Introduction

This module stores data from botanical survey and other plot samples - these being any-area sized 'plots' or unit areas where species are enumerated together with further data as required.

Plots may range from small botanical survey areas to large, regular sized forest blocks. The simplest of plot sample data files may only record species presence - i.e. the relevant data file may just include a list of species codes or names. A more complex data file used for example in a forest management context may include a list of trees with the species identification, tree number, diameter, height, stem form, images, voucher reference, and more. Each tree may also have an X and Y coordinate relative to the plot origin for mapping purposes. Data from multiple enumerations of the sample plot sample (i.e. permanent plots) can be stored using the ENUM (enumeration) field.

An important aspect of the PlotSample module is flexibility. The structure of the data files used to describe your plots (plot sample metadata) and those used to store the plot measurement data can be modified as necessary.

Plant vouchers may be taken where identification is unknown or there is a plant worthy of collection for some other reason. Vouchers can be linked to data records. Images can be linked to plot descriptions and individual data records.

Plot sample data can be queried from individual or multiple plots into extract files and these data subsequently analyzed using tools provided in BRAHMS or exported for analysis elsewhere. Example analysis options relevant to plot sample data are using the Distribution Summary Table (DST) and Cross Tabulation.

Sample data are organised in BRAHMS in a 3 level hierarchy (refer to the data layout diagram):

1. Sample plot category file: a file that registers each user-defined category of sample plot. Examples are Botanical Survey Plots; Forest inventory; Permanent Sample Plots; My Research Plots. The category file also holds the name and location of the plot metadata/description (header) file and all related data files. Each sample category has one metadata/description file. Normally, the data being collected from all plots stored under a particular category will be broadly of the same nature - the data files for these plots will usually have the same structure - although this is not enforced. The category file is included as part of your BRAHMS database - its structure cannot be modified.

2. Sample plot metadata/description files (sample headers): There is one metadata file per sample category. The header file is created when you create a new category. It's structure can be defined at that time and/or modified at any stage later on. In this file, each plot is described in a single record with a unique numeric SCODE, an optional sample name (e.g. 'PLOT556'), its geo-location including lat/long map reference - together with any other details about the plot as relevant (manager name, soil properties, establish dates, etc). The plot sample metadata file can be linked to the BRAHMS gazetteer va the GAZCODE field. It also includes a file name in the DATAFILE field pointing to the sample plot data for this plot sample. There are no restrictions on the fields added to the metadata file.

3. Sample plot data files: Data files store the data for each sample plot. For example, a plot metadata/description entry with SCODE 100 may include the DATAFILE "INVENTORY_001". This file (its full path recorded in the category record) will include one record per plot data record, each record coded with SCODE 100. Note that the same data file (here "INVENTORY_001") may include records from many plots and in this case, the SCODE values will change. Datafiles include the numeric*9 field SPNUMBER - linking through to the BRAHMS species file. There are no restrictions on the fields added to data files.

With the exception of the category file, plot data (metadata/descriptions and the actual data files) are maintained in files outside BRAHMS. Unlike RDE files, they are never imported into BRAHMS. However, as mentioned above, there are links to BRAHMS database files, especially the species and gazetteer dictionaries. Also note that sample plot data extracts can be combined with other data stored in BRAHMS (voucher data and field observations) to build species distribution summary tables.