During one of my recent field excursions I observed the mulching effect of big leaf maple. The leaves covered the gravel logging road I was traversing and had completely filled the ditches.
Within the forest off road and trail the covering leaves made footing more an act of feeling versus seeing with branches and logs and small streams and mud holes completely covered. At another site it took some looking to find a culvert entrance and the leaves had completely obscured tension cracks in a poorly built road.
Big leaf maples are of the western Pacific Northwest are the biggest maples in North America. They are somewhat restricted to the milder weather side of the Pacific Northwest. Ecologically they appear to play a big role in soil development with intense leaf litter adding significant potassium and calcium to the forest floor soils. The tree does produce sweet sap but it is of lower quality than the northeast and eastern Canadian sugar maple and the sap flow is not as productive.