The dataset consists of proportions of ozone injured or senesced leaves from a study which investigated how the presence of competing species in a community affects these two common responses to ozone. Monocultures and mixtures of Trifolium repens and Lolium perenne were grown in large containers and were exposed in solardomes to either a rural episodic ozone profile (AOT40 (Accumulated Ozone Threshold exposure of 40 parts per billion) of 12.86 ppm h) or control conditions (AOT40 of 0.02 ppm h) for 12 weeks. The proportion of ozone-injured or senesced leaves was determined in different regions of the canopy, the upper canopy (>14cm high), the canopy edge and the inner canopy, by separating injured/senesced leaves from healthy leaves. The experiment was carried out at the CEH Bangor Air Pollution Facility. This work was funded by the Centre for Ecology & Hydrology Integrating Fund Initiative Full details about this dataset can be found at https://doi.org/10.5285/bc4d0325-b67b-4fff-a14b-6e06edf397bd

The data are biomass measurements from an ozone exposure experiment, during which Trifolium repens and Lolium perenne were exposed as both monocultures and two-species mixtures to an episodic rural ozone regime in large, well-watered containers within solardomes for 12 weeks. Treatments were elevated ozone (AOT40 (Accumulated Ozone Threshold exposure of 40 parts per billion) of 12.86 ppm h) or control conditions (AOT40 of 0.02 ppm h). Measurements were dry weight, with a cutting height of 7cm above soil level. The distribution of plant material within the canopy was determined by separating material growing in the upper canopy (>14cm) from the canopy edge and the inner canopy for both species. The experiments were carried out in the CEH Bangor Air Pollution Facility. Work was funded by the Centre for Ecology & Hydrology Integrating Fund Initiative. The observed decreases in photosynthetic efficiency and capacity in elevated ozone indicate that the ability of such ubiquitous vegetation to act as a sink for atmospheric carbon may be reduced in future climates. Full details about this dataset can be found at https://doi.org/10.5285/5de90f7a-dec9-4bd5-af52-d0873a09d25d