Final Exam Flashcards
Why can oak species found on dry sites compete successfully with or without regular fire?
Because few other taxa tolerated the soil conditions.
Upland oaks are typically not the fastest-growing species on good-quality sites. What are 4 factor(s) allow oaks to dominate these sites?
- Regular fire favored oaks because of their thicker bark
- Oak roots will continue to grown while a seedling grows and dies back again and again
- Oaks live longer than pines
- Oak’s vessels are very efficient at moving water
Which oak species are dependent upon periodic fire to dominate moist, fertile (mesic) sites?
white oak (Quercus alba) northern red oak (Quercus rubra)
Outline the successional sequence [=change in species composition] typical of upland forests
in oak-dominated regions of the East.
- Pines were pioneers,
- but with the absence of frequent fires, oaks and chestnut dominated.
- Fire favored thick-barked oaks and chestnut and faster-growing species like maples, beech, sweetgum and yellow-poplar.
- The regions were cleared for agriculture, then abandoned, and are in various stages of succession to oak.
- Over the last few hundred years, agriculture has replaced forests on better soils.
- Chestnut blight eliminated chestnuts as canopy dominant.
- Over the last 100 years, fire suppression has favored thin-barked species, like beech and maples, creating higher density stands.
What species are common pioneers in the oak dominated region?
Virginia pine (Pinus virginiana) shortleaf pine (Pinus echinata) pitch pine (Pinus rigida) loblolly pine (Pinus taeda)
How often are large crops of acorns produced? What is this periodicity called? Why did cyclic fruiting likely develop?
- Every 4-10 years
- Advanced regeneration
- Seedlings will grow and die back, each time the roots will continue to grow.
Outline the differences between the red oak and the white oak groups; consider leaves, fruits,
wood, bark, wildlife, and commercial uses. (Hint: In my crystal ball, I see a chart.)
RED OAKS: Leaves: bristle tips Fruits: 2 yrs., germinate in spring Wood: slack cooperage Bark: ridges, furrows, "ski trails" Wildlife value: acorns less desirable Commercial uses: barrels for storing solids
WHITE OAKS:
Leaves: rounded
Fruits: 1 yr., germinates in fall
Wood: tight cooperage
Bark: narrow scaly ridges, shallow furrows, shaggy
Wildlife value: acorns high value
Commercial uses: barrels for storing liquid
What is the difference between tight and slack cooperage?
Tight cooperage:
The transition from early wood to late wood is abrupt, and the wood pores become naturally plugged with tyloses, making the wood watertight and able to store liquids.
Slack cooperage:
The transition is gradual and the pores lack tyloses, making the wood unsuitable for barrels storing liquids.
Which oak group provides which type of cooperage? Are there any exceptions?
Tight cooperage: white oaks
Slack cooperage: red oaks, except blackjack oak (Quercus marilandica)
How do upland oak species grow to become a member of the middle- or upper-canopy?
Grow slowly and do well in the presence of fire.
They can also dominate on soils that do not support other species.
Why is it difficult to increase the proportion of upland oaks following disturbance (e.g., fire, windthrow or clearcutting) on good sites?
They grow much slower than other species. They depend on regular fire to maintain dominance.
What are tyloses? What do they do?
A balloon-like outgrowth of a parenchyma cell through a pit into the cavity of a plant vessel.
When the transition from early wood to late wood is abrupt, they naturally plug the wood pores, making the wood watertight.
What effect has farming had on the soils of the Piedmont over the last 300 years?
Agriculture has replaced forests on the better soils. It has increased the production of pioneer species.
What effect has farming had on the vegetation of the Piedmont over the last 300 years?
The habit of clearing and abandoning farm fields has increased the proportion of pioneer species.
Compared to the 1600s, the amount of oak in our forests today has almost certainly declined, especially in the foothills and mountains. Why?
Fire suppression has allowed faster-growing species to dominate.
What features allow shortleaf pine to tolerate occasional fires?
By a basal crook: stem turns and lies flat on the soil surface and is protected from fire and able to re-sprout (when it’s young).
How is the U.S. Forest Service “restoring” national forests in Arkansas to the conditions found in the year 1491?
By harvesting certain trees so that the forests are not as dense.
What is the fire return interval in oak forests?
6-15 years
Where do oak-dominated forests occur? (Be able to locate the regions on a map.)
(see map)
On either side of the Mesophytic Forests.
What are the commercially most-valuable oaks in oak-dominated regions?
white oak (Quercus alba) northern red oak (Quercus rubra) black oak (Quercus velutina) chestnut oak (Quercus montana)
What effect has fire suppression had on the forests of the Oak-dominated Region?
It has favored thin-barked species, especially beech and maple, and created stands of higher density.
What adaptations allow upland oaks to cope with fire?
- Advanced regeneration: seedlings grow and die back, each time the roots will continue to grow
- Oaks can move water through vessels
- Thicker bark
Name at least six of the dominant tree species found in the Mesophytic Region.
- yellow-poplar (Liriodendron tulipifera)
- American beech (Fagus grandifolia)
- eastern hemlock (Tsuga canadensis)
- yellow buckeye
- yellow birch
- sweet birch
What geologic history is characteristic of the Mesophytic Region?
It developed on the non-glaciated portions of the Cumberland Plateau. It is the oldest region in the biome.