These data consist of stream water chemistry for selected Welsh upland rivers. The sampling sites were located in sixty one small and medium catchments. Catchments were chosen from the Welsh Acid Water Surveys (WAWS) program (41 sites) and the Wye catchment (20 sites). Results for pH, alkalinity, conductivity and major cation and anion measurements are presented for the WAWS catchments. Results for pH, alkalinity, conductivity and major anion measurements are presented for the Wye catchment. Samples from the Wye catchment were collected in May 2012. Samples from the WAWS catchments were taken during the summer and autumn of 2012 and spring and summer of 2013. The data were collected to characterise water chemistry variation along a gradient of aquatic biodiversity associated with different environmental settings for example land-use intensify and recovery from acidification. Dr Isabelle Durance was responsible for organising the surveys, Dr Hugh Feeley was in charge of collecting and preserving the water samples. Analysis of the water samples was carried out at the Forest Research Laboratories. The work was carried out under Diversity in Upland Rivers for Ecosystem Service Sustainability (DURESS) project (Grant reference NERC NE/J014818/1). DURESS was a project funded by the Natural Environment Research Council (NERC) Biodiversity and Ecosystem Service Sustainability (BESS) programme. Full details about this dataset can be found at https://doi.org/10.5285/d329ca18-c3d8-49f0-b2fd-5243d76dc650

These data are for macroinvertebrate taxonomy and abundance of Welsh upland rivers. The sampling sites were located in small and medium catchments across Wales. Sampling took place in either spring 2013 for sites in the Wye catchment or during 2012 for the other catchments. At each sampling point, 2-minute kick-samples were taken from river riffles to represent macroinvertebrate composition. Samples were preserved in industrial methylated spirit on site. Samples were then sorted and identified in the laboratory. The main goal of this survey was to characterise a gradient of aquatic biodiversity associated with different environmental settings for example land-use intensify and recovery from acidification. Dr Isabelle Durance was the responsible of organising the surveys, Dr Hugh Feeley was in charge of collecting, processing and sorting the invertebrate samples. Kath Layer was commissioned by Cardiff University for the identification. The work was carried out under Diversity in Upland Rivers for Ecosystem Service Sustainability (DURESS) project (Grant reference NERC NE/J014818/1). DURESS was a project funded by the Natural Environment Research Council (NERC) Biodiversity and Ecosystem Service Sustainability (BESS) programme. Full details about this dataset can be found at https://doi.org/10.5285/8f7b2269-73b1-449f-8590-e36c7c850913

These data are macroinvertebrate composition and size in eight Welsh upland rivers with contrasting land-use, moorland and exotic conifer, in response to riparian deciduous leaf addition. Eight sampling reaches were chosen at two sites, Llyn Brianne (4 reaches) and Plynlimon (4 reaches). The experiment consisted of adding deciduous leaves to half of the reaches whilst the other half were maintained as a control (no addition of deciduous leaves). To characterise the benthic macroinvertebrate communities of the studied streams, Surber net sampling was used to collect monthly samples during 2013 in January (before deciduous leaf addition) and from February to April (after deciduous leaf addition) in each sampling reach. Some of the collected individuals were used to characterise the invertebrate biomass of each reach. The main goal of this survey was to examine how aquatic biodiversity responds to leaf addition in moorland and conifer forested rivers. Dr Isabelle Durance was responsible for organising the surveys, Dr Hugh Feeley and Marian Pye, were in charge of collecting, processing and sorting the invertebrate samples. The work was carried out under Diversity in Upland Rivers for Ecosystem Service Sustainability (DURESS) project (Grant reference NERC NE/J014818/1). DURESS was a project funded by the Natural Environment Research Council (NERC) Biodiversity and Ecosystem Service Sustainability (BESS) programme. Full details about this dataset can be found at https://doi.org/10.5285/d07fe8a7-d4da-43e5-834d-e1b0f4cff0ac

These data are benthic organic matter stocks of coarse and fine particulate organic matter in eight Welsh upland rivers with contrasting land-use, moorland and exotic conifer, in response to riparian deciduous leaf addition. Eight sampling reaches were chosen at two sites, Llyn Brianne (4 reaches) and Plynlimon (4 reaches). The experiment consisted of adding deciduous leaves to half of the reaches whilst the other half were maintained as a control (no addition of deciduous leaves). To characterise the benthic organic matter of the studied streams, a Surber net was used to collect monthly samples during 2013 on January (before deciduous leaf addition) and from February to April (after deciduous leaf addition) in each sampling reach. The main goal of this survey was to examine how aquatic biodiversity and organic matter stocks respond to leaf addition in moorland and conifer forested rivers. Dr Isabelle Durance was responsible of organising the surveys, Marian Pye was in charge of collecting, processing and sorting the samples. The work was carried out under Diversity in Upland Rivers for Ecosystem Service Sustainability (DURESS) project (Grant reference NERC NE/J014818/1). DURESS was a project funded by the Natural Environment Research Council (NERC) Biodiversity and Ecosystem Service Sustainability (BESS) programme. Full details about this dataset can be found at https://doi.org/10.5285/32eaf811-be10-40cb-9794-7c5a1b97a915

These data are macroinvertebrate composition and abundance in eight Welsh upland rivers with contrasting land-use, moorland and exotic conifer, in response to riparian deciduous leaf addition. Eight sampling reaches were chosen at two sites, Llyn Brianne (4 reaches) and Plynlimon (4 reaches). The experiment consisted of adding deciduous leaves to half of the reaches whilst the other half were maintained as control (no addition). Nylon mesh bags containing deciduous leaves were fixed in both experimental and control reaches to estimate leaf decomposition rates. The macroinvertebrate composition of the nylon mesh bags was surveyed in January 2013 and again in March 2013 in each sampling reach. The main goal of this survey was to examine how aquatic biodiversity responds to leaf addition in moorland and conifer forested rivers. Dr Isabelle Durance was responsible for organising the surveys, Dr Hugh Feeley, Dr Dan Perkins and Marian Pye were in charge of collecting, processing and sorting the invertebrate samples. The work was carried out under Diversity in Upland Rivers for Ecosystem Service Sustainability (DURESS) project (Grant reference NERC NE/J014818/1). DURESS was a project funded by the Natural Environment Research Council (NERC) Biodiversity and Ecosystem Service Sustainability (BESS) programme Full details about this dataset can be found at https://doi.org/10.5285/3e6a9ffd-59f2-48ea-840b-1582dc6c1e3d