This dataset provides photosynthesis data for the plant species Calluna vulgaris, Vaccinium myrtillus and Empetrum nigrum. Photosynthesis response curves were measured for Calluna vulgaris and Vaccinium myrtillus only. Photosynthesis was measured at the climate change field site Climoor which is located in Clocaenog forest, North East Wales. Photosynthesis measurements have been carried out in 2001, 2002, 2003, 2005 and 2007; photosynthesis light response curves and Net Carbon Dioxide (CO2) assimilation rate (A), versus calculated substomatal CO2 concentration (Ci), (A/Ci), responses have been measured in 2002 and 2003. In 2005, the effects of drought on photosynthesis of all three species has been measured. In 2007, the effect climate change (warming and drought) has been measured on healthy, fungal affected and herbivory affected Vaccinium myrtillus leaves. The experimental field site consists of three untreated control plots, three plots where the plant canopy air is artificially warmed during night time hours and three plots where rainfall is excluded from the plots at least during the plants growing season (March to September). Photosynthesis measurements were carried out by trained members of CEH Bangor staff.
The Climoor field experiment intends to answer questions regarding the effects of warming and drought on ecosystem processes. Plot level photosynthesis measurements are important to investigate ecosystem carbon dynamics and changes in the soil carbon under the imposed climatic treatments.
Publication date: 2016-06-07
This dataset is part of the following
Measurements were taken with a CIRAS-2 infrared gas analyser (PP Systems, UK) between 11 am and 3 pm. The plant leaves/branches photosynthesis was measured on were sampled and dried at 65 degrees Celsius to determine the leaf mass and area. Non-flowering and non-fruiting, sun-exposed tips were used for all measurements. The tip was inserted in the cuvette and remained there until photosynthesis and transpiration rates were seen to equilibrate. Light response curves were measured at constant internal carbon dioxide (CO2) concentration by reducing the photosynthetically active light. Net CO2 assimilation rate (A), versus calculated substomatal CO2 concentration (Ci), (A/Ci), curves were measured at constant light conditions and reducing internal CO2 concentration. Photosynthesis data were measured at saturated light conditions,1000 micromole photons per square metre per second and constant near ambient CO2 concentration, 350 to 400 micromoles per mole. Measurements were downloaded to Excel spreadsheets and exported as .csv files for ingestion into the EIDC.