Myrtle Beach suffers flooding from Hurricane Fran
The East Aiken Elementary kids discovered that it was not an easy hike from the North Carolina sandhills eastward to the coast, but they arrived on September 29, 1999. Hurricane Floyd generated heavy rainfall in many parts of the eastern U.S., but especially in coastal North Carolina. In the fall of 1999 rainfall totals of more than 20 inches (50 cm) created floods that ravaged towns near the Tar and Neuse Rivers, with floodwaters greater than 20 feet (6.1 m) deep in some areas. Fortunately the course of the East Aiken hike (and swim?) was closer to the Waccamaw and Cape Fear Rivers, which were not as flooded.
High winds can cause blow downs and create forest gaps
Fires cause vigorous regrowth and create habitat mosaics
Natural "disasters" are, well…natural. The events that humans think of as disastrous (and that Hollywood makes movies about)—hurricanes, earthquakes, fires, tornadoes, floods—are important forces that make the natural world so dynamic and ever-changing. In the science of ecology such disasters are called disturbances.
When viewed at the appropriately large scale, disturbances such as storms and fires are often ecologically positive, because they generate a diversity of habitats across a landscape. High winds blow down trees and create small and large gaps in forests. Sediment-laden floodwaters crest riverbanks, scour out new pond depressions and, as the water slows down across the floodplain, deposit rich soils and nutrients. Wind-swept fires create mosaics of burned patches next to unscathed forests. Usually a high diversity of habitats means a high diversity of plants and animals that inhabit those habitats.
Certainly some individual organisms are killed during extreme events such as hurricanes, massive mudslides, or volcanic eruptions. Catastrophes carried to the extreme, such as asteroid impacts with Earth, can cause species extinctions. In general, though, populations and species will survive more typical disturbances, which are apt to simply reset the ecological clock by knocking back the impacted ecosystem to an earlier stage of succession [Note: We’ll say more about the ecological process of "Succession" at another time]. Ecologists generally believe (like Goldilocks) that if disturbances are not too big, and not too severe or frequent, then the result will be "just right" for creating a rich diversity of species.
Pigmy Rattlesnakes (Sistrurus miliarius)
Pigmy rattlesnake (Sistrurus miliarius)
On their walk to the North Carolina coast the East Aiken classes might have spotted a pigmy rattlesnake in some of the pine flatwoods. In flooded areas the snakes may have been seen coiled in the branches of trees. Perhaps a student even commented on how similar the small pigmy is (at first glance) to some of the hognose snake hatchlings the kids have seen recently at their school. In some parts of coastal North Carolina pigmy rattlesnakes have an unusual reddish coloration that distinguishes them from pigmies elsewhere. Pigmy rattlesnakes are one of six species of venomous snakes found in the Southeast. The other five venomous species are: cottonmouth (also called water moccasin), copperhead, timber rattlesnake (known in some areas as canebrake), eastern diamondback rattlesnake, and coral snake (see species account for Venomous Snakes). Of the 49 species of snakes the East Aiken schoolchildren might encounter on their southeastern journey, only six are venomous. BUT (and notice that is a big BUT), because a bite from a venomous snake can be lethal, certain rules are important.
Adherence to these two rules will virtually eliminate the chance of being bitten by a venomous snake (see fact sheet on Snakebite).
Pigmy rattlesnakes are in the group of venomous snakes called pit vipers. This group includes all of the Southeast’s venomous species except the coral snake. Pit vipers derive their name from the heat-sensing organs located between the eyes and nostrils—the pits. The pits help in directing the strike toward warm-blooded prey.
Aside ...A little (very little) snake humor...
So a coachwhip crawls under a bush and says to the pigmy rattler, "Pigmy…every time I catch a mouse it’s such a struggle—it dodges this way and that, back and forth, and to top it all off it often bites me in the head—I’m sick of it, just sick of it I tell you. But you, Mr. Pigmy, you make it look so easy. How?" The pigmy cocks his head and replies "It’s the pits." The coachwhip says, "Believe me, I know. Catching food can be such a pain. But how do you…?" "It’s the pits," the pigmy states again. The coachwhip, getting a bit irritated as coachwhips do, again says, "Yeah, I know it’s a drag. But how do you succeed so often, especially at night when…" A clearly exasperated pigmy says, "THE PITS…I’m telling you I have PITS. Pay attention. What are you…deaf?"