Changes in light intensity and soil temperature as a result of forest decline on Camels Hump, Vermont

1987 ◽  
Vol 17 (6) ◽  
pp. 565-568 ◽  
Author(s):  
T. D. Perkins ◽  
H. W. Vogelmann ◽  
R. M. Klein
Keyword(s):  
Light Intensity ◽  
Boreal Forest ◽  
Soil Temperature ◽  
Forest Decline ◽  
Red Spruce ◽  
Time Period

Light intensity, measured by the anthracene–benzene technique, significantly increased in the montane boreal forest of Camels Hump mountain, Vermont, since the mid- 1960's. The region of increased light corresponds to those elevations where red spruce (Picearubens Sarg.) has declined significantly over the same time period. Soil temperature measured at 15 cm has increased and there is higher week-to-week variability than in the 1960's, especially where canopy decline is most severe.

scholarly journals Influences of Shading and Fall Fertilization on Fluorescence, Freeze Resistance, Flower Production and Growth of Rhododendron ×kurume ‘Pink Pearl’

2012 ◽  
Vol 30 (1) ◽  
pp. 28-34
Author(s):  
Frank P. Henning ◽  
Timothy J. Smalley ◽  
Orville M. Lindstrom ◽  
John M. Ruter
Keyword(s):  
Light Intensity ◽  
Dry Weight ◽  
Fertilizer Application ◽  
High Rate ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Freeze Resistance ◽  
Time Period ◽  
Shade Cloth ◽  
Main Plot

We investigated the influences of fall fertilization and light intensity on photosynthesis and freeze resistance of Rhododendron ×kurume ‘Pink Pearl’, an evergreen azalea cultivar, grown outdoors in containers under nursery conditions. The study included two main-plot fall fertilization treatments: 1) 0.5 liter solution containing 75 mg·liter−1 N applied for 60 days from August 1 through September 29 and 2) 0.5 liter solution containing 125 mg·liter−1 N applied for 120 days from August 1 through November 28, and four subplot light intensity treatments 1) 100% ambient photon flux density (PPFD) from May 1, 2004, through May 1, 2005, 2) shade fabric rated to reduce PPFD by 50% from May 1 through September 30, 2004, followed by 100% PPFD from October 1, 2004, through May 1, 2005, 3) 100% PPFD from May 1 through September 30, 2004, followed by 50% PPFD from October 1, 2004, through May 1, 2005, and 4) 50% PPFD from May 1, 2004, through May 1, 2005. Fertilizer application and shade treatments did not interact in their effects on stem freeze resistance or the timing of anthesis. The high rate of extended fertigation (125 mg·liter−1 N applied August 1 through September 28) reduced freeze resistance of azalea stems and advanced anthesis by 4.9 days compared to plants that received moderate fertigation (75 mg·liter−1 N from August 1 through September 29). The high rate of extended fall fertigation failed to increase leaf or stem dry weight compared to plants that received the moderate rate of fertigation. Plants grown in 50% PPFD from May 1 through September 30 produced 163% more above ground dry weight compared to plants grown in 100% light during the same time period. The addition or removal of shade cloth beginning October 1 failed to enhance azalea stem freeze resistance compared to plants that were only exposed to 100 or 50% PPFD respectively. Shade treatments affected the chlorophyll fluorescence ratio (Fv · Fm−1) of leaves, but leaf fluorescence was unrelated to stem freeze resistance. Shade treatments affected azalea growth and photosynthetic stress, but shade neither interacted with fall fertilization to increase stem freeze resistance, nor had a biologically significant effect on stem freeze resistance.

scholarly journals The Effect of Tillage Treatments on Soil Temperature at Planting and on Corn (Zea mays L.) Yield

2001 ◽  
pp. 40-44
Author(s):  
Miklós Pakurár ◽  
László Lakatos ◽  
János Nagy
Keyword(s):  
Zea Mays ◽  
Soil Temperature ◽  
Zea Mays L ◽  
Time Period ◽  
Soil Temperatures ◽  
Time Periods ◽  
Time Required ◽  
Corn Hybrid

The effect of soil temperature was evaluated on the yield of the Occitan corn hybrid at a depth of 5 cm. We examined this effect on the time required from planting to emergence for three average durations: five, ten and fifteen days, all calculated from the day of planting. Winter plowing (27 cm), spring plowing (23 cm), disc-till (12 cm) treatments and 120 kg N per hectare fertilizer were applied. As a result of our analysis, we determined the post planting optimum soil temperatures for various time periods. The average soil temperature for a time period of 15 days post planting is the most usable for determining actual yields, followed by ten days, with five days proved to be the least usable (winter plow R2 = 0.86, spring plow R2 = 0.87, disc-till R2 = 0.64).

Induction of nitrate reductase activity in red spruce needles by NO2 and HNO3 vapor

1989 ◽  
Vol 19 (7) ◽  
pp. 889-896 ◽  
Author(s):  
Richard J. Norby ◽  
Yohan Weerasuriya ◽  
Paul J. Hanson
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Forest Decline ◽  
Reductase Activity ◽  
Control Level ◽  
Red Spruce ◽  
Acid Vapor ◽  
Unexposed Control ◽  
Acid Mist ◽  
Spruce Needles

The induction of the enzyme nitrate reductase in needles may be a prerequisite for the assimilation of foliar-absorbed nitrogen oxide pollutants by red spruce (Picearubens Sarg.) trees. To test for induction of nitrate reductase, 1-year-old red spruce seedlings were exposed to NO2, HNO3 vapor, or acid mist containing nitrate, and the activity of nitrate reductase in needles was measured. One day after exposure to NO2 (75 nL•L−1) began, nitrate reductase activity was three times greater than that of unexposed control plants. One day after exposure ended, the nitrate reductase activity returned to the control level. Older red spruce seedlings that had been excavated from a spruce–fir stand exhibited a similar pattern of response, but the level of nitrate reductase activity was much lower than that of the 1-year-old seedlings. Nitric acid vapor (75 nL•L−1) also induced nitrate reductase in red spruce needles, and the pattern of response was similar to that with NO2, except that the nitrate reductase activity did not return to control levels until 2 days after exposure ended. Exposure of seedlings to acid mist containing nitrate (pH 3.5 and 5.0) did not result in a change in nitrate reductase activity. These results indicate that red spruce is capable of assimilating NO2 and HNO3 vapor and that hypotheses of forest decline based on foliar assimilation of pollutant nitrogen oxides are tenable.

Seasonal air and soil temperature effects on photosynthesis in red spruce (Picea rubens) saplings

1997 ◽  
Vol 17 (3) ◽  
pp. 187-194 ◽  
Author(s):  
P. A. Schwarz ◽  
T. J. Fahey ◽  
T. E. Dawson
Keyword(s):  
Soil Temperature ◽  
Temperature Effects ◽  
Picea Rubens ◽  
Red Spruce

The Ontario Hardwood Forest Health Survey: 1986 – 1998

2000 ◽  
Vol 76 (5) ◽  
pp. 783-791 ◽  
Author(s):  
D. L. McLaughlin ◽  
M. Chiu ◽  
D. Durigon ◽  
H. Liljalehto
Keyword(s):  
Air Pollution ◽  
Forest Decline ◽  
Acidic Deposition ◽  
Forest Health ◽  
Leaf Size ◽  
Hardwood Forest ◽  
Time Period ◽  
Northern Regions ◽  
Branch Dieback ◽  
Shallow Soils

In 1986 the Ontario government established a long-term program to monitor hardwood forest health. The program was initiated in response to widespread reports of forest decline in North America and Europe and the implication that air pollution, specifically acidic deposition, was a causal factor. Visual symptoms of branch dieback, leaf colour, and leaf size, have been quantitatively evaluated on about 15 000 trees in 110 plots. This report summarizes the results of the first 12 years (1986 to 1998). Over that time period, relative to the 1986 baseline year, 84% of the plots have improved in condition, 12% have not changed, and 4% have deteriorated. Generally, hardwood forest health in the province appears to be quite good; severe decline is limited and very site-specific, occurring only in selected northern regions on acid-sensitive and/or marginal sites, or in southern areas on very shallow soils. Northern forests growing on coarse-textured shallow soils underlain by precambrian rock are in poorer health relative to southern forests growing on finer-textured, deeper soil over limestone. On soils sensitive to acidic deposition, tree health deteriorated as soil pH and exchangeable aluminum levels increased. Key words: forest health, forest decline, decline index, Ontario, hardwood, air pollution, acid rain

Cation-anion relationships in crop nutrition:V. The effects of soil temperature, light intensity and soil-water tension

1965 ◽  
Vol 64 (3) ◽  
pp. 379-386 ◽  
Author(s):  
R. K. Cunningham ◽  
K. F. Nielsen
Keyword(s):  
Light Intensity ◽  
Soil Temperature ◽  
Soil Water ◽  
Clay Loam ◽  
The Third ◽  
Rye Grass ◽  
Soil Water Tension ◽  
Water Tension

The effects of soil temperature, light intensity, soil-water tension and amount and form of N, on cation-anion relationships in Italian rye-grass were tested by growing grass in a clay loam in three experiments under glass. The grass had six levels of NO3-N or NH4-N with a uniform dressing of P, S, K, Ca and Mg; NH4-N was treated with 'NServe' to prevent nitrification. In the first experiment the grass was grown at 11°, 19-5° and 28° C, in the second in 100, 68 and 44% glasshouse ' daylight', and in the third at three soil-water tensions. Yields were greatest at 19-5° C, 100% glasshouse

scholarly journals Do recent NDVI trends demonstrate boreal forest decline in Alaska?

2020 ◽  
Vol 15 (9) ◽  
pp. 095007
Author(s):  
N M Fiore ◽  
M L Goulden ◽  
C I Czimczik ◽  
S A Pedron ◽  
M A Tayo
Keyword(s):  
Boreal Forest ◽  
Forest Decline
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