Temperate Hardwood Hammocks

1. Temperate Hardwood Hammocks Chapter 6

2. Hardwoods Hardwoods – broad-leafed flowering trees, usually deciduous Softwoods – cone-bearing trees; have needles, usually not deciduous

3. Hardwoods • Hardwoods are more common in the southeast now than in the past • - fire exclusion • - wetland drainage • Examples of hardwoods: • oaks, beech, magnolia, bays, cherries • cabbage palm may be found in hardwood forests, although it is not a hardwood

4. American beech Live oak Carolina laurel cherry Southern magnolia Red bay

5. Hardwoods • Hardwood forests may be xeric, mesic, or hydric • - different conditions mean different species • Other conditions that affect the species types: • climate • flooding frequency • steepness of terrain • direction slope faces • soil texture and chemistry • age of forest

7. Beech-Magnolia Forests • Found in northern Florida • Beech and magnolia are the dominant species, but there may be 25+ types of trees • Trees are much more tightly packed than in a pine grassland – dense shade means not much ground-level growth

8. Beech-Magnolia Forests • Heavy shade is a problem for germinating seeds • - new trees can only spring up where an old tree has died – this is called gap succession • Any gap is quickly used by a succession of seedlings, only some of which will survive. • Always ongoing – the forest therefore has many differently-aged trees

9. Beech-Magnolia Forests • Not fire-adapted – resists burning • Moisture is held in by the thick canopy and dense leaf litter • Trees are not particularly flammable

10. Beech-Magnolia Forests • Adaptations to a shady life: • if you need lots of light, grow fast; or else, grow more slowly but get by on less light • smaller trees and shrubs can capture the more bluish light that gets through the canopy • smaller trees can also leaf out earlier, or hold onto their leaves longer

11. Beech-Magnolia Forests • Beeches and magnolias rule: • both can handle shade • as they get older, they create shade • magnolia leaves also shade out the ground • decaying beech leaves inhibit growth of other species

12. Beech-Magnolia Forests • Importance of fallen trees: • - they leave tip-up mounds and pits where the roots are pulled up • - this micro-topography allows different plants and fungi to colonize the area

13. Hardwood Forests vs. Pinelands Pinelands Hardwoods Thick shade Dense tree canopy captures most of the sun; not much ground cover Decay recycles nutrients • Open, sunny • Dense ground cover captures much sun • Fire recycles nutrients

14. Beech-Magnolia Forests • Animals • - most can fly or climb • - diverse tree species mean many different types of flowers and fruit for food • - decaying matter on forest floor gives lots of opportunities for insects and other invertebrates

15. Florida Forests • Forests in Florida are going to vary from north to south – southern Florida is going to have a completely different array of tropical species. • Topography and local climate will also make a difference.

16. Apalachicola Steephead Ravines • The Apalachicola river flows from the Blue Ridge mountains in northern Georgia. • The deep ravines of its tributaries harbor ancient plant species from before Florida emerged from the ocean.

17. Apalachicola Steephead Ravines • The steep ravines of the river’s tributaries show a range of conditions from top to bottom, so diversity is very high. • Top: dry, windy, sunny, well-drained • Bottom: cool, moist, still, shaded • A steam or tributary will flow out the ravine towards the river.

19. Apalachicola Steephead Ravines • Since the ravines run east/west, there is a shaded north-facing slope and a sunny south-facing slope. • - the north-facing slope can harbor plants that are generally found much farther north • The bottom of each ravine is like a moist island isolated from all the others – species may differ from ravine to ravine.

20. Apalachicola Steephead Ravines • Huge diversity of rare species: • a 35-mile stretch on the east side of the river has more total animal species than any other comparably-sized parcel on the coastal plain • home to over 100 rare and endangered species • still not well-surveyed – more to be discovered

21. Florida yew Florida torreya, or gopherwood Apalachicola rosemary

22. Xeric Oak Hammocks • Beech and white oak don’t occur as south as central Florida • Central Florida hammocks are typically other oaks and hickories, sometimes with cabbage palms.

23. Xeric Oak Hammocks • Spanish moss (Tillandsia) • - an epiphyte (lives on other species) • - not a parasite – depends on trees for structure and shelter, but still photosynthesizes • - shady oak canopies keep it from drying out • Some animals (birds, bats) nest or roost in it.

24. Xeric Oak Hammocks • Oaks (Quercus species) • - live oak, laurel oak, turkey oak, Chapman’s oak • - live oak and laurel oak can get quite large (100 feet in crown diameter) and may be over 100 years old • Oaks and hickories produce mast (nut-type fruits)

25. Xeric Oak Hammocks • Some years are “mast years” – a greater than normal abundance of fruit is produced • These are bonanzas for a wide array of animals:

26. Xeric Oak Hammocks • Other animals that depend on oak forests:

27. MesicOak Hammocks • More trees besides oaks and hickories: bays, magnolia, sweetgum, and many more • Diverse tree types mean that different fruits are ripe at different times – especially important for migrating birds - many birds fly through Florida on their seasonal migrations

29. MesicOak Hammocks • How birds help the forest: • spread seeds (with a fertilizer bonus) • control insect pests

30. Hardwood Hammocks • How the forests help us: • regulate climate, release moisture back into air • control runoff and purify water • allow for decay of organic material into soil • aesthetically pleasing and shady • diverse microhabitats for numerous species • absorb sound, provide privacy