Fire history and management of Pinuscanariensis forests on the western Canary Islands Archipelago, Spain

Abstract

Many studies report the history of fire in pine dominated forests but almost none have occurred on islands. The endemic Canary Islands pine (Pinuscanariensis C.Sm.), the main forest species of the island chain, possesses several fire resistant traits, but its historical fire patterns have not been studied. To understand the historical fire regimes we examined partial cross sections collected from fire-scarred Pinuscanariensis stands on three western islands. Using dendrochronological methods, the fire return interval (ca. 1850–2007) and fire seasonality were summarized. Fire-climate relationships, comparing years with high fire occurrence with tree-ring reconstructed indices of regional climate were also explored. Fire was once very frequent early in the tree-ring record, ranging from 2.5 to 4years between fires, and because of the low incidence of lightning, this pattern was associated with human land use. After ca. 1960, the fire regime changed to a more widespread pattern at a lower frequency. Climate variability was not associated with widespread fires early in the fire record. After 1960, widespread fire years were significantly drier than normal while antecedent conditions were wetter. Over the last several decades fire suppression has essentially eliminated all but the largest, higher intensity wildfires, establishing a new fire regime. We suggest strategies that promote fire as a forest management tool to restore a fire regime consistent with historical patterns. Canary Island pine could be useful in management programs in fire prone environments of the world because of its fire trails (fire tolerance and sprouting ability).