FW4421 Climate Change And Forests Week 2

Leading edge

Area that is cooler and/or wetter, usually northerly or higher elevation

Trailing edge

are of range that is warmer and/or drier, usually southerly or lower elevation

Productivity

• Positively correlated with max tree height

• Correlated w/ amount of carbon storage

Peaks of tree height in the US

West coast, Southeast

Average projected biomass in NA Forests

100 Mg/Ha or 45 tons/acre

Ownership trends of NA forests

More federal ownership in the West, more family ownership in the East; higher corporate ownership in high value/high productivity areas

Orographic effect

Moist air masses undergo it producing abundant precipitation over mountains and causing rain shadows

E Lucy Braun

Wrote Deciduous Forests of Eastern North America; IDed first accurate regional forest types

Tension Zone

• Hemlock-white-pine-northern-hardwoods and Southerly forest types, named by John Curtis in Wisconsin

• Goes at a diagonal, meaning fire/precip are important as well as temp

Succession

Gradual replacement of one community of plants by another over long time periods

Succession Process

1. Bare Rock

2. Mosses, Grasses

3. Perenials

4. Woody Pioneers

5. Fast Growing Trees

6. Climax Forest

Types of Distrubences

Stand-replacing, gap creation

Aggregation

Fastest growing trees aggregate resources, excluding other trees

Stages of Disturbence

1. Clear Cut

2. Stand initiation (reorganization)

3. Stem exclusion (aggregation)

4. Understory initiation (transition)

5. Old growth (steady state)

Forest biomass trend since early 1900s

Increasing

Chronosequence

Sampling forests that differ in age to project temporal dynamics; substituting space for time

Big assumption of chronosequencing

Soil conditions and site productivity are comparable across forests

Exceptional forests

Can store immense amounts of biomass, up to 400 Mg/Hectare

Impact of forest industry

Keeps forests young and minimizes the amount of dead biomass, impacting carbon storage and biodiversity

1 mg/ha

0.446 tons/acre

John Curtis

Wrote “The Vegetation of Wisconsin” which classified the temperate to boreal ecotone as the “tension zone”

Use of Palynology in Upper Great Lakes

Warming temperatures will cause northward and eastward shifts in vegetation because warming causes greater drought impacts at the westward trailing edge

Biomass in numbers

avg: 100 mg/ha

peak in NA: 200-400 mg/ha

peak in the world: 2000-4000 mg/ha

Dead wood in terms of biomass

Much of biomass is from dead wood, amount of dead wood is less in forests managed for timber

Soils in terms of biomass

Soils store more carbon than biomass, but it takes much longer to accrue

Productivity changes based on

Site quality, ie soil, climate, and topography properites