Forest Management in Hinkle Creek Watersheds: Baseline Seasonal Stream Water Nutrient Concentrations and Soil Resources

Investigators: Kermit Cromack, Jr., PI, and Dave Hibbs, Co-PI, OSU Forest Science Department; Arne Skaugset and Stephen Schoenholtz, Co-PIs, OSU Forest Engineering Department.

Relevance to program mission

This research addresses the need to obtain baseline data for both stream chemistry and soil resources for the North and South Forks of the Hinkle Creek Paired Watershed Study. Current forest management practices are designed to promote sustainable silvicultural systems on these paired watersheds, which are productive for timber, water, fish, and wildlife resources. A solid representative database for both stream and soil nutrients in these watersheds would provide a model upon which to help gauge the effects of current and expected intensive forest management practices on industrial forest land.

Objectives

1. To obtain monthly water nutrient concentration data for two consecutive years in six headwater streams, and in the North and South Forks of Hinkle Creek. Stream nutrients to be measured include: total N, P, and base cations (Ca, K, Mg, Na), dissolved organic N ( DON ), and inorganic N ( DIN ), plus stream pH.
2. To obtain data for soil resources and geomorphology on these watersheds, including soil physical properties (bulk density), pH, soil texture, soil C, N, S, and cation exchange capacity. This research is designed to integrate with the Hinkle Creek Paired Watershed Study on Hydrology and Water Quality being led by Arne Skaugset, OSU Forest Engineering Department.

Overview

Oregon has highly productive forests growing on soils that can be effectively managed for timber resources while maintaining stream water quality suitable for fish and wildlife resources. In addition to maintaining productive forests, one goal of current forest management is to maintain stream water of high quality for fish and wildlife. Both fish and wildlife species require the same nutrients essential in adequate quantities for tree growth. This project would provide a valuable initial database of stream nutrient concentrations and soil resources.

Approach

To accomplish the first objective for obtaining seasonal nutrient concentration data, collect samples directly from streams monthly for the first year and seasonally afterwards, while minimizing disturbance to stream sediment. The second objective, to collect soil samples in riparian zones and upslope forest areas, is being accomplished using recently published soil survey maps as a guide to select representative locations within the overall watershed. In addition, representative soil pits are being dug to obtain soil descriptions and underlying parent materials, and to check soil map accuracy.

Please click here for the full report