The data are the habitat association (phi coefficient of association) of ground beetles (Carabidae) in Great Britain. The analysis used all 100 m carabid records from the NBN Atlas website for the analysis. The habitats are those from the CEH Land Cover Map 2015 (LCM2015) and for each beetle species each habitat has a score between 1 and -1 representing association through to disassociation and a p-value giving significance of the association score.
The recommended output shows habitat weighted analysis using an absence threshold of fourteen other species. Five other versions are also provided, with thresholds of seven and 28 and the unweighted versions of the analysis, to allow the user to ascertain for themselves confidence in the association of a habitat to a species.
Publication date: 2019-04-01
Biological records of carabid beetles were sourced from the NBN atlas. habitats are those from Centre for Ecology and Hydrology (CEH) Land Cover Map 2015 (LCM2015). Correlation indices were calculated for the carabids and habitats. A weighted version of the indices was calculated to allow the incorporation of carabid data from 100m squares that contain more than one habitat type.
The NBN does not include absence data. To allow us to have confidence that a species was genuinely not at a particular location, we counted the number of other species found in each location as a measure of survey effort, using a threshold value for the number of species taken into account before deciding on whether the target species could be considered absent. The NBN data contained a separate record for each species at each relevant 100 m location meaning that individual locations appeared multiple times. We created a version of the data with each location represented once, giving presence or absence (absences determined as described above) for each species at that location.
The datasets published include our recommended output, which shows habitat weighted analysis using an absence threshold of 14 other species. Versions with a threshold of seven and 28, and the unweighted versions of the analysis, are also included to allow the user to ascertain for themselves confidence in the association of a habitat to a species.