Seasonal Watercourses in Agricultural Lands of the Upper Willamette Valley

Historically the upper Willamette River Valley, western Oregon, was characterized by seasonal floods and large expansions of its stream network. During the past century, human activities have altered or eliminated many intermittent stream and floodplain habitats in the valley. As a result, the remaining intermittent streams and ditches, referred to as watercourses, may still provide habitat critical for native fish. The objectives of this study were to determine: (a) fish presence; (b) spatial gradients of fish distribution (including species identity, native vs. non-native, and numbers); (c) fish use of the intermittent streams as spawning and nursery habitats; and (d) main factors that influence numbers of both fish and fish species. In winter and spring of 2002-2003, we examined the distributions of fish species in five sub-basins within the Willamette River Valley. Sampling sites were in intermittent watercourses that drained grass seed producing fields. We collected water samples and sampled fish December to May with minnow traps and an electrofishing unit, and collected standard fish habitat variables at all sites in spring. Thirteen fish species were found and only three of them were exotic. The presence of recently hatched and juvenile fish shows intermittent watercourses offer conditions suitable for spawning and juvenile rearing. The two watershed-scale variables with the most influence on fish species richness were % watershed covered by forest and distance to perennial water, which showed a direct and inverse relationship, respectively, to species diversity. In turn, fish abundance showed a negative, albeit modest, relationship with distance to perennial water. Among local-scale variables, water velocity and conductivity were inversely related to species richness and fish numbers. Our results highlight the relevance of intermittent agricultural watercourses for native fish species in the Willamette River Valley, and call for promotion of agricultural conservation practices that benefit farmers while maintaining aquatic biodiversity in floodplain habitats.

This study provided the foundation for a larger effort involving colleagues from various disciplines under a research project titled: Assessing Trade-Offs Between Crop Production and Ecological Services: The Calapooia Basin.

Additional Research Information:

Field Guide to Common Fish of the Willamette Valley Floodplain
Josh E. Williams, Guillermo R. Giannico and Brad Withrow-Robinson
Order Printed Version

Fish Use of Intermittent Watercourses Draining Agricultural Lands in the Upper Willamette Valley, Oregon
R.W. Colvin, G.R. Giannico, J. Li and K.S. Boyer

Fish and Amphibian Use of Vegetated and Non-Vegetated Intermittent Channels in the Upper Willamette Basin
R.W. Colvin, K.S. Boyer, G.R. Giannico, J.L. Li and S.M. Griffith
Oregon Seed Extension Research Program Seed Production Research Report 2006 – 60 p.

Fish and Amphibian Use of Intermittent Agricultural Waterways in the South Willamette Valley
G.R. Giannico, J.L. Li, K.L. Boyer, R.W. Colvin, W.J. Gerth, M.E. Mellbye, S.M. Griffith and J.J. Steiner
Oregon Seed Extension Research Program Seed Production Research Report 2005 – 61-64 p.

Assessing Trade-Offs Between Crop Production and Ecological Services:  The Calapooia Basin

The Calapooia River begins on the west side of the Cascade Mountains at 5,169 feet, dropping to 184 feet near Albany where it joins the Willamette River. Rainfall is predominately in the winter, with around half coming between December and February; precipitation is negligible in the summer. Higher elevations are forested; the lower basin flattens out with some hay, pasture, and grazing land, but the bulk of the farmland is in grass seed production. Around 35% of this agricultural land has been drained. No major dams or flood control structures are in the system, and there is very little irrigated agriculture. The river is on the Oregon 303(d) impairment list for bacteria and temperature under the Clean Water Act. The average nitrate concentration is more than three times its concentration in the Willamette River. The watershed supports several vertebrate species that have been listed as threatened or endangered under the Endangered Species Act, such as: bald eagle, western pond turtle, red-legged frog, steelhead trout, Oregon chub, and chinook salmon.

The area of this study includes 61 sub-basins that form the lower Calapoooia Basin. Assessments will be made both at the sub-basin and the entire basin levels. The approach complements the 2003 USDA-National Resource Conservation Service’s Conservation Effects Assessment Project (CEAP) that seeks to quantify the environmental benefits of conservation practices used by private landowners who participate in conservation programs, using conservation tillage and/or riparian vegetation buffers.

This project is using existing and supplemental water quality and land-use cover data, in combination with biological indicators of water quality, to explore optimum tradeoffs between economic costs of conservation practices and ecological services. The two selected practices-conservation tillage and vegetation buffers on stream banks-are being linked to quantified biophysical responses, including water quality and a number of biological indicators. A model is being developed to assess tradeoffs between agricultural practices that seek to maximize both economic benefits and conservation actions that sustain or improve ecosystem services.

To achieve these ambitions purposes, a multidisciplinary team, led by Giannico (fish), was assembled, including fishery and wildlife scientists, Garcia (amphibians), McComb (songbirds) and Dugger (waterfowl), Li and Herlihy (aquatic invertebrates), Boyer (fisheries habitat management); also, Confesor (a hydrologist), Mueller-Warrant (a Geographic Information Systems expert), Griffith (a soils and water quality analyst), and economists Whittaker, Fare, and Grosskopf.

The team is addressing (1) the extent, timing, and placement of conservation practices currently in the study area, (2) the effects of those conservation practices, their location, and interaction with water quality and quantity, and (3) the effects of conservation practices on key biological indicators that respond to cumulative alterations in land cover and resulting water quality and quantity. (4) An objective-optimization model is being developed, based on the information derived in (1) through (3). (5) Findings will be disseminated to specific target audiences (e.g., landowners and regulators) through outreach activities and Extension products. Note that Mark Mellbye is on board to lead the dissemination effort.

About the multiobjective optimization model-in lay language:

The model has two conflicting objectives to maximize-grower profit and environmental quality. It arrives at a set of solutions, not just one, because of the tradeoffs between the two objectives. This is called a Pareto Optimum solution, meaning that each “soft” point between the two objectives cannot be improved on without worsening the other.

An algorithm-a kind of iterative flow chart-is used. As it runs through, it stops and asks each objective if the solution is optimal. If the answer is “no,” it runs through again creating a new generation of possibilities. If it is “yes” from both objectives, that solution is recorded, and it goes ahead to create a new generation of possibilities for 1,000 iterations (or however many the model is set for). A run of 1,000 iterations (on a bank of parallel PC computers) takes almost 11 hours. Visually-if it could be visualized-it creates “soft” places on a multi-dimensional “surface.”

These “soft” places provide the parameters of a hydrology model, built through USDA-ARS, called the Soil and Water Assessment Tool (SWAT), which “predicts the impact of land management practices on water, sediment, and agricultural chemical yields in large complex watersheds with varying soils, land use, and management conditions over long periods of time.” (Quote from a paper by Confesor and Whittaker). Repeating the above explanation in a slightly more technical way-paraphrasing from the Confesor-Whittaker paper: This study investigates the application of Multi-Objective Evolutionary Algorithm and Pareto ordering optimization in the automatic calibration of SWAT, a complex hydrological model, run with data from the Calapooia watershed. The calibrated SWAT model simulates well the daily stream-flow of the Calapooia watershed for a three-year period. Pareto ordering optimization results in a set of optimal solutions that account for the tradeoffs between the objectives. As all the solutions are Pareto optimal, the choice of a solution depends on preference and interest.

Remaining work is to: (1) simultaneously calibrate water quality and quantity parameters and (2) link the model with economic models. Finally and importantly, the resulting Pareto optimization solutions will be applied in decision- and policy-making, related to the conflicting objectives of economic costs (minimized) and environmental quality (maximized).

Additional Research Information:

Agricultural land use and macroinvertebrate assemblages in lowland temporary streams of the Willamette Valley Oregon
William Gerth, Judith Li and Guillermo R. Giannico

Remote Sensing Classification of Grass Seed Cropping Practices in Western Oregon
Mueller-Warrant, G.W., G.W. Whittaker, S.M. Griffith, G.M. Banowetz, B.D. Dugger, T.S. Garcia, G.R. Giannico, K.L. Boyer and B.C. McComb.

Making Sense of Nitrogen Flux Patterns in the Calapooia River Basin (2011)
Mueller-Warrant, G., S. Griffith, G. Whittaker, G. Banowetz, W. Pfender, T. Garcia, and G. Giannico.
Seed Production Research at Oregon State University. 2010– Ext/CrS 130, 3/11. 40-44 p.

Grass Seed Agriculture and Invertebrate Communities of Seasonal Wetlands in the Southern Willamette Valley (2011)
Wyss, L., A. Herlihy, B. Dugger, J. Li, B. Gerth, and G. Giannico
Seed Production Research at Oregon State University. 2010– Ext/CrS 130, 3/11.

Assessing Trade-Offs Between Crop Production and Ecological Services: The Calapooia Basin (2008)
R.W. Colvin, G.R. Giannico, A.T. Herlihy, W.J. Gerth, R.B. Confessor, R.G. Fare, T.S. Garcia, S.M. Griffith, S.P. Grosskopf, B.C. McComb, G.W. Whittaker and G.W. Mueller-Warrant
Seed Production Research at Oregon State University. 2007- EXT/CrS 127, 3/08 – 78-79 p.