Snowmelt induced stemflow in northern hardwood forests: a theoretical explanation on the causation of a neglected hydrological process

Snowmelt induced stemflow is an under-studied and poorly understood hydrological process. The aim of the present manuscript is to set forth several testable hypotheses and conceptual models concerning the production of snowmelt induced stemflow. The first testable hypothesis is that tree species with lower canopy albedos of snow-covered and snow-free surfaces (portions of the canopy are usually exposed and snow-free while the remainder is covered) will generate larger snowmelt induced stemflow volumes than trees with higher canopy albedos of snow-covered and snow-free surfaces. It is also hypothesized that snow-to-rain events produce larger volumes of snowmelt induced stemflow than snow events of the same magnitude because of differences in precipitation type (snow-to-rain vs. snow) and the additional melt energy from the latent heat of fusion associated with rain infiltrating the intercepted snow mass. For deciduous tree species with similar branching geometries, it is hypothesized that larger longwave radiative flux will generate larger snowmelt induced stemflow volumes. The conceptual models describe the components and the flux directions necessary to generate snowmelt induced stemflow. Through a test of the hypotheses and conceptual models in subsequent work, it is hoped that quantitative models are developed that will be able to estimate snowmelt induced stemflow volumes and yield a new understanding of winter water flux in forested ecosystems. (C) 2004 Elsevier Ltd. All rights reserved.