{"@type": "dcat:Dataset", "accessLevel": "public", "bureauCode": ["005:18"], "contactPoint": {"fn": "Hamerlynck, Erik P.", "hasEmail": "mailto:erik.hamerlynck@usda.gov"}, "description": "<p dir=\"ltr\">These data were collected in a field study at the USDA-ARS Northern Great Basin Experimental Range, Oregon, USA, aimed at assessing the photochemical efficiency and ability of florets and flag leaves of two important sagebrush steppe bunchgrasses -- Crested wheatgrass (<a href=\"https://www.google.com/search?q=Agropyron+cristatum&ved=2ahUKEwimwYDi4baTAxWQ5skDHYH4EXUQgK4QegQIARAD\" target=\"_blank\"><i>Agropyron cristatum</i></a>), and Bluebunch wheatgrass (<a href=\"https://www.google.com/search?q=Pseudoroegneria+spicata&sca_esv=539c00fc8c0dc83a&ei=jZXBaerNBb7hp84PipK1cA&biw=1536&bih=825&ved=2ahUKEwj84NWL4raTAxX_4MkDHTvyIqEQgK4QegQIARAD&uact=5&oq=bluebunch+wheatgrass&gs_lp=Egxnd3Mtd2l6LXNlcnAiFGJsdWVidW5jaCB3aGVhdGdyYXNzMgUQLhiABDIKEAAYgAQYQxiKBTIFEAAYgAQyBRAAGIAEMgYQABgWGB4yBhAAGBYYHjIGEAAYFhgeMgYQABgWGB4yBhAAGBYYHjIGEAAYFhgeMhQQLhiABBiXBRjcBBjeBBjfBNgBAUipMVAAWABwAHgBkAEAmAFqoAFqqgEDMC4xuAEDyAEA-AEC-AEBmAIDoAKyMpgDALoGBggBEAEYFJIHCTAuMS44LTEuMaAHhw2yBwMwLjG4B3LCBwMyLTPIBxGACAA&sclient=gws-wiz-serp\" target=\"_blank\"><i>Pseudoroegneria spicata</i></a>) -- to dissipate excess light energy over the 2025 plant reproductive period. Chlorophyll fluorescence measurements were made on flag leaves and distal and basal florets at night to determine dark-adapted baseline (Fo) and maximum fluorescence yields (Fm) and to calculate maximum photosystem II quantum efficiency (Fv/Fm = (Fm-Fo)/Fm). The same florets were then measured again the following morning when exposed to full incident ambient photosynthetic photon flux densities to determine light-adapted steady state fluorescence (Fs), maximum fluorescence yields (Fm') and light-adapted photosystem II quantum efficiency (PhiPSII = (Fm'-Fs)/Fs). Fs, Fm and Fm\u2019 were used to estimate the quantum yield of non-photochemical energy loss (NPQ) in PS II that is physiologically regulated (PhiNPQ = (Fs/Fm\u2019)-(Fs/Fm)) and unregulated (PhiNO = Fs/Fm). Data was collected five times over the entire reproductive cycle (pre-anthesis, anthesis, and post-anthesis), with concurrent average daily volumetric soil moisture at 10 cm soil depth (Vsm) from six Vsm observations made daily.</p>", "distribution": [{"@type": "dcat:Distribution", "downloadURL": "https://ndownloader.figshare.com/files/61153936", "format": "xlsx", "mediaType": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", "title": "FPBData.xlsx"}], "identifier": "10.15482/USDA.ADC/31101193.v1", "keyword": ["Bluebunch wheatgrass", "Chlorophyll fluorescence", "Florets", "Fv/Fm", "PhiPSII", "Reproduction", "crested wheatgrass", "flag leaves", "non-photochemical quenching (NPQ)"], "license": "https://creativecommons.org/publicdomain/zero/1.0/", "modified": "2026-03-30", "programCode": ["005:040"], "publisher": {"@type": "org:Organization", "name": "Agricultural Research Service"}, "spatial": "{\"type\": \"Point\", \"coordinates\": [-119.691386, 43.472069000000005]}", "temporal": "2025-06-13/2025-07-09", "title": "Data from: Photochemical and non-photochemical chlorophyll fluorescence dynamics in reproductive structures of semi-arid rangeland perennial bunchgrasses"}