The destructive impacts of Category 4 Hurricane Michael on the forests of northwest Florida were captured by ForWarn II's routinely produced Early Detect product one week after the event. The stark pattern of greatest damage in red and orange consists of a 50 km-wide swath that stretches from near the track of the hurricane's eye to the Apalachicola River which likely had reduced greenness from both wind damage and flooding.
Hurricane impacts to forests can vary greatly depending on the qualities of the storm. Hurricane Florence stood out for its slow speed and heavy rainfall to the Carolinas, while Hurricane Michael, that crossed Florida's panhandle just a few weeks later in 2018, was a powerful wind-event that passed relatively quickly. ForWarn II's near-real-time capabilities reveal the initial storm effects, then in concert with higher resolution imagery and ancillary data assessments can discriminate among water and wind impacts more precisely.
ForWarn has detected bottomland areas of North Carolina, South Carolina, Georgia and Florida that were affected by Hurricane Matthew in October, 2016. The data shows the intensity of the wetland flooding.
The Forest Tent Caterpillar (Malacosoma disstria) is a widespread native defoliator of deciduous forests in the Eastern US. While host trees differ regionally, the insect prefers sweet gum (Liquidambar styraciflua), tupelo gum, black gum (Nyssa spp.) and species of oak (Quercus spp.) in the bottomland forests of North Carolina's Coastal Plain.
The larvae hatch in early spring as the tree buds swell, then larvae defoliate emerging and growing leaves in April and early May. After a few weeks, caterpillars form pupae, then adults emerge in late May.
ForWarn has detected anomalies in Columbia, South Carolina in wetlands and forested lands. Heavy rains caused flooding in the area however, this is likely not a sign of damage.
ForWarn has potentially detected a multiple factored defoliation event in wetlands of southeast Louisiana. Identified in September 2015, rerouted water from Mississippi river caused flooding and created stress defoliation from trees as well as inundated the understory. The flood also may have caused defoliating insects to infest the area, decreasing vegetation greenness in the overstory.
ForWarn detected a decline in vegetation greenness in September 2015 in Wisconsin. There are several possible causes for the departure. Flooding causing stress in wetlands of Green Bay as well as previous season's drought could cause defoliation of trees. Insects such as spruce budworm or larch beetle infestations could be defoliating the trees in the Green Bay area as well.
ForWarn identified vegetation greenness departure along the Red River in Texas, Oklahoma, Arkansas, and Louisiana. In July 2015, flooding of the river in these areas caused die back from waterlogging plants. Additionally, the grasslands of Oklahoma were affected by a hail streak, damaging foliage.
ForWarn detected a disturbance in the croplands of east Texas. Excess precipitation in the previous months on bare soil croplands caused waterlogging and flooding. The wet spring caused severe decline especially along the riverine flood plains of eastern Texas including portions of Trinity and Brazo Rivers.
ForWarn discovered a reoccurring anomaly in the bottomland wetlands of South Carolina. Similar anomalies were seen in 2010, 2014, and 2015 in the area of concern. Starting in January, the winter anomaly excludes association with insect defoliation. The decline in vegetation greenness can be attributed to an unusually cold winter or flooding.