Wetlands Final

silviculture

techniques that manipulate stand establishment, composition, and growth in order to achieve management objectives

based on management goals

management objectives of silviculture

recreation

timber production

watershed protection

wildlife management

3 main phases of silviculture

regeneration

tending

harvest

silvicultural systems should be

biologically sound

environmentally feasible

socially acceptable

harvest operations are often used as a silvicultural tool

seedbed preparation

climate of forest floor

advanced regeneration

site preparation

control of non-desirable woody species

removal of competition

Economic goals of timber harvesting

timber values

land values

silvicultural goals of timber harvesting

regeneration

stand improvements for wildlife, residual stand value, species manipulations, salvage

water/snow yields

2 reasons timber harvests are conducted

to attain an economic goal

to attain a silvicultural goal

common silvicultural systems are based on these

age structure

source of regeneration (natural or artificial)

Even aged systems

clearcut

shelterwood

seed tree

Uneven-aged systems

single tree selection

group selection

Two aged systems

deferment harvest

leave tree

clearcut advantages

good for shade intolerant species

control of spacing/stocking

logistics

minimal effort

may use genetically improved seedlings

more uniform products

some wildlife prefer this type of stand

clearcut disadvantages

appearance/perception

some wildlife don’t prefer

water table/runoff

longer period between economic returns

clearcut with natural regeneration

most commonly used technique for bottomland hardwoods

can work well for sites having good seed or seedling years or for coppicing species

sources of regeneration

seed

seedling

stump sprouts

root sprouts

layering

clearcut with planting

good system for many conifers and some hard woods

expensive

clearcut with planting considerations

traditional harvest equipment works well

site preparation is facilitated by less slash

on some sites you know harvest traffic effects will be mitigated by site preparation

clearcut with natural regeneration considerations

seed bed

advanced regeneration

residual basal area

3 things to send when applying for a permit

aerial photo

soil map

topographic map of watershed

plan view

looking down

profile view

cross section

bearing of stream crossing

90 degrees

pebble counts measure

energy

disturbances

habitat

manning shizay equation

measures water yield

wetted perimeter

surface of the channel bottom and sides that touch the water

cross sectional area

width times depth

Rosgen requirements

single or double channel

width to depth ratio

entrenchment ratio

bed material

sinuosity

Pfankuch rating

-upper bank

-lower bank

-stream bottom

Lower number is better

as you go up the stream at moon hollow

rosgen ratings increase

phankuck ratings increase

stream slope decreases

discharge decreases

5 conditions for valid silvicultural operations

satisfy landowners goal

biologically feasible

economically feasible

sustainable

logistics

pine stand regeneration possibilities

clearcut with planting

seed tree

shelterwood

group selection

shelterwood

requires marking by skilled personnel

requires repeat visits in cycles

need to consider access during entire regeneration phase

shelterwood advantages

can work well with intermediate shade tolerant species

doesn’t look like a clearcut

maintain mast production

maintain seed source until regeneration is obtained

can be used if high water tables are an issue

shelterwood disadvantages

logistics

epicormic branching

repeated stand entries

may shift toward shade tolerant species

cost more per unit volume of wood produced

seed tree

can be used successfully for light seeded species

need to consider scarification of seed bed and protection of seed trees

seed tree advantages

inexpensive

can work well for light seeded species

seed tree disadvantages

over/under stocking

wind/lightning damage

repeated entry

must ensure good seed year and soil scarification

deferment cut/leave tree advantages

may be used to enhance value of target trees for next rotation

visual

maintain mast production

deferment cut/leave tree disadvantages

must protect residual trees

risking some of most valuable trees

reduced growth of younger trees near leave trees

single tree selection

not as well suited for species of intermediate or shade intolerant

can work for shade tolerant

very hard to mark and harvest

equipment size may be limited

may need to consider equipment for very large trees

must protect residual stems

tends to traffic higher proportion of site than even aged systems

single tree selection advantages

looks good visually

some wildlife prefer

can work for limited number of species

single tree selection disadvantages

does not work well for most commercial species

very challenging to implement

repeated stand entries

high grading

selecting the very best trees and leaving the rest

maximizes current economic return

maximizes short term profits not long term

cutting trees above a “‘diameter limit”

residual harvest

not a silvicultural system

land conversion

leads to deforestation

thinning

designed to reduce stocking in order to redistribute growth on residual trees

can be used to provide an earlier economic return

low thin

removes trees from lower crown classes

results in salvage of mortality but provides little increased growth of residuals

high thin

removes trees from upper crown classes to favor growth of better upper crown class trees

selection thinning

removes vigorous overstory trees to favor understory

limited applications

free thin

combination of low and high thinning

release

freeing young stand of desirable trees from competition of undesirable trees that threaten to suppress them

cleaning

removal of undesirable species or individuals of same age that threaten to overtop desirable species

liberation

removal of undesirable species or individuals of older age that overtop desirable species

types of release

cleaning

liberation

weeding

types of thinning

low thin

high thin

selection thin

free thin

mechanical thin

precommercial thin

timber stand improvement

combination of thinning and improvement cuttings

improvements

cuttings made in stand past sapling stage

designed to improve future stand conditions and growth by removal of inferior species, poorly formed trees, diseased or injured trees

salvage harvest

commercial harvests following disturbances such as wildfires or hurricanes

sanitation harvests

used to prevent spread of some pathogen such as beetles

3 main purposes of site preparation

enhancing microsite

reducing slash

controlling competition

3 major types of site preparation

mechanical

chemical

prescribed fire

mechanical site preparation

shearing

chopping

disking

bedding

ripping

chemical site preparation

herbicides

aerial and ground

basal, overtop, band

prescribed fire site preparation

slash removal

competition control

fertiliziation

Nitrogen and Phosphorous are often added during site preparation

harvesting site preparation

better utilization minimizes slash

managing for high value timber

shelterwood

clearcut

group selection

deferment

managing for pulpwood in plantation

clearcut with planting

landowner wants to manage timber for hunting

deferment

clearcut with planting

shelterwood

seed tree

manage for riparian buffer

site preparation

species selection for the site

manage for establishing wildlife habitat

can’t just walk away

oak establishment

manage for historic purposes

shelterwood

thin

manage for waterfowl habitat

green tree reservoir

have to make sure not to overflood trees

manage for bird sanctuary and wilderness

patch clear cut

group selection

clearcut types

standard

patch

strip

manage for recreation and wilderness

thinning

group selection

fire

PDF

prior drained farmland

manage for red cockaded woodpeckers

people climb into trees to make cavities for them

burning

thinning

manage for water quality and timber value

leave SMZ’s

minimize roads and skid trails

manage for watershed protection and timber

group selection

SMZ

helicopter to minimize roads and skid trails

wench assist machine

manage to increase snowpack and water yeild

linear openings in the stand

strip clearcut

manage to ameliorate site disturbance (wet area)

fill if you have a permit

wait for it to dry

bedding

mechanical site preparation

manage to create a wetland as a mitigation for wetland destruction

go to low topographic position

wet flats

widespread through coastal plain

types of wet flats

wet mineral flats

flatwoods

pine savannah

need to account for when managing wet flats

access

stream crossings

planning BMP’s

harvests

site preparation

chemical, fertilizer, fire

thinnings

wet flat hydrology

have increased water and runoff

have implications for regeneration, water yield, water quality

churning

tilling

interrupts subsurface water flow

churning affects

wet-liquid limit

aeration/drainage

soil strength

site hydroperiod

aeration/gas exchange

soil chemistry

soil volume

tree growth

species

compaction affects

moist-plastic limit

soil strength

root penetration

soil volume

tree growth

deep rutting

decreased microporosity and soil water movement

site became wetter

wide tires

can be used to minimize site impact

bedding and/or disking on growth-soils-hydrology

were affected more on better drained sites than on poorly drained sites

bedding with fertilizer

only treatment for skid trails that had similar individual tree volume

recommendations for sandy sites for siliviculture

initial survival is key to long term success

bedding and disking/bedding doubled stand biomass

skid trails recovered but initial effects of rutted skid trails were still evident

reduce are and severity of skid trails

use planning/harvest equipment/slash/site prep

bedding and disking/bedding

increase stand volumes

increase early survival of trees

trees on skid trails

have less individual tree biomass than off skid trails

skid trail disturbances over time

soil health recovered over time

(bulk density, Ksat, macroporosity)

wet harvests vs dry harvests

initially wet weather harvest had increased bulk density, hydraulic conductivity, and macroporosity

these changes went away over time

microporosity

holds water against force of gravity and keeps it in the site