Physical comparative tables - guidance notes

The "All Biotopes" worksheet

The "All Biotopes" worksheet shows a summary of the physical data contained in the core records for each biotope. Biotopes are shown in rows, with the first four columns containing "header" information. The first column shows biotope codes, followed in subsequent columns by the EUNIS level (coloured using the standard classification colour scheme), the biotope sort order (allowing the rows to be displayed in the correct classification order), and the number of core records for each biotope.
 
The remaining columns, where cells have a white background, show summary physical information as indicated by the column headers in the top two rows. Physical factors are split into a number of categories.  For example, "salinity" is split into "full", "variable" and "low". The categories are equivalent to the categories used in MNCR field recording, as described here.
 
It is possible to filter the data on any of the columns, i.e. biotope code, EUNIS level, number of core samples, and physical categories (e.g. it is possible to select all samples that fall within a particular salinity category).
 
The figures in the table show the following:
Salinity
Wave Exposure
Tidal Streams
Height / Depth Band
Biological Subzone
 
(% Frequency)
Each of these factors is split into a number of categories. For each biotope, the figures show the percentage of core biotope records falling into a given category for a given factor.
 
Note that these categories are not recorded as percentage fractions, i.e. a single field record will not be recorded as 50% full salinity and 50% variable salinity. It either falls within the full and/or variable salinity category, or it doesn't.
 
It is possible for a single sample to fall into more than one category for some of the factors. Conversely, some of the samples have no data recorded for some of the factors. This means that the figures will not always add up to 100%.
Mean Height / Depth Range
 
These two columns show the mean upper and lower height limit of biotopes (in metres above / below chart datum).
Substratum
Inclination
Particle Size Analysis
 
(Mean Percentages)
Again, these physical factors are split into a number of categories. Unlike the factors above, however, the field records contain percentage figures for these factors. A single field record where a particle size analysis was carried out, for example, may contain 20% gravel, 50% sand and 30% mud. The figures in this table show the mean percentage value for each category.
 

Littoral sediment, Littoral Rock, Infralittoral Rock and Circalittoral rock worksheets

These worksheets display the same data as the "All Biotopes" sheet, but with the samples in columns and the physical data in rows. Because there are more than 256 biotopes, the information will not fit on a single worksheet, and has therefore been split into the five broad habitats.
 
The reason for displaying the data this way around is to allow easy cross-referencing between biological and physical sets of comparative tables. By hiding unwanted columns in these worksheets, it is possible to display any combination of physical biotope profiles adjacent to each other (provided they are from within the same broad habitat).
 

Biotopes which do not appear in the physical comparative tables

There are a limited number of biotopes that have no core biotope records. They were included in the classification based on information from sources other than the JNCC marine database. For these biotopes, there is no information in the physical (and biological) comparative tables. In the physical tables, the codes have been included, highlighted in red. The biotopes which have no core records are listed above.
 

Download the comparative tables

Comparative tables guidance - File format pdf (45KB)
Physical comparative tables - File format zip (148KB)
Biological comparative tables - File format zip (945KB)