Conservation planning in a changing world
233
Table 9.2 Review of the published studies that report estimates of community similarity change between two time
periods in the context of biotic (taxonomic) homogenization. Change in similarity refers to mean pair - wise difference
between historical and extant community similarity across all sites, unless otherwise noted. Positive values indicate
homogenization and negative values indicate differentiation. Note that this table only includes studies for which
estimates of per cent change in community composition were reported.
Taxonomic group
Location
Spatial extent
Unit
Change in
similarity
Reference
Freshwater fi shes
Australia
Country - wide
Basin divisions
3.0%
Olden et al. (2008)
3
North - eastern
coastal
Coastal watersheds
− 1.4%
Canada
Country - wide
Provinces/territories
1.3%
Taylor (2004)
1
British Columbia
Aquatic ecoregions
− 3.5%
Europe
Country - wide
Major basins
2.2%
Leprieur et al. (2008)
1
Iberian Peninsula
and France
Major basins
17.1%
Clavero & Garc í a - Berthou
(2006)
1
USA
Country - wide
States
7.2%
Rahel (2000)
1
California
Zoogeographic
provinces
20.3%
Marchetti et al. (2001)
1
Watersheds
− 10.7%
South Dakota
Geomorphic provinces
8.0%
Hoagstrom et al. (2007)
1
Watersheds
2.4%
Minnesota
Lakes
9.0%
Radomski & Goeman (1995)
1
Kansas
Streams
− 0.2%
Eberle & Channell (2006)
1
Amphibians and reptiles
USA
Florida
Select counties
− 0.8%
Smith (2006)
1
Terrestrial plants
Canada & USA
Country - wide
States and provinces
1.2%
Qian & Ricklefs (2006)
1
Canada & USA
Select regions
States and provinces
− 0.6%
Rejm á nek (2000)
1
Chile
Country - wide
Administrative regions
0.3%
Castro & Jaksic (2008)
1,7
South - eastern
Pacifi c
Islands
2.0%
Castro et al. (2007)
1
Europe
Germany
Grid cells (130 km
2
)
3.9%
K ü hn & Klotz (2006)
5
Europe & USA
Select regions
Forest stands
3.9%
Vellend et al. (2006)
6
Great Britain
Country - wide
Grid cells (1 km
2
)
− 1.0%
Smart et al. (2006)
1
United States
Select regions
Parks and local areas
0.8%
McKinney (2004)
1
Countries
0.5%
Schwartz et al. (2006)
3
Wisconsin
Forest stands
2.6%
Rooney et al. (2004)
2
233
Table 9.2 Review of the published studies that report estimates of community similarity change between two time
periods in the context of biotic (taxonomic) homogenization. Change in similarity refers to mean pair - wise difference
between historical and extant community similarity across all sites, unless otherwise noted. Positive values indicate
homogenization and negative values indicate differentiation. Note that this table only includes studies for which
estimates of per cent change in community composition were reported.
Taxonomic group
Location
Spatial extent
Unit
Change in
similarity
Reference
Freshwater fi shes
Australia
Country - wide
Basin divisions
3.0%
Olden et al. (2008)
3
North - eastern
coastal
Coastal watersheds
− 1.4%
Canada
Country - wide
Provinces/territories
1.3%
Taylor (2004)
1
British Columbia
Aquatic ecoregions
− 3.5%
Europe
Country - wide
Major basins
2.2%
Leprieur et al. (2008)
1
Iberian Peninsula
and France
Major basins
17.1%
Clavero & Garc í a - Berthou
(2006)
1
USA
Country - wide
States
7.2%
Rahel (2000)
1
California
Zoogeographic
provinces
20.3%
Marchetti et al. (2001)
1
Watersheds
− 10.7%
South Dakota
Geomorphic provinces
8.0%
Hoagstrom et al. (2007)
1
Watersheds
2.4%
Minnesota
Lakes
9.0%
Radomski & Goeman (1995)
1
Kansas
Streams
− 0.2%
Eberle & Channell (2006)
1
Amphibians and reptiles
USA
Florida
Select counties
− 0.8%
Smith (2006)
1
Terrestrial plants
Canada & USA
Country - wide
States and provinces
1.2%
Qian & Ricklefs (2006)
1
Canada & USA
Select regions
States and provinces
− 0.6%
Rejm á nek (2000)
1
Chile
Country - wide
Administrative regions
0.3%
Castro & Jaksic (2008)
1,7
South - eastern
Pacifi c
Islands
2.0%
Castro et al. (2007)
1
Europe
Germany
Grid cells (130 km
2
)
3.9%
K ü hn & Klotz (2006)
5
Europe & USA
Select regions
Forest stands
3.9%
Vellend et al. (2006)
6
Great Britain
Country - wide
Grid cells (1 km
2
)
− 1.0%
Smart et al. (2006)
1
United States
Select regions
Parks and local areas
0.8%
McKinney (2004)
1
Countries
0.5%
Schwartz et al. (2006)
3
Wisconsin
Forest stands
2.6%
Rooney et al. (2004)
2