Needle ultrastructure and starch content in Scots pine and Norway spruce after ozone fumigation

1996 ◽  
Vol 74 (1) ◽  
pp. 67-76 ◽  
Author(s):  
Toini Holopainen ◽  
Seija Anttonen ◽  
Virpi Palomäki ◽  
Pirjo Kainulainen ◽  
Jarmo K. Holopainen

The ultrastructure of current and previous year needles of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L.) Karst. was studied after exposures to several different ozone concentrations (100 to 600 nL∙L−1) and doses in a chamber system. The ultrastructural changes observed in different experiments in both of these species were qualitatively very similar. Changes were observed in the mesophyll tissue, in which increased density of chloroplast stroma and an increase of ribosome-like granules were the early symptoms, followed by a decrease of the size of chloroplasts and starch grains. Simultaneously a decline of needle starch content could be measured. After fumigation with the lower concentrations, hypertrophy of microbodies were also apparent. When the seedlings were fumigated with the highest concentration (600 nL∙L−1) a subsequent disintegration of cytoplasm and other cell organelles and finally a collapse of the contents of the mesophyll cells, leading to visible injuries, was found. Scots pine nursery stock seedlings appeared to be about equal in sensitivity to ozone as Norway spruce clonal stock. The spruce clones showed differences in sensitivity to the ozone fumigations. Since the observed symptoms are consistent in two species through a concentration gradient of ozone, and also agree with the information dealing with ozone injuries in literature, it is possible to use ultrastructural observations for diagnosing the presence of ozone injuries. Keywords: ozone, Picea abies, Pinus sylvestris, needle ultrastructure, starch.

1989 ◽  
Vol 46 (Supplement) ◽  
pp. 553s-556s ◽  
Author(s):  
S. Huttunen ◽  
M. Turunen ◽  
J. Reinikainen

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.


1999 ◽  
Vol 29 (6) ◽  
pp. 647-661 ◽  
Author(s):  
H Peltola ◽  
S Kellomäki ◽  
H Väisänen ◽  
V -P Ikonen

A mechanistic model for assessing the risk of wind and snow damage to single trees and stands of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.), and birch (Betula spp.) is presented. The model predicts the critical turning moment and wind speed at which the trees will be uprooted or break at forest margins. The resistance to uprooting is predicted using the estimate of the root-soil plate weight to derive a resistive moment, while the resistance to stem breakage relies on values for the modulus of rupture determined for different species of timber. A tree is assumed to be uprooted if the total turning moment exceeds the support provided by the root-soil plate anchorage. Similarly, a tree is assumed to break if the breaking stress acting on the stem exceeds a critical value of the modulus of rupture. The model is in general quite sensitive to parameter changes, which partly results from the location in the forest to which it was designed to apply (the stand edge). The predictions of the critical turning moments needed to uproot and break trees nevertheless give a good agreement on average with the Finnish tree-pulling data for Scots pine, Norway spruce, and birch.


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