Insect Diversity in the Coastal Pinewood and Marsh at Schinias, Marathon, Greece: Impact of Management Decisions on a Degraded Biotope

The insects trapped in 63 plots positioned in a mixed pinewood and a marsh in Schinias, Marathon, Greece is studied relative to the anthropogenic disturbance. The last anthropogenic impact was recently intensified because of the Olympic Games in the area. One hundred and forty insect species were found that had abundances greater than two individuals in each sampling session in all plots. Seven insect community types were found using cluster analysis. The types, which corresponded to recognized habitats, re-emerged in a non-metric multidimensional scaling ordination. It was also found that insects tended to dwell in different plots, even in the same habitat. The invading P. halepensis Mill., which replaces P. pinea L., changed the entomofauna. The seven habitats had different numbers of bioindicators out of 74 insect species, not in general correlated with human impact. Three components of insect diversity were measured, and the temporal species turnover was consistently higher than the spatial one. In this sense, pine habitats were rated first in terms of overall insect diversity. In terms of biodiversity, the impact on the various biotopes was assessed utilizing the diversity–equitability index V, which indicated that the two P. halepensis-dominated habitats have negative V values together with the habitat dominated by Tamarix hampeana Nied. The conservation of P. pinea and the marsh habitats is recommended for conserving local entomofauna and stopping the progression of P. halepensis. The optimization of management strategies to meet the management goals of all elements of this degraded ecosystem seems to be crucial.