characteristics of forest landscapes throughout the...

Characteristics of Forest Landscapes Throughout the World

Approaches to interpreting landscapes in a region

• Basic determinants of landscape pattern

• Geophysical template

• Biota

• disturbances

Physical template and Macroclimate (including gradients)

To what degree does the physical environment exert control over the landscape pattern?

Bedrock

Landforms and Topography and their effects on the operational environment

Hydrologic Regime

• Type, density, definition of drainage networks 

Topography as it effects ponding of water and air

BiotaNatural and Introduced

Introduced biota may result in homogenized landscapes

Disturbances• To what degree has the disturbance regime modified the landscapes reflection of the geophysical template?

Disturbances• What do we need to consider?

• Type• Frequency• Scale• Intensity

Human Disturbances• What do we need to consider?

• Conversion of landscape

Human Disturbances• What do we need to consider?

• Modification of landscape

Aspects of landscape form and function

• Focus on analyzing landscapes in terms of the basic quantitative and qualitative aspects of the ecosystem

• 1. Types (content) of patches• 2. Size, shape, and distribution of patches• 3. Matrix patch type• 4. Level of contrast among patches

Aspects of landscape form and function

• Focus on analyzing landscapes in terms of the basic quantitative and qualitative aspects of the ecosystem

• 5. Overall grain and extent of patchwork• 6. Edges – amount of edge, structure of edges, and level of contrast• 7. Overall connectivity and apparent pathways for movement of organisms

• 8. Importance of topography/landform as a determinant of pattern

Aspects of landscape form and function

• Focus on analyzing landscapes in terms of the basic quantitative and qualitative aspects of the ecosystem

• 5. Overall grain and extent of patchwork• 6. Edges – amount of edge, structure of edges, and level of contrast• 7. Overall connectivity and apparent pathways for movement of organisms

• 8. Importance of topography/landform as a determinant of pattern

Forest Landscapes Around the World• Pacific Northwest

• Distinctive macroclimate which is important in influencing the physical template, biota, and disturbance regimes

Forest Landscapes Around the World• Pacific Northwest

• Even subalpine regions are relatively warm but very snowy which has consequences for tree line patterns and parkland mosaics.

Forest Landscapes Around the World• Pacific Northwest

• Strong east/west gradient

• North/south trends

• East winds

• Unique features (Columbia Gorge, plateau regions)

Forest Landscapes Around the World• Pacific Northwest

• Biota• Dominated by evergreen conifer forests• Hardwoods are a relatively minor component of the forests

Forest Landscapes Around the World• Pacific Northwest

• Disturbance regimes

• Fire as the primary natural disturbance with contrasting fire regimes on the west and east sides of the Cascades

Forest Landscapes Around the World• Pacific Northwest

• Disturbance regimes

• Wind a primary natural disturbance on the west side particularly close to the coast

• 1921 storm• Columbus day storm

Forest Landscapes Around the World• Pacific Northwest

• Human disturbance

• Conversion of most of the low elevation forestland to intensively managed tree farms

• Conversion of low elevations into farmland mosaics

• Creation of urban areas 

• Dispersed patch clearcutting

• Alteration of fire regime

Moist Temperate Forests in other parts of the Northern Hemisphere

• eastern United States, western Europe, eastern and northeastern China, and Japan

Moist Temperate Forests in other parts of the Northern Hemisphere• Geophysical Template

• Precipitation is well distributed throughout the year

• Nutrient regime is often considered more important than moisture

• Highly varied geologies/topographies:

Moist Temperate Forests in other parts of the Northern Hemisphere

• Biota• Typically dominated by deciduous hardwood

• Very rich in tree diversity

• Conifers are generally a minor component of natural forests and they dominate in early succession

Moist Temperate Forests in other parts of the Northern HemisphereDisturbance regimes

‐small wind dominates but large episodic hurricanes, cyclones, thunderstorms DO occur

Moist Temperate Forests in other parts of the Northern HemisphereHuman Disturbance

Long period of human alteration to these landscapes

‐most of the NE is forest despite heavily populated urban areas

‐most of the NE is secondary forest that was cleared

Moist Temperate Forests of the Southern Hemisphere

• Australia• Mediterranean climate• Dominated by Eucalyptus species• Large long‐lived species• Infrequent stand replacement fire• Extensive plantations of radiata pine

Moist Temperate Forests of South America• Seasonal precipitation except in Tierra del Fuego • Generally hardwood dominated: genus = Nothofagus spp.• Wind and geomorphic processes as disturbance regime• Extensive creation of plantations (Douglas‐fir, radiate pine, ponderosa pine)

They do have unique conifers though!

Xeric Forests• Montane forests of more arid regions• Often mosaics of forest and grassland• Controlled by topography and nutrient limitations• Fire (all severity) and insects are dominant disturbance regime

Woodlands• Dry/hot environments creating a partially forested area• Strong patterning within the woodlands related to riparian areas and soil chemistry

• Fire is dominant• Grazing and fire suppression

Subalpine forests

Deserts‐high degree of variability – American deserts are considered to be “too” wet!‐Macroclimate is very important‐physical and chemical processes dominate, much less control by vegetation‐strongly differentiated riparian zones

Deserts