Arctic habitats: Difference between revisions

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===Primary Production===
===Primary Production===
Many thaw pools and sea ice contain either photosynthetic cynobacteria or green algae. These make up the lowest spot on the food chain and provide most of the energy to the arctic environment.


===Nitrogen Cycle===
===Nitrogen Cycle===

Revision as of 11:07, 6 April 2011

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location of Arctic circle

Introduction

The Arctic is any space that is within the arctic circle that lies around the 66 degree latitude line. The arctic region is mostly made up of water and floating ice and what land that is contained within the arctic circle is made up of coastlines and small islands. The average temperature is very low with very little rainfall per year and do to its position on earth the arctic circle can experience weeks without the sun rising or vise versa weeks where the sun never sets. Such strange conditions limits what organisms can survive in the arctic. Since all of the circle is above the tree line only small shrubs, mosses and lichens grow and larger fuana include artic hares, foxes and musk oxen. Within this environment many habitats exist that are home to varieties microbes. Sea ice, permafrost soils, and thaw ponds on the thick ice shelves are the three main habitats for microbial life in the arctic (Vincent et al. 2009). In the floating sea ice, algae thrive in the pore spaces in the ice and make up an essential part of the primary producers for the micro ecosystem contained on the sea ice. On land decomposers and nitrogen fixaters dominate the environment and allows what little vegetation that is there to survive.

Physical and Chemical environment

Temperature

The average temperature in the Arctic circle region in winter is -40 degrees F and temperatures as low as -90 degrees F have been recorded(Kenneth 2002).

Sea Ice

Microbes living inside the pore spaces of sea ice are greatly effected by temperature since pore space increase/decreases based on the temperature which can limit the photosynthetic activity of the inhabiting algae(Krembs and Deming 2011).

Nutrient Deficiencies

permafrost soils do not allow for nutrients to be able to be easily accessible do to the frost layer and since the temperature is below freezing for most the year decomposition rates are slowed down making nutrients obtained from decomposition to cycle slower(Ostroumov and Siegert 1996).

a band of algae found in an ice core of floating sea ice

Microbial communities

In Sea Ice

Filamentous photosynthetic algae is the main microbe that you will find in floating sea ice. These algae are very important to the local ecosystem of the arctic and provide 57 percent of the marine primary production that occurs(Krembs and Deming 2011). The algae usually inhabits the lower areas of the ice and my make chains that extend out into the sea water itself to obtain nutrients.

In permafrost soils

Many nitrogen fixing bacteria exist in permafrost soils due to the lack of nutrients that are available to them. Mycorrhizal fungi are also prevalent and form a symbiosis with many arctic plants allowing them the ability to obtain nitrogen in the poor soil(Hobbie et. al. 2009). If you want to read more on permafrost soil microbes a more detailed explanation can be found on the alaskan tundra page.

In Thaw Pools

Thaw pools have a wide variety of microbes inhabiting them. photosynthetic cynobacteria are present allowing for primary production to occur. Many nitrogen fixing archaea are present in thaw pools due to the pools freezing and thawing cycles throughout year leaving void of many nutrients found in southern unfrozen permanent lakes (Vincent et al. 2009).

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.

Decompostion

decomposition occurs slowly in the Arctic due to such low temperatures and anaerobic conditions in permafrost soils(Heal et al. 1981).

Primary Production

Many thaw pools and sea ice contain either photosynthetic cynobacteria or green algae. These make up the lowest spot on the food chain and provide most of the energy to the arctic environment.

Nitrogen Cycle

Current Research

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

References

Buckeridge K. M., Zufelt E., Chu H. Y. & Grogan P. 2010. Soil nitrogen cycling rates in low arctic shrub tundra are enhanced by litter feedbacks. Plant and Soil 330: 407-421.

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

Hobbie, J. E., E. A. Hobbie, H. Drossman, M. Conte, J. C. Weber, J. Shamhart, and M. Weinrobe. 2009. Mycorrhizal fungi supply nitrogen to host plants in Arctic tundra and boreal forests: 15N is the key signal. Canadian Journal of Microbiology 55:84-94.



Edited by <Adam Klein>, a student of Angela Kent at the University of Illinois at Urbana-Champaign.