6533b831fe1ef96bd12998ec

RESEARCH PRODUCT

Saproxylic beetle assemblages in the Mediterranean region:Impact of forest management on richness and structure

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Forests cover almost 30% of the Mediterranean region today, yet forest management activities have influenced structure and composition of both natural and planted forests. To date no study has been conducted to evaluate the impact of forest management on saproxylic beetle assemblages, although it is known that the Mediterranean is a biodiversity hotspot with a long-lasting human pressure on natural habitats. We provide an overview of saproxylic beetle assemblages of three forest types (mature Pinus halepensis forests, mature Pinus brutia forests, young Quercus calliprinos forests) in the East Mediterranean region using a one-year sample from 12 forest plots located in the north of Israel. The studied forest types differed in forest structure, but we found no significant difference in saproxylic beetle species richness. Aleppo pine forests showed the largest number of saproxylic beetle species. Forests dominated by P. brutia, a non-native tree species in Israel, show the lowest species number of all three forest types. Species composition differs substantially between oak and pine forests. A third of the species found either in P. halepensis or in Q. calliprinos forests being unique to these habitats, while a smaller proportion of unique beetle species is found in P. brutia forests. Several beetle species that were found both in oak and pine plots in our study develop exclusively on broadleaved shrubs or trees. This may be explained by the small distances between the studied pine trees and oaks in their proximity. Biodiversity in pine forests can be increased when these are mixed with broad-leaved trees, e.g. oaks in the understorey layer, as can be observed the natural regrowth in most of the planted pine stands in our research area. There is some evidence from other studies that older successional stages of oak forests are likely to host more species overall than the mature pine forests studied here. In order to enhance structural diversity foresters should allow for aging of single trees or stands, regardless of the tree species. (C) 2010 Elsevier B.V. All rights reserved. Forests cover almost 30% of the Mediterranean region today, yet forest management activities have influenced structure and composition of both natural and planted forests. To date no study has been conducted to evaluate the impact of forest management on saproxylic beetle assemblages, although it isknown that the Mediterranean is a biodiversity hotspot with a long-lasting human pressure on natural habitats. We provide an overview of saproxylic beetle assemblages of three forest types (mature Pinus halepensis forests, mature Pinus brutia forests, young Quercus calliprinos forests) in the EastMediterranean region using a one-year sample from 12 forest plots located in the north of Israel. The studied forest types differed in forest structure, but we found no significant difference in saproxylic beetle species richness. Aleppo pine forests showed the largest number of saproxylic beetle species. Forests dominated by P. brutia, a non-native tree species in Israel, show the lowest species number of all three forest types. Species composition differs substantially between oak and pine forests.Athird of the species found either in P. halepensis or in Q. calliprinos forests being unique to these habitats, while a smaller proportion of unique beetle species is found in P. brutia forests. Several beetlespecies that were found both in oak and pine plots in our study develop exclusively on broadleaved shrubs or trees. Thismaybe explained by the small distances between the studied pine trees and oaks intheir proximity. Biodiversity in pine forests can be increased when these are mixed with broad-leaved trees, e.g. oaks in the understorey layer, as can be observed the natural regrowth in most of the planted pine stands in our research area. There is some evidence from other studies that older successional stagesof oak forests are likely to host more species overall than the mature pine forests studied here. In order to enhance structural diversity foresters should allow for aging of single trees or stands, regardless of the tree species.