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- Permanent Link:
- http://dpanther.fiu.edu/dpService/dpPurlService/purl/FI14090869/00001
Notes
- Scope and Content:
- Source: Lightning 1
Length of Segment: 00:01:15
Hi, I'm Dr. Jerry Jackson, out with the wild things. Draw a line from Ft.Meyers to Disney World and you've got a belt nearly across Florida. I'm talking about a belt of lightning, the focus of the most frequent and intense lightning in North America. On average, from this line south through the Florida peninsula, Floridians see lightning on about 90 days per year, mostly in summer. Across North Florida, and the northern Gulf of Mexico, west to East Texas, the frequency of lightning decreases to about 70 days per year. That's still a lot, compared with the frequency averaging 30 days per year in New York, and ten days per year in California. Lightning starts fires, and under natural conditions, upland forests and grasslands burned almost annually in South Florida. Lightning also injures and kills trees, resulting in infestations of bark beetles. Beetles provide food, and dead trees provide nest sites for woodpeckers and other cavity-nesting birds. Lightning brings both death and life, constantly renewing the cycle of life and creating habitat mosaics. Lightning shapes landscapes of Florida and dramatically influences where the wild things are. ( English )
- Scope and Content:
- Source: Lightning 2
Length of Segment: 00:01:15
Hi, I'm Dr. Jerry Jackson, out with the wild things. What causes lightning? Why does Florida have so much of it? Why is it mostly in the afternoon and evening? Slide across your car seat on a dry winter day, then touch someone and you may experience a spark of static electricity. Friction between molecules generates it. Lightning is a gigantic release of static electricity, and mega-bolts of Florida lightning are also the product of friction. With summer heat, more water evaporates from the surface of the Gulf of Mexico, raising the humidity. Afternoon summer heat raises the temperature of sand beaches and sidewalks to foot-burning hot. Such hot surfaces heat surrounding air, and hot air rises. As it rises, more air is sucked in to replace it both from the Atlantic and the Gulf of Mexico. This air, latent with evaporated moisture, also heats and rises. The hotter the day, the faster the rise, and the bigger the thunderheads. Friction between water molecules racing upwards generates static electricity. This charge builds up all afternoon, until released as a bolt of lightning. Lightning starts fires, and fires have a dramatic impact on where the wild things are. ( English )
- Scope and Content:
- Source: Lightning 3
Length of Segment: 00:01:15
Hi, I’m Dr. Jerry Jackson, out with the wild things. Wild fires in Florida often result from arson or carelessness, but sometimes it's just Mother Nature doing what Mother Nature does. With lightning frequencies as high as 40 strikes per year, per square mile in southwest Florida, lightning-started fires are natural in our landscape. Some Florida forests naturally burned almost annually, and many native creatures have unique adaptations for surviving fire. Pines, saw palmetto, wiregrass, and many other Florida plants are fire resistant. Some keep growing tips and store nutrients underground, protected from fires and ready to make a quick comeback after a fire. Red-cockaded woodpeckers make nest cavities in fire resistant living pines. Gopher tortoises, gopher frogs, diamond back rattlesnakes, and others find safety from fire within gopher tortoise burrows. Many creatures depend on fire for the habitats they need. Without fire, habitats change, and species that depend on them disappear. Every road acts as a fire break, and natural fires don't travel as far as they once did. In managing Florida's pine forest ecosystems and to prevent dangerous build up of fuels, foresters mimic nature by introducing fire under controlled conditions. ( English )
- Scope and Content:
- Source: Lightning 4
Length of Segment: 00:01:15
Hi, I'm Dr. Jerry Jackson, out with the wild things. Southern pines dominate Florida landscapes in a complex dance with fire. They not only survive fire, but promote it and depend on it. Some seedlings remain at ground level for nearly ten years developing strong roots, safe from fire. Pine stem tips are protected by a whirl of long needles. When the needles burn, they may release moisture, cooling the growing tip, allowing it to survive. After a fire, southern pines may grow several feet in a year. Fertilized by ashes of neighbors, they thrive in sunlight. Bark of older pines resists fire if it doesn't burn in one spot for long. Pine needles are high in resins and dried needles are highly flammable. In a loose duff on the forest floor, they ignite easily and burn quickly, ensuring the lightning-started fires race through pinelands. A moving fire is a cool fire, an effect like the trick of passing one's finger through a candle flame. There is no pain if you keep the finger moving; no damage to pines if the fire moves. A passing fire kills less fire-tolerant plants, fertilizes soil with their ashes, heats cones, causing them to open, and pine seeds fall to the ground under optimum conditions for survival. ( English )
- Scope and Content:
- Source: Lightning 5
Length of Segment: 00:01:15
Hi, I'm Dr. Jerry Jackson, out with the wild things. Even in death, a 200-year old pine provides services for the forest that young pines cannot provide. Among these services are the little-understood roles that fat pine plays in pine forest communities. In old age, the inner wood of pines becomes saturated with resins; such wood is called fat pine. Resins make the wood hard and slow decay, so that fat pine and stumps and logs can survive for decades. While these big old stumps and logs provide shelter for an abundance of creatures, during a hot wildfire the fat pine ignites and will burn until it has been totally consumed. It's no wonder that fat pine has been prized as a source of kindling. But big stumps with fat pine have a far more important natural value: they produce habitats missing from modern forests. When the fat pine stump is totally consumed, what's left is a hole three to four feet deep, with smaller holes extending several feet in every direction where roots with fat pine burned. The stump hole fills with water, and becomes an important breeding site for frogs, toads, and salamanders. Root holes provide safe havens for small mammals, reptiles, amphibians, and birds. ( English )
Record Information
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- Resource Identifier:
- FI00900201
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