Characteristics of Forest Landscapes Throughout the World

Transcription

1 Characteristics of Forest Landscapes Throughout the World

2 Approaches to interpreting landscapes in a region Basic determinants of landscape pattern Geophysical template Biota disturbances

3 Physical template and Macroclimate (including gradients) To what degree does the physical environment exert control over the landscape pattern?

4 Bedrock

5 Landforms and Topography and their effects on the operational environment

6 Hydrologic Regime Type, density, definition of drainage networks

7 Topography as it effects ponding of water and air

8 Biota Natural and Introduced

9 Introduced biota may result in homogenized landscapes

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

11 Disturbances What do we need to consider? Type Frequency Scale Intensity

12 Human Disturbances What do we need to consider? Conversion of landscape

13 Human Disturbances What do we need to consider? Modification of landscape

14 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

15 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

16 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

17 Forest Landscapes Around the World Pacific Northwest Distinctive macroclimate which is important in influencing the physical template, biota, and disturbance regimes

18 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.

19 Forest Landscapes Around the World Pacific Northwest Strong east/west gradient North/south trends East winds Unique features (Columbia Gorge, plateau regions)

20 Forest Landscapes Around the World Pacific Northwest Biota Dominated by evergreen conifer forests Hardwoods are a relatively minor component of the forests

21 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

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23 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

24 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

25 Moist Temperate Forests in other parts of the Northern Hemisphere eastern United States, western Europe, eastern and northeastern China, and Japan

26 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:

27 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

28 Moist Temperate Forests in other parts of the Northern Hemisphere Disturbance regimes small wind dominates but large episodic hurricanes, cyclones, thunderstorms DO occur

29 Moist Temperate Forests in other parts of the Northern Hemisphere Human 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

30 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

31 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)

32 They do have unique conifers though!

33 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

34 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

35 Subalpine forests

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37 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

38 Deserts