Visible and invisible effects of hurricanes on forest ecosystems: an international review

Hurricanes have visible and invisible effects on forests. The visible effects are dramatic, noticeable over the short-term and relatively well documented in the literature. Invisible effects are less understood as they require well-focused research both in the short- and long-term time scales. This review of the literature on hurricane effects focuses on the Neotropics and the temperate zone of North America. The material is organized according to a heuristic model that distinguishes between immediate effects (0 to 3 years), immediate responses (0 to 20 years), trajectories of responses (0 to 100 years) and long-term legacies (>100 years). It is suggested that the ecological role of hurricanes involves six principal effects: 1. they change the ecological space available to organisms; 2. they set organisms in motion; 3. they increase the heterogeneity of the landscape and the variability in ecosystem processes; 4. they rejuvenate the landscape and its ecosystems and redirect succession; 5. they shape forest structure, influence their species composition and diversity and regulate their function; and 6. they induce evolutionary change through natural selection and ecological creativity through self-organization. A new approach to hurricane research will study hurricanes at the same scale at which they operate (i.e., across latitudes and longitudes and over disturbed and undisturbed landscapes). This research will require networks of observation platforms located along expected hurricane paths to facilitate forest structure and functioning observations across gradients of hurricane frequency and intensity. This research will also require use of remote sensing and automated wireless technology, hardened to survive hurricane-strength winds and floods to assure real time measurements of the characteristics of hurricanes and ecosystem responses. No progress will be forthcoming in the understanding of hurricane effects if we do not learn to quantify objectively the energy dissipation of hurricanes on the full grid of affected forests as the hurricane passes over a landscape.