Ground flora and associated arthropod communities of forest road edges in Connemara, Ireland

Forest road edges in a conifer plantation in Connemara, Ireland were sampled for ground flora and associated terrestrial invertebrates along the northern edge of a forest road bordered by conifers (Conifer 1 site), broadleaves (Broadleaf site) and a clearfelled area (Open site). In addition, the southern edges of the road bordered by a clearing (Scallop site) and of an adjacent forest road bordered by conifers (Conifer 2 site) were sampled. Median ground plant species richness per quadrat was lower at the Conifer sites than at the other sites. A positive relationship between plant species richness and light levels was apparent. Median arthropod morphospecies richness per sweep was significantly greater (P < 0.01) at the Broadleaf site (39.0) than at the Conifer 2 site (25.5). Median morphospecies richness for Hemiptera was significantly greater at the Open (7.0) and Broadleaf (6.5) sites than at the Conifer 1 site (2.0, P < 0.001) and Conifer 2 site (2.0, P < 0.01). For Diptera, median morphospecies richness was significantly greater at the Open site (13.5) than at the Conifer 1 site (6.0, P < 0.01), Conifer 2 site (6.0, P < 0.001) and Scallop site (8.0, P < 0.05). There was a positive relationship between plant species richness and arthropod morphospecies richness with stronger species richness relationships evident between plants and Diptera and between plants and Hemiptera, respectively. The results of this study suggest that open spaces and broadleaf plantings in this commercial conifer plantation in the west of Ireland could be important for biodiversity.