Differential Growth Responses of Cassiope tetragona, an Arctic Dwarf-Shrub, to Environmental Perturbations among Three Contrasting High- and Subarctic Sites

Oikos ◽  
1993 ◽  
Vol 66 (3) ◽  
pp. 389 ◽  
Author(s):  
Mats Havström ◽  
Terry V. Callaghan ◽  
Sven Jonasson ◽  
Mats Havstrom
Keyword(s):  
Dwarf Shrub ◽  
Growth Responses ◽  
Differential Growth ◽  
Environmental Perturbations ◽  
Cassiope Tetragona

scholarly journals Differential Growth Responses of Wheat Seedlings to Elevated CO2

2018 ◽  
Vol 10 (3) ◽  
pp. 400-409 ◽  
Author(s):  
Hamid Reza ESHGHIZADEH ◽  
Morteza ZAHEDI ◽  
Samaneh MOHAMMADI
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Elevated Co2 ◽  
Co2 Concentration ◽  
Tolerance Index ◽  
Dry Matter Accumulation ◽  
Wheat Cultivars ◽  
Growth Responses ◽  
Differential Growth ◽  
Wheat Seedlings

Intraspecific variations in wheat growth responses to elevated CO2 was evaluated using 20 Iranian bread wheat (Triticum aestivum L.) cultivars. The plants were grown in the modified Hoagland nutrient solution at a greenhouse until 35 days of age using two levels of CO2 (~380 and 700 µmol mol–1). The shoot and root dry weights of the wheat cultivars exhibited average enhancements of 17% and 36%, respectively, under elevated CO2. This increase was associated with higher levels of chlorophyll a (25%), chlorophyll b (21%), carotenoid (30%), leaf area (54%) and plant height (49.9%). The leaf area (r = 0.69**), shoot N content (r = 0.62**), plant height (r = 0.60**) and root volume (r = 0.53*) were found to have important roles in dry matter accumulation of tested wheat cultivars under elevated CO2 concentration. However, responses to elevated CO2 were considerably cultivar-dependent. Based on the stress susceptibility index (SSI) and stress tolerance index (STI), the wheat cultivars exhibiting the best response to elevated CO2 content were ‘Sistan’, ‘Navid’, ‘Shiraz’, ‘Sepahan’ and ‘Bahar’, while the ones with poor responses were ‘Omid’, ‘Marun’, ‘Sorkhtokhm’ and ‘Tajan’. The findings from the present experiment showed significant variation among the Iranian wheat cultivars in terms of their responses to elevated air CO2, providing the opportunity to select the most efficient ones for breeding purposes.

scholarly journals Holocene stratigraphy and vegetation history in the Scoresby Sund area, East Greenland

1978 ◽  
Vol 129 ◽  
pp. 1-66
Author(s):  
S Funder
Keyword(s):  
Vegetation History ◽  
High Arctic ◽  
Dwarf Shrub ◽  
Betula Nana ◽  
Isostatic Uplift ◽  
Cassiope Tetragona ◽  
Pollen Diagrams ◽  
Salix Arctica ◽  
Low Arctic ◽  
Holocene Stratigraphy

The Holocene stratigraphy in Scoresby Sund is based on climatic change as reflected by fluctuations in fjord and valley glaciers, immigration and extinction of marine molluscs, and the vegetation history recorded in pollen diagrams from five lakes. The histories are dated by C-14, and indirectly by emergence curves showing the patterns of isostatic uplift. From c. 10100-10400 to 9400 yr BP the major fjord glaciers showed oscillatory retreat with abundant moraine formation, the period of the Milne Land Moraines. The vegetation in the ice-free areas was a sparse type of fell field vegetation but with thermophilous elements indicating temperatures similar to the present. From 9400 yr BP the fjord glaciers retreated rapidly in the narrow fjords, the few moraines formed are referred to the Rødefjord stages and indicate topographically conditioned stillstands. At 8000 yr BP the low arctic Betula nana immigrated into the area, and in the period until 5000 yr BP dense dwarf shrub heath grew in areas where it is now absent. In the fjords the subarctic Mytilus edulis and Pecten islandica lived, suggesting a climate warmer than the present. From c. 5000 yr BP the dense dwarf shrub heath began to disappear in the coastal areas, and a 'poor' heath dominated by the high arctic Salix Arctica and Cassiope tetragona expanded. These two species, which are now extremely common, apparently did not grow in the area until c. 6000 yr BP. In lakes in the coastal area minerogenic sedimentation at c. 2800 yr BP, reflecting the general climatic deterioration.

scholarly journals Differential Growth Responses of Marine Phytoplankton to Herbicide Glyphosate

PLoS ONE ◽  
2016 ◽  
Vol 11 (3) ◽  
pp. e0151633 ◽  
Author(s):  
Cong Wang ◽  
Xin Lin ◽  
Ling Li ◽  
Senjie Lin
Keyword(s):  
Marine Phytoplankton ◽  
Growth Responses ◽  
Differential Growth ◽  
Herbicide Glyphosate

Responses of carbon and nitrogen concentrations in high arctic plants to experimental warming

2001 ◽  
Vol 79 (6) ◽  
pp. 711-718 ◽  
Author(s):  
Anne Tolvanen ◽  
Gregory HR Henry
Keyword(s):  
Nutrient Uptake ◽  
Plant Species ◽  
Ellesmere Island ◽  
Total Carbon ◽  
Dwarf Shrub ◽  
Dwarf Shrubs ◽  
N Concentration ◽  
Cassiope Tetragona ◽  
Increased Risk ◽  
Nitrogen Concentrations

We studied total carbon (C) and nitrogen (N) concentration in five arctic plant species, Cassiope tetragona (L.) D. Don (evergreen dwarf shrub), Dryas integrifolia Vahl (semi-evergreen dwarf-shrub), Salix arctica Pall. (deciduous, dioecious dwarf shrub), Oxyria digyna (L.) Hill (forb), and Carex stans Drej. (graminoid, sedge), after five growing seasons of experimental increase in temperature. The experiments were established in different habitats along a moisture gradient in a coastal lowland at Alexandra Fiord, Ellesmere Island (79ºN). Sampling was conducted three times during the growing season. The seasonal patterns of C and N concentration were similar across all investigated species, even though the absolute concentrations differed. Nitrogen concentrations were high early in the season during the active growth period but declined later in the season. Warming decreased the N concentration and increased the C/N ratio in the three woody species, whereas N concentrations in the forb and the sedge were not affected. Although not measured directly in our study, the differences in concentrations may be due to the slower response in nutrient uptake and growth in the dwarf shrubs but increased nutrient uptake and growth in the forb and the sedge. Among-site differences were only significant in C concentrations of old tissues of Cassiope tetragona and S. arctica. Male and female S. arctica did not differ in their responses to warming. Differences among plant species in their plastic responses may relate to survival during rapid environmental change. Slow-responding dwarf shrubs may be under increased risk of competition from more responsive and faster growing species, such as forbs and graminoids.Key words: allocation, climate change, dwarf shrub, forb, graminoid, ITEX, Ellesmere Island.

scholarly journals Differential Growth Responses to Water Balance of Coexisting Deciduous Tree Species Are Linked to Wood Density in a Bolivian Tropical Dry Forest

PLoS ONE ◽  
2013 ◽  
Vol 8 (10) ◽  
pp. e73855 ◽  
Author(s):  
Hooz A. Mendivelso ◽  
J. Julio Camarero ◽  
Oriol Royo Obregón ◽  
Emilia Gutiérrez ◽  
Marisol Toledo
Keyword(s):  
Water Balance ◽  
Wood Density ◽  
Tree Species ◽  
Tropical Dry Forest ◽  
Dry Forest ◽  
Deciduous Tree ◽  
Growth Responses ◽  
Differential Growth

scholarly journals Dendrochronological Potential of the Arctic Dwarf-Shrub Cassiope tetragona

2005 ◽  
Vol 61 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Shelly A. Rayback ◽  
Gregory H. R. Henry
Keyword(s):  
Dwarf Shrub ◽  
The Arctic ◽  
Cassiope Tetragona
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