Shelter from the storm? Use and misuse of coastal vegetation bioshields for managing natural disasters

TLDR

Vegetated coastal ecosystems provide essential goods and services to billions, and following recent disasters such as the Indian Ocean Tsunami, Hurricane Katrina, and Cyclone Nargis, they have been widely promoted as a means to reduce storm surge and tsunami impacts. This review seeks to influence bioshield policy by examining the use of coastal vegetation as a protective “bioshield” and by highlighting ways to reduce its long‑term negative effects on biodiversity and human capital. The authors survey post‑2004 literature on wave attenuation by vegetation, analyze case studies from the Indian subcontinent, assess the detrimental impacts of bioshield plantations on native ecosystems, and place these findings within a political context to propose new policy and research directions.

Abstract

Abstract Vegetated coastal ecosystems provide goods and services to billions of people. In the aftermath of a series of recent natural disasters, including the Indian Ocean Tsunami, Hurricane Katrina and Cyclone Nargis, coastal vegetation has been widely promoted for the purpose of reducing the impact of large storm surges and tsunami. In this paper, we review the use of coastal vegetation as a “bioshield” against these extreme events. Our objective is to alter bioshield policy and reduce the long‐term negative consequences for biodiversity and human capital. We begin with an overview of the scientific literature, in particular focusing on studies published since the Indian Ocean Tsunami in 2004 and discuss the science of wave attenuation by vegetation. We then explore case studies from the Indian subcontinent and evaluate the detrimental impacts bioshield plantations can have upon native ecosystems, drawing a distinction between coastal restoration and the introduction of exotic species in inappropriate locations. Finally, we place bioshield policies into a political context, and outline a new direction for coastal vegetation policy and research.