The influences of anthropogenic modification after the Great East Japan Earthquake on ground insects and their relationship with vegetation

Abstract

ABSTRACT On the Pacific coast of Northeastern Japan, tidal embankments and coastal forests were constructed following the Great East Japan Earthquake. Although coastal forests are regarded as green infrastructure, the impact of their reconstructions on ecosystems is concerning. To mitigate these impacts on the Sendai coast of Miyagi prefecture, non-modified areas were established, and coastal sand was covered over the mounds constructed as coastal forest beds. This study surveyed the distribution of ground insects and vegetation in this area to evaluate differences associated with these anthropogenic modifications and mitigations. The results showed that coastal insect abundance and vegetation coverage were lower on the mounds compared to the areas without afforestation or mounding. However, inland insect abundance and vegetation coverage was higher on the landward side of the tidal embankment compared to the seaward side, regardless of the mounds. On the landward side of the tidal embankment, coastal insect abundance was lower when inland vegetation coverage was dense. Additionally, no quantitative differences in coastal insects and plants were observed between the sand-covered mounds and not covered mounds. We suggest that the influence of green infrastructures such as coastal forests on the native ecosystem should be considered.