Fall Cold Research Articles

Family variation for fall cold hardiness in two Washington populations of coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco)

In order to assess the genetics of fall cold hardiness in coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco), shoot cuttings were collected in October from saplings (9-year-old trees) of open-pollinated families in two progeny tests in each of two breeding zones in Washington, one in the Coast range (80 families) and one on the west slope of the Cascade Mountains (89 families). Samples from over 5500 trees were subjected to artificial freezing and visually evaluated for needle, stem and bud tissue injury. The extent to which cold injury is genetically related to tree height and shoot phenology (timing of bud burst and bud set) was also evaluated.Significant family variation was found for all cold hardiness traits; however, individual heritability estimates were relatively low (ranging from 0.09 to 0.22). Significant family-by-test site interaction was detected for needle injury in the Cascade breeding zone, but not in the coastal zone. Genetic correlations (rA) among needle, stem and bud tissues for cold damage were weak (0.16 ≤ rA ≤ 0.58) indicating that genes controlling fall hardening are somewhat different for different tissues. Timing of bud burst and bud set were only weakly correlated with cold injury (rA ≤ 0.49). Thus, bud phenology is a poor predictor of fall cold hardiness in this species. There was no consistent relationship between tree height and cold injury in the coastal zone. In the Cascade zone, taller trees appeared to be more susceptible to cold injury, but the association was weak (mean rA = 0.38, range 0.20–0.72).

Frost injury prediction model for Douglas-fir seedlings in the Pacific Northwest.

Because simple seed- or breeding-zone guidelines are inadequate for controlling the risk of maladaptation to environmental stresses, we are developing operational procedures to assess the risk of frost kill to genetically improved families of Douglas-fir (Pseudotsuga menziesii Mirb. Franco). We have (1) determined the time course of cold hardening and dehardening of nursery-grown Douglas-fir seedlings over four winters, by means of controlled freezing tests, (2) fitted curves to relationships between temperature sum and both fall cold hardening and spring dehardening, (3) applied the temperature sum models to daily temperature records of 80 weather stations to estimate frequency of years with significant frost kill at those stations, (4) interpolated frost kill probabilities for tree farms, using a thin plate spline procedure with elevation, latitude and longitude as variables, and (5) prepared a coarse-scale frost risk map from the resulting grid point estimates. With the exception of a few high-elevation stations, the most damaging frost at any station in any year occurred in either the fall (October and November) or late spring (mid-April to mid-May). In general, damaging spring frosts were two to three times more frequent than fall frosts, and areas in Oregon were at greater risk than areas at similar elevations and longitudes further north. The spline surface was less precise for predicting spring frost risk than fall frost risk.

Dissolved oxygen in streams and reservoirs

Water Environment ResearchVolume 66, Issue 4 p. 601-602 Fate and Effects of PollutantFree Access Dissolved oxygen in streams and reservoirs John A. Gordon, John A. GordonSearch for more papers by this authorJulia B. Avera, Julia B. AveraSearch for more papers by this author John A. Gordon, John A. GordonSearch for more papers by this authorJulia B. Avera, Julia B. AveraSearch for more papers by this author First published: 01 June 1994 https://doi.org/10.1002/j.1554-7531.1994.tb00124.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. REFERENCES Ashby, S.L., and Kennedy, R.H. (1993) Effects of Artificial Destratification on Water Quality at East Sidney Lake, New York. Miscellaneous Paper W-93-2, U.S. Army Engineer Waterways Experiment Station, Vicksburg, Miss. Cerco, C.F. (1993) Predictive Modeling of Sediment Oxygen Demand and Nutrient Flux. Water Operations Technical Support, Vol. E-93-3, U.S. Army Engineer Waterways Experiment Station, Vicksburg, Miss. Dean, K.E., et al. (1993) Particle-mediated Transport and Fate of a Hydrophobic Organic Contaminant in Southern Lake Michigan—The Role of Major Water Column Particle Species. J. Great Lakes Res., 19, 2. DiToro, D., and Fitzpatrick, J. (1993) Chesapeake Bay Sediment Flux Model. Contract Report EL-93-2, U.S. Army Engineer Waterways Experiment Station, Vicksburg, Miss. Ferris, J.M., and Tyler, P.A. (1993) The Effects of Inflow and Outflow on the Seasonal Behaviour of a Stratified Reservoir in Temperate Australia—A 20 Year Analysis. Arch. Hydrobiol. (Ger.), 126, 2. Greb, S.R., and Graczyk, D.J. (1993) Dissolved Oxygen Characteristics of Wisconsin Streams. Water Sci. Technol. (G.B.), 28, 3– 5. Molot, L.A., et al. (1992) Predicting End-of-summer Oxygen Profiles in Stratified Lakes. Can. J. Fish. Aquat. Sci., 49, 11. Rutherford, J.C., et al. (1993) Bedform Mobility and Benthic Oxygen Uptake. Water Res. (G.B.), 27, 10. Stauffer, R.E. (1993) Effects of an Early Fall Cold Front on Heat, Phosphorus, Silica, and Manganese Distributions in the Hypolimnion of Lake Mendota, Wisconsin. J. Hydrol., 151, 1. Volume66, Issue41994 Literature ReviewJune 1994Pages 601-602 ReferencesRelatedInformation

Effects of an early fall cold front on heat, phosphorus, silica, and manganese distributions in the hypolimnion of Lake Mendota, Wisconsin

I examined the effects of an early fall (8–10 September 1977) cold front on eutrophic Lake Mendota, Wisconsin, during which ‘Lake Number’ L N (dimensionless) attained a minimum 3 h value of 0.45, and remained below 1.0 for a total of 39 h. The front accelerated heat transport downward through the main thermocline, resulting in hypolimnetic warming; the vertical eddy conductivity K z increased monotonically with depth from a minimum 0.8 m 2 day −1 at 16 m to 1.9 m 2 day −1 at 21 m. The front also affected significant lateral and vertical redistribution of three passive solute ‘tracers’: phosphate (P), silicic acid (Si) and soluble reduced manganese (Mn 2+). Lateral concentration gradients along isopycnals predating the storm were erased. For Mn, especially, the vertical redistribution within the hypolimnion agreed with modeled changes based on vertical gradients and the K z profile. Mn and P behaved quasi-conservatively within the anoxic hypolimnion (no net sources or sinks), but additional supplies of Si appeared in the hypolimnion (8.0 ± 1.5 mg m −3 day −1). This rate over 4 days agreed with the mean rate of hypolimnetic Si accumulation over the 80 day interval preceding 7 September 1977 (8.7 mg m −3 day −1). These results corroborate other environmental evidence that Mn and P both enter Lake Mendota's hypolimnion mainly during the first half of the summer, prior to the onset of bulk hypolimnetic anoxia, whereas Si is released by hypolimnetic sediments continuing into the late summer.

Circannual cycles in golden-mantled ground squirrels: fall and spring cold pulses

Endogenous circannual rhythms of male golden-mantled ground squirrels (Spermophilus lateralis) exposed to low ambient temperature (6 °C) at various times were compared to the rhythms of a control group kept in a warm room (21 °C) throughout. A 20-week pulse of cold in the spring delayed the subsequent peak body weight and molt offset. However, in the second year after the spring cold pulse, a delay in the rhythm was evident only using peak weight as a phase marker. A 20-week cold pulse in the fall resulted in an earlier peak body weight and earlier onset of pigmented scrotum and descended testes, but there was no evidence from subsequent years that rhythms had been phase advanced. A third of the animals kept continuously at 6 °C remained with pigmented scrotum, descended testes and low body weight for more than a year. Circannual periodicities of animals that continued to display rhythms in the cold room were not significantly longer than those of controls in the warm room. The results suggest that low temperature in the fall can alter the expression of circannual rhythms without much affecting their phasing, while low temperature in the spring produces phase delays which last longer but have not been proved to be persistent.

Fruiting as a Factor in Accumulation of Carbohydrates and Nitrogen and in Fall Cold Hardening of Day-neutral Strawberry Roots

Nitrogen and carbohydrate content of roots and the onset of crown cold hardiness were compared in `Tristar' day-neutral (DN) strawberries (Fragaria × ananassa Duch.) that were given various fruit removal treatments. Nontreated `Hecker' DN and `Redcoat' Junebearer were also used to determine genotypic variation. The removal of fruit after 15 or 30 Sept. promoted the accumulation of starch and increased cold tolerance of crowns as compared to fruiting plants. Nitrogen was increased only when fruit was removed after 15 Sept. DN cultivars were less hardy than Junebearing cultivars, but `Tristar' was almost as hardy as `Redcoat'. When compared to `Redcoat', DN cultivars had a less abrupt temperature-kill profile, perhaps because they were multicrowned.

Growth and cold hardiness of container-grown Douglas-fir, noble fir, and Sitka spruce seedlings in simulated greenhouse regimes

Seedlings of Pseudotsugamenziesii (Mirb.) Franco, Abiesprocera Rehd., and Piceasitchensis (Bong.) Carr. were grown for 5 months in growth rooms which simulated hot, warm, or cool growing regimes in greenhouses in western Oregon. Temperature, humidity, light intensity, and photoperiod were changed diurnally and seasonally. In all three species, maximum heights of seedlings were attained in the hot regime, whereas stem diameters were similar under the hot and warm regimes. Dry weight increment was greatest in the warm regime. The cool regime was suboptimal for all aspects of growth. Seedlings grown in the hot regime were least resistant to cold in early fall. Differences in resistance to cold of seedlings grown in the warm and cool regimes varied by species and type of damage.