Symposium Long-term weed management studies in the Pacific Northwest

Abstract Native lamprey populations are declining worldwide. In the Pacific Northwest focus on conservation and management of these ecologically and culturally important species has increased. Concern has emerged regarding the effects of sampling and handling of lamprey, with little to no attention given to the larval lifestage. We monitored the survival of larval Pacific Lamprey Entosphenus tridentatus and Lampetra spp. after backpack electrofishing, deepwater electrofishing and suction-pumping, anesthesia, and handling. We performed survival trials on wild-caught lamprey (n = 15 larvae in each trial) collected from the Clackamas River drainage in Oregon, USA, coupled with control group trials from lamprey sourced from a hatchery (n = 10 larvae). Short-term (96 h) survival was >98% with only one observed mortality. Delayed mortality (1 wk) was observed for four individuals that had fungus; two of those were positive for the bacteria Aeromonas hyrdrophila. We recorded blood hematocrit as a secondary measure of stress. The baseline, nonstressed larvae hematocrit levels did not differ from those of fish that had undergone stress through electrofishing, suction-pumping, and handling without anesthesia. Electrofishing, suction-pumping, and anesthesia showed no short-term negative effects on larval lamprey although potential long-term effects remain unstudied. These techniques appear to provide efficient and relatively safe methods for collecting and surveying larval lamprey.

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Long-Term Effects of Tillage, Nitrogen, and Rainfall on Winter Wheat Yields in the Pacific Northwest

Agronomy Journal ◽

10.2134/agronj2003.8280 ◽

2003 ◽

Vol 95 (4) ◽

pp. 828-835 ◽

Cited By ~ 31

Author(s):

K. M. Camara ◽

W. A. Payne ◽

P. E. Rasmussen

Keyword(s):

Winter Wheat ◽

Pacific Northwest ◽

Long Term Effects ◽

The Pacific

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Economic Costs of Different Riparian Management Regulations in the Pacific Northwest

Western Journal of Applied Forestry ◽

10.1093/wjaf/22.1.36 ◽

2007 ◽

Vol 22 (1) ◽

pp. 36-41 ◽

Cited By ~ 3

Author(s):

Kevin W. Zobrist ◽

Bruce R. Lippke

Keyword(s):

Pacific Northwest ◽

Lower Cost ◽

Riparian Habitat ◽

Economic Costs ◽

Wood Production ◽

Riparian Management ◽

The Pacific ◽

Western Washington ◽

Management Issues

Abstract Riparian management is an important consideration for sustainable wood production in the Pacific Northwest. Western Washington and Oregon have similar riparian management issues but different regulatory prescriptions. Application of these prescriptions to a sample of 10 small private ownerships illustrate some of the economic differences of each state's approach. Economic costs tend to be higher in Washington but can be significant in both states. Lower cost strategies through alternate plans may be important for protecting riparian habitat while ensuring the long-term economic viability of forestry in the region.

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Effects of Herbicide, Tillage, and Grass Seeding on Wild Chervil (Anthriscus sylvestris)

Invasive Plant Science and Management ◽

10.1614/ipsm-d-10-00068.1 ◽

2011 ◽

Vol 4 (3) ◽

pp. 326-331 ◽

Cited By ~ 4

Author(s):

Timothy W. Miller ◽

Danielle E. D'Auria

Keyword(s):

Pacific Northwest ◽

Weed Management ◽

Dry Weight ◽

Integrated Weed Management ◽

Native Plant ◽

Forage Production ◽

Perennial Weed ◽

Native Plant Species ◽

Herbicide Treatment ◽

The Pacific

AbstractWild chervil is an invasive biennial or short-lived perennial weed introduced into North America that negatively impacts forage production and degrades habitat for native plant species. A 2-yr study using prebloom mowing followed by combinations of herbicide, tillage, and grass seeding was conducted in the Pacific Northwest to identify an effective integrated weed management strategy for this species. By 2 mo after herbicide treatment (MAHT), wild chervil control with glyphosate + ammonium sulfate (AMS) and clopyralid was 83 and 73%, respectively. Tillage with or without herbicide pretreatment resulted in 92 to 98% wild chervil control at 2 MAHT, whereas herbicide without tillage gave only 45% control across all treatments. Tillage with or without subsequent grass seeding reduced wild chervil density four-fold compared to herbicide alone at 9 MAHT. Herbicide + tillage + grass seeding resulted in similar wild chervil cover (1 to 5% cover) as herbicide + tillage (1 to 6% cover) without subsequent grass seeding. Wild chervil biomass at 1 yr after herbicide treatment (YAHT) was reduced to 487 kg ha−1 (439 lb ac−1) with herbicide + tillage compared to 4,256 kg ha−1 for herbicide treatment alone. Herbicide + tillage + grass seeding increased grass dry weight at 1 YAHT from 201 kg ha−1 for herbicide + tillage to 1,575 kg ha−1, compared to 351 kg ha−1 in herbicide-only plots.

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Nitrogen Fertility and Weed Management Critical for Continuous No-Till Wheat in the Pacific Northwest

Weed Technology ◽

10.1614/wt-05-133r.1 ◽

2006 ◽

Vol 20 (3) ◽

pp. 658-669 ◽

Cited By ~ 3

Author(s):

Frank L. Young ◽

Mark E. Thorne ◽

Douglas L. Young

Keyword(s):

Winter Wheat ◽

Pacific Northwest ◽

Crop Yield ◽

Spring Wheat ◽

Weed Management ◽

Weed Density ◽

N Level ◽

No Till ◽

The Pacific ◽

Density And Biomass

No-till cropping is an option for growers needing to reduce soil erosion in the Palouse annual-cropped region of the Pacific Northwest, which is well suited for wheat production. A 6-yr field study was conducted to determine optimum levels of fertilizer and herbicide inputs in a no-till continuous wheat crop production system. Three levels of nitrogen (N) and two weed management levels (WML) were compared in a spring wheat (SW)–winter wheat (WW)–WW rotation through two rotation cycles. The high WML reduced weed densities about 50% compared with the low WML. In general, herbicide treatments were more effective on broadleaf weeds and may have facilitated a shift toward grass weeds. The high WML reduced grass weed biomass only at the reduced N levels, whereas the high WML reduced broadleaf weed density at all N levels. Variable environmental conditions affected wheat yield; however, yield tended to be highest where winter wheat immediately followed spring wheat. Nitrogen had little effect on weed density but increased crop yield about 13% with each increased N level. Crop yield was greater at the high versus low WML at each N level, even though weed density and biomass were reduced least between WMLs at the highest N level. The highest crop yield and net returns were obtained with the highest N and WML; however, none of the N and WML combinations were profitable.

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The 1912 Douglas-Fir Heredity Study: Long-Term Effects of Climatic Transfer Distance on Growth and Survival

Journal of Forestry ◽

10.1093/jofore/fvz064 ◽

2019 ◽

Vol 118 (1) ◽

pp. 1-13 ◽

Cited By ~ 1

Author(s):

J Bradley St. Clair ◽

Glenn T Howe ◽

Jennifer G Kling

Keyword(s):

Pacific Northwest ◽

Douglas Fir ◽

Future Climate Change ◽

Long Term Effects ◽

Term Survival ◽

Growth And Survival ◽

Seed Sources ◽

The Pacific ◽

Near Term

Abstract The 1912 Douglas-Fir Heredity Study is one of the first studies undertaken by the US Forest Service, and one of the first forest genetics studies in North America. The study considers provenance variation of 120 parent trees from 13 seed sources planted at five test sites in the Pacific Northwest. The unique, long-term nature of the study makes it valuable to revisit and consider its biological and historical significance. This analysis considers how far climatically Douglas-fir populations may be moved without incurring unacceptable declines in growth and survival. Results indicate that Douglas-fir seed sources may be moved at least 2° C cooler or warmer and still retain good long-term survival and productivity. However, projected future climate change beyond 2° C may lead to lower survival and productivity. One option to address these concerns is assisted migration; however, if seed sources are moved beyond 2–3° C to a cooler climate in anticipation of warming, or from a more continental to a maritime climate, we are likely to see increased mortality and associated losses in productivity in the near-term. Lessons from this study include: (1) pay attention to good experimental design; we were able to overcome limitations from the design by using new statistical approaches; (2) maladaptation may take time to develop; poorer survival was not evident until more than two decades after planting; and (3) long-term studies may have value for addressing new, unforeseen issues in the future.

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Seasonal Climate Variability and Change in the Pacific Northwest of the United States

Journal of Climate ◽

10.1175/jcli-d-13-00218.1 ◽

2014 ◽

Vol 27 (5) ◽

pp. 2125-2142 ◽

Cited By ~ 128

Author(s):

John T. Abatzoglou ◽

David E. Rupp ◽

Philip W. Mote

Keyword(s):

Climate Variability ◽

Pacific Northwest ◽

Time Scales ◽

Potential Evapotranspiration ◽

Seasonal Precipitation ◽

Seasonal Temperature ◽

Temperature Trends ◽

The Pacific ◽

Precipitation Trends

Abstract Observed changes in climate of the U.S. Pacific Northwest since the early twentieth century were examined using four different datasets. Annual mean temperature increased by approximately 0.6°–0.8°C from 1901 to 2012, with corroborating indicators including a lengthened freeze-free season, increased temperature of the coldest night of the year, and increased growing-season potential evapotranspiration. Seasonal temperature trends over shorter time scales (<50 yr) were variable. Despite increased warming rates in most seasons over the last half century, nonsignificant cooling was observed during spring from 1980 to 2012. Observations show a long-term increase in spring precipitation; however, decreased summer and autumn precipitation and increased potential evapotranspiration have resulted in larger climatic water deficits over the past four decades. A bootstrapped multiple linear regression model was used to better resolve the temporal heterogeneity of seasonal temperature and precipitation trends and to apportion trends to internal climate variability, solar variability, volcanic aerosols, and anthropogenic forcing. The El Niño–Southern Oscillation and the Pacific–North American pattern were the primary modulators of seasonal temperature trends on multidecadal time scales: solar and volcanic forcing were nonsignificant predictors and contributed weakly to observed trends. Anthropogenic forcing was a significant predictor of, and the leading contributor to, long-term warming; natural factors alone fail to explain the observed warming. Conversely, poor model skill for seasonal precipitation suggests that other factors need to be considered to understand the sources of seasonal precipitation trends.

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The Intracloud Lightning Fraction in the Contiguous United States

Monthly Weather Review ◽

10.1175/mwr-d-16-0426.1 ◽

2017 ◽

Vol 145 (11) ◽

pp. 4481-4499 ◽

Cited By ~ 24

Author(s):

Gina Medici ◽

Kenneth L. Cummins ◽

Daniel J. Cecil ◽

William J. Koshak ◽

Scott D. Rudlosky

Keyword(s):

United States ◽

Pacific Northwest ◽

Central California ◽

The Pacific ◽

Lightning Detection ◽

Maximum Period ◽

Total Lightning ◽

Imaging Sensor ◽

Optical Transient

This work addresses the long-term relative occurrence of cloud-to-ground (CG) and intracloud (IC; no attachment to ground) flashes for the contiguous United States (CONUS). It expands upon an earlier analysis by Boccippio et al. who employed 4-yr datasets provided by the U.S. National Lightning Detection Network (NLDN) and the Optical Transient Detector (OTD). Today, the duration of the NLDN historical dataset has more than tripled, and OTD data can be supplemented with data from the Lightning Imaging Sensor (LIS). This work is timely, given the launch of GOES-16, which includes the world’s first geostationary lightning mapper that will observe total lightning (IC and CG) over the Americas and adjacent ocean regions. Findings support earlier results indicating factor-of-10 variations in the IC:CG ratio throughout CONUS, with climatological IC fraction varying between 0.3 and greater than 0.9. The largest values are seen in the Pacific Northwest, central California, and where Colorado borders Kansas and Nebraska. An uncertainty analysis indicates that the large values in the northwest and central California are likely not due to measurement uncertainty. The high IC:CG ratio (>4) throughout much of Texas reported by Boccippio et al. is not supported by this longer-term climatology. There is no clear evidence of differences in IC fraction between land and coastal ocean. Lightning characteristics in six selected large regions show a consistent positive relationship between IC fraction and the percent of positive CG flashes, irrespective of lightning incidence (flash density), dominant season, or diurnal maximum period.

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