BIOME
| REGION/
COUNTRY/
AUTHOR
| THRESHOLD
| EFFECTS
| OTHER FACTORS
|
Tidal coastal marsh
| NE USA/
Connecticut
Warren & Niering (1993)
| Relative sea-level rise: 10.0-12.5 cm/century
| Change in plant community structure. Replacement of Juncus geradi-Spartina patens complex
| Storms, sediment supply, human alterations
|
Coastal Mangroves
| Oceanic islands (Pacific,Indian Ocean, Atlantic)
Ellison and Stoddart (1991)
| Relative sea-level rise: 9-12 cm/century
| Mangroves not receiving significant levels of sediment input will be stressed, and at rates of sea-level rise greater than 12 cm/century, will begin to retreat
| Sediment supply
|
Coral reefs
| IndoPacific
Smith and Buddemeier (1993)
| Temperature: 2 day exposures of 34oC above the normal maximum. Or several weeks of temperatures 12oC above normal
| Can cause temperature induced bleaching. Mortality can be more than 90% at 4oC above normal maximum for even a few hours. Recovery is normal for bleaching induced by changes of less than 2oC
| Irradiance (visible and UV). Variable according to taxa. Related to longterm,, sitehistorical mean temperature of warmest month. ther human impacts
|
Marine
| East coast/USA
Ray, McCormickRay and Potter (1993),
| Water temperature: 1318oC
| Shad (Alosa sapidissima) track water temperatures within this range, and spawning peaks at 15oC. Temperature changes could reduce number of repeat spawners and reduce success
| Overfishing
|
Riverine wetlands
| Mississippi River, Illinois/USA
Janzen (1994)
| Mean July temperature:
Increase of 4oC
| Elimination of production of male offspring in a population of painted turtles (Chrysemys picta)
| |
Bogs
| Wales/Germany/
Ireland/
Netherlands
Schouten, Streefkerk and van der Molen (1992)
| Mean annual temperature:
11oC
| 11oC appears to be the limiting temperature for formation of ombrotrophic bogs in NW Europe
| Drought and moisture stress
|
Heathland
| South coast & Lancashire/UK
Gates (1992)
| Daily average sunshine hours:
Not less than 6.5 hours through May
| The 6.5 hour May isohel limits UK distribution of sand lizards
| |
Alpine
| Austrian and Swiss Alps
Grabherr (1994)
| Mean annual temperature:
Increase of 11.5oC. over the last 100 years
| Rates of upslope migration for Alpine plants is between 3 and 12 feet per decade,, but would need to be 30 feet to keep up with rate of warming
| Animal movements, CO2 concentrations
|
Alpine
| Yellowstone/
USA
Romme and Turner (1991)
| Summer drought stress:
Increases may lead to upward shift in lower timberline of 460m
| This scenario would reduce available habitat for whitebark pine in Yellowstone National Park by 90%. Whitebark pine is a key food source for grizzly bears and Clark's nutcrackers
| |
Tropical montane forest
| Luquillo/ Puerto Rico
0'Brien et al. (1992)
| Hurricane frequency:
Greater than once every nine years,
| Model experiments for the Tabonoco rainforest predict a trend towards early successional forest types, reduced biomass and declining populations of large commercial species including Dacroydes excelsa and Sloanea berteriana
| Increase in destructive potential of hurricanes, size, and possibly in multiple landfalls
|
Caves
| Indiana/USA
Richter et al. (1993)
| Mean winter temperature:
Cave roost sites 5oC higher than normal
| Increased winter body mass loss (42% more than control) during hibernation of Indiana bats (Myotis sodalis). High mortality. Warm caves may act as metapopulation sinks
| |
Temperate forest
| Northern Rocky Mountains/North America
| Mean fire return frequency:
40 years
| Rapid decline of Whitebark pine stands (over 200 years)
| (Using FIRESUM model)
|
Temperate forest
| Southern Appalachia/USA
Clinton,, Boring and Swank (1993)
| Drought length:
Severe, prolonged, drought from 1985 through 1988. Annual precipitation averaged 24% below normal, peak deficit was 31% below normal in 1986
| 66% of all canopy gaps surveyed in 1988 in a midelevational mixedoak forest were created after 1986. 44% of gaps were formed by scarlet oak (Quercus coccinea). Canopy turnover rate based on 1988 rates would be 8 times faster (66 years) than in 1985 (526 years)
| Scarlet oak decline can be linked to droughtinduced infection with the shoestring fungus, Armillaria mellea
|
Temperate zone
| UK
Dennis (1993)
| Ambient temperature:
Prolonged summer chilling (less than 4oC)
Ambient temperature above 33oC
| Prolonged chilling is lethal to the small white butterfly (Pieris Brassicae).
Eggs laid at ambient temperatures over 33oC are infertile
| |
Arctic
| Circumpolar
Sveinbjornsson (1992)
| Ambient temperature:
<Treeline is correlated with mean temperature of 10oC for the warmest month and a minimum of 30 days with a mean daily temperature above 10oC
| Warming would cause northward migration of tree line
| |
Arctic/Alpine
| Norway
Holten (1993)
| Winter temperature:
Increases of 4oC or more
| Warming threatens the group of Norwegian plant species limited by a January isotherm of 10oC or lower,, including Campanula uniflora,, Draba alpina,, Luzula arctica,, Poa arctica,, Ranunculus nivalis,, Stellaria crassipes, and Carex capitata
| |
Warm desert
| USA
Nobel (1985)
| Minimum winter temperature:
Below freezing
| Carnegia gigantica is restricted to regions where freezing temperatures do not exceed 24 hours. Four Opuntia spp. die at temperatures below 8oC. Only 3 of the 65 species of arborescent ceroid cacti occurring in the Sonoran desert are found north of the frost line |