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Unformatted text preview: surface of the globe Boreal forest region dominates terrestrial interactions with the Earth's climate north of 50N Global warming expected to be most pronounced in the high latitudes of the northern hemisphere Boreal forests Account for ~20% of the world's reactive soil carbon pool Has been estimated that understory could contribute more than 1/3 of forest photosynthesis Predominant understory type are mosses which insulate the soil (reduce soil temp.), absorb atmospheric nutrients and decompose very slowly Climate warming likely to reduce productivity of mosses Schuur and Trumbore Second paper detailed current research to determine rates of respiration of various components of the boreal forest ecosystem Difference between net ecosystem uptake of C (photosynthesis) and release of C (respiration) = NEE (determines if ecosystem is a source or sink) Difficulty in separating components of an ecosystem and determining rates of respiration This paper looks at separating plant and microbial respiration from total soil respiration Specifically difference in autotrophic and heterotrophic respiration Methodology and Results Different sources (microbes vs. plant roots) are expected to respire C with differing isotopic signatures Measurements should show differing concentrations of 14C as a result of utilizing different stores of carbon. Residence time is largest factor determining 14C concentration in carbon pool....
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- Spring '08