Airborne Laser Scanning Quantification of Disturbances from Hurricanes and Lightning Strikes to Mangrove Forests in Everglades National Park, USA

Abstract

Airborne light detection and ranging (LIDAR) measurements derived before and after Hurricanes Katrina and Wilma (2005) were used to quantify the impact of hurricanes and lightning strikes on the mangrove forest at two sites in Everglades National Park (ENP). Analysis of LIDAR measurements covering 61 and 68 ha areas of mangrove forest at the Shark River and Broad River sites showed that the proportion of high tree canopy detected by the LIDAR after the 2005 hurricane season decreased significantly due to defoliation and breakage of branches and trunks, while the proportion of low canopy and the ground increased drastically. Tall mangrove forests distant from tidal creeks suffered more damage than lower mangrove forests adjacent to the tidal creeks. The hurricanes created numerous canopy gaps, and the number of gaps per square kilometer increased from about 400~500 to 4000 after Katrina and Wilma. The total area of gaps in the forestincreased from about 1~2% of the total forest area to 12%. The relative contribution of hurricanes to mangrove forest disturbance in ENP is at least 2 times more than that from lightning strikes. However, hurricanes and lightning strikes disturb the mangrove forest in a related way. Most seedlings in lightning gaps survived the hurricane impact due to the protection of trees surrounding the gaps, and therefore provide an important resource for forest recovery after the hurricane. This research demonstrated that LIDAR is an effective remote sensing tool to quantify the effects of disturbances such as hurricanes and lightning strikes in the mangrove forest.

Hurricane disturbance and recovery of energy balance, CO2 fluxes and canopy structure in a mangrove forest of the Florida Everglades

“…Our results also suggest that the impact of the storm on energy balance and soil temperatures persisted through the initial leaf-out and subsequent changes in leaf area distribution into [2008][2009]. The relatively rapid recovery of daytime CO 2 uptake after Hurricane Wilma reflects an adaptation to the frequent disturbance from hurricanes and lightning damage in the Florida Everglades region (Smith et al, 1994;Zhang et al, 2008).…”

New perspectives on an iconic landscape from comparative international long‐term ecological research

“…Comparisons of mangrove productivity aided by international LTER collaborations suggest these high values, promoted by biogeochemical and hydrological forces unique to subtropical karstic estuaries, typify the Caribbean region (RiveraMonroy et al 2008, Castañeda-Moya et al 2010, Jardel et al 2013, Stalker et al 2014. Because climate disturbance is such a critical modulator of these biogeochemical and hydrological controls, collaborations between FCE and Mexican Long-Term Ecological Research Network (Red Mexicana de Investigación Ecológica a Largo Plazo) researchers are underway to identify gaps in climatological datasets and in our understanding of the frequency, duration and degree of impact of different types of disturbances structuring these forested wetlands (Calderon-Aguilera et al , Farfán et al 2014.…”

“…These studies will also generate regional maps of shortand long-term changes in land use to determine the differentiated vulnerability of mangrove forests in the Americas to land use change and disturbance. The proof of concept in the application of such remote sensing techniques began in the FCE mangrove ecotone region (Simard et al 2006, Zhang et al 2008, and now has allowed v www.esajournals.org further expansion in other mangrove dominated coastal regions around the world (Fatoyinbo et al 2008, Simard et al 2012, Lagomasino et al 2015. Notably, these studies integrate social science analytical frameworks with the remote sensing data to go beyond identifying the types or proximate sources of change (e.g., mangrove conversion to shrimp ponds, agriculture, urban uses) to evaluating the causal drivers of that change (e.g., population growth, local/global markets for fisheries or agricultural commodities, policies, land tenure, etc.…”

Extraction of Mangrove Biophysical Parameters Using Airborne LiDAR

“…However, there are only a few scientific articles discussing the application of LiDAR to mangrove biophysical parameter extraction. Most of these studies were focused on the mapping of mangrove distributions [35][36][37][38], gap identification [27], and assessment of hurricane disturbance [10]. LiDAR has been used to generate the canopy height profile for validating the mangrove canopy height, which was computed from the Shuttle Radar Topography Mission (SRTM) at the plot level [39,40].…”