Creating a map using DIVA GIS

Before doing this exercise you need to install DIVA and one or more basemaps.

Based on the Leucaena or Conifer database , you will create a black and white map of two species and plot these with an appropriate legend. The map will then be saved to a Word document or elsewhere.

Create a data file to map in BRAHMS

The first step is to extract data for 2 species

• Select BotanicalRecords > Extract/query data...        .

• If using the Leucaena database, select Taxa/det > Individual species and choose Leucaena trichandra. Repeat this command sequence to select Leucaena diversifolia.

• If using the Conifer database, select Taxa/det > Individual species and choose Pinus devoniana. Repeat this command sequence to select Pinus maximinoi.
• Click on the and/or button to change the AND/OR value to 'OR'. If you do not do this, you will get no records in your extract file.
• Open the extract file by selecting Extracts > BotanicalRecords - assuming it is not auto-opened after your extraction.

Opening DIVA GIS

• Click on the toolbar and select the DIVA GIS option.
• Ensure the option Restrict map to tagged is not selected. You do not need to register the map in your map library at this stage.
• Click on Map all to prepare the BRAHMS data points file and open DIVA. If DIVA does not open automatically, check that your map configuration link is correct.

Note on the above form the map file to be prepared is called MYMAPFILE and here, the location is c:\mapping\mapping points from brahms\.

Add the map layer(s)

• In DIVA, select Layer > Add layer and locate a .SHP file to plot.
• Select the file CNTRY.SHP as provided on training courses or downloaded from the BRAHMS website. 
• You can add several map layers at this stage if you have other relevant .SHP files.
• To select a different area on your base map, use the toolbar and drag a rectangle on your map. This can be done at any stage. The maps prodced here will be (roughly) in Mexico and Central America.
• To change the properties of a map layer such as the thickness of the map coastline, dbl-click the small map layer rectangle in the left DIVA margin and then dbl-click the small rectangle on the resulting properties form and set the layer properties as prompted. Note that these actions can be carried out on any layer listed in the left margin.

For further notes on editing map layer properties, refer to the notes on editing map areas and layers.

Add your map data points as a layer

• To plot your species data on the selected base map, select Data > Import points to Shapefile > From dBASE (DBF).
• Click on the Input file option and locate the BRAHMS .DBF map file that you created above. The default input map name is MYMAPFILE.DBF located in this example in c:\mapping\mapping points from brahms\.
• As prompted, select the X field LONG (for longitude) and the Y field LAT (for latitude).

• The Input file is the .DBF map file you created in BRAHMS. This file includes the (now) decimalised fields LONG and LAT which are selected for the X and Y map coordinates. You must choose an Output file .SHP file for DIVA to create from your BRAHMS file. In the above example, the name is 'map1.shp'.
• Click on the Apply button to add the data points to the map. Initially all points will have the same colour and symbol. Bear in mind, here we have data for two taxa.

Choosing different symbols for each species

• After adding the data points, double click the 'map1' data file map layer in the left margin (it will be the top one) to open the properties form for that layer.
• Select the Unique tab and then scroll down to locate the field SPECIES. In this example, you are choosing the SPECIES field to control the legend and potential separation of the points by colour, symbol or size.
• In this exercise, the data file includes 2 different species. Note that you could use any other field of interest to set the legend, for example YEAR for year of collection.
• Select the Reset legend option after you change the UNIQUE field setting.
• This mean that you can now assign colours/symbols/size for each different species in the map file and create a map legend.

Our objective is to differentiate the two species by symbol as we are aiming to produce a publication map in black and white.

• To change the symbol and/or size of a given entry in the legend list (in this case the two species), you need to double click on the symbol of each species. Thus to set L. diversifolia to a black triangle point size 5, double click exactly on the default symbol for that species and change the settings as prompted.

Changing the point properties suitable for a black and white map. In this example, the triangle and cross symbols were selected from the list offered. The sizes were increased to 5 and the colour changed to black for both taxa.

If you want to add a graticule to show lat/long squares, select Tools > Graticule. For a 5 degree square grid, set the Interval  value to 5. You need to select an output file to name the grid .SHP file created.

Adding a grid with 5 degree intervals.

Final stages in Design mode

• In the bottom right corner of your map screen, there are 2 tabs Data and Design. So far you have been working in the Data screen.
• Switch now to Design mode - this is where you will produce the finished map.
• Click on the OK button in the left margin to redraw your map.
• Now click on the legend toolbar option (2nd toolbar)

As you only want a legend generated for the species data component, remove the ticks for the base map and graticule layers in the left margin and then click on the Legend OK button.

Clicking anywhere on the map will add the legend. You can experiment clicking in different parts of the map to see where the legend looks most appropriate. When satisfied, you can use the Undo button or clear everything and start the map in design view again using the red X toolbar option.

Note: to change the legend heading (here "map1"), return to Data mode, dbl-click on the left margin map1 layer and then edit the Label setting to the required map name.

To add a scalebar, choose the 3rd toolbar option and set the scaebar properties as you want.

To add other text captions, use the TXT toolbar option. You can adjust the text font using the Ff toolbar. The actual text is typed into the (rather small) Text box in the left margin - again click on the map to place the text, using the Undo button until you get it in the best place.

Save map to a Word document, PowerPoint or elsewhere

The easiest way to copy the completed map into Word or elsewhere is simply to copy the map to the clipboard in the Design screen using the Copy toolbar option . Then in Word, use Ctrl+V to paste the map in.

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