The data consists of plant physiological measurements from 15 sites located in the Conwy catchment (North Wales) and from 2 sites in North West England. Plant photosynthetic parameters for the maximum rate of carboxylation (Vcmax), the maximum rate of electron transport (Jmax) and the maximum light saturated photosynthesis (Asat) were measured on the dominant plant species as were foliar nitrogen (Foliar N) and phosphorus (Foliar P). Leaf mass area (LMA) and specific leaf area (SLA) were recorded on the same leaves. Data were collected in 2013, 2014 and 2016. The sites were chosen to represent habitat types and the terrestrial productivity gradient in Britain from intensive agriculturally managed lowland grasslands through to montane heath. Plots within the sites were located using a stratified random sampling design. Plant parameters were tested across a land use intensification gradient to detect parameters that can predict aboveground biomass production across different land management types. Data were used to enhance the predictions of biomass production in the Joint UK Land Environment Simulator model (JULES). Measurements informed the improvement of the nitrogen cycle component in the model. Measurements were undertaken by trained members of staff from Bangor University, the Centre for Ecology & Hydrology and Exeter University. This data was collected for the NERC project 'The Multi-Scale Response of Water quality, Biodiversity and Carbon Sequestration to Coupled Macronutrient Cycling from Source to Sea' (NE/J011991/1). The project is also referred to as Turf2Surf. Full details about this dataset can be found at https://doi.org/10.5285/a9226e79-d4da-4d4d-bd39-3a6b4a7a327d

The data consists of, standing aboveground biomass, and belowground biomass measurements, from sites in the Conwy catchment. Standing aboveground biomass was measured at 7 sites and belowground biomass measurements were made at 8 sites. Data were collected in 2013 and 2014. The sites were chosen to represent habitat types and the terrestrial productivity gradient in Britain from intensive agriculturally managed lowland grasslands through to montane heath. Standing aboveground biomass (grams of dry mass per metre square) in habitats dominated by herbaceous biomass was measured on 1x1 metre quadrats in four plots per site. Standing aboveground biomass in woodlands was measured in two 200 square metre areas by means of stem cores and litter collections. Belowground total root biomass (grams of dry mass per square metre) was assessed for the topsoil 0-15 centimetres in three plots per site. Measurements were undertaken by trained members of staff from Bangor University and the Centre for Ecology & Hydrology. This data was collected for the NERC project 'The Multi-Scale Response of Water quality, Biodiversity and Carbon Sequestration to Coupled Macronutrient Cycling from Source to Sea' (NE/J011991/1). The project is also referred to as Turf2Surf. Full details about this dataset can be found at https://doi.org/10.5285/46bb0117-ed5d-4167-a375-d84d1237cf21