1 Assessing the impact of field of view on monitoring understorey and overstorey 1 phenology using digital repeat photography 2 3 M. Vartanian 1 , W. Nijland 1 , N. C Coops 1 , C. Bater 2 , M. A Wulder 3 , G. Stenhouse 4 4 5 1 Department of Forest Resources Management, University of British Columbia, 2424 Main Mall, Vancouver, BC 6 V6T 1Z4, Canada. 7 2 Alberta Environment and Sustainable Resource Development, 9920 - 108 Street, Edmonton, AB, T5K 2M4, 8 Canada. 9 3 Canadian Forest Service (Pacific Forestry Center), Natural Resources Canada, 506 West Burnside Road, Victoria, 10 BC V8Z 1M5, Canada. 11 4 Foothills Research Institute, Hinton, Alberta, T7V 1X6, Canada 12 13 14 ABSTRACT 15 Phenological patterns of the components within forest ecosystems, such as understorey vegetation, are 16 important indicators of climate variability, productivity, and additional ecosystem services such as food and 17 habitat availability for wildlife. Proximal sensing systems (e.g. repeat photography) can provide highly 18 detailed temporal and spatial phenological records at a relatively low cost. As interest in these datasets 19 increases, the need for additional information regarding the effect of different approaches on the scale of 20 observations and camera field of view has become apparent. In this research, we examine the impact of field 21 of view on the capacity of cameras to detect changes in phenology of individual species in an image time 22 series. We examine two co-located series of oblique images acquired using a fine and broad field of view and 23 compare a number of phenological indicators, including the start and end of season derived for individual 24 plant species. Camera derived phenological events from both fields of view were compared to field based 25 records of plant phenophases. Our results indicate both fine and broad field of view camera systems are 26 highly effective at detecting key markers of plant phenology with no significant differences between the two. 27 This result supports environmental monitoring using cost effective broad field of view cameras, or even – 28 subject to some constraints – readily available camera stations installed for tourism or traffic monitoring. 29