Exposure of mature Norway spruce to ozone in twig-chambers: effects on gas exchange

Author(s):  
Gerhard Wieser ◽  
Wilhelm M. Havranek

SynopsisLittle is known about ozone (O3) effects on adult trees in the field, where ecophysiological parameters control pollutant uptake. It was the goal of this study to examine how ambient and above ambient O3 concentrations affect gas exchange of mature Norway spruce (Picea abies (L.) Karst.). Therefore, twigs were enclosed in chambers and exposed to different O3 concentrations for one and two seasons over three years. During winter periods twigs were maintained under ambient conditions. Data from the shade crown of spruce trees at 1000 m a.s.l. are presented. After one and two fumigation periods no clear treatment effects on gas exchange were observed in twigs fumigated with O3 concentrations ranging from zero up to ambient (A) + 60 ppb. However, O3 at 90 ppb reduced photosynthesis and conductance. CO2 response curves indicated that in A + 90 twigs the efficiency of CO2 uptake was diminished. Observed losses in Pn of A + 90 twigs were greater than reductions in conductance indicating that stomatal closure alone did not limit CO2 uptake. We conclude that ambient and slightly above ambient O3 concentrations do not alter gas exchange of mature Norway spruce. Therefore, suppositions on O3 damage on mature spruce trees should be critically questioned.

2017 ◽  
Vol 47 (4) ◽  
pp. 488-499 ◽  
Author(s):  
Minna Kivimäenpää ◽  
Sirkka Sutinen ◽  
Hanna Valolahti ◽  
Elina Häikiö ◽  
Johanna Riikonen ◽  
...  

Acclimation of conifer needle anatomy to climate change is poorly understood. We studied needle anatomy, shoot gas exchange, current-year shoot length, and stem diameter growth in Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) seedlings exposed to elevated ozone (1.35× to 1.5× ambient concentration) and elevated temperature (0.9–1.3 °C + ambient temperature) alone and in combination for two exposure seasons in two separate open-field experiments in central Finland. Pines grew also at two soil nitrogen levels. In spruce, warming increased mesophyll intercellular space and reduced gas exchange and shoot growth and made needles narrower and the epidermis and hypodermis thinner. In pine, warming made needles bigger, increased shoot and stem growth, stomatal row number, and proportions of vascular cylinder, phloem, and xylem and reduced the proportion of mesophyll. These responses indicate that pine benefited and spruce suffered from moderate warming. Ozone caused a thickening of epi- and hypo-dermis and a lower stomatal conductance in both species, reduced stomatal density in spruce, and increased proportions of phloem, xylem, and sclerenchyma and reduced growth in pine. Ozone responses suggest increased oxidative stress defense. Stomatal responses were affected by interactions of elevated temperature and ozone in both species. Nitrogen availability modified ozone and temperature responses, particularly in the vascular tissues in pine.


1987 ◽  
Vol 5 (3) ◽  
pp. 97-101
Author(s):  
J.C. Neal ◽  
W.A. Skroch

Glyphosate [N-(phosphonomethyl)glycine] was applied at four rates, 0.4, 0.8, 1.5 and 3.0 kg ai/ha (0.36, 0.71, 1.34 and 2.7 lb ai/A) each at four dates, May 26, July 14, September 10, and October 27, 1982, over Fraser fir (Abies fraseri (Pursh) Poir.), Norway spruce (Picea abies (L.) Karst.), and Canadian hemlock (Tsuga canadensis (L.) Carriere). Plants were treated in 1982 and evaluated in 1983 and 1984. Plant height best described the treatment effects for hemlock and fir. Plant height plus budset on the terminal best described treatment effects for spruce. Fir and spruce were tolerant to September and October applications of glyphosate, however, May and July treatments resulted in significant phytotoxicity. Hernlock plants were injured by May, July and September glyphosate treatments, but not bv similar applications in October. Injury to all species persisted into the 1984 season from single applications in 1982.


2020 ◽  
Author(s):  
C Vincent ◽  
MO Pierre ◽  
JR Stinziano

AbstractA/Ci curves are an important gas-exchange-based approach to understanding the regulation of photosynthesis, describing the response of net CO2 assimilation (A) to leaf internal concentration of CO2 (Ci). Low stomatal conductance species pose a challenge to the measurement of A/Ci curves by reducing the signal-to-noise ratio of gas exchange measures. Additionally, the stomatal attenuation effect of elevated ambient CO2 leads to further reduction of conductance and may lead to erroneous interpretation of high Ci responses of A. Rapid A/Ci response (RACiR) curves offer a potential practice to develop A/Ci curves faster than the stomatal closure response to elevated CO2. We used the moderately low conductance Citrus to compare traditional steady state (SS) A/Ci curves with RACiR curves. SS curves failed more often than RACiR curves. Overall parameter estimates were the same between SS and RACiR curves. When low stomatal conductance values were removed, triose-phosphate utilization (TPU) limitation estimates increased. Overall RACiR stomatal conductance values began and remained higher than SS values. Based on the comparable resulting parameter estimates, higher likelihood of success and reduced measurement time, we propose RACiR as a valuable tool to measure A/Ci responses in low conductance species.


2014 ◽  
Vol 75 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Justyna Anna Nowakowska ◽  
Tadeusz Zachara ◽  
Agata Konecka

Abstract The genetic variability and biodiversity of tree populations ensure the stability and sustainability of forest ecosystems. New research tools based on molecular DNA markers enable precise characterisation of forest genetic resources, i.e. detection of different allele frequencies in mature trees and progeny populations. The paper describes the genetic structure of mature stands of Scots pine (Pinus sylvestris L.) in Oława Forest District and Norway spruce (Picea abies L. Karst.) in Jawor Forest District and stands of their respective progeny. In the Scots pine stand, there was a slight increase (0.6%) in heterozygosity level and a larger increase (4.9%) in the inbreeding coefficient of progeny trees. In the Norway spruce stand, despite a small reduction (0.9%) in heterozygosity, a similar increase (4.6%) in the inbreeding coefficient of progeny was revealed. In both stands, allele richness and the partition probability of basic clustering were high. Both pine and spruce adults and progeny trees were characterised by high levels of genetic similarity (96% and 79%, respectively). Gene flow between the mature and progeny populations was high (Nm > 1) for both Scots pine and Norway spruce. Conservation of the gene pool within forest tree stands requires an increase in the proportion of natural regeneration. To estimate the extent to which genes are transmitted between adult trees and their progeny, more studies are needed, especially taking into account the influence of silviculture measures, like selective tree cutting, on the genetic variability of the younger generation. These results confirm that the gene pool was conserved when transmitted between the stands studied, as well as highlight the usefulness of such a study for silvicultural purposes


1994 ◽  
Vol 72 (1) ◽  
pp. 86-92 ◽  
Author(s):  
D. Le Thiec ◽  
C. Rose ◽  
J. P. Garrec ◽  
D. Laffray ◽  
P. Louguet ◽  
...  

Two clones of Norway spruce Picea abies (L.) Karst. (Gerardmer clone and Istebna clone) were subjected to an ozone-enriched atmosphere. The X-ray microanalysis of elements present in the guard cells showed a decrease in potassium for the Gerardmer clone along with a larger closing of guard cells and an increase in calcium contents; for the Istebna clone, ozone did not affect these contents. When a drought stress was applied, an increase in calcium content of guard cells of the Istebna clone was also found. However, the potassium content was smaller in this case for the two clones and could well be due to stomatal closure. When ozone and drought stress were applied together, the potassium content in the Istebna clone was not affected, but for the Gerardmer clone, ozone reduced the decrease in potassium content that occurred as drought stress developed. However, calcium (and manganese) content increased significantly when the Gerardmer clone was exposed to ozone. It seems likely that the Gerardmer clone is sensitive to ozone and when subjected to a drought stress this sensitivity is increased. For the Istebna clone, the resistance to ozone is unaffected by the drought stress treatment. The Istebna clone, however, seems sensitive to drought. These characteristic responses in the two different Norway spruce clones are probably due to genetic differences and may explain the contradictory observations in the response of the stomata during the simultaneous implementation of the complex stresses. Key words: Picea abies, guard cells, ozone, drought stress, X-ray microanalysis, elements.


Holzforschung ◽  
2013 ◽  
Vol 67 (3) ◽  
pp. 277-283 ◽  
Author(s):  
Pasi Karinkanta ◽  
Mirja Illikainen ◽  
Jouko Niinimäki

Abstract Norway spruce (Picea abies) has been submitted to oscillatory ball milling at room temperature and at -196°C. The effects of moisture content (MC) and cryogenic milling on the morphology and crystallinity of cellulose were investigated. At room temperature, MC had a significant effect on particle morphology and it was possible to produce powders of smaller particle size and rounder shape when the wood feed had a lower MC. Under cryogenic conditions, MC had less influence on the morphology, and the particle size was even smaller than that produced under ambient conditions. The degree of cellulose crystallinity in the milled wood was influenced by the MC of the feed, milling time, and milling temperature.


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