THE SOIL BIODIVERSITY DATABASE

Database Structure

The Soil Biodiversity Database was designed to store and link information on all aspects of the Programme's research. It includes information such as details of the site structure, treatment applications and site visits (e.g. sampling, measurement and experiment details) through to baseline datasets (e.g. soil & vegetation surveys, meteorology, topography) as well as the more detailed project results datasets.  In addition it stores meta-information such as data definitions, coding systems and analytical methods, necessary to fully describe the data held. A relational database design was adopted and the diagram below gives an overview of the structure and content of the database.

In the first year of the Programme much information on site visits, sampling, experiments, measurements and treatments populated the database. In addition, several baseline datasets were incorporated including the initial soil and vegetation surveys of the field experiment site prior to treatments, hourly automatic weather station data, biomass analysis and pH data from across the site at various time intervals since the Programme began. The next stage was to begin to link in project results as they became available, and of particular interest were further 'baseline' datasets from the individual projects which could be shared across the Programme to aid integration. Results datasets were linked to the initial field activity via the Sample Unit IDs (SUID), Experiment or Measurement IDs, which could then be linked to the other information held in the database, in both space & time.

Database Queries

By structuring the Soil Biodiversity data in a relational database all the various components of the 'system' are inherently linked. This gives great flexibility in terms of being able to interrogate the information within the database, and makes it relatively easy to extract or summarise information at a number of different levels, or based on a variety of elements.

The following gives an example of a simple database query using Microsoft Access (which is a Relational Database Management System (RDMS)). This query summarises the number of sample units taken by each project and by plot type, based on data in the Soil Biodiversity Database as at 29 May 2000. Note, the Mainplot, Subplot, Cells & Loc_code tables shown are all part of the 'Site Stucture' entity given in the overview diagram above.

Programme participants with specific requests for information from the database should contact the data management section within the Programme (see data management page).