Arborcheck systems are designed specifically for arborists. Quick and easy, non-destructive physiological assessments of tree health are made using hand-held, cost effective instruments based on proven scientific techniques which have been and continue to be widely used in photosynthesis research the world over. The system has been developed in response to the scale in which chlorophyll fluorescence is gaining popularity with arborists around the world as an effective and comprehensive method of assessing tree health. Readings taken by Arborcheck systems are compared to a species specific Nursery Benchmark Database which has been independently compiled and verified by Dr. Glynn Percival and colleagues from Bartlett Tree Research Laboratories based on identical measurements made annually since 2009 on trees grown in optimum conditions at the Barcham Trees nursery in the UK. The Nursery Benchmark Database currently contains optimum photosynthetic efficiency, vitality and chlorophyll content values from more than 600,000 individual leaf sample measurements taken from more than 350 tree species. Arborcheck systems can be used effectively in many areas of arboriculture from the selection of physiologically sound planting stock through to quantitative assessment of stress in veteran trees on development sites. The techniques used by Arborcheck systems are scientifically proven to allow early detection of severely damaging stress factors well before visible symptoms are apparent. Arborcheck systems can also indicate a sound physiological framework on a tree that looks visibly in poor condition. Prompt and efficient remediation in these cases can often lead to a swift recovery of a tree that may otherwise have been felled based on a visual analysis. Chlorophyll fluorescence testing is also cited in the new British Standard BS 8545: Trees: from nursery to independence in the landscape as a recommended tool for ongoing monitoring of tree health post-planting.