Nitrogen fertilization enhances cold tolerance of red spruce seedlings

1989 ◽  
Vol 19 (8) ◽  
pp. 1037-1043 ◽  
Author(s):  
D. H. DeHayes ◽  
M. A. Ingle ◽  
C. E. Waite
Keyword(s):  
Cold Tolerance ◽  
N Uptake ◽  
Late Summer ◽  
N Deposition ◽  
Early Summer ◽  
Red Spruce ◽  
Atmospheric N Deposition ◽  
N Application ◽  
Cold Tolerant ◽  
Autumn And Winter

Red spruce (Picearubens Sarg.) seedlings were treated with one of four concentrations of NH4NO3 (0, 300, 1500, and 3000 kg N•ha−1•year−1) applied to the soil, with and without triple superphosphate, during early, mid-, or late summer. Laboratory freezing assessments indicated that cold tolerance of treated seedlings generally increased with increasing nitrogen (N) uptake, with the exception of the highest N treatment. Seedlings receiving 1500 kg N•ha−1•year−1 were most cold tolerant on most sample dates. In general, these seedlings were hardier than those receiving 300 kg N•ha−1•year−1, which were hardier than unfertilized control seedlings. Seedlings receiving supplemental N also acclimated to cold more rapidly in autumn and deacclimated more slowly in spring than unfertilized controls. Supplemental phosphorus (P) had no influence on cold tolerance, and there was no evidence of a N × P interaction. Significant differences in cold tolerance associated with time of N application (early, mid-, and late summer) were detected in autumn and winter, but not in spring. In general, seedlings receiving N in mid- or late summer were as hardy or hardier than seedlings fertilized in early summer, regardless of the concentration of fertilizer. Significant interactions between N and timing of treatments occurred primarily because N applied in early summer resulted in only a slight increase in cold tolerance, whereas mid- and late summer N application resulted in a substantial increase in cold tolerance. Combined results suggest that it is highly unlikely that either the amount or timing of atmospheric N deposition is responsible for the winter injury frequently observed in red spruce.

scholarly journals Spatial and temporal distribution of phytoplankton in Lake Skadar

2012 ◽  
Vol 64 (2) ◽  
pp. 585-595 ◽  
Author(s):  
Jelena Rakocevic
Keyword(s):  
Spatial Heterogeneity ◽  
Phytoplankton Community ◽  
General Pattern ◽  
Seasonal Succession ◽  
Temporal Distribution ◽  
Late Summer ◽  
Early Summer ◽  
Quantitative Composition ◽  
Autumn And Winter ◽  
Lake Skadar

Phytoplankton seasonal succession and spatial heterogeneity were studied in Lake Skadar from February to December 2004. A total of 167 taxa from 6 algal divisions were observed, with Bacillariophyta being best represented (52.8%). The general pattern of phytoplankton seasonal succession in Lake Skadar was: Bacillariophyta in the spring, Chlorophyta in early summer, Cyanobacteria and Chlorophyta in late summer and Bacillariophyta and Chlorophyta in autumn and winter. Distinct spatial heterogeneity was observed. The central, open part of the lake (pelagic zone) was characterized by dominant euplanktonic species, mostly diatoms, whereas the western and northwestern parts (more isolated and shallower) had higher abundance of greens and blue-greens and a higher percentage of resuspended benthic-epiphytic forms in the phytoplankton community. Comparison with former phytoplankton data showed distinct differences in terms of the qualitative and quantitative composition of the phytoplankton community of Lake Skadar, which indicates lake deterioration.

scholarly journals Nutritive and photosynthetic ecology of subsurface chlorophyll maxima in Canadian Arctic waters

2012 ◽  
Vol 9 (12) ◽  
pp. 5353-5371 ◽  
Author(s):  
J. Martin ◽  
J. É. Tremblay ◽  
N. M. Price
Keyword(s):  
Primary Production ◽  
N Uptake ◽  
Canadian Arctic ◽  
Late Summer ◽  
Ecosystem Model ◽  
Early Summer ◽  
Model Parameters ◽  
Large Contribution ◽  
Total N ◽  
N Assimilation

Abstract. Assessments of carbon and nitrogen (N) assimilation in Canadian Arctic waters confirmed the large contribution of subsurface chlorophyll maxima (SCM) to total water-column production from spring to late fall. Although SCM communities showed acclimation to low irradiance and greater nitrate (NO3−) availability, their productivity was generally constrained by light and temperature. During spring–early summer, most of the primary production at the SCM was sustained by NO3−, with an average f-ratio (i.e., relative contribution of NO3− uptake to total N uptake) of 0.74 ± 0.26. The seasonal decrease in NO3− availability and irradiance, coupled to the build up of ammonium (NH4+), favoured a transition toward a predominantly regenerative system (f-ratio = 0.37 ± 0.20) during late summer and fall. Results emphasize the need to adequately consider SCM when estimating primary production and to revisit ecosystem model parameters in highly stratified Arctic waters.

scholarly journals Midwinter dehardening of montane red spruce during a natural thaw

1995 ◽  
Vol 25 (12) ◽  
pp. 2040-2044 ◽  
Author(s):  
G.R. Strimbeck ◽  
D.H. DeHayes ◽  
J.B. Shane ◽  
G.J. Hawley ◽  
P.G. Schaberg
Keyword(s):  
Cold Tolerance ◽  
Photosynthetic Capacity ◽  
Red Spruce ◽  
Balsam Fir ◽  
Freezing Injury ◽  
Field Site ◽  
Risk Of Injury ◽  
Warm Weather ◽  
Cold Tolerant ◽  
Net Assimilation

We documented 3 to 14 °C of dehardening in current-year foliage of 10 mature, montane red spruce (Picearubens Sarg.) trees during a natural thaw from 12 to 21 January 1995. Mean cold tolerance was about −47 °C before the onset of thaw conditions, and individuals ranged from −38 to −52 °C. After 3 days of thaw, mean cold tolerance dropped to −39 °C, with a range of −32 to −44 °C. Trees did not regain prethaw levels of cold tolerance until sometime between 31 January and 9 February, or 10 to 20 days after subfreezing temperatures resumed. The least cold tolerant tree was at risk of injury when temperature at the field site fell to an estimated −33.8 °C on 6 February, and this same tree developed noticeably more injury than other trees when injury symptoms developed in late March. No evidence of dehardening was found in balsam fir (Abiesbalsamea (L.) Mill.) trees from the same stand. All red spruce trees also showed the potential for net assimilation of carbon during the thaw, as determined by measurement of photosynthetic capacity under laboratory conditions. From the abrupt and substantial dehardening and persistence of the dehardened state, we conclude that dehardening during periods of warm weather may be a significant factor in freezing injury and decline of montane red spruce populations.

scholarly journals Aridity and plant uptake interact to make dryland soils hotspots for nitric oxide (NO) emissions

2016 ◽  
Vol 113 (19) ◽  
pp. E2608-E2616 ◽  
Author(s):  
Peter M. Homyak ◽  
Joseph C. Blankinship ◽  
Kenneth Marchus ◽  
Delores M. Lucero ◽  
James O. Sickman ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
N Uptake ◽  
N Deposition ◽  
N Availability ◽  
Plant N Uptake ◽  
N Loss ◽  
Atmospheric N Deposition ◽  
Soil Microbial ◽  
California Grassland ◽  
No Emissions

Nitric oxide (NO) is an important trace gas and regulator of atmospheric photochemistry. Theory suggests moist soils optimize NO emissions, whereas wet or dry soils constrain them. In drylands, however, NO emissions can be greatest in dry soils and when dry soils are rewet. To understand how aridity and vegetation interact to generate this pattern, we measured NO fluxes in a California grassland, where we manipulated vegetation cover and the length of the dry season and measured [δ15-N]NO and [δ18-O]NO following rewetting with15N-labeled substrates. Plant N uptake reduced NO emissions by limiting N availability. In the absence of plants, soil N pools increased and NO emissions more than doubled. In dry soils, NO-producing substrates concentrated in hydrologically disconnected microsites. Upon rewetting, these concentrated N pools underwent rapid abiotic reaction, producing large NO pulses. Biological processes did not substantially contribute to the initial NO pulse but governed NO emissions within 24 h postwetting. Plants acted as an N sink, limiting NO emissions under optimal soil moisture. When soils were dry, however, the shutdown in plant N uptake, along with the activation of chemical mechanisms and the resuscitation of soil microbial processes upon rewetting, governed N loss. Aridity and vegetation interact to maintain a leaky N cycle during periods when plant N uptake is low, and hydrologically disconnected soils favor both microbial and abiotic NO-producing mechanisms. Under increasing rates of atmospheric N deposition and intensifying droughts, NO gas evasion may become an increasingly important pathway for ecosystem N loss in drylands.

scholarly journals Transcriptome sequencing and iTRAQ of different rice cultivars provide insight into molecular mechanisms of cold-tolerance response in japonica rice

2020 ◽  
Author(s):  
Yan Jia ◽  
Hualong Liu ◽  
Zhaojun Qu ◽  
Jin Wang ◽  
Xinpeng Wang ◽  
...  
Keyword(s):  
Cold Stress ◽  
Cold Tolerance ◽  
Nitrogen Metabolism ◽  
N Uptake ◽  
Differentially Expressed ◽  
Japonica Rice ◽  
Rice Cultivars ◽  
Gene And Protein Expression ◽  
Cold Tolerant ◽  
Cold Sensitive

Abstract Background: Rice ( Oryza sativa L.), one of the most important crops cultivated in both tropical and temperate regions, has a high sensitivity to cold stress. Chilling stress limits N uptake and nitrogen metabolism in rice. To identify the genes and pathways involved in cold tolerance, specifically within the nitrogen metabolism pathway, we compared gene and protein expression differences between a cold-tolerant cultivar, Dongnong428 (DN), and a cold-sensitive cultivar, Songjing10 (SJ). Results: Using isobaric tags for relative or absolute quantification (iTRAQ) with high-throughput mRNA sequencing (RNA-seq) techniques, we identified 5,549 genes and 450 proteins in DN and 6,145 genes and 790 proteins in SJ, that were differentially expressed during low water temperature (T w ) treatment. There were 354 transcription factor (TF) genes (212 down, 142 up), and 366 TF genes (220 down, 146 up), including 47 gene families, differentially expressed in the DN under control (CKDN) vs. DN under low-T w (D15DN) and CKSJ vs. D15SJ, respectively. Genes related to rice cold-related biosynthesis pathways, particularly the mitogen-activated protein kinase (MAPK) signaling pathway, zeatin biosynthesis, and plant hormone signal transduction pathways, were significantly differentially expressed in both rice cultivars. Differentially expressed proteins (DEPs) related to rice cold-related biosynthesis pathways and particularly glutathione metabolism were significantly differentially expressed in both rice cultivars. Transcriptome and proteome analysis of the nitrogen metabolism pathways showed that major genes and proteins that participated in γ-aminobutyric acid (GABA) and glutamine synthesis were downregulated. Conclusion: Under cold stress conditions during reproductive growth, genes and proteins related to the biosynthesis pathways of cold stress were significantly differentially expressed in DN and SJ. The present study confirmed the known cold stress-associated genes and identified a number of putative new cold-responsive genes. We also found that translational regulation under cold stress plays an important role in cold-tolerant DN. Low-T w treatments affected N uptake and N metabolism in rice, and promoted Glu metabolism, and the synthesis of ornithine and proline in cold-sensitive SJ.

scholarly journals Variation in overstory nitrogen uptake in a small, high-elevation southern Appalachian spruce-fir watershed

2002 ◽  
Vol 32 (10) ◽  
pp. 1741-1752 ◽  
Author(s):  
M Barker ◽  
H Van Miegroet ◽  
N S Nicholas ◽  
I F Creed
Keyword(s):  
Stand Structure ◽  
N Uptake ◽  
High Elevation ◽  
N Deposition ◽  
Root Turnover ◽  
Betula Alleghaniensis ◽  
Atmospheric N Deposition ◽  
Great Smoky Mountains ◽  
Smoky Mountains ◽  
Balsam Woolly Adelgid

High-elevation red spruce (Picea rubens Sarg.) – Fraser fir (Abies fraseri (Pursh) Poir.) forests of the southern Appalachians exhibit considerable spatial heterogeneity in structure, and possibly in N uptake, because of a combination of natural disturbances and heavy fir mortality caused by infestations of the exotic balsam woolly adelgid (Adelges piceae Ratz). The objectives of this study are to determine spatial variability in tree N uptake in a small high-elevation catchment in the Great Smoky Mountains National Park, compare outcomes among calculation methods, and assess the influence of stand and landscape properties on N uptake. Tree N uptake is estimated for fifty 20 × 20 m plots in the Noland Divide Watershed (NDW). Components considered in the calculations are stem growth, foliage increment, and mortality of spruce, fir, and yellow birch (Betula alleghaniensis Britt.) from 1993 and 1998 stand inventories; throughfall N flux measured in summers 1998 and 1999; litterfall N return for 1 year in a subset of 12 plots; tissue N analyses; and atmospheric N deposition and root turnover estimates from the literature. Overstory N uptake varies spatially within NDW, with a CV of 9–41% depending on the calculation method. Variability among methods is even higher, with an almost 15-fold difference between the smallest and largest average overstory uptake estimate (5 vs. 74 kg·ha–1·year–1). Only 5 and 3 kg·ha–1·year–1 of N is sequestered in wood and foliar increment, respectively, while 36 kg·ha–1 of N returns annually as aboveground litterfall. Uptake and its components are correlated with measures of stand structure but not with elevation or aspect.

Growth and carcass characteristics of crossbred and straightbred Hereford steers. I. Post-weaning growth

1981 ◽  
Vol 32 (1) ◽  
pp. 161 ◽  
Author(s):  
JM Thompson ◽  
R Barlow ◽  
B Johnston ◽  
PJ Nicholls
Keyword(s):  
Growth Rate ◽  
Slow Growth ◽  
Carcass Characteristics ◽  
Late Summer ◽  
Coastal Environment ◽  
Early Summer ◽  
Significant Difference ◽  
The Mean ◽  
The Difference ◽  
Autumn And Winter

Post-weaning growth characteristics were examined in 28 Hereford, 27 Brahman x Hereford, 23 Simmental x Hereford and 26 Friesian x Hereford steers which were grazed on pasture in a central coastal environment at Paterson, N.S.W. Sixty-seven steers from a 1973 calving were allocated to three groups to be slaughtered when the mean liveweights of the Herefords were approximately 270, 370 and 470 kg. Thirty-seven steers from a 1974 calving were allocated to two groups to be slaughtered when the average liveweights of the Herefords were 470 and 570 kg. Average daily liveweight gains of the crossbred steers were greater (average 19%) than the Hereford steers from weaning to the four slaughter weights (P < 0.05). Of the crossbreds, the Brahman cross steers grew faster than the Simmental cross steers (P < O.05), although the difference was not significant at the highest slaughter weight. The growth advantage of the crossbreds was mainly realized in the periods of slow growth (mean growth rate of 320 g/day) during the late summer, autumn and winter months. During these periods the Brahman cross steers grew faster than the Herefords by an average of 89% (P < 0.05) and the Simmental and Friesian cross steers grew 39% faster than the Herefords (P < 0.05). In the periods of fast growth (mean growth rate of 667 g/day), during the spring and early summer months, there was no significant difference between the sire breeds in growth rate (P > 0.05).

Factors Controlling Cold Tolerance and Breeding in Balanus Balanoides

1984 ◽  
Vol 64 (1) ◽  
pp. 125-145 ◽  
Author(s):  
D. J. Crisp ◽  
A. H. Lewis
Keyword(s):  
Cold Tolerance ◽  
Chemical Potential ◽  
Lipid Fraction ◽  
Common Factor ◽  
The Body ◽  
Cold Tolerant ◽  
Food Assimilation ◽  
Autumn And Winter ◽  
Balanus Balanoides ◽  
Tolerant State

Measurements during autumn and winter of the lower median lethal temperature of the barnacle Balanus balanoides (L.) under natural and modified environmental conditions in field and laboratory, show that the cold resistant state is advanced by three factors: short day photoperiod, reduced food assimilation and reduced temperature. Their relative efficacy is in that order.These factors combine in promoting breeding and the acquisition of the cold tolerant state during autumn and winter. Although normally associated, breeding and cold tolerance are not mutually dependent; the one can be induced without the other under abnormal conditions.Similar measurements made in the spring show that only a single factor is required to terminate the cold tolerant state — resumption of food assimilation. If feeding is discontinued in the spring, however, the cold tolerant state tends to return, but animals that have bred do not breed again until the following autumn.Of the three well established mechanisms for seasonal cold tolerance — production of substances to cause freezing hysteresis, production of cryoprotective agents, and nucleating agents to promote freezing in the intercellular compartment — only the last can be entertained since the cold tolerant animal survives some 80% of the body fluids being converted to ice. The cold tolerant condition may also relate to higher levels of polyunsaturated fatty acids being present in the membrane lipid fraction in winter, so rendering cell membranes less prone to damage by ice crystals.The suggestion is made that normal metabolic activity and tolerance of low chemical potential of water - the common factor in freezing and desiccation - are not compatible.

scholarly journals Low nitrogen retention in a Japanese cedar plantation in a suburban area, western Japan

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ru Yang ◽  
Masaaki Chiwa
Keyword(s):  
N Uptake ◽  
Nitrogen Retention ◽  
Japanese Cedar ◽  
N Fertilization ◽  
N Deposition ◽  
N Leaching ◽  
Atmospheric N Deposition ◽  
Soil Nitrification ◽  
Rooting Zone ◽  
Steep Slopes

AbstractThis study aimed to evaluate nitrogen (N) leaching from Japanese cedar, the main plantation species in Japan, in response to elevated atmospheric N deposition. N leaching and possible factors, including soil nitrification, tree N uptake, and topographic steepness, were evaluated in mature (64–69 year) Japanese cedar trees planted on steep slopes (25°–40°) and neighboring Japanese oak plantations in suburban forests, which served as reference sites. N fertilization (50 kg N ha−1 year−1 as ammonium nitrate) was conducted to evaluate the response of N leaching to an elevated inorganic N pool in the surface soil. The soil water nitrate (NO3−) concentration below the rooting zone in the Japanese cedar forest (607 ± 59 μmol L−1) was much higher than that in the Japanese oak plantations (8.7 ± 8.1 μmol L−1) and increased immediately after fertilization, indicating high N leaching from the Japanese cedar plantations. The relatively low N uptake by Japanese cedar planted on the steep slopes could be an important contributor to the high N leaching. This study highlights the importance of vegetation composition for managing the water quality in headwater streams from forest ecosystems disturbed by atmospheric N deposition.

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