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• 1401. [Article] City of Warrenton natural hazards mitigation plan addendum

  88 pp. Maps, tables, figures, illus.

  Citation × Citation Citation Abstract Copy Title: City of Warrenton natural hazards mitigation plan addendum Author: Oregon Partnership for Disaster Resilience, Warrenton (Or.) Year: 2010 88 pp. Maps, tables, figures, illus. Title: City of Warrenton natural hazards mitigation plan addendum Author: Oregon Partnership for Disaster Resilience, Warrenton (Or.) Year: 2010 88 pp. Maps, tables, figures, illus. Close

• 1402. [Article] Tower Fire ecosystem analysis forest vegetation report and forest vegetation BAER report

  72 pp. Tables, figures, maps, references, appendix, illus. "Pre-fire forest types were very diverse, largely in response to a relatively steep elevational gradient ranging from 3,000 feet near the North ...

  Citation × Citation Citation Abstract Copy Title: Tower Fire ecosystem analysis forest vegetation report and forest vegetation BAER report Author: North Fork John Day Ranger District (Or.), Powell, David C., Erickson, Vicky Year: 2008, 1997 72 pp. Tables, figures, maps, references, appendix, illus. "Pre-fire forest types were very diverse, largely in response to a relatively steep elevational gradient ranging from 3,000 feet near the North Fork of the John Day River at the southwestern corner of the fire perimeter to 6,850 feet at Tower Mountain lookout on the extreme eastern edge of the analysis area." Date of BAER report is September 1996. Captured June 18, 2008. Title: Tower Fire ecosystem analysis forest vegetation report and forest vegetation BAER report Author: North Fork John Day Ranger District (Or.), Powell, David C., Erickson, Vicky Year: 2008, 1997 72 pp. Tables, figures, maps, references, appendix, illus. "Pre-fire forest types were very diverse, largely in response to a relatively steep elevational gradient ranging from 3,000 feet near the North Fork of the John Day River at the southwestern corner of the fire perimeter to 6,850 feet at Tower Mountain lookout on the extreme eastern edge of the analysis area." Date of BAER report is September 1996. Captured June 18, 2008. Close

• 1403. [Article] Middle Fork Coquille 2007 commercial thinning and density management environmental assessment

  126 pp. Tables, references, figures, appendices, maps. The stands proposed for treatment are located in the Twelve Mile Creek and Headwater Middle Fork Coquille River 6th-field subwatersheds of the Middle ...

  Citation × Citation Citation Abstract Copy Title: Middle Fork Coquille 2007 commercial thinning and density management environmental assessment Author: United States. Bureau of Land Management. Roseburg District Office Year: 2008, 2007 126 pp. Tables, references, figures, appendices, maps. The stands proposed for treatment are located in the Twelve Mile Creek and Headwater Middle Fork Coquille River 6th-field subwatersheds of the Middle Fork Coquille 5th-field watershed. Individual units are located in: Sections 5, 15, 29, 31, 32 and 33 in T. 29 S., R. 8 W.; Sections 1, 11, and 35 in T. 29 S., R. 9 W.; Sections 5, 9, 15, 27, and 33 in T. 30 S., R. 8 W.; and Section 3 in T. 30 S., R. 9 W., W.M. Captured July 25, 2007. Title: Middle Fork Coquille 2007 commercial thinning and density management environmental assessment Author: United States. Bureau of Land Management. Roseburg District Office Year: 2008, 2007 126 pp. Tables, references, figures, appendices, maps. The stands proposed for treatment are located in the Twelve Mile Creek and Headwater Middle Fork Coquille River 6th-field subwatersheds of the Middle Fork Coquille 5th-field watershed. Individual units are located in: Sections 5, 15, 29, 31, 32 and 33 in T. 29 S., R. 8 W.; Sections 1, 11, and 35 in T. 29 S., R. 9 W.; Sections 5, 9, 15, 27, and 33 in T. 30 S., R. 8 W.; and Section 3 in T. 30 S., R. 9 W., W.M. Captured July 25, 2007. Close

• 1404. [Article] Five Creeks Rangeland restoration project final decision record

  3 pp. It includes portions of the Smyth-Kiger (#5331), Happy Valley (#5309), Riddle Mountain (#5310), Riddle/Coyote (#5329), Burnt Flat (#5604), Stonehouse (#6040), Jenkins Burnt Flat Fenced Federal Range ...

  Citation × Citation Citation Abstract Copy Title: Five Creeks Rangeland restoration project final decision record Author: United States. Bureau of Land Management. Burns District Year: 2008, 2006 3 pp. It includes portions of the Smyth-Kiger (#5331), Happy Valley (#5309), Riddle Mountain (#5310), Riddle/Coyote (#5329), Burnt Flat (#5604), Stonehouse (#6040), Jenkins Burnt Flat Fenced Federal Range (FFR) (#5327), Clemens FFR (#5323), and Riddle FFR (#5324) grazing allotments (T. 29 S., R. 33 E., T. 28 S., R. 34 E., T. 29 S., R. 34 E., T. 29 S., R. 35 E., T. 30 S., R. 33 E., T. 30 S., R. 34 E., T. 30 S., R. 35 E., T. 30.5 S., R. 34 E., T. 31 S., R. 35 E., T. 31 S., R. 34 E.) in the Three Rivers Resource Area. Captured August 7, 2007. Title: Five Creeks Rangeland restoration project final decision record Author: United States. Bureau of Land Management. Burns District Year: 2008, 2006 3 pp. It includes portions of the Smyth-Kiger (#5331), Happy Valley (#5309), Riddle Mountain (#5310), Riddle/Coyote (#5329), Burnt Flat (#5604), Stonehouse (#6040), Jenkins Burnt Flat Fenced Federal Range (FFR) (#5327), Clemens FFR (#5323), and Riddle FFR (#5324) grazing allotments (T. 29 S., R. 33 E., T. 28 S., R. 34 E., T. 29 S., R. 34 E., T. 29 S., R. 35 E., T. 30 S., R. 33 E., T. 30 S., R. 34 E., T. 30 S., R. 35 E., T. 30.5 S., R. 34 E., T. 31 S., R. 35 E., T. 31 S., R. 34 E.) in the Three Rivers Resource Area. Captured August 7, 2007. Close

• 1405. [Article] Spatial and temporal variability of freshwater discharge into the Gulf of Alaska

  This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://agupubs.onlinelibrary.wiley.com/agu/jgr/journal/10.1002/%28ISSN%292...

  Citation × Citation Citation Abstract Copy Title: Spatial and temporal variability of freshwater discharge into the Gulf of Alaska Author: Beamer, J., Bruhis, N., Arendt, A., Calos, S. E., Hill, D. F. This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://agupubs.onlinelibrary.wiley.com/agu/jgr/journal/10.1002/%28ISSN%292169-9291/. Title: Spatial and temporal variability of freshwater discharge into the Gulf of Alaska Author: Beamer, J., Bruhis, N., Arendt, A., Calos, S. E., Hill, D. F. This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://agupubs.onlinelibrary.wiley.com/agu/jgr/journal/10.1002/%28ISSN%292169-9291/. Close

• 1406. [Article] A bioeconomic analysis of altering instream flows anadromous fish production and competing demands for water in the John Day River basin, Oregon

  The growing demand for water in the arid regions of the West increases the need for optimal allocation of water among competing uses. An efficient allocation of water between instream and out-of-stream uses ...

  Citation × Citation Citation Abstract Copy Title: A bioeconomic analysis of altering instream flows anadromous fish production and competing demands for water in the John Day River basin, Oregon Author: Johnson, Neal S. The growing demand for water in the arid regions of the West increases the need for optimal allocation of water among competing uses. An efficient allocation of water between instream and out-of-stream uses has been impeded by institutional constraints and the scarcity of information regarding instream flow benefits. The objectives of this thesis were to provide preliminary economic data on the value of instream water in "producing" recreational fishing and to examine the effect of forestry, agriculture, and livestock practices on temporal streamflow patterns and anadromous fish production. The steelhead trout (Salmo gairdneri) sport fishery within the John Day River basin in north-central Oregon provided the setting for this research. The interdisciplinary methodology employed in estimating the marginal value of water with respect to steelhead production consisted of two tasks. The first task involved valuing a marginal change in the quality of the steelhead recreational fishery. The contingent valuation method (CVM) was selected for this purpose. Both open- and closed-ended willingness-to-pay (WTP) questions were included in a questionnaire administered to John Day River steelhead anglers during the 1986/87 steelhead fishing season. Survey data were analyzed to arrive at individual and aggregate bid functions relating WTP to expected angling success rates. Results indicate that, under current conditions, the average angler is willing to pay approximately $7.20 to catch an additional steelhead. The second task of the instream water valuation methodology was directed at deriving a streamflow/steelhead production relationship. By including variables influencing steelhead production in a Ricker stock-recruitment model, it was possible to develop a model which could be estimated using linear regression techniques. Some difficulty arose, however, with interpretation of the model due to the unavailability of cohort escapement data and the subsequent use of standing crop data. While possibly masking the true magnitude of streamflow's effect on fish production, this drawback was not deemed limiting within the general context of the interdisciplinary methodology. Results of the biological model conformed to a priori expectations. Increases in summer and winter streamflows led to increased steelhead survival, whereas higher spring flows increased mortality levels. Other results indicate that the John Day Dam was responsible for a 31.5 percent decline in the population index for the 1969-1983 period. Combining the economic and biological results into one equation yielded an estimate of the marginal value of summer instream water in "producing" recreational steelhead angling. Similar equations were developed for winter and spring flows. The marginal value of water in producing recreational steelhead fishing within the John Day basin was estimated at $0.56 per acre-foot for summer flows, $0.046 for winter flows, and -$0.075 for spring flows. By including out-of-basin benefits, these values increased to $2.26, $0.19, and -$0.30, respectively. In comparison, water's value in irrigation within the John Day basin has been estimated at between $10 to $24 per acre-foot. However, nonuse values of steelhead, as well as the increased production of other fish species (such as spring chinook salmon) were not included in the instream water values. In addition, no attempt was made at valuing instream water's contribution to boating, camping, or other benefit-producing activities. A secondary objective of this thesis was to briefly examine the possible benefits accruing to other instream and out-of-stream users due to an alteration in streamflow patterns. In addition, the impact of activities by other resource users -- namely forestry, agriculture, and livestock production --on anadromous fish production was reviewed. Improper management practices by these activities can negatively impact the aquatic and riparian ecosystems. While no firm conclusions were drawn, it appears the quality of these ecosystems, as opposed to the amount of streamflow, has the largest marginal impact on anadromous fish populations. Title: A bioeconomic analysis of altering instream flows anadromous fish production and competing demands for water in the John Day River basin, Oregon Author: Johnson, Neal S. The growing demand for water in the arid regions of the West increases the need for optimal allocation of water among competing uses. An efficient allocation of water between instream and out-of-stream uses has been impeded by institutional constraints and the scarcity of information regarding instream flow benefits. The objectives of this thesis were to provide preliminary economic data on the value of instream water in "producing" recreational fishing and to examine the effect of forestry, agriculture, and livestock practices on temporal streamflow patterns and anadromous fish production. The steelhead trout (Salmo gairdneri) sport fishery within the John Day River basin in north-central Oregon provided the setting for this research. The interdisciplinary methodology employed in estimating the marginal value of water with respect to steelhead production consisted of two tasks. The first task involved valuing a marginal change in the quality of the steelhead recreational fishery. The contingent valuation method (CVM) was selected for this purpose. Both open- and closed-ended willingness-to-pay (WTP) questions were included in a questionnaire administered to John Day River steelhead anglers during the 1986/87 steelhead fishing season. Survey data were analyzed to arrive at individual and aggregate bid functions relating WTP to expected angling success rates. Results indicate that, under current conditions, the average angler is willing to pay approximately $7.20 to catch an additional steelhead. The second task of the instream water valuation methodology was directed at deriving a streamflow/steelhead production relationship. By including variables influencing steelhead production in a Ricker stock-recruitment model, it was possible to develop a model which could be estimated using linear regression techniques. Some difficulty arose, however, with interpretation of the model due to the unavailability of cohort escapement data and the subsequent use of standing crop data. While possibly masking the true magnitude of streamflow's effect on fish production, this drawback was not deemed limiting within the general context of the interdisciplinary methodology. Results of the biological model conformed to a priori expectations. Increases in summer and winter streamflows led to increased steelhead survival, whereas higher spring flows increased mortality levels. Other results indicate that the John Day Dam was responsible for a 31.5 percent decline in the population index for the 1969-1983 period. Combining the economic and biological results into one equation yielded an estimate of the marginal value of summer instream water in "producing" recreational steelhead angling. Similar equations were developed for winter and spring flows. The marginal value of water in producing recreational steelhead fishing within the John Day basin was estimated at $0.56 per acre-foot for summer flows, $0.046 for winter flows, and -$0.075 for spring flows. By including out-of-basin benefits, these values increased to $2.26, $0.19, and -$0.30, respectively. In comparison, water's value in irrigation within the John Day basin has been estimated at between $10 to $24 per acre-foot. However, nonuse values of steelhead, as well as the increased production of other fish species (such as spring chinook salmon) were not included in the instream water values. In addition, no attempt was made at valuing instream water's contribution to boating, camping, or other benefit-producing activities. A secondary objective of this thesis was to briefly examine the possible benefits accruing to other instream and out-of-stream users due to an alteration in streamflow patterns. In addition, the impact of activities by other resource users -- namely forestry, agriculture, and livestock production --on anadromous fish production was reviewed. Improper management practices by these activities can negatively impact the aquatic and riparian ecosystems. While no firm conclusions were drawn, it appears the quality of these ecosystems, as opposed to the amount of streamflow, has the largest marginal impact on anadromous fish populations. Close

• 1407. [Article] Mosby Creek Limiting Factors Analysis and Restoration Plan

  Abstract -- The Mosby Creek Limiting Factors Analysis (Rapid Bio-Assessment) assessed stream conditions for native salmonids and prioritized projects of benefit to spring Chinook, cutthroat trout, rainbow ...

  Citation × Citation Citation Abstract Copy Title: Mosby Creek Limiting Factors Analysis and Restoration Plan Abstract -- The Mosby Creek Limiting Factors Analysis (Rapid Bio-Assessment) assessed stream conditions for native salmonids and prioritized projects of benefit to spring Chinook, cutthroat trout, rainbow trout, and Pacific lamprey in this high-priority, free-flowing stream in the Coast Fork Willamette Watershed. To gain access to private properties adjacent to the 75 miles of surveyed streams, the applicant conducted landowner outreach and coordinated two years of continuous temperature data collection by volunteers. The contractor conducted a modified limiting factors analysis and a snorkel survey in the Mosby Creek main stem and tributaries up to 6 percent gradient. The resulting study results include a prioritized restoration plan that has been shared with local landowners and restoration partners and used for restoration planning. Title: Mosby Creek Limiting Factors Analysis and Restoration Plan Abstract -- The Mosby Creek Limiting Factors Analysis (Rapid Bio-Assessment) assessed stream conditions for native salmonids and prioritized projects of benefit to spring Chinook, cutthroat trout, rainbow trout, and Pacific lamprey in this high-priority, free-flowing stream in the Coast Fork Willamette Watershed. To gain access to private properties adjacent to the 75 miles of surveyed streams, the applicant conducted landowner outreach and coordinated two years of continuous temperature data collection by volunteers. The contractor conducted a modified limiting factors analysis and a snorkel survey in the Mosby Creek main stem and tributaries up to 6 percent gradient. The resulting study results include a prioritized restoration plan that has been shared with local landowners and restoration partners and used for restoration planning. Close

• 1408. [Article] Towards Improving Drought Forecasts Across Different Spatial and Temporal Scales

  Recent water scarcities across the southwestern U.S. with severe effects on the living environment inspire the development of new methodologies to achieve reliable drought forecasting in seasonal scale. ...

  Citation × Citation Citation Abstract Copy Title: Towards Improving Drought Forecasts Across Different Spatial and Temporal Scales Author: Madadgar, Shahrbanou Year: 2014 Recent water scarcities across the southwestern U.S. with severe effects on the living environment inspire the development of new methodologies to achieve reliable drought forecasting in seasonal scale. Reliable forecast of hydrologic variables, in general, is a preliminary requirement for appropriate planning of water resources and developing effective allocation policies. This study aims at developing new techniques with specific probabilistic features to improve the reliability of hydrologic forecasts, particularly the drought forecasts. The drought status in the future is determined by certain hydrologic variables that are basically estimated by the hydrologic models with rather simple to complex structures. Since the predictions of hydrologic models are prone to different sources of uncertainties, there have been several techniques examined during past several years which generally attempt to combine the predictions of single (multiple) hydrologic models to generate an ensemble of hydrologic forecasts addressing the inherent uncertainties. However, the imperfect structure of hydrologic models usually lead to systematic bias of hydrologic predictions that further appears in the forecast ensembles. This study proposes a post-processing method that is applied to the raw forecast of hydrologic variables and can develop the entire distribution of forecast around the initial single-value prediction. To establish the probability density function (PDF) of the forecast, a group of multivariate distribution functions, the so-called copula functions, are incorporated in the post-processing procedure. The performance of the new post-processing technique is tested on 2500 hypothetical case studies and the streamflow forecast of Sprague River Basin in southern Oregon. Verified by some deterministic and probabilistic verification measures, the method of Quantile Mapping as a traditional post-processing technique cannot generate the qualified forecasts as comparing with the copula-based method. The post-processing technique is then expanded to exclusively study the drought forecasts across the different spatial and temporal scales. In the proposed drought forecasting model, the drought status in the future is evaluated based on the drought status of the past seasons while the correlations between the drought variables of consecutive seasons are preserved by copula functions. The main benefit of the new forecast model is its probabilistic features in analyzing future droughts. It develops conditional probability of drought status in the forecast season and generates the PDF and cumulative distribution function (CDF) of future droughts given the past status. The conditional PDF can return the highest probable drought in the future along with an assessment of the uncertainty around that value. Using the conditional CDF for forecast season, the model can generate the maps of drought status across the basin with particular chance of occurrence in the future. In a different analysis of the conditional CDF developed for the forecast season, the chance of a particular drought in the forecast period can be approximated given the drought status of earlier seasons. The forecast methodology developed in this study shows promising results in hydrologic forecasts and its particular probabilistic features are inspiring for future studies. Title: Towards Improving Drought Forecasts Across Different Spatial and Temporal Scales Author: Madadgar, Shahrbanou Year: 2014 Recent water scarcities across the southwestern U.S. with severe effects on the living environment inspire the development of new methodologies to achieve reliable drought forecasting in seasonal scale. Reliable forecast of hydrologic variables, in general, is a preliminary requirement for appropriate planning of water resources and developing effective allocation policies. This study aims at developing new techniques with specific probabilistic features to improve the reliability of hydrologic forecasts, particularly the drought forecasts. The drought status in the future is determined by certain hydrologic variables that are basically estimated by the hydrologic models with rather simple to complex structures. Since the predictions of hydrologic models are prone to different sources of uncertainties, there have been several techniques examined during past several years which generally attempt to combine the predictions of single (multiple) hydrologic models to generate an ensemble of hydrologic forecasts addressing the inherent uncertainties. However, the imperfect structure of hydrologic models usually lead to systematic bias of hydrologic predictions that further appears in the forecast ensembles. This study proposes a post-processing method that is applied to the raw forecast of hydrologic variables and can develop the entire distribution of forecast around the initial single-value prediction. To establish the probability density function (PDF) of the forecast, a group of multivariate distribution functions, the so-called copula functions, are incorporated in the post-processing procedure. The performance of the new post-processing technique is tested on 2500 hypothetical case studies and the streamflow forecast of Sprague River Basin in southern Oregon. Verified by some deterministic and probabilistic verification measures, the method of Quantile Mapping as a traditional post-processing technique cannot generate the qualified forecasts as comparing with the copula-based method. The post-processing technique is then expanded to exclusively study the drought forecasts across the different spatial and temporal scales. In the proposed drought forecasting model, the drought status in the future is evaluated based on the drought status of the past seasons while the correlations between the drought variables of consecutive seasons are preserved by copula functions. The main benefit of the new forecast model is its probabilistic features in analyzing future droughts. It develops conditional probability of drought status in the forecast season and generates the PDF and cumulative distribution function (CDF) of future droughts given the past status. The conditional PDF can return the highest probable drought in the future along with an assessment of the uncertainty around that value. Using the conditional CDF for forecast season, the model can generate the maps of drought status across the basin with particular chance of occurrence in the future. In a different analysis of the conditional CDF developed for the forecast season, the chance of a particular drought in the forecast period can be approximated given the drought status of earlier seasons. The forecast methodology developed in this study shows promising results in hydrologic forecasts and its particular probabilistic features are inspiring for future studies. Close

• 1409. [Article] The effect of the size and orientation of large wood on pool volume in two Oregon Coast Range streams

  This study was conducted to determine how the size and orientation of large wood placed in streams in combination with peak flows, substrate and channel gradient affect pool volume, surface area and maximum ...

  Citation × Citation Citation Abstract Copy Title: The effect of the size and orientation of large wood on pool volume in two Oregon Coast Range streams Author: Lombard, Pamela This study was conducted to determine how the size and orientation of large wood placed in streams in combination with peak flows, substrate and channel gradient affect pool volume, surface area and maximum depth in two coastal Oregon streams. Eighteen Douglas-fir (Pseudotsuga menziesii) logs were placed in each of two streams, J-Line Creek and Preacher Creek, in the summer of 1989. Surveys were conducted annually from 1989-1996 at summer low flow using a total station electronic theodolite. The orientation of the introduced wood and the parameters of residual pools associated with the wood were determined from high resolution topographic maps made from the surveys. Residual pool volume associated with the introduced wood increased 2,500 percent over the seven years for J-Line Creek and 30 percent for Preacher Creek. Large spanners, logs placed perpendicular to the stream flow and flush with the stream bottom, had the greatest pool volume associated with them, however horizontal orientations shifted downstream over time. Large ramps, logs placed at a downstream orientation and angled up onto the bank, were the most stable treatment. Differences between the two watersheds and an interaction variable between the diameter of the introduced wood and the horizontal orientation of the introduced wood were the significant variables which entered the multiple linear regression model for residual pool volume. These variables, as well as the vertical orientation of the introduced wood, were significantly correlated to both residual pool surface area and maximum depth. The recurrence interval of the annual maximum instantaneous peak flow was not significantly associated with residual pool volume, surface area nor maximum depth. Multiple regression models explained, at most, twenty-eight percent of the variability in residual pool volume, maximum depth and surface area. Estimates of pool volume obtained with aquatic habitat inventories (Bisson et al., 1982) were compared with residual pool calculations determined from the topographic maps. Pool volume in a reach determined by aquatic habitat inventories explained 96 percent of the variability of residual pool volume in a reach, however estimates of individual pool volume explained only 40 percent of the variability in residual pool volume. Title: The effect of the size and orientation of large wood on pool volume in two Oregon Coast Range streams Author: Lombard, Pamela This study was conducted to determine how the size and orientation of large wood placed in streams in combination with peak flows, substrate and channel gradient affect pool volume, surface area and maximum depth in two coastal Oregon streams. Eighteen Douglas-fir (Pseudotsuga menziesii) logs were placed in each of two streams, J-Line Creek and Preacher Creek, in the summer of 1989. Surveys were conducted annually from 1989-1996 at summer low flow using a total station electronic theodolite. The orientation of the introduced wood and the parameters of residual pools associated with the wood were determined from high resolution topographic maps made from the surveys. Residual pool volume associated with the introduced wood increased 2,500 percent over the seven years for J-Line Creek and 30 percent for Preacher Creek. Large spanners, logs placed perpendicular to the stream flow and flush with the stream bottom, had the greatest pool volume associated with them, however horizontal orientations shifted downstream over time. Large ramps, logs placed at a downstream orientation and angled up onto the bank, were the most stable treatment. Differences between the two watersheds and an interaction variable between the diameter of the introduced wood and the horizontal orientation of the introduced wood were the significant variables which entered the multiple linear regression model for residual pool volume. These variables, as well as the vertical orientation of the introduced wood, were significantly correlated to both residual pool surface area and maximum depth. The recurrence interval of the annual maximum instantaneous peak flow was not significantly associated with residual pool volume, surface area nor maximum depth. Multiple regression models explained, at most, twenty-eight percent of the variability in residual pool volume, maximum depth and surface area. Estimates of pool volume obtained with aquatic habitat inventories (Bisson et al., 1982) were compared with residual pool calculations determined from the topographic maps. Pool volume in a reach determined by aquatic habitat inventories explained 96 percent of the variability of residual pool volume in a reach, however estimates of individual pool volume explained only 40 percent of the variability in residual pool volume. Close

• 1410. [Article] Influence of cover crops on vine performance at two Willamette Valley vineyards

  It is estimated that 50-75% of Oregon vineyards cultivate at least every other alley in order to 1) reduce water stress 2) increase vineyard canopy temperatures and 3) increase nutrient availability. Because ...

  Citation × Citation Citation Abstract Copy Title: Influence of cover crops on vine performance at two Willamette Valley vineyards Author: Sweet, Rebecca Marie It is estimated that 50-75% of Oregon vineyards cultivate at least every other alley in order to 1) reduce water stress 2) increase vineyard canopy temperatures and 3) increase nutrient availability. Because many vineyards are situated on steep hillsides, frequent tillage could result in increased soil erosion, decreased soil quality and potential pollution of watersheds. Seven cover crop treatments were established at two commercial vineyards in the northern Willamette Valley in the fall of 2003 and monitored for establishment and their impact on grapevines in 2004 and 2005. Treatments were as follows: 1) winter annuals (oats, rye and vetch), 2) clover mix (subclovers, clovers and medic), 3) native grass mix (Willamette Valley upland prairie species), 4) native meadow mix (forbs plus grasses), 5) perennial grass mix (sheep fescue, dwarf perennial rye and hard fescue), 6) resident vegetation, and 7) a clean cultivated control. Each treatment was replicated four times at each of the vineyards in a randomized complete block design. Treatments were applied to four adjacent alleys flanking 8 or 10 vines in three vine rows with one clean cultivated boarder dividing blocks. Cover crop establishment was measured by destructively removing biomass during the growing season. Weeds were sorted from cover crops, and both were dried, weighed and measured for nitrogen (N) content. Over the course of the growing season, soil water was measured in the vine row and alleys with time domain reflectometry, and midday vine leaf water potential was measured with a pressure bomb. Shoot lengths were measured twice during the season. Vine leaf blades were collected at bloom and veraison for nutrient analysis (N,P,K, S, Ca, Mg, Mn, Cu, B, Zn and Fe). Root samples were taken at bloom and post harvest in the vine row and alley in three treatments (winter annuals, perennial grass mix and clean cultivated) and analyzed for colonization by arbuscular mycorrhizal fungi (AMF). At harvest, fruit yield was measured and fruit quality assessed by measuring soluble solids (BRIX), titratable acidity, pH and N content. Shoot prunings were collected and measured after vine dormancy. We expected to see 1) a higher amount of water in the soil, less vine water stress and more vigorous vine growth in the clean cultivated treatment compared to the others and 2) either an increase in vigor or concentration of N in vine tissues in response to the clover mix treatment. Biomass production and coverage of the soil by cover crops, as well as responses to treatments in the soil and vine often varied between sites. In general, cover crop treatments, including the clean cultivated control, had little effect on soil water content, vine water status, or vine vegetative growth. There was, however, a clear N affect from the clover mix treatment on vines, even without mechanical incorporation of cover crop residues. Vine leaf N and juice YANC both increased, and yield per vine and cluster weights both decreased in the clover mix treatment. However, the yield reductions were more pronounced in year two and only at one site. The increase in juice N was possibly an indirect effect of the lower yield, concentrating N in the remaining fruit. Results from this two year study indicate no apparent advantage to keeping the alleyways of established vineyards weed free with cultivation. Title: Influence of cover crops on vine performance at two Willamette Valley vineyards Author: Sweet, Rebecca Marie It is estimated that 50-75% of Oregon vineyards cultivate at least every other alley in order to 1) reduce water stress 2) increase vineyard canopy temperatures and 3) increase nutrient availability. Because many vineyards are situated on steep hillsides, frequent tillage could result in increased soil erosion, decreased soil quality and potential pollution of watersheds. Seven cover crop treatments were established at two commercial vineyards in the northern Willamette Valley in the fall of 2003 and monitored for establishment and their impact on grapevines in 2004 and 2005. Treatments were as follows: 1) winter annuals (oats, rye and vetch), 2) clover mix (subclovers, clovers and medic), 3) native grass mix (Willamette Valley upland prairie species), 4) native meadow mix (forbs plus grasses), 5) perennial grass mix (sheep fescue, dwarf perennial rye and hard fescue), 6) resident vegetation, and 7) a clean cultivated control. Each treatment was replicated four times at each of the vineyards in a randomized complete block design. Treatments were applied to four adjacent alleys flanking 8 or 10 vines in three vine rows with one clean cultivated boarder dividing blocks. Cover crop establishment was measured by destructively removing biomass during the growing season. Weeds were sorted from cover crops, and both were dried, weighed and measured for nitrogen (N) content. Over the course of the growing season, soil water was measured in the vine row and alleys with time domain reflectometry, and midday vine leaf water potential was measured with a pressure bomb. Shoot lengths were measured twice during the season. Vine leaf blades were collected at bloom and veraison for nutrient analysis (N,P,K, S, Ca, Mg, Mn, Cu, B, Zn and Fe). Root samples were taken at bloom and post harvest in the vine row and alley in three treatments (winter annuals, perennial grass mix and clean cultivated) and analyzed for colonization by arbuscular mycorrhizal fungi (AMF). At harvest, fruit yield was measured and fruit quality assessed by measuring soluble solids (BRIX), titratable acidity, pH and N content. Shoot prunings were collected and measured after vine dormancy. We expected to see 1) a higher amount of water in the soil, less vine water stress and more vigorous vine growth in the clean cultivated treatment compared to the others and 2) either an increase in vigor or concentration of N in vine tissues in response to the clover mix treatment. Biomass production and coverage of the soil by cover crops, as well as responses to treatments in the soil and vine often varied between sites. In general, cover crop treatments, including the clean cultivated control, had little effect on soil water content, vine water status, or vine vegetative growth. There was, however, a clear N affect from the clover mix treatment on vines, even without mechanical incorporation of cover crop residues. Vine leaf N and juice YANC both increased, and yield per vine and cluster weights both decreased in the clover mix treatment. However, the yield reductions were more pronounced in year two and only at one site. The increase in juice N was possibly an indirect effect of the lower yield, concentrating N in the remaining fruit. Results from this two year study indicate no apparent advantage to keeping the alleyways of established vineyards weed free with cultivation. Close