We utilise the final catalogue from the Pan-Andromeda Archaeological Survey to investigate the links between the globular cluster system and field halo in M31 at projected radii R _ { proj } = 25 - 150 kpc .
In this region the cluster radial density profile exhibits a power-law decline with index \Gamma = -2.37 \pm 0.17 , matching that for the stellar halo component with [ Fe / H ] < -1.1 .
Spatial density maps reveal a striking correspondence between the most luminous substructures in the metal-poor field halo and the positions of many globular clusters .
By comparing the density of metal-poor halo stars local to each cluster with the azimuthal distribution at commensurate radius , we reject the possibility of no correlation between clusters and field overdensities at 99.95 \% significance .
We use our stellar density measurements and previous kinematic data to demonstrate that \approx 35 - 60 \% of clusters exhibit properties consistent with having been accreted into the outskirts of M31 at late times with their parent dwarfs .
Conversely , at least \sim 40 \% of remote clusters show no evidence for a link with halo substructure .
The radial density profile for this subgroup is featureless and closely mirrors that observed for the apparently smooth component of the metal-poor stellar halo .
We speculate that these clusters are associated with the smooth halo ; if so , their properties appear consistent with a scenario where the smooth halo was built up at early times via the destruction of primitive satellites .
In this picture the entire M31 globular cluster system outside R _ { proj } = 25 kpc comprises objects accumulated from external galaxies over a Hubble time of growth .