Vegetated canopies and woody debris dams form porous obstructions that alter the local flow field as fluid is forced to move around canopy elements. In some situations, a canopy shear layer forms between flow streams diverted around an obstruction and decelerated flow within the obstructed region, with momentum transferred through a mixing layer. The presence of a canopy shear layer alters the fate and transport of ecologically relevant particles including sediment, pollen grains, and pathogenic fungal spores. Improved understanding of particle transport within canopy shear layers is needed to predict the effects and improve the design of environmental interventions such as submerged aquatic vegetation restoration, natural flood management, and integrated pest management initiatives. In this talk I present the results of laboratory experiments and numerical modelling investigating particle transport in the canopy shear layer, relating observed particle transport trends to physical parameters and field data.