scholarly journals Differences in Leaf Temperature between Lianas and Trees in the Neotropical Canopy

2018 ◽  
Author(s):  
J. Antonio Guzmán Q. ◽  
G. Arturo Sánchez-Azofeifa ◽  
Benoit Rivard
Keyword(s):  
Primary Productivity ◽  
Net Primary Productivity ◽  
Temperature Response ◽  
Life Forms ◽  
Leaf Temperature ◽  
Response Curves ◽  
Tropical Environments ◽  
Host Trees ◽  
Temperature Responses ◽  
Photosynthesis And Respiration

Leaf temperature (Tleaf) influences photosynthesis and respiration. Currently, there is a growing interest on including lianas in productivity models due to their increasing abundance, and their detrimental effects on net primary productivity in tropical environments. Therefore, understanding the differences of Tleaf between lianas and trees is important for future of forest on whole ecosystem productivity. Here we determined the displayed leaf temperature (Td= Tleaf – ambient temperature) of several species of lianas and their host trees during ENSO and non-ENSO years to evaluate if the presence of lianas affects the Td of their host trees, and if leaves of lianas and their host trees exhibit differences in Td. Our results suggest that close to midday, the presence of lianas does not affect the Td of their host trees; however, lianas tend to have higher values of Td than their hosts across seasons, in both ENSO and non-ENSO years. Although lianas and trees tend to have similar physiological-temperature responses, differences in Td could lead to significant differences in rates of photosynthesis and respiration based temperature response curves. Future models should thus consider differences in leaf temperature between these life forms to achieve robust predictions of productivity.

scholarly journals Thermal Acclimation of Foliar Carbon Metabolism in Pinus taiwanensis Along an Elevational Gradient

2022 ◽  
Vol 12 ◽  
Author(s):  
Min Lyu ◽  
Mengke Sun ◽  
Josep Peñuelas ◽  
Jordi Sardans ◽  
Jun Sun ◽  
...  
Keyword(s):  
Climate Change ◽  
Temperature Response ◽  
Elevational Gradient ◽  
Thermal Acclimation ◽  
Optimal Conditions ◽  
Climatic Warming ◽  
Response Curves ◽  
Respiration Rates ◽  
Time Substitution ◽  
Photosynthesis And Respiration

Climate change could negatively alter plant ecosystems if rising temperatures exceed optimal conditions for obtaining carbon. The acclimation of plants to higher temperatures could mitigate this effect, but the potential of subtropical forests to acclimate still requires elucidation. We used space-for-time substitution to determine the photosynthetic and respiratory-temperature response curves, optimal temperature of photosynthesis (Topt), photosynthetic rate at Topt, temperature sensitivity (Q10), and the rate of respiration at a standard temperature of 25°C (R25) for Pinus taiwanensis at five elevations (1200, 1400, 1600, 1800, and 2000 m) in two seasons (summer and winter) in the Wuyi Mountains in China. The response of photosynthesis in P. taiwanensis leaves to temperature at the five elevations followed parabolic curves, and the response of respiration to temperature increased with temperature. Topt was higher in summer than winter at each elevation and decreased significantly with increasing elevation. Q10 decreased significantly with increasing elevation in summer but not winter. These results showed a strong thermal acclimation of foliar photosynthesis and respiration to current temperatures across elevations and seasons, and that R25 increased significantly with elevation and were higher in winter than summer at each elevation indicating that the global warming can decrease R25. These results strongly suggest that this thermal acclimation will likely occur in the coming decades under climate change, so the increase in respiration rates of P. taiwanensis in response to climatic warming may be smaller than predicted and thus may not increase atmospheric CO2 concentrations.

Temperature responses of photosynthesis and respiration in a sub-Antarctic megaherb from Heard Island

2015 ◽  
Vol 42 (6) ◽  
pp. 552
Author(s):  
Marcus Schortemeyer ◽  
John R. Evans ◽  
Dan Bruhn ◽  
Dana M. Bergstrom ◽  
Marilyn C. Ball
Keyword(s):  
Temperature Response ◽  
Carbon Gain ◽  
Warming Climate ◽  
Heard Island ◽  
Natural Temperature ◽  
Relationship Of ◽  
The Relationship ◽  
Rate Limiting ◽  
Temperature Responses ◽  
Photosynthesis And Respiration

Understanding the response of sub-Antarctic plants to a warming climate requires an understanding of the relationship of carbon gain and loss to temperature. In a field study on Heard Island, we investigated the responses of photosynthesis and respiration of the sub-Antarctic megaherb Pringlea antiscorbutica R. Br. to temperature. This was done by instantaneously manipulating leaf temperature in a gas exchange cuvette on plants adapted to natural temperature variation along an altitudinal gradient. There was little altitudinal variation in the temperature response of photosynthesis. Photosynthesis was much less responsive to temperature than electron transport, suggesting that Rubisco activity was generally the rate-limiting process. The temperature response of leaf respiration rates was greater in cold-grown (high altitude) plants compared with warm-grown (low altitude) plants. This thermal acclimation would enable plants to maintain a positive carbon budget over a greater temperature range.

scholarly journals Effects of climate warming and declining species richness in grassland model ecosystems: acclimation of CO<sub>2</sub> fluxes

2007 ◽  
Vol 4 (1) ◽  
pp. 27-36 ◽  
Author(s):  
S. Vicca ◽  
P. Serrano-Ortiz ◽  
H. J. De Boeck ◽  
C. M. H. M. Lemmens ◽  
I. Nijs ◽  
...  
Keyword(s):  
Species Richness ◽  
Plant Cover ◽  
Temperature Response ◽  
Thermal Acclimation ◽  
Continuous Heating ◽  
Co2 Fluxes ◽  
Response Curves ◽  
Model Ecosystems ◽  
Declining Species ◽  
Photosynthesis And Respiration

Abstract. To study the effects of warming and declining species richness on the carbon balance of grassland communities, model ecosystems containing one, three or nine species were exposed to ambient and elevated (ambient +3°C) air temperature. In this paper, we analyze measured ecosystem CO2 fluxes to test whether ecosystem photosynthesis and respiration had acclimated to warming after 28 months of continuous heating, and whether the degree of acclimation depended on species richness. In order to test whether acclimation occurred, short term temperature response curves were established for all communities in both treatments. At similar temperatures, lower flux rates in the heated communities as compared to the unheated communities would indicate thermal acclimation. Because plant cover was significantly higher in the heated treatment, we normalized the data for plant cover. Subsequently, down-regulation of both photosynthesis and respiration was observed. Although CO2 fluxes were larger in communities with higher species richness, species richness did not affect the degree of acclimation to warming. These results imply that models need to take thermal acclimation into account to simulate photosynthesis and respiration in a warmer world.

scholarly journals ANALYSIS OF FLOWER BUD DEVELOPMENT TEMPERATURE RESPONSE CURVES OF ORCHARD SPECIES

HortScience ◽  
1992 ◽  
Vol 27 (12) ◽  
pp. 1263b-1263
Author(s):  
Schuyler D. Seeley
Keyword(s):  
Temperature Response ◽  
Tart Cherry ◽  
Flower Bud ◽  
Response Curves ◽  
Bud Development ◽  
Thermally Driven ◽  
Sigmoidal Curve ◽  
Development Temperature ◽  
Temperature Responses ◽  
Flower Bud Development

The effect of thermal accumulation on anthesis rate in apricot, apple, peach, and tart cherry flowers during dormancy, dormancy release, and normal anthesis was determined. Data from several studies in warm and cold climates have indicated that thermally driven anthesis has an early low-temperature optimum that rises during anthesis. This is not true. Erroneous interpretation of results may have been due to inadequate measurements of the endodormancy status of seeds and buds. After endodormancy, flower-bud development temperature responses follow a normal sigmoidal curve with small but significant contributions at temperatures as low as 2C. The grand phase of the growth curve occurs between 16 and 20C in tart cherry. Asymptotic growth vs. temperature responses occurred at <10 and >22C, with minima near 0 and optima >24C. These data indicate that asymmetric curvilinear anthesis models need to be fitted to each species.

Satellite-based estimation of net primary productivity for southern China’s grasslands from 1982 to 2012

2017 ◽  
Vol 71 (3) ◽  
pp. 187-201 ◽  
Author(s):  
W Yang ◽  
T Lu ◽  
S Liu ◽  
J Jian ◽  
F Shi ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Net Primary Productivity
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