Northward migration of trembling aspen will increase growth but reduce resistance to drought-induced xylem cavitation

Botany ◽  
2019 ◽  
Vol 97 (11) ◽  
pp. 627-638 ◽  
Author(s):  
Sahari Inoue ◽  
Qing-Lai Dang ◽  
Rongzhou Man ◽  
Binyam Tedla
Keyword(s):  
Soil Moisture ◽  
Leaf Area ◽  
Populus Tremuloides ◽  
Specific Leaf Area ◽  
Leaf Size ◽  
Field Capacity ◽  
Interactive Effects ◽  
Xylem Cavitation ◽  
Trembling Aspen ◽  
Photoperiod Regime

Tree migration to higher latitudes may occur in response to future changes in climate, exposing the trees to higher concentrations of carbon dioxide ([CO2]), new photoperiods, different levels of soil moisture, and other new conditions. These new conditions can influence the physiology, survival, and growth of trees. This study examined the interactive effects of [CO2], photoperiod, and soil moisture on the morphology and resistance to xylem cavitation in trembling aspen (Populus tremuloides Michx.). One-year-old seedlings, in greenhouses, were exposed to two [CO2] (ambient [CO2] 400 μmol·mol−1 or an elevated [CO2] 1000 μmol·mol−1), four photoperiod regimes corresponding to latitudes 48°N (seed origin), 52°N, 55°N, and 58°N, and two levels of soil moisture (60%–75% and 13%–20% of field capacity) for one growing season. Seedling growth, leaf size, specific leaf area, biomass allocation, and xylem resistance to cavitation (water potentials for 20%, 50%, and 80% loss of hydraulic conductivity) were assessed. The seedlings under the longest photoperiod regime (58°N latitude) had greatest height and biomass but smallest specific leaf area. Under the elevated [CO2], however, the longest photoperiod regime significantly reduced xylem resistance to drought-induced cavitation compared with the photoperiod corresponding to 48°N. These results suggest that when migrating to higher latitudes, trembling aspen may grow faster but could become less resistant to drought and more prone to hydraulic failure during a drought spell.

Photoperiod and CO2 elevation influence morphological and physiological responses to drought in trembling aspen: implications for climate change-induced migration

2020 ◽  
Vol 40 (7) ◽  
pp. 917-927 ◽  
Author(s):  
Sahari Inoue ◽  
Qing-Lai Dang ◽  
Rongzhou Man ◽  
Binyam Tedla
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Leaf Area ◽  
Populus Tremuloides ◽  
Maximum Rate ◽  
Physiological Responses ◽  
Leaf Size ◽  
Interactive Effects ◽  
Shoot Ratio ◽  
Root Shoot Ratio

Abstract Past research suggests climate change will cause the climate envelopes of various tree species to shift to higher latitudes and can lead to a northward migration of trees. However, the success and scope of the migration are likely affected by factors that are not contained in the climate envelope, such as photoperiod and interactive effects of multiple environmental factors, and these effects are currently not well understood. In this study, we investigated the interactive effects of CO2 concentrations ([CO2]), photoperiod and soil moisture on the morphological and physiological traits of Populus tremuloides Michx. We grew seedlings under two levels of [CO2] (ambient [CO2] (AC) 400 vs elevated [CO2] (EC) 1000 μmol mol−1), four photoperiod regimes (growing season photoperiods at 48 (seed origin), 52, 55 and 58°N latitude) and two soil moisture regimes (high soil moisture (HSM) vs low soil moisture (LSM), −2 MPa) for two growing seasons in greenhouses. Both morphological and physiological responses were observed. Low soil moisture reduced leaf size, total leaf area and height growth by 33, 46 and 12%, respectively, and increased root/shoot ratio by 20%. The smaller leaf area and increased root/shoot ratio allowed the seedlings in LSM to maintain higher the maximum rate of Rubisco carboxylation (Vcmax) and the maximum rate of electron transport for RuBP regeneration (Jmax) than control seedlings (55 and 83% higher in July, 52 and 70% in August, respectively). Photoperiod and [CO2] modified responses to LSM and LSM altered responses to photoperiod and [CO2], e.g., the August photosynthetic rate was 44% higher in LSM than in HSM under EC but no such a difference existed under AC. The increase in Vcmax and Jmax in response to LSM varied with photoperiod (Vcmax: 36% at 52°N, 22% at 55°N, 47% at 58°N; Jmax: 29% at 52°N, 21% at 55°N, 45% at 58°N). Stomatal conductance and its reduction in response to LSM declined with increasing photoperiod, which can have significant implications for soil moisture effect on northward migration. This study highlights the need to consider the complex interactions of [CO2], photoperiod and soil moisture when planning assisted migration or predicting the natural migration of boreal forests in the future.

scholarly journals Dynamics of change of leaf attributes of Brussels sprouts in response to switches between high and low supply of nitrogen

1996 ◽  
Vol 44 (1) ◽  
pp. 31-42
Author(s):  
J. Vos ◽  
H. Biemond ◽  
P.C. Struik
Keyword(s):  
Leaf Area ◽  
Specific Leaf Area ◽  
Leaf Growth ◽  
Leaf Size ◽  
Application Rate ◽  
Supply Rate ◽  
Brussels Sprouts ◽  
N Supply ◽  
High Treatment ◽  
Reverse Switch

In a greenhouse pot experiment with Brussels sprouts grown in sand, 4 treatments were compared: a control without N limitation, a continuously N-deficient control and 2 treatments with a switch from the high to the low supply or vice versa. All treatments received nutrient solution at 9 dates during the experiment. The high-N and low-N controls received 1.96 and 0.56 g/application, respectively. In the high-low treatment the switch from the higher to the lower application rate took place 57 days after planting (DAP) and in the low high treatment the reverse switch took place 85 DAP; these 2 treatments received the same total amount of N. Plant N concentrations changed rapidly upon changes in N supply regime. When the supply rate was increased, N concentration increased in leaves that had completed their expansion. Changes in leaf growth started about 15 days after the switch in N regime. Leaves that were expanding at the switch responded by increase in area when N supply increased without a change in mass, i.e. specific leaf area increased. Leaf areas and specific leaf area of expanding leaves decreased when the N supply became smaller. The control of leaf size during initiation and expansion is discussed.

scholarly journals Leaf area of common bean genotypes during early pod filling as related to plant adaptation to limited phosphorus supply

2010 ◽  
Vol 34 (1) ◽  
pp. 115-124 ◽  
Author(s):  
Roberto Santos Trindade ◽  
Adelson Paulo Araújo ◽  
Marcelo Grandi Teixeira
Keyword(s):  
Common Bean ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Leaf Size ◽  
Net Assimilation Rate ◽  
Leaf Number ◽  
Growth Stages ◽  
Assimilation Rate ◽  
Plant Adaptation ◽  
Net Assimilation

Low phosphorus supply markedly limits leaf growth and genotypes able to maintain adequate leaf area at low P could adapt better to limited-P conditions. This work aimed to investigate the relationship between leaf area production of common bean (Phaseolus vulgaris) genotypes during early pod filling and plant adaptation to limited P supply. Twenty-four genotypes, comprised of the four growth habits in the species and two weedy accessions, were grown at two P level applied to the soil (20 and 80 mg kg-1) in 4 kg pots and harvested at two growth stages (pod setting and early pod filling). High P level markedly increased the leaf number and leaf size (leaf area per leaf), slightly increased specific leaf area but did not affect the net assimilation rate. At low P level most genotypic variation for plant dry mass was associated with leaf size, whereas at high P level this variation was associated primarily with the number of leaves and secondarily with leaf size, specific leaf area playing a minor role at both P level. Determinate bush genotypes presented a smaller leaf area, fewer but larger leaves with higher specific leaf area and lower net assimilation rate. Climbing genotypes showed numerous leaves, smaller and thicker leaves with a higher net assimilation rate. Indeterminate bush and indeterminate prostrate genotypes presented the highest leaf area, achieved through intermediate leaf number, leaf size and specific leaf area. The latter groups were better adapted to limited P. It is concluded that improved growth at low P during early pod filling was associated with common bean genotypes able to maintain leaf expansion through leaves with greater individual leaf area.

Elevated CO2 causes large changes to morphology of perennial ryegrass (Lolium perenne)

2019 ◽  
Vol 70 (6) ◽  
pp. 555
Author(s):  
Rose Brinkhoff ◽  
Meagan Porter ◽  
Mark J. Hovenden
Keyword(s):  
Leaf Area ◽  
Elevated Co2 ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Specific Leaf Area ◽  
Water Availability ◽  
Leaf Blade ◽  
Leaf Size ◽  
Plant Morphology ◽  
Relative Water

Plant morphology and architecture are essential characteristics for all plants, but perhaps most importantly for agricultural species because economic traits are linked to simple features such as blade length and plant height. Key morphological traits likely respond to CO2 concentration ([CO2]), and the degree of this response could be influenced by water availability; however, this has received comparatively little research attention. This study aimed to determine the impacts of [CO2] on gross morphology of perennial ryegrass (Lolium perenne L.), the most widespread temperate pasture species, and whether these impacts are influenced by water availability. Perennial ryegrass cv. Base AR37 was grown in a well-fertilised FACE (free-air carbon dioxide enrichment) experiment in southern Tasmania. Plants were exposed to three CO2 concentrations (~400 (ambient), 475 and 550 µmol mol–1) at three watering-treatment levels (adequate, limited and excess). Shoot dry weight, height, total leaf area, leaf-blade separation, leaf size, relative water content and specific leaf area were determined, as well as shoot density per unit area as a measure of tillering. Plant morphology responded dramatically to elevated [CO2], plants being smaller with shorter leaf-blade separation lengths and smaller leaves than in ambient (control) plots. Elevated [CO2] increased tillering but did not substantially affect relative water content or specific leaf area. Water supply did not affect any measured trait or the response to elevated [CO2]. Observed impacts of elevated [CO2] on the morphology of a globally important forage crop could have profound implications for pasture productivity. The reductions in plant and leaf size were consistent across a range of soil-water availability, indicating that they are likely to be uniform. Elucidating the mechanisms driving these responses will be essential to improving predictability of these changes and may assist in breeding varieties suited to future conditions.

The effect of fire severity and salvage logging traffic on regeneration and early growth of aspen suckers in north-central Alberta

2004 ◽  
Vol 80 (2) ◽  
pp. 251-256 ◽  
Author(s):  
Erin Fraser ◽  
Simon Landhäusser ◽  
Victor Lieffers
Keyword(s):  
Leaf Area ◽  
Populus Tremuloides ◽  
Negative Impact ◽  
Fire Severity ◽  
Trembling Aspen ◽  
North Central ◽  
Salvage Logging ◽  
Logging Damage ◽  
Area Reduction ◽  
Leaf Area Reduction

Density and growth of trembling aspen (Populus tremuloides Michx.) were measured in the first two years following wildfire to determine the effects of: 1) fire severity and 2) salvage logging damage on sucker regeneration. Results indicate that stand leaf area was not affected by fire severity, although the greatest number of suckers was produced following high severity burns. In contrast, plots with the highest level of machine disturbance in the salvage-logging study had 60% fewer suckers compared to the non-trafficked plots. These suckers tended to be smaller and had less leaf area than the non-trafficked plots, resulting in a stand leaf area reduction of up to 75%. This suggests that salvage logging could have a negative impact on the future growth and productivity of regenerating aspen stands. Key words: trembling aspen, regeneration, suckering, leaf area, wildfire, fire severity, salvage logging, machine traffic

Jack pine becomes more vulnerable to cavitation with increasing latitudes under doubled CO2 concentration

Botany ◽  
2018 ◽  
Vol 96 (2) ◽  
pp. 111-119 ◽  
Author(s):  
Md. Shah Newaz ◽  
Qing-Lai Dang ◽  
Rongzhou Man
Keyword(s):  
Soil Moisture ◽  
Hydraulic Conductivity ◽  
Pinus Banksiana ◽  
Carbon Dioxide Concentration ◽  
Field Capacity ◽  
Co2 Concentration ◽  
Jack Pine ◽  
Photoperiod Regime ◽  
Seed Origin ◽  
Doubled Co2 Concentration

Trees may migrate northward in response to climate change and become exposed to new photoperiod and soil moisture regimes. This study assessed the impacts of photoperiod and its interaction with soil moisture and carbon dioxide concentration ([CO2]) on the hydraulic conductivity in jack pine (Pinus banksiana Lamb.) and its vulnerability to xylem embolism. Seedlings were exposed to 400 vs. 950 μmol·mol−1 [CO2], 60%–70% vs. 30%–40% (of field capacity) soil moisture, and photoperiods of seed origin and 5° and 10° north of seed origin in greenhouses. Cavitation vulnerability curves were measured for determining the xylem pressure at which 50% hydraulic conductivity was lost (ΨPLC50). It was found that elevated [CO2] significantly increased hydraulic conductivity, whereas low soil moisture decreased it. Under elevated [CO2], the xylem became progressively more vulnerable to embolism with changes in photoperiod regime from the seed origin to 10° north of the seed origin, as indicated by the progressively less negative ΨPLC50. However, no such a trend was detected under the ambient [CO2]. The results suggest that the species may become less resistant to drought as the atmospheric [CO2] increases, hindering the northward migration or seed transfers. Even within its current natural distribution range, trees near its northern boundary of the range may be more vulnerable to embolism as the atmospheric [CO2] increases even without any change in moisture conditions.

Interactive effects of season and light environment on growth and leaf dynamics of evergreen tree seedlings in the humid subtropics

1996 ◽  
Vol 74 (4) ◽  
pp. 589-598 ◽  
Author(s):  
J. H. C. Cornelissen
Keyword(s):  
Leaf Area ◽  
Growth Rates ◽  
Leaf Size ◽  
Light Environment ◽  
Interactive Effects ◽  
Tree Seedlings ◽  
Total Leaf Area ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Total Leaf

Interactive effects of season and light environment on tree seedling growth were studied in four evergreen species in the humid subtropics of China. These species were the needle-leaved pioneer Pinus massoniana and the broad-leaved shade-tolerant Castanopsis fargesii, Sloanea leptocarpa, and Elaeocarpus japonicus. The experimental outdoor light environments, which broadly simulated those in forest gaps and clearings, were 100, 55, 33, and 18% of incident light quantity. Mean relative growth rates for both total leaf area and s tem height revealed interaction of season and light environment in Pinus, Castanopsis, and Elaeocarpus. In these species, mean relative growth rates were higher in summer in more shaded environments and in autumn in more exposed environments, but this shift was not as clear in Castanopsis. Winter growth was virtually nil in all species, although Pinus still achieved some winter stem height change. The hypothesis that late-successional rather than early-successional species would demonstrate interactions of season and light environment on growth and development was not sufficiently supported by the data. Variation in mean relative growth rates for total leaf area was due to changes in whole-plant average leaf size as well as leaf numbers. In Sloanea and Elaeocarpus seedlings in high light environments, reduced leaf size and enhanced leaf abscission rates gave rise to negative mean relative growth rates for total leaf area. The more sun-tolerant Castanopsis seedlings revealed no such leaf size response and shed few, if any, leaves in any of the light environments. These results indicate that seasonal variability in the growth response of tree seedlings to the light environment is an important factor to be taken into account in studies on gap dynamics of subtropical forests. Keywords: China, leaf area, leaf turnover, leaf size, mean relative growth rate, shade, subtropical, sun.

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