Saproxylic Quality Index: Evaluated sites ranked by SQI

The Saproxylic Quality Index (Fowles, Alexander & Key, 1999) is a scoring system designed to assist with the evaluation of the conservation significance of wooded habitats in Great Britain for saproxylic Coleoptera. For this purpose 598 saproxylic beetles were defined as species "dependent upon microhabitats associated largely with the processes of damage and decay in the bark and wood of trees and larger woody shrubs and climbers. This includes sap runs, fungal hyphae or fruiting bodies, rot holes, etc.". The Index is calculated against a list of 596 saproxylic species for which rarity scores, based on their known distribution, have been assigned (Anoplodera livida was included in the published list in error and Anaspis septentrionalis has been synonymised with A. thoracica). The IEC (Index of Ecological Continuity) is also calculated for each site list: the species and grades used are taken from the latest revision (Alexander, 2004).

There have been considerable advances in our understanding of the ecology and status of saproxylic Coleoptera in Britain since the SQI Index was developed; new species have been added to the British list, several have extended their range such that their conservation status needs revising, and others have been shown not to be as strongly associated with saproxylic habitats as once thought. All of these changes need to be incorporated into a revised Index that takes account of our increased knowledge of the fauna, including the new IUCN statuses that are currently being generated . This is a project for the future and, until such time as that Index is developed, the SQI and IEC versions used here will utilise the published species and scores.

Calculating indices: To calculate SQI and IEC values for site inventories, click on the 'Submit New List' button in the top toolbar and enter relevant data.
Rankings: All sites with at least 40 qualifying saproxylic species are displayed by clicking on the Rankings button
Search: This allows you to look for sites with data already entered or to see which sites a particular species has been reported from


Alexander, K.N.A. 2004. Revision of the Index of Ecological Continuity as used for saproxylic beetles. English Nature Research Reports. 574.
Fowles, A.P., Alexander, K.N.A. & Key, R.S. 1999. The Saproxylic Quality Index: evaluating wooded habitats for the conservation of dead-wood Coleoptera. The Coleopterist, 8: 121-141