Difference between revisions of "Alaskan tundra"

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(References)
(References)
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Billings, W. D. 1987. Carbon balance of Alaskan tundra and taiga ecosystems – past, present, and future. Quaternary Science Reviews 6:165-177.  
 
Billings, W. D. 1987. Carbon balance of Alaskan tundra and taiga ecosystems – past, present, and future. Quaternary Science Reviews 6:165-177.  
 +
 
Graglia, E., S. Jonasson, A. Michelsen, I. K. Schmidt, M. Havstrom, and L. Gustavsson. 2001. Effects of environmental perturbations on abundance of subarctic plants after three, seven and ten years of treatments. Ecography 24:5-12.  
 
Graglia, E., S. Jonasson, A. Michelsen, I. K. Schmidt, M. Havstrom, and L. Gustavsson. 2001. Effects of environmental perturbations on abundance of subarctic plants after three, seven and ten years of treatments. Ecography 24:5-12.  
 +
 
Heal, O. W., P. W. Flanagan, D. D. French, and S. F. MacLean, Jr. 1981. Decomposition and accumulation of organic matter in tundra. Tundra ecosystems: a comparative analysis.:587-633.  
 
Heal, O. W., P. W. Flanagan, D. D. French, and S. F. MacLean, Jr. 1981. Decomposition and accumulation of organic matter in tundra. Tundra ecosystems: a comparative analysis.:587-633.  
 +
 
Jonasson, S. and G. R. Shaver. 1999. Within-stand nutrient cycling in arctic and boreal wetlands. Ecology 80:2139-2150.  
 
Jonasson, S. and G. R. Shaver. 1999. Within-stand nutrient cycling in arctic and boreal wetlands. Ecology 80:2139-2150.  
 +
 
Remer, L. 2009. Temperature and Precipitation Graphs. NASA Earth Observatory. http://earthobservatory.nasa.gov/Experiments/Biome/graphs.php. November 12, 2009.
 
Remer, L. 2009. Temperature and Precipitation Graphs. NASA Earth Observatory. http://earthobservatory.nasa.gov/Experiments/Biome/graphs.php. November 12, 2009.
  

Revision as of 23:10, 11 April 2010

Introduction

Electron micrograph of the Ebola Zaire virus. This was the first photo ever taken of the virus, on 10/13/1976. By Dr. F.A. Murphy, now at U.C. Davis, then at the CDC.


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Legend/credit: Electron micrograph of the Ebola Zaire virus. This was the first photo ever taken of the virus, on 10/13/1976. By Dr. F.A. Murphy, now at U.C. Davis, then at the CDC.
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Even though the relative productivity across the tundra biome may be small, it still plays a large role in the carbon cycle. The tundra biome consists of a twenty percent of the Earth’s terrestrial surface (Kaplan 1996), and contains approximately 14% of the global carbon stored within soils (Billings 1987); making it a significant contributor to widespread global processes.

Physical Environment

Temperature

During the warmest summer months, the tundra biome typically has an average temperature nearly 10 degrees Celsius. During the coldest months, the average temperature is found to be around 30 degrees Celsius (Remer 2009).

Drought

The tundra also exhibits extremely low amounts of precipitation. The typical amount of precipitation received throughout the tundra biome is only approximately 15-20 cm a year (Remer 2009).

Nutrient Limitations

Because of lower temperatures and high levels of moisture (due mostly to permafrost), decomposition is limited. This leads to nutrients existing in a form that is not readily available to many organisms.

Heavy Winds

The tundra biome typically exhibits periods of high winds.

High Levels of Solar Radiation

The tundra biome has a relatively higher level of solar radiation compared to other biomes.

Biological interactions

Lower temperatures result in lower decomposition rates. Even though the tundra exhibits low annual precipitation, much of the ground remains saturated through much of the year. This water is typically frozen and inaccessible to plants. This high moisture content limits oxygen availability, which is needed to decompose the dead organic matter. Despite the low productivity of the tundra climate, organic matter accumulates because the decomposition of plant litter is limited by low soil temperatures and often wet, anaerobic conditions (Heal et al. 1981; Graglir et al. 2001). This leaves much of the nutrients that plants and microorganisms need for growth and development in a form that remains inaccessible to them (Jonasson and Shaver 1999).

Subsection 1

Subsection 1a

Subsection 1b

Subsection 2

Microbial processes

What microbial processes define this environment? Describe microbial processes that are important in this habitat, adding sections/subsections as needed. Look at other topics in MicrobeWiki. Are some of these processes already described? Create links where relevant.

Subsection 1

Subsection 1a

Subsection 1b

Subsection 2

Key Microorganisms

What kind of microbes do we typically find in this environment? Or associated with important processes in this environment? Describe key groups of microbes that we find in this environment, and any special adaptations they may have evolved to survive in this environment. Add sections/subsections as needed. Look at other microbe listings in MicrobeWiki. Are some of the groups of microbes from your environment already described? Create links to those pages. Specific microbial populations will be included in the next section.

Subsection 1

Subsection 1a

Subsection 1b

Subsection 2

Examples of organisms within the group

List examples of specific microbes that represent key groups or are associated with important processes found in this environment. Link to other MicrobeWiki pages where possible.

Current Research

Enter summaries of recent research here--at least three required

References

Billings, W. D. 1987. Carbon balance of Alaskan tundra and taiga ecosystems – past, present, and future. Quaternary Science Reviews 6:165-177.

Graglia, E., S. Jonasson, A. Michelsen, I. K. Schmidt, M. Havstrom, and L. Gustavsson. 2001. Effects of environmental perturbations on abundance of subarctic plants after three, seven and ten years of treatments. Ecography 24:5-12.

Heal, O. W., P. W. Flanagan, D. D. French, and S. F. MacLean, Jr. 1981. Decomposition and accumulation of organic matter in tundra. Tundra ecosystems: a comparative analysis.:587-633.

Jonasson, S. and G. R. Shaver. 1999. Within-stand nutrient cycling in arctic and boreal wetlands. Ecology 80:2139-2150.

Remer, L. 2009. Temperature and Precipitation Graphs. NASA Earth Observatory. http://earthobservatory.nasa.gov/Experiments/Biome/graphs.php. November 12, 2009.

Edited by Eric Johnston, a student of Angela Kent at the University of Illinois at Urbana-Champaign.