Dendrology Exam #1

What is a tree?

Tall and composed of woody tissue (secondary growth)

Exceptions to species definition

Asexual organisms, hybridization, and polyploidy

What are the four phylums of gymnosperms?

Cycadophyta, Ginkgophyta, Gnetophyta, and Pinophyta

Only surviving species of Phylum Ginkgophyta

Ginkgo biloba

ID Tips for Ginkgo biloba

- Leaf is distinctly fan shaped

- Alternate buds, leaves aren't really alternate

- Leaves clustered around buds, almost whorled in appearance

Ginkgo biloba fruit

Dioecious, fruit smells horrible, nut is edible but in small amounts, flesh contain urishol

Ginkgo biloba: lumber

Used, but brittle, so commonly used for carvings.

Important/famous use of Ginkgo biloba

Memory aid, never proven to work

Families of Pinophyta (Conifers) in TN

Pinaceae, Cupressaceae and Taxaceae

Pinophyta reproduction

Reproduce with cones, separate male & female structures, Pine cones are female, male cones much smaller.

Pinophyta ecology/economic

Dominate many landscapes, important pioneer species, harvested for lumber

Family Taxaceae: Distribution

More common in the North/out west, only one in Tennessee (Taxus canadensis)

Family Taxaceae: Value

Harvesting taxanes, Taxol was derived from the bark of Pacific Yew (Taxis lorevifolia), used for chemo

Family Cupressaceae Taxonomy: Important genera

Sequoia, Sequiadendron, Taxodium, Thuja, Juniperus

Family Cupressaceae: Value

Very important economically, harvested for their high value lumber which is rot resistant, perfect for wood-soil contact situations. Important ornamental

Family Cupressaceae: 3 species in TN

Juniperus virginiana, Thuja occidentalis, and Taxodium distichum

Juniperus virginiana ID tips

Needles branch constantly, seemingly ransom when examine with hand lens, needles are very scaly

Juniperus virginiana: importante info

Family: Cupressaceae

Dioecious trees, often had berries from previous years

Indicative of abandoned farmland, shape intolerant, fire intolerant, used for cedar planking for moth resistance, rot resistant, important wildlife food and cover, also controls wind erosion well

Thuja occidentalis ID tips

Leaf is more flattened with the branches all along one plane, fruit not as berry-like spiky ball instead

Thuja occidentalis: important info

TN is southern extreme of range, restricted to high mountains, lumber used for wooden canoe and fences. Important for wildlife food/cover

Taxodium distichum ID tips

Leaves much more feather like

Cones looks like golf ball

Wider at the base, particular when in water

Knees

Taxodium distichum: important info

Found in areas with prolonged flooding

Very slow growing

Highly desirable lumber due to rot resistance

Ecologically important, and old growth stand home to several endangered species

Harvesting required girdling tree, letting it dry out for one years before it could be floated

Not all floated, many sank and log divers now hunt and recover these

Family Pinaceae Taxonomy

Pinus, Abies, Larix, Picea, Pseudotusga, Tsuga

Family Pinaceae Importance

More economically important tree in NA, pine is used for housing construction, important ornamental

Pinus taeda ID Tips:

3 needles per fascicle

Slightly twisted

5-9in long

Sheath 0.25-0.5 in long

Platy, furrowed bark

Pine cones 4in

Very pointy

Pinus taeda: Important info

Can tolerate wide variety of soil types

Moderately shade intolerant

Commonly grown in monocultures

Fire resistant

Pinus echinata ID tips

- 2, sometimes 3 needles/fascicle

- mostly straight needles

- needles 2.5-5 in long

- Sheath: 2.5-0.5in

- Fairly small cones (1-2in)

- Platy, furrowed bark

Pinus echinata: important info

Intermediate shape tolerance

moderately fire tolerant

Monocultures in the north

Highly desirable lumber , used for flooring

Pinus virginiana: ID Tips

- 2 needles

- Strongly twisted

- Short needles

- Very small sheath

- Small cones and tend to be very abundant

- Tend to be very scrubby, branchy trees

- platy, not deeply furrowed bark

Pinus virginiana: important info

Shade intolerant

Common pioneer

Fire intolerant

Shallow root system and persistent branching reduces its economic value

Trash tree

Christmas tree farms

Pulpwood

Pinus rigida: ID Tips

- Appalachian spp

- 3 needles/fascicle

- 3-5in long

- Distinctly twisted

- 0.3-0.5 in sheath

- Bark furrowed, rather irregular

- Cones are often about wide as long

Pinus rigida: important info

Usually found in sandy, rocky, xeric soils

Produces a lot of resin which was used as a sealant for ships to create turpentine

Not quality lumber, typically used of pallets and pulpwood

Pinus pungens: ID tips

- Appalachian spp

- Only found in high altitudes, very rocky, inaccessible areas

- Needles similar to Pinus virginiana but tend to be shorter

- Lots of cones

- Cones similar to Pinus rigida, but longer

Pinus pungens: important info

- regenerates well after fires

- very vulnerable to pine beetles

- Not used much for lumber, sometimes pulpwood

- More of an indicator species: high altitude, xeric soils

Tsuga canadensis: ID tips

- Short, rounded needles

- Underside of needles will have white stripes

- Needles tend to be flattened along a branch on a plane

- Bark is "normal"

Tsuga canadensis: Important info

Prefers mesic, cool locations

Extremely shade tolerant

Extremely slow growing

Appalachian mtns

Threatened with extinction by the hemlock wooly adelgid

Tsuga caroliniana: ID Tips

- Longer needles, and the needles ar much more randomly angled on branch

Tsuga caroliniana: important info

- Occurs on rocky hillsides

- Affected by wooly adelgid

- Produces a more substantial taproot, more common ornamental

Appalachian Mtns

Abies fraseri: ID TIps

- Occurs right along the North Carolina/TN Border

- High altitude spp

- Needles branch off in mostly an upward direction

- Needle underside has the white stripes

- Needle tips have a slight indentation

- Bark tends to be smooth and slightly platy

Picea rubens: ID Tips

- North spp

- High altitiudes

Fir/Spruce Decline

High elevation forests in Appalachia used to be dominated by Fraser fir and red spruce, but accidental introduction of balsam wooly adelgid resulted in a loss. No effect control has been found