This information supports sound forest management, forest valuation and silvicultural management. An intrinsic feature of this type of data is the length of period over which it is collected, usually over many years. By using a traditional relational database with scope for recording a wide range of attributes, ATLAS PSP is designed to minimise the effects of changes in staff and computer systems over time. The PSP application is based on a system that was initiated in the 1970′s and the PSP installation at Scion now includes over 190,000 records of plot measurements for over 100 species.

ATLAS PSP at a glance



Accurate data collection Comprehensive error checking, configurable to specific species and age attributes.
Complete data sets In field warnings for missing data and notification of heights required; comprehensive error reports when updating database.
Wide range of variables Site, Plot, and Measurement information; various measures of height and diameter; summary results are stored and can be queried
User-definable fields All entities support user-defined fields.
Comments fields There is generous scope for recording textual comments.
Graphing Graphs can be generated to monitor changes in an attribute over time, to compare a selection of plots and to display distributions of attributes (eg DBH) within plots
Partial plot measurements A subset of trees within plots can be measured such as height trees or stems affected by a particular condition.
Convenient standard reports There are a range of reports that publish plot data at differing levels of detail.
Powerful extraction tools Query tools e.g. to provide lists of plots that meet query conditions. Summary data can be queried. Extraction options include SQL.


A comprehensive range of data can be recorded for plots including a plot description, plot purpose, location, topography, geology, aspect etc. A description of how to find the plot is included to help crews locate a plot for re-measurement. Details of the crop type and plot history can also be recorded. The type of data collected is very flexible. ATLAS PSP caters for different plot types (linear, bounded, gauge) and multiple species.  Partial measurement can be undertaken (i.e. a sub-sample of all the trees), and for young stands root collar diameters can be recorded. User-defined fields are available for all entities such as the plot, a tree or a measurement, and comments can also be recorded.


ATLAS-PSP-Permanent-Sample-Plot-SystemATLAS PSP makes collecting accurate and complete field data easy. Field data can be collected manually on paper forms, or electronically using PSPDC, a DOS based data capture program for use on field computers. In either case, previous measurement data is available for data checking in the field. Field computers will issue warnings about growth outside the expected range or missing data and provide alerts as to which tree heights are required for Mean Dominant Height and Mean Top Height. Meaningful warnings are generated by specifying the expected value range for the type of crop. For example, eucalypts can increase in height faster than pines and young trees grow faster than mature trees. All these features greatly reduce the likelihood of measurement errors and omissions and hence the need to revisit plots.


Comprehensive checks are made on the data when updating the database from field data to identify missing or incomplete data so it can be corrected, if necessary by a repeat field visit. The data is stored securely with features to minimise careless or malicious data loss. Typically just the PSP administrator has update rights to the database while other users have read-only access.


The PSP data are summarised as per-hectare values using either default or user-specified tree volume, tree taper, and age adjustment tables. Summary data can be stored in ATLAS GeoMaster and the plot locations can be linked to GIS.

ATLAS PSP provides many reports and utilities for presenting and extracting the plot data. Predefined report formats provide a range of reports from one line to a full summary report for each plot. Customised reports of the summarised data can be created where data are extracted by selecting required fields and saving these to a file. A graphing facility enables graphs of measurement data to be viewed, printed or saved to a data file.

ATLAS PSP integration with the ATLAS suite of Forest Management Tools

Integration between ATLAS modules enables information from one application to be accessed or presented within another which greatly increases the power of each individual module, and the suite as a whole. For example, summaries from PSP can be stored in GeoMaster.

Use PSP to monitor plot data over time; add in these other ATLAS modules to efficiently and effectively undertake a wide range of tasks:

  • Use GeoMaster to manage information about forest area, crops and operations.
  • Use Document Manager to access documents relevant to specific forest locations.
  • Use Assessment Planner to generate plot location maps for assessments.
  • Use GeoMapper to define and generate standard maps
  • Use SilviQC to store and analyse data from quality control assessments.
  • Use FieldMan to manage a complex field measurement programmes.
  • Use Cruiser to forecast yields using forest inventory assessments.
  • Use Yield Table Manager to manage yield tables for many users.
  • Use Harvest Manager to design and track harvest operations and to summarise yields.
  • Use Forecaster to simulate stand growth and quality for forest planning, silvicultural scheduling and regime analysis.


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Freephone within New Zealand:
0800 786 285

99 Sala Street, Rotorua 3010, New Zealand