Forest Response to Catastrophic Wind: Results from an Experimental Hurricane

Abstract

Abstract. Infrequent, intense wind disturbance is an important factor in northeastern U.S. forests, yet little is known about the early stages of vegetation reorganization, or the processes that facilitate biotic regulation of ecosystem function after such storms. We designed an experiment, based on a simulated hurricane blowdown, to examine the relationship of tree damage patterns to mortality and regeneration, community dynamics, vegetation recovery, and ecosystem processes. In October 1990, selected canopy trees in a 50 X 160 m area within a 75-yr-old Quercus rubra-Acer rubrum forest in central Massachusetts were pulled over by a winch, using records from the 1938 hurricane to determine the number of trees and direction of fall. The resulting damage to 65% of trees closely approximated effects of the 1938 storm on New England forests. Damage and mortality varied by tree species and size, indicating the importance of pre-disturbance forest structure and composition in determining the range and severity of impact. Measurements of vegetation and environment in the experimental area and control indicated that, although the manipulated stand sustained dramatic damage and structural reorganization, resilience of trees and understory vegetation provided tight biotic control of ecosystem processes, including nutrient cycling. Continued leaf-out and induced sprouting by damaged trees, increased growth by saplings and understory plants, and seedling establishment on disturbed microsites stabilized the microenvironment. Our findings are in contrast to studies of disturbances in which mortality was higher when damaged trees were removed from the site. This suggests that salvage logging following wind disturbance may have serious long-term implications.

Responses to canopy loss and debris deposition in a tropical forest ecosystem: Synthesis from an experimental manipulation simulating effects of hurricane disturbance

“…Thus, the understory fern community in the LEF is more resistant and resilient to hurricane effects than is the woody plant community. Although future research is needed, the high resilience of the understory fern community may enact some inhibitory effects on the recruitment and establishment of woody plant species (Royo and Carson, 2006), as previously observed with the temperate fern, Dennstaedtia punctilobula, that increased 100% in cover after the experimental blowdown study at the Harvard Forest LTER site (Cooper-Ellis et al, 1999), and with the tree fern Cyathea arborea, and scrambling ferns in the Gleicheniaceae on landslide scars in the LEF (Walker et al, 2010).…”

“…A similar result was found in the Harvard Forest blowdown study, where saplings and sprouts increased fourfold, including early successional species such as Betula spp. (Carlton and Bazzaz, 1998;Cooper-Ellis et al, 1999). Community analysis in the CTE demonstrated that the dominant individuals in the small size classes of the trimmed plots were pioneer species, and the establishment of pioneers in the canopy trimmed plots (3-6 new species on average) resulted in significant increases in woody plant species richness relative to intact canopy plots (Zimmerman et al, 2014).…”

“…For example, Hurricane Hugo was a category 4 storm that passed over our study site in 1989 and with the majority of tree structural effects manifesting as branch and leaf loss; only 9% of trees were uprooted and 11% had snapped trunks (Walker, 1991). In contrast, the experimental blow-down study at the Harvard Forest LTER site uprooted whole trees to simulate the predominant effects of natural hurricane effects in New England (Cooper-Ellis et al, 1999).…”

“…Previous research (Walker et al, , 1996aZimmerman et al, 1996; identified canopy loss and the accumulation of debris on the forest floor as key factors that govern responses during secondary succession. Although the CTE is the first experimental study of hurricane effects conducted in a tropical forest, there was an experiment in temperate forest at the Harvard Forest LTER site in northeastern USA, where whole trees were pulled down in a single plot to simulate conditions of a previous major hurricane (Bowden et al, 1993;Carlton and Bazzaz, 1998;Cooper-Ellis et al, 1999;Barker Plotkin et al, 2013). The main effects observed in the temperate experiment were reduced basal area of trees due to the physical application of the manipulation, increased light levels, and establishment of pioneer tree species in areas of soil disturbance caused by uprooting (Carlton and Bazzaz, 1998;Cooper-Ellis et al, 1999;Barker Plotkin et al, 2013).…”

Responses of Ground-Dwelling Invertebrates to Gap Formation and Accumulation of Woody Debris from Invasive Species, Wind, and Salvage Logging

“…Species richness and diversity of ground beetles were higher in salvaged gaps following severe wind disturbance (>70% tree mortality) [61], and activity-abundance was higher in salvaged gaps following wildfire [122]. Koivula and Spence [123] reported increased activity-abundance and species richness with increasing salvage logging intensity (low: 23-30% timber removed, moderate: Severe wind storms generally fell a high proportion of canopy trees forming large, patchy gaps, although some trees lose only branches and remain standing [96]. Tipped trees form pits and mounds that mix organic and mineral layers, expose rocks and roots, and create distinct microsites that differ from neighboring undisturbed soil [97][98][99][100][101].…”