scholarly journals Warming sensitivity of spring phenology of deciduous species lies in their bud energy budget

2021 ◽  
Author(s):  
Marc Peaucelle ◽  
Josep Penuelas ◽  
Hans Verbeeck
Keyword(s):  
Air Temperature ◽  
Energy Budget ◽  
Deciduous Forests ◽  
Tissue Temperature ◽  
Plant Tissues ◽  
Environmental Constraints ◽  
Climatic Warming ◽  
Deciduous Species ◽  
Spring Phenology

Spring phenology is mainly driven by temperature in extratropical ecosystems. Contrasting responses of foliar phenology to climatic warming, however, have been reported in recent decades, raising important questions about the role of other environmental constraints, especially light. In fact, temperatures differ substantially between plant tissues and the air because plants absorb and lose energy. Yet, phenology studies always substitute plant tissue temperature by air temperature. Here, we explored how solar radiation, wind, and bud traits might affect spring phenology of deciduous forests through the energy budget of buds. We show that air temperature might be an imprecise and biased predictor of bud temperature. Our current interpretation of the plant phenological response to warming should be reconsidered, which will require new observations of bud traits and temperature for accurately quantifying their energy budget.

Phenology studies need to account for tissue temperature, not air

2021 ◽  
Author(s):  
Marc Peaucelle ◽  
Josep Peñuelas ◽  
Hans Verbeeck
Keyword(s):  
Climate Change ◽  
Simple Model ◽  
Air Temperature ◽  
Tissue Temperature ◽  
Plant Tissues ◽  
Environmental Constraints ◽  
Field Observations ◽  
Climatic Warming ◽  
Real Temperature

<p>Plant phenology is mainly driven by temperature in extratropical ecosystems. Contrasting responses of foliar phenology to climatic warming, however, have been reported in recent decades, raising important questions about the role of other environmental constraints, especially light. A striking and common aspect to past phenological studies is that all analyses have been solely based on air temperature. In fact, temperatures differ substantially between plant tissues and the air, because plants absorb and radiate energy. Using a simple model of bud energy balance, we explore how using bud instead of air temperature could change our interpretation of the phenological response to warming and explain several observed responses of phenology to temperature and light. Not accounting for the real temperature of plant tissues represents a real gap in phenology studies. Field observations of plant tissues temperature as well as experiments are needed for accurately assessing the response of vegetation to climate change.</p>

scholarly journals Surface temperature of plant tissues. Which method of air temperature measurement fits best?

2019 ◽  
Vol 49 (1) ◽  
pp. 11-23 ◽  
Author(s):  
Tomáš Litschmann ◽  
Tomáš Středa
Keyword(s):  
Energy Balance ◽  
Surface Temperature ◽  
Temperature Measurement ◽  
Air Temperature ◽  
Plant Tissue ◽  
Negative Energy ◽  
Tissue Temperature ◽  
Plant Tissues ◽  
Radiation Shield ◽  
Increased Risk

Abstract Climate change is contributing to an increased risk of flower damage by late spring frosts. Monitoring flower temperature is critical for the timely start of frost protection systems. However, there are many weak points that complicate the use of this method. The aims of this study were to: i) find the method of air temperature measurement with the best relationship to the surface temperature of plant tissues and ii) quantify the differences between plant tissues surface temperature and ambient temperature during different weather situations. The surface temperature of plant tissues (budding leaves of grapevine, apricot flower, and unripe pear fruit), air temperature and humidity in the radiation shield, wet bulb temperature and air temperature with an unsheltered thermometer were measured at ten-minute intervals in the spring months. The average temperatures obtained by the individual methods as well as the lowest temperatures were determined from each measurement. Differences between air temperatures and plant surface temperatures, including variation ranges, were also determined. An unsheltered thermometer, in which the energy balance corresponds approximately to that of the evaluated plant surfaces, provided the best relationship with plant tissue temperature. The air temperature measured by the standard method (in a Stevenson screen or in the radiation shield) was almost always higher than the temperature of the plant tissue during periods of negative energy balance. The difference between the minimum temperatures was approximately 0.5 °C. Temperatures more than 1.5 °C higher than the actual temperature of plant tissues were measured in extreme cases.

The role of silicon in forages: A quantitative X-Ray study

1987 ◽  
Vol 45 ◽  
pp. 416-417
Author(s):  
Janet H. Woodward ◽  
D. E. Akin
Keyword(s):  
Sodium Acetate ◽  
Dry Matter ◽  
Acetate Buffer ◽  
Plant Tissues ◽  
Sodium Acetate Buffer ◽  
X Ray ◽  
Dry Matter Digestibility ◽  
Percent Composition

Silicon (Si) is distributed throughout plant tissues, but its role in forages has not been clarified. Although Si has been suggested as an antiquality factor which limits the digestibility of structural carbohydrates, other research indicates that its presence in plants does not affect digestibility. We employed x-ray microanalysis to evaluate Si as an antiquality factor at specific sites of two cultivars of bermuda grass (Cynodon dactvlon (L.) Pers.). “Coastal” and “Tifton-78” were chosen for this study because previous work in our lab has shown that, although these two grasses are similar ultrastructurally, they differ in in vitro dry matter digestibility and in percent composition of Si.Two millimeter leaf sections of Tifton-7 8 (Tift-7 8) and Coastal (CBG) were incubated for 72 hr in 2.5% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0. For controls, sections were incubated in the sodium acetate buffer or were not treated.

scholarly journals Transition between segregation and aggregation: the role of environmental constraints

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Stamatios C. Nicolis ◽  
José Halloy ◽  
Jean-Louis Deneubourg
Keyword(s):  
Environmental Constraints

Extrafloral nectary morphology and the role of environmental constraints in shaping its traits in a common Cerrado shrub (Maprounea brasiliensis A. St.-Hill: Euphorbiaceae)

2014 ◽  
Vol 37 (4) ◽  
pp. 495-504 ◽  
Author(s):  
Marina Neves Delgado ◽  
Sônia Nair Báo ◽  
Lourdes I. V. Amaral ◽  
Davi Rodrigo Rossatto ◽  
Helena Castanheira de Morais
Keyword(s):  
Environmental Constraints ◽  
Extrafloral Nectary

scholarly journals Recent changes of relative humidity: regional connection with land and ocean processes

2017 ◽  
Author(s):  
Sergio M. Vicente-Serrano ◽  
Raquel Nieto ◽  
Luis Gimeno ◽  
Cesar Azorin-Molina ◽  
Anita Drumond ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Interannual Variability ◽  
Air Temperature ◽  
Spatial Scales ◽  
Global Scale ◽  
Sea Surface ◽  
Positive Trend ◽  
Source Regions ◽  
Strong Agreement

Abstract. We analyzed changes in surface relative humidity (RH) at the global scale from 1979 to 2014 using both observations and ERA-Interim dataset. We compared the variability and trends of RH with those of land evapotranspiration and ocean evaporation in moisture source areas across a range of selected regions worldwide. The sources of moisture for each particular region were identified by integrating different observational data and model outputs into a lagrangian approach. The aim was to account for the possible role of changes in air temperature over land, in comparison to sea surface temperature (SST), on RH variability. Results demonstrate a strong agreement between the interannual variability of RH and the interannual variability of precipitation and land evapotranspiration in regions with continentally-originated humidity. In contrast, albeit with the dominant positive trend of air temperature/SST ratio in the majority of the analyzed regions, the interannual variability of RH in the target regions did not show any significant correlation with this ratio over the source regions. Also, we did not find any significant association between the interannual variability of oceanic evaporation in the oceanic humidity source regions and RH in the target regions. Our findings stress the need for further investigation of the role of both dynamic and radiative factors in the evolution of RH over continental regions at different spatial scales.

Stress-Induced Changes in Ubiquinone Concentration and Alternative Oxidase in Plant Mitochondria

2001 ◽  
Vol 21 (3) ◽  
pp. 369-379 ◽  
Author(s):  
Vasily N. Popov ◽  
Albert C. Purvis ◽  
Vladimir P. Skulachev ◽  
Anneke M. Wagner
Keyword(s):  
Alternative Oxidase ◽  
Respiratory Activity ◽  
Plant Mitochondria ◽  
High Oxygen ◽  
Plant Tissues ◽  
Respiration Rates ◽  
Bell Peppers ◽  
Respiration Of Mitochondria ◽  
Induced Changes

We have investigated the influence of stress conditions such as incubation at 4°C and incubation in hyperoxygen atmosphere, on plant tissues. The ubiquinone (Q) content and respiratory activity of purified mitochondria was studied. The rate of respiration of mitochondria isolated from cold-treated green bell peppers (Capsicum annuum L) exceeds that of controls, but this is not so for mitochondria isolated from cold-treated cauliflower (Brassica oleracea L). Treatment with high oxygen does not alter respiration rates of cauliflower mitochondria. Analysis of kinetic data relating oxygen uptake with Q reduction in mitochondria isolated from tissue incubated at 4°C (bell peppers and cauliflowers) and at high oxygen levels (cauliflowers) reveals an increase in the total amount of Q and in the percentage of inoxidizable QH2. The effects are not invariably accompanied by an induction of the alternative oxidase (AOX). In those mitochondria where the AOX is induced (cold-treated bell pepper and cauliflower treated with high oxygen) superoxide production is lower than in the control. The role of reduced Q accumulation and AOX induction in the defense against oxidative damage is discussed.

Sign in / Sign up

Export Citation Format

Share Document