This dataset contains information about photosynthesis and gas exchange from tree species in Alice Holt Forest, Hampshire, UK. Data were collected between 18th-20th July 2023, alongside other observations examining the forest canopy structure and photosynthesis. Leaves were sampled across one hazel tree within the understory, and two oak trees. Data from the oak trees were collected with height, using a 12 m tower (six 2 m platforms), with leaves sampled across three platforms. The photosynthesis parameters were collected using a Handy PEA+ continuous excitation chlorophyll fluorimeter and gas exchange data were collected using a LI-COR 6400. This research was funded by UKRI NERC as part of the SPLICE project (NE/W006596/1). Full details about this dataset can be found at https://doi.org/10.5285/40365cee-fda6-402f-9839-c206463dbe7d
