scholarly journals Rooting Volume Impacts Growth, Coverage and Thermal Tolerance of Green Façade Climbing Plants

Land ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1281
Author(s):  
Pei-Wen Chung ◽  
Stephen J. Livesley ◽  
John P. Rayner ◽  
Claire Farrell
Keyword(s):  
Heat Stress ◽  
Chlorophyll Fluorescence ◽  
Plant Growth ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Thermal Tolerance ◽  
High Rise ◽  
Plant Coverage ◽  
Air Temperatures ◽  
Species Specific

Green façades can provide cooling benefits through the shading of walls, evapotranspiration, and insulation. These benefits depend on good plant coverage and tolerance of heat stress. This requires sufficient rooting volume for plant growth and an adequate supply of moisture. On high-rise buildings, plants can be constrained by small rooting volumes due to engineering weight limits and cost. We assessed effects of rooting volume (21, 42, and 63 L) on the growth and coverage of Akebia quinata and Pandorea pandorana and leaf stress (chlorophyll fluorescence) in response to increasing air temperatures. We showed that 42 and 63 L rooting volumes significantly increased early plant growth and the percentage wall coverage for both species. Specific leaf area was significantly greater when grown in 63 L compared with 21 L. Shoot/root ratio did not change with rooting volumes. Regardless of rooting volume, higher air temperatures on west-facing aspects led to afternoon leaf stress. In practice, for each cubic meter of rooting volume, 21 m2 (P. pandorana) and 10 m2 (A. quinata) canopy coverage can be expected within six months.

scholarly journals Biological and climatic controls on leaf litter decomposition across European forests and grasslands revealed by reciprocal litter transplantation experiments

2015 ◽  
Vol 12 (21) ◽  
pp. 18053-18084
Author(s):  
M. Portillo-Estrada ◽  
M. Pihlatie ◽  
J. F. J. Korhonen ◽  
J. Levula ◽  
A. K. F. Frumau ◽  
...  
Keyword(s):  
Leaf Area ◽  
Litter Decomposition ◽  
Air Temperature ◽  
Specific Leaf Area ◽  
Soil Type ◽  
Vegetation Composition ◽  
Carbon And Nitrogen ◽  
Air Temperatures ◽  
Transplantation Experiments ◽  
Insight Into

Abstract. Projection of carbon and nitrogen cycles to future climates is associated with large uncertainties, in particular due to uncertainties how changes in climate alter soil turnover, including litter decomposition. In addition, future conditions are expected to result in changes in vegetation composition, and accordingly in litter type and quality, but it is unclear how such changes could potentially alter litter decomposition. Litter transplantation experiments were carried out across 6 European sites (4 forest and 2 grasslands) spanning a large geographical and climatic gradient (5.6–11.4 °C in annual temperature 511–878 mm in precipitation) to gain insight into biological (litter origin and type, soil type) and climatic controls on litter decomposition. The decomposition k rates were overall higher in warmer and wetter sites than in colder and drier sites, and positively correlated to the litter total specific leaf area. Also, litter N content increased as less litter mass remained and decay went further. Surprisingly, this study demonstrates that climatic controls on litter decomposition are quantitatively more important than species, litter origin and soil type. Cumulative climatic variables, precipitation and air temperature (ignoring days with air temperatures below 0 °C), were appropriate to predict the litter remaining mass during decomposition (Mr). And Mr and cumulative air temperature were found to be the best predictors for litter carbon and nitrogen remaining during decomposition. We concluded with an equation for predicting the decomposition k rate by using mean annual air temperature and litter total specific leaf area.

scholarly journals Reduced thermal tolerance of massive coral species in a highly variable environment

2020 ◽  
Vol 287 (1933) ◽  
pp. 20201379 ◽  
Author(s):  
C. N. Klepac ◽  
D. J. Barshis
Keyword(s):  
Heat Stress ◽  
Thermal Tolerance ◽  
Coral Cover ◽  
Thermal Anomaly ◽  
American Samoa ◽  
Variable Environment ◽  
Thermal Anomalies ◽  
Thermal Environments ◽  
Acute Heat Stress ◽  
Species Specific

Coral bleaching events are increasing in frequency and severity, resulting in widespread losses in coral cover. However, branching corals native to highly variable (HV) thermal environments can have higher bleaching resistance than corals from more moderate habitats. Here, we investigated the response of two massive corals, Porites lobata and Goniastrea retiformis , from a moderately variable (MV) and a low variability (LV) pool transplanted into a HV pool on Ofu Island in American Samoa. Paired transplant and native ramets were exposed to an acute thermal stress after 6 and 12 months of exposure to the HV pool to evaluate changes in thermal tolerance limits. For both species, photosynthetic efficiency and chlorophyll loss following acute heat stress did not differ between ramets transplanted into the HV pool and respective native pool. Moreover, HV native P. lobata exhibited the greatest bleaching susceptibility compared to MV and LV natives and there was no effect of acute heat stress on MV P. lobata . There was also a thermal anomaly during the study, where Ofu's backreef thermal regime surpassed historical records—2015 had 8 degree heating weeks (DHW) and 2016 had up to 5 DHW (in comparison to less than or equal to 3 over the last 10 years)—which may have exceeded the upper thermal limits of HV native P. lobata . These results strongly contrast with other research on coral tolerance in variable environments, potentially underscoring species-specific mechanisms and regional thermal anomalies that may be equally important in shaping coral responses to extreme temperatures.

scholarly journals Leaf Area Estimation in Chamomile

2019 ◽  
Vol 11 (2) ◽  
pp. 429
Author(s):  
Jocélia Rosa da Silva ◽  
Arno Bernardo Heldwein ◽  
Andressa Janaína Puhl ◽  
Adriana Almeida do Amarante ◽  
Daniella Moreira Salvadé ◽  
...  
Keyword(s):  
Plant Growth ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Dry Matter ◽  
Direct Methods ◽  
Area Index ◽  
Area Estimation ◽  
Sowing Dates ◽  
Plant Densities ◽  
Area Determination

The knowledge of the variables specific leaf area and leaf area index is important for direct or indirect quantification of plant growth, development and yield. However, there is a lack of these information due to the difficulty in measuring the leaf area of chamomile. Measuring leaf area by direct methods, such as the use of leaf area integrator is a very laborious and time consuming activity because the plant has many leaves and with small size. The use of leaf dry matter is a promising variable for the leaf area estimation. As an important measure to evaluate plant growth, the present study aimed to obtain a model for chamomile leaf area estimation through leaf dry matter. The experiment was conducted in two sowing dates (March 18 and June 30, 2017) at different plant densities (66, 33, 22, 16, 13, 11 and 8 plants m-2). The leaves of chamomile plants were collected in the plant vegetative and reproductive phases. The leaf area determination was performed using the electronic integration method of leaf area. The specific leaf area was 133 cm2 g-1, with no differences between sowing dates, plant densities and phenological phases of plant collection. The leaf area measured with the electronic leaf area integrator exhibited high correlation with chamomile leaf dry matter and the resulting model of leaf area data by the integrator presented optimum performance. This model is indicated for leaf area determination of chamomile when there is availability of leaf dry matter data.

Growth of sugar-beet crops including the influence of synthetic plant growth regulators

1986 ◽  
Vol 107 (2) ◽  
pp. 285-297 ◽  
Author(s):  
C. F. Green ◽  
L. V. Vaidyanathan ◽  
J. D. Ivins
Keyword(s):  
Plant Growth ◽  
Sugar Beet ◽  
Leaf Area ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Specific Leaf Area ◽  
Dry Matter ◽  
Biomass Accumulation ◽  
Sucrose Accumulation ◽  
Dry Matter Partitioning

SummaryObservations are presented from a crop of sugar beet grown in Cambridgeshire during 1978, and a field trial at Sutton Bonington during 1985 in which the influence of synthetic plant growth regulators (PGRs) daminozide, chlormequat, GA4+7 and ethephon were compared.Several distinct patterns of growth were evident, being similar for both growing seasons and described by two intersecting straight lines. Early development was characterized by a slow rate of biomass accumulation, a dominance of foliage production with a constant but small root fraction (around 40%), a low specific leaf area and a slow but conservative rate of sucrose fractionation. Later in the season the rate of stand growth was both constant and maximal, the root fraction doubled, specific leaf area increased and the rate of sucrose accumulation rose markedly.Transitions between developmental phases occurred at various times dependent on variate under consideration. The onset of the main growth period began at the end of June, followed by an increase in the rate of sucrose accumulation about 2 weeks later. Finally, near the end of July, partition of assimilate into the root assumed a faster rate. Changes in the partitioning into both roots and sucrose are discussed in relation to the development of the secondary cambium.Generally there were no effects of PGRs on biomass accumulation, dry-matter partitioning, specific leaf area and sucrose accumulation. However, daminozide increased early canopy expansion and early dry-matter production but failed to influence biomass or sugar yield.

Sources of Variation in Specific Leaf Area in Wheat Grown at High Temperature

1987 ◽  
Vol 14 (3) ◽  
pp. 287 ◽  
Author(s):  
HM Rawson ◽  
PA Gardner ◽  
MJ Long
Keyword(s):  
Plant Growth ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Plant Density ◽  
Unit Area ◽  
Flag Leaf ◽  
Leaf Age ◽  
Vapour Pressure Deficit ◽  
High Growth ◽  
Sources Of Variation

In the belief that specific leaf area (SLA, cm2 g1 dry weight) may be correlated with plant growth rate under certain conditions, and thus may be used in selecting genotypes for high growth rates, studies were commenced to examine the main sources of variation in SLA. In most studies, wheat plants were grown in controlled environments with high mean temperature and vapour pressure deficit and with varying radiation regimes. All environmental variables followed cosine patterns which in amplitude mimicked field conditions. Specific leaf area varied depending on: (1) location along a leaf: it decreased from tip to base by some 35%; (2) leaf age: SLA declined between leaf appearance and 10-12 days later then, after a plateau of varying length, it rose again; (3) leaf insertion: SLA of the flag leaf was the most stable with leaf age; (4) plant density: in canopies the final rise in SLA with leaf age occurred earlier than in spaced plants; (5) radiation: SLA declined at approximately 4 cm2 g-1 for each mol quanta m-2 day-1 increase in radiation; (6) genotype: SLA differed among genotypes and the ranking was unchanged by changes in radiation. In two genotypes studied in detail, higher SLA equated with faster leaf area production and larger leaves, but not with chlorophyll content per unit area, stornatal frequency or net CO2 exchange rate per unit area (CER), though it was noted that both SLA and CER changed inversely with leaf aging after the leaf was fully expanded. The importance of SLA in active (positive and negative) and passive roles in plant growth is discussed.

scholarly journals Thermal Inactivation of Susceptible and Multiantimicrobial-Resistant Salmonella Strains Grown in the Absence or Presence of Glucose

2003 ◽  
Vol 69 (7) ◽  
pp. 4123-4128 ◽  
Author(s):  
R. T. Bacon ◽  
J. R. Ransom ◽  
J. N. Sofos ◽  
P. A. Kendall ◽  
K. E. Belk ◽  
...  
Keyword(s):  
Heat Stress ◽  
Protective Effect ◽  
Thermal Tolerance ◽  
Thermal Inactivation ◽  
Survival Curves ◽  
Acid Adaptation ◽  
Circulating Water ◽  
Glucose Levels ◽  
Study Results ◽  
Peptone Water

ABSTRACT The heat resistance of susceptible and multiantimicrobial-resistant Salmonella strains grown to stationary phase in glucose-free tryptic soy broth supplemented with 0.6% yeast extract (TSBYE−G; nonadapted), in regular (0.25% glucose) TSBYE, or in TSBYE−G with 1.00% added glucose (TSBYE+G; acid adapted) was determined at 55, 57, 59, and 61°C. Cultures were heated in sterile 0.1% buffered peptone water (50 μl) in heat-sealed capillary tubes immersed in a thermostatically controlled circulating-water bath. Decimal reduction times (D values) were calculated from survival curves having r 2 values of >0.90 as a means of comparing thermal tolerance among variables. D 59°C values increased (P < 0.05) from 0.50 to 0.58 to 0.66 min for TSBYE−G, TSBYE, and TSBYE+G cultures, respectively. D 61°C values of antimicrobial-susceptible Salmonella strains increased (P < 0.05) from 0.14 to 0.19 as the glucose concentration increased from 0.00 to 1.00%, respectively, while D 61°C values of multiantimicrobial-resistant Salmonella strains did not differ (P > 0.05) between TSBYE−G and TSBYE+G cultures. When averaged across glucose levels and temperatures, there were no differences (P > 0.05) between the D values of susceptible and multiantimicrobial-resistant inocula. Collectively, D values ranged from 4.23 to 5.39, 1.47 to 1.81, 0.50 to 0.66, and 0.16 to 0.20 min for Salmonella strains inactivated at 55, 57, 59, and 61°C, respectively. zD values were 1.20, 1.48, and 1.49°C for Salmonella strains grown in TSBYE+G, TSBYE, and TSBYE−G, respectively, while the corresponding activation energies of inactivation were 497, 493, and 494 kJ/mol. Study results suggested a cross-protective effect of acid adaptation on thermal inactivation but no association between antimicrobial susceptibility and the ability of salmonellae to survive heat stress.

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