Quantifying phenology in the deciduous tree and phytophagous insect system: a methodological comparison

There are many studies of phenology of components of the tri-trophic tree-insect-bird system - a useful model for understanding the effects of climate change. But how do different measures relate to each other? We compared 5 methods, deriving 9 metrics, across 6 tree species.

We were particularly interested in understanding how measures relate at small spacial scales, and how drone-based imaging could help us scale this up, through lots of fieldwork led by Lucy Morley and a team as part of Lucy's DPhil. 

Rea the preprint for more detail, but the bottom line is that there are variable degrees of agreement between methods and in different species, hence they can't be used interchangeably without testing that agreement. NDVI measured from drones relates well to ground-scored bud-burst.

Schematic of field methods performed on each tree: a) multispectral drone imaging, b) bud scoring observations, c) hemispherical canopy photography, d) caterpillar water traps, and e) frass traps

Link to prepint: DOI