Dendrology Final Lecture Exam

Stump Treatment

Applying herbicide to a freshly cut stump

Injection

Applying herbicide beneath the bark

Hack & Squirt (Cup Girdle)

Spacing cuts on the stem and applying herbicide

Basal Spray

Spraying bark or lower stem on trees < 3in in diameter

Foliar Spray

Applying herbicide to the leaves

Girdle

Cutting a band of bark around the tree and applying herbicide

Bottomland Forest

Occur adjacent to rivers and streams in the Southeastern US

Silviculture

Controlling the growth of forest trees

Stocking

Like a fridge

1) overstocked

2) fully stocked

3) understocked

Soil Mottling

Water is removed very slowly and the soil is saturated during 3 or more months of the year

2, 4-D (2, 4-Dichlorophenoxyacetic acid)

general use herbicide

selective and systematic used for annual and perennial broadleaf plants

• not effective on most grasses

growth regulator

mobile in soils, especially sandy soils (10 day half life)

Picloram

restricted use herbicide

selective and systematic used for annual and perennial broadleaf plants and woody plants

• not effective on most grasses

growth regulator

soil active (high mobility) (90 day half life)

• wait up to 6 months for pine planting

Commercial name: Tordon

Triclopyr

general use herbicide

nonselective (mostly) and systematic used for annual and perennial broadleaf plants and woody plants

• not effective on grasses

• good for waxy leaf species

growth regulator

high soil mobility (30 day half life)

Commercial name: Garlon

Hexazinone

general use herbicide

nonselective (mostly) and systematic used for annual and perennial grasses, forbs, and woody plants

• most effective on oaks (and sweetgum)

• little effect on wiregrass or blueberry

photosynthesis inhibitor

absorbed in clay and organic matter (90 day half life)

Brockway et al.

• assessed hexazinone application on a turkey oak dominated landscape in South Central Florida

• the objective was to assess methods of longleaf pine and wiregrass community restoration

• results: 83-93% oak mortality (overstory and understory)

Why is Hexazinone liked?

It has a low toxicity, it degrades faster, and it bioaccumulates less

Glyphosate

general use pesticide

nonselective and systematic used for woody plants and annual and perennial broadleaves and grasses

amino acid inhibitor

tightly bound to soil (47 day half life)

Commercial name: Accord, Rodeo, Roundup

Imazapyr

general use herbicide

nonselective (except many conifers) and systematic for woody plants, annual and perennial broadleaves and grasses

amino acid inhibitor

soil active (125-142 day half life)

Commercial name: Arsenal, Chopper

How did farmers control the invasion of Cogongrass?

• the Cogongrass was being transported by sticking to farming equipment

• Arsenal (Imazapyr) was applied

• 8-10 months later there was a successful longleaf pine establishment and a highly desirable forb community

LD50

• can compare relative toxicities among pesticides

• the lower the dose, the more toxic the pesticide

1 (most toxic)

6 (least toxic)

How do herbicides improve wildlife habitat?

1) spatial and temporal arrangement of vegetation (alter plant structure and composition, snag locations, forest openings)

2) creating early successional stages

3) restoration of degraded communities

Herbicides vs Fire

Herbicides: used to mimic ecological processes; can be important after long periods of fire suppression

Fire: an ecological process; not as controlled

4 Herbicide application methods

Girdle

Basal Spray

Cup Girdle (Hack & Squirt)

Foliar Spray

5 Habitat Management Tools

Cow

Plow

Ax

Fire

(Gun)

8 Benefits of Bottomlands

1) prevent downstream flooding

2) filter pollutants (urban runoff)

3) curb soil erosion

4) store excess water

5) provide wildlife habitat

6) sequester and store carbon

7) provide timber products

8) recreational opportunities

3 stages of silviculture

Establishment (plant)

Intermediate Operations (tend)

Final Harvest (harvest)

4 challenges of bottomlands

flooding and poor drainage (lack of O2 is bad for roots & microbial activity)

high water table

soil compaction (heaviness of water packs in soil)

diverse soil properties (deposition)

What percentage of the soil has to have a gray color for gleyed matrix to be met?

50%

Which 3 oak species can tolerate 50% gleyed matrix at a 9in depth

Nutall, pin, and overcup

Biggest challenge due to disturbance

disturbance to the forest allows increased sunlight and exposed soil which allows light-seeded species to invade

Preferred hardwood (oak) regeneration comes via:

encroachment after harvest (poor)

advanced reproduction prior to harvest

coppicing: cutting down a tree to a stump

planting (use large seedlings, recent successes)

The most important reproduction factor for bottomland oaks is

the amount of pre-harvest advanced growth and its size

Decision tool for harvest

if advanced seedlings are >4ft tall and abundant = harvest

if less, conduct midstory release, then harvest

if absent, underplant w/ midstory release

well timed harvest to coincide with year of good acorn crop

What are the two reasons that timber harvesting occurs?

to thin immature stands

to regenerate mature stands

Methods for precommercial thinning (2)

double girdle

hack & squirt

Cutting stock

ready for harvest

Preferred growing stock

good investment potential

1. desired species

2. good form

3. good grade

Reserve growing stock

lower value healthy trees left to maintain stock level

Cull stock

trees not meeting objectives; not desirable

Which trees should be selected for harvest?

harvest all cutting and (most) cull stock

harvest very few preferred growing stock

reserve growing stock may be harvested or left to grow

How does herbicide aid in creating dead trees?

it causes them to decay more quickly

What’s one reason why herbicides are useful?

they have the ability to treat individual stems

Palmetto stands

Longer intervals between burning allow them to sprout up in these stands

They need fire and herbicide to keep them from resprouting

Invasive ferns and Chestnut Sided Warbler

Invasive ferns shade out everything, so herbicide could be used to knock them back. Chestnut sided warblers do well in early successional areas