Legacies of Management

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Legacies of Management Land use

• Homogenized stands and landscapes
• Loss of OG
• Type Conversions
• Fragmentation/ Permeation (roads etc)
• Altered disturbance regimes

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Forest cover in 56 km2 pixels Red low (lt.4)
Green high (gt.6)
Fragmentation is pervasive and extensive
where forests do occur. Locations with
intermediate amounts of forest may represent
landscapes near critical thresholds of
fragmentation. Riitters et al 2002
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Legacies of Past Landuse

• New England Still recovering from early logging
  and clearing for farms. Long-lived,
  late-successional tree species replaced by
  shorter-lived, early successional ones. Result
  homogenized landscape
• SE US. Extensive conversion of longleaf pine to
  loblolly slash pine plantations. gtgt
  vulnerability to bark beetles and some pathogens
• Lake States. a distinct and rapid trajectory of
  vegetation change toward historically
  unprecedented and simplified conditions. lower
  species diversity, functional diversity, and
  structural complexity compared to
  pre-Euro-American forests. (Schulte et al in
  press)
• West. In PNW, 85 conversion of mesic and dry
  OG to plantations. In dry forests throughout,
  fuels buildup due to fire suppression, grazing,
  high-grading. On both counts, gtgt landscape
  vulnerability to crown fire

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Many eruptive herbivores, nearly everywhere in
the world, are linked to monocultures or
near-monoculturesCoyle et al. 2005
One Consequence of Homogenization The Lunch
Table Effect
H. annosum, A. mellea, and H. weirii are
important diseases only because of modern
forestry practice Mannion 1981
Why? Bottom up Concentration of resources
Top-down Weakening the natural enemy complex
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Schowalter in press
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Swiss needle cast. Epidemic in Oregon Coast Range
Fusiform rust. Epidemic in SE Coastal Plain
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Susceptibility to Crown Fires
Plantations
OG
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It is abundantly evident that forest structure
and fuel changes have occurred in some extensive
ecosystem types following disruption of fire
regimes, especially in forests that previously
sustained frequent, low severity surface fires
1909
Swetnam 2006
1949
1990
Biondi, F. 1999. Ecol. Appl. 9 216-227
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Land clearing fires Borneo Source NASA
Aftermath of Borneo fires
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What to Do

• Build/restore appropriate heterogeneity species
  composition (protecting habitat, streams, soils)
• Protect and buffer large, intact blocks
• Protect all forests (forestry instead of
  developmente.g. TNC Hawaii)
• Restore connectivity