Evaluating the Transfer of Energy in Coastal Temperate Rainforest Terrestrial and Aquatic Ecosystems Through Hydropedology.

The distribution of water on the landscape influences many ecological functions such as the patterns of vegetation, soil development and biogeochemical transformations. All of these functions are subject to change as a result of variations in the duration of soil water saturation and flow of water from soils to streams through the distributed channel networks of watersheds. The geomorphology of the perhumid coastal temperate rainforest (PCTR) is dominated by glacial and fluvial landforms, and the diverse vegetation habitats that are a hallmark of the PCTR are heavily influenced by groundwater hydrology. Therefore, the distribution of water as ground water and surface water is a powerful indicator of functions across the PCTR. Soil moisture serves as an indicator of function, but can also be used as a surrogate for the transfer of energy and material within the diverse ecosystems of the PCTR. Individual ecosystem response such as accumulation of carbon have a direct correspondence to patterns of saturation. Quantifying the intensity of the biogeochemical transfers and transformations within soil pedons and to the surrounding environment is an important approach for detecting, evaluating, and predicting changes to soils. Time series data and models of biogeochemical transfers within a range of soil types were used to establish a first order energy model for terrestrial ecosystems on the PCTR. The terrestrial models provided estimates of nutrient turnover rates driven by alterations to soil saturation. These terrestrial links were combined with aquatic measurements to determine the relationship between the terrestrial cycles and associated nutrient export to aquatic ecosystems. Late seral forested ecosystems had tight terrestrial cycles of N and P, but were still non-conservative with N and P export. Carbon was vigorously cycled and exported from these systems with abundant export from forested wetlands. Overall, there is a conservation of reduced compounds in the terrestrial system, but a portion of the nutrient energy is transferred to aquatic systems in forms that are readily available.