{"id":35,"date":"2017-11-08T16:57:35","date_gmt":"2017-11-08T20:57:35","guid":{"rendered":"http:\/\/sites.nd.edu\/rocha-laboratory\/?page_id=35"},"modified":"2017-11-10T14:28:50","modified_gmt":"2017-11-10T18:28:50","slug":"35-2","status":"publish","type":"page","link":"https:\/\/sites.nd.edu\/rocha-laboratory\/research\/35-2\/","title":{"rendered":"Understanding controls on photosynthesis and ecosystem respiration in tundra ecosystems"},"content":{"rendered":"<p><strong>Understanding controls on photosynthesis and ecosystem respir<\/strong><strong>ation in tundra ecosystems<\/strong><\/p>\n<p>The ability of arctic ecosystems to sequester carbon depends on the balance between carbon gain through photosynthesis and carbon losses through autotrophic and heteorotrophic respiration. All of these processes respond to environmental and biological variability, but understanding the controls on each individual process has been hampered by our ability to measure the component fluxes.<\/p>\n<p>The eddy covariance technique measures the net flux of CO<sub>2<\/sub>, which is the difference between ecosystem respiration and canopy photosynthesis. Partitioning the net flux of CO<sub>2<\/sub>\u00a0(NEE) into photosynthesis and respiration requires nighttime measurements of NEE, when photosynthesis is zero and respiration dominates the flux, to be extrapolated to daytime periods. This is difficult in the arctic because of the constant daylight during the growing season. In this project, we have built automated chambers to measure the net exchange and its components in the same area over the course of a day. \u00a0The chambers seal the system and allow CO<sub>2<\/sub>\u00a0 exchange to be measured by the increase or decrease in CO<sub>2<\/sub>\u00a0 concentrations in the air. \u00a0NEE is determined by the clear chamber, the dark chamber determines ecosystem respiration, and the difference between these two measures is canopy photosynthesis. \u00a0These measurements will be coupled with existing eddy flux databases in the arctic and mathematical modeling to improve our understanding of the biological and environmental controls on NEE in the arctic.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-36 aligncenter\" src=\"http:\/\/sites.nd.edu\/rocha-laboratory\/files\/2017\/11\/photo-10-1024x768-300x225.jpg\" alt=\"\" width=\"574\" height=\"431\" srcset=\"https:\/\/sites.nd.edu\/rocha-laboratory\/files\/2017\/11\/photo-10-1024x768-300x225.jpg 300w, https:\/\/sites.nd.edu\/rocha-laboratory\/files\/2017\/11\/photo-10-1024x768-768x576.jpg 768w, https:\/\/sites.nd.edu\/rocha-laboratory\/files\/2017\/11\/photo-10-1024x768.jpg 1024w\" sizes=\"auto, (max-width: 574px) 100vw, 574px\" \/><\/p>\n<p style=\"text-align: center\">\u00a0Automated NEE Partitioning Chamber System<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Understanding controls on photosynthesis and ecosystem respiration in tundra ecosystems The ability of arctic ecosystems to sequester carbon depends on the balance between carbon gain through photosynthesis and carbon losses through autotrophic and heteorotrophic respiration. All of these processes respond &hellip; <a href=\"https:\/\/sites.nd.edu\/rocha-laboratory\/research\/35-2\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":2817,"featured_media":0,"parent":9,"menu_order":3,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-35","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sites.nd.edu\/rocha-laboratory\/wp-json\/wp\/v2\/pages\/35","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.nd.edu\/rocha-laboratory\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sites.nd.edu\/rocha-laboratory\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sites.nd.edu\/rocha-laboratory\/wp-json\/wp\/v2\/users\/2817"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.nd.edu\/rocha-laboratory\/wp-json\/wp\/v2\/comments?post=35"}],"version-history":[{"count":7,"href":"https:\/\/sites.nd.edu\/rocha-laboratory\/wp-json\/wp\/v2\/pages\/35\/revisions"}],"predecessor-version":[{"id":172,"href":"https:\/\/sites.nd.edu\/rocha-laboratory\/wp-json\/wp\/v2\/pages\/35\/revisions\/172"}],"up":[{"embeddable":true,"href":"https:\/\/sites.nd.edu\/rocha-laboratory\/wp-json\/wp\/v2\/pages\/9"}],"wp:attachment":[{"href":"https:\/\/sites.nd.edu\/rocha-laboratory\/wp-json\/wp\/v2\/media?parent=35"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}