BG3.3
Orals: Fri, 28 Apr | Room N2
Food security is threatened by co-occurring stresses (e.g. salinity and drought) under global climate change. To circumvent major impacts on food production, the vulnerabilities and tolerances to these threats need to be characterized. Traditionally, the tolerance of crops is evaluated in highly controlled small-scale experiments involving only a limited number of crop types. To increase our understanding in actual agricultural tolerances, plant functioning, as observed by functional traits, need to be performed in real-life scenarios for as many crops as possible. Remote sensing is presently the only tool capable of monitoring such plant functional traits simultaneously over large areas.
The aim of this research therefore is to evaluate the crop tolerances to combined drought and salinity stress across various plant functions in real-life conditions. We evaluated drought and salinity tolerance impacts on different types of crops across the entire US continent, using five traits representative of different plant functions. Given crop tolerance highly depended on the moments, we evaluated the dominant stress and the onset among individual and combined effects of drought and salinity for five traits from March to October.
We found strong interaction effects between stress and time using two-way ANOVAs. In general, crops were more sensitive to combined drought and salinity, although they differ significantly between species and moments. Of the individual traits, LAI was triggered first by stresses, followed by FAPAR and FVC, and Cab and Cw were the last to respond to stresses. This implies that plants reduce primary production before reducing water content.
Our study provides a way of evaluating the tolerance of diverse crops to co-occurrence stresses both separately and in combination. Through applications to other vegetation types and stresses, our approach creates a quantitative backbone to inform sustainable food production.
How to cite: Wen, W., Timmermans, J., Chen, Q., and van Bodegom, P. M.: Diverse responses of multiple crops to drought and salinity stress , EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-1175, https://doi.org/10.5194/egusphere-egu23-1175, 2023.
Agricultural lands provide a near-term opportunity to address climate change, food, and water security challenges. Addressing these complex challenges will require the integration of empirical data on the natural variation of vegetation traits with computational approaches that can integrate this empirical information toward an understanding of canopy-scale impacts. The relationships between leaf chlorophyll content, leaf optical properties, and biochemical photosynthetic capacity were measured in a collection of soybean (Glycine max) accessions showing large variations in leaf chlorophyll content (Chl). These relationships were integrated into a biophysical model of canopy-scale photosynthesis to simulate the within-canopy light environment, carbon dioxide assimilation and water use. Simulations were conducted for each accession to identify possible opportunities for improving canopy photosynthesis through foliar chlorophyll modification. These simulations demonstrate that canopy photosynthesis may not increase as Chl is reduced due to increases in leaf reflectance and nonoptimal distribution of canopy nitrogen. However, similar rates of canopy photosynthesis can be maintained with a 9% savings in leaf nitrogen resulting from decreased Chl. Additionally, analysis of these simulations indicates that the inability of Chl reductions to increase photosynthesis arises primarily from the connection between Chl and leaf reflectance and secondarily from the mismatch between the vertical distribution of leaf nitrogen and the light absorption profile. These simulations motivated the use of numerical optimization to quantify the extent to which low Chl mutations can be used to improve canopy performance by adapting the distribution of the “saved” nitrogen within the canopy to take greater advantage of the more deeply penetrating light. We conclude with a discussion of the impact of the re-distribution of nitrogen vertically through the canopy to improve photosynthesis and canopy water use.
How to cite: Drewry, D.: Simulating the field-scale potential of natural variation in soybean leaf optical properties on carbon assimilation and water use, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-4045, https://doi.org/10.5194/egusphere-egu23-4045, 2023.
Efficient and safe water transport in plants depends on specific wood anatomical structures. Comparing the hydraulic vulnerability among tree species and individuals can be biased by differences in the sampling procedure resulting in unjustified conclusions. In fact, water-transporting conduits of the xylem widen from the tree-tip toward the base potentially influencing xylem vulnerability to embolism formation.
The resistance to cavitation and embolism formation (hydraulic vulnerability curves) was empirically tested at different positions from the tree-tip to the trunk base in a mature Norway spruce and a silver fir tree. Anatomical analyses (conduit diameter, pit traits) were performed on the same material used for hydraulic measurements.
Substantial intra-plant variation in xylem anatomy and vulnerability to embolism was observed in both species scaling with the distance from the apex. The P50 values (i.e. the water potential resulting in 50% loss of hydraulic conductivity) were about 3 MPa more negative at the tip than at the trunk base. Tracheid diameters and pit dimensions increased from the apex downwards, confirming the tip-to-base conduit widening. The highest variability of both anatomical and physiological traits was observed within the first 3 m from the apex. We propose a method for the prediction of drought vulnerability based on hydraulically weighed conduit diameter distribution.
A clear pattern of anatomical traits’ variation along the longitudinal axes of the tree was observed, likely playing a role in the increase of vulnerability to embolism. In comparative studies, we thus recommend to standardize the sampling of material according to the distance from the apex.
How to cite: Savi, T., Zambonini, D., Zagudaeva, K., Rosner, S., and Petit, G.: From tree-tip to trunk-base: interplay of resistance to embolism formation and wood anatomy in two conifers, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-5633, https://doi.org/10.5194/egusphere-egu23-5633, 2023.
The increasing occurrence and intensity of climate extremes, such as droughts, threaten forests and the many services they provide to society. Mixed-species forests are promoted as a forest management strategy for climate change adaptation, but whether they are generally more resistant to drought than monospecific forests remains unresolved. Particularly, the trait-based mechanisms driving tree resistance to drought remain elusive, making it difficult to predict which functional identities of species best improve tree growth and decrease tree physiological water stress under drought.
Here, we investigated tree growth and physiological stress responses (i.e. increase in wood carbon isotopic ratio; δ13C) to changes in climate-induced water availability (wet-to-dry years) along gradients in neighbourhood tree species richness and drought-tolerance traits. For this purpose, we sampled tree cores in a large-scale forest biodiversity experiment (BEF-China experiment). We tested the overarching hypothesis that neighbourhood species richness increases growth and decreases δ13C. We further hypothesized that the abiotic (i.e. climatic conditions) and the biotic context modulate these biodiversity-ecosystem functioning relationships. We characterized the biotic context using drought-tolerance traits of focal trees and their neighbours. These traits are related to cavitation resistance vs. resource acquisition and stomatal control.
We found that tree growth increased with neighbourhood species richness. However, we did not observe a universal relief of water stress in species-rich neighbourhoods, nor an increase in the strength of the relationship between richness and growth and between richness and δ13C from wet-to-dry years. Instead, these relationships depended on both the traits of the focal trees and their neighbours. At either end of the resistance-acquisition and stomatal control trait gradient, species responded in opposing directions during drought and non-drought years.
We report that the biotic context can determine the nature of biodiversity-ecosystem functioning relationships in experimental tree communities. We derive two key conclusions: (1) drought-tolerance traits of focal trees and their neighbours can explain divergent tree responses to drought and diversity, and (2) contrasting, trait-driven responses of tree species to wet vs dry climatic conditions can promote forest community stability. Mixing tree species with a range of drought-tolerance traits may therefore increase forest productivity and stability but may not universally relieve drought stress.
How to cite: Schnabel, F., Barry, K. E., Eckhardt, S., Guillemot, J., Geilmann, H., Kahl, A., Moossen, H., Bauhus, J., and Wirth, C.: Species richness and drought-tolerance traits explain opposing tree growth and δ13C responses to climate extremes , EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-6187, https://doi.org/10.5194/egusphere-egu23-6187, 2023.
Breeding drought resilient crops requires understanding the mechanisms underlying plant physiological responses to different drought patterns and how these vary within species.Two main plant water use strategies are distinguished in the literature, referred to as “risk – taking” (anisohydric) and “conserving” (isohydric). Under well-watered conditions, risk takers exhibit a higher transpiration rate (TR) associated with a greater CO2 assimilation rate, and hence, greater dry matter production than conserving plants which have a tighter stomatal control. Depending on the root traits the transpiration-limiting soil moisture level (θcrit) can differ between plants with similar shoot traits. A high θcrit (e.g. due to shallow roots) entails early stomata closure. This study aimed at examining the drought response of four high-yielding European spring barley cultivars considered to exhibit different response behavior.
We collected detailed plant physiological data with a high- throughput functional phenotyping platform (Plantarray®, Plant-Ditech) and analyzed final yield parameters. Around flowering cv. Chanelle (CHAN), RGT Planet (RGT), Formula (FORM), and Baroness (BAR) were exposed to 12 days of drought. Based on higher TR, higher biomass and grain yield under well-watered conditions and the faster TR reduction below θcrit ,CHAN ranked as very risk taking and RGT as risk taking in contrast to conserving FORM and very conserving BAR.
Drought effects on final yield are closely linked to the plants recovery potential, i.e. the ability to increase TR to control plant levels upon re-irrigation. The highest yielding cultivar under ample water supply, CHAN, showed a significantly impaired recovery potential and suffered notable yield penalties under drought (24%). The very conserving response behavior of BAR resulted in good recovery, minimal yield loss (-2% yield) and a final grain yield that was almost similar to very risk taking CHAN (Δ 5g/pot). FORM produced the lowest yields under control and stress conditions yet suffered no drought induced yield penalties, probably due to a better adapted root system. The lower θcrit of FORM delayed stomata closure and the breakdown of assimilation. FORM and RGT had similar recovery rates.
RGT produced the second highest yield under well-watered conditions and drought did not cause any yield losses. Under ample water supply, RGT behaved like a risk taker, whereby the high TR allowed it to be more productive than the conserving cultivars. RGT switched to a more conserving behavior under drought where it only gradually (same slope as FORM) decreased TR below θcrit and was thereby more productive than very risk taking CHAN. This rather dynamic water use behavior made RGT the best performing cultivar in the here examined drought scenario.
A higher number of seeds per spike (along with reduced kernel size) likely contributed to the yield stability observed under drought in FORM and RGT the exact physiological mechanisms of which still require more investigation. Prospective studies will examine different drought patterns and durations and implement the gained knowledge into crop simulation models for upscaling.
Keywords: water-response behavior, isohydric; anisohydric; spring barley, drought
How to cite: Appiah, M., Abdulai, I., Dewi, E. S., Daszkowska-Golec, A., Bracho-Mujica, G., Schulman, A., Moshelion, M., and Rötter, R. P.: Drought response behavior of risk-taking and conserving spring barley cultivars, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-7999, https://doi.org/10.5194/egusphere-egu23-7999, 2023.
The presence of unique environmental factors such as ionizing radiation (IR) in Space may be a major hindrance to the survival of terrestrial organisms. Therefore, understanding the impact of Space radiation on organisms is an essential part of exploration research to successfully inhabit Moon and Mars.
Given the pivotal role of plants in sustainable closed artificial ecosystems in Space (i.e. Bioregenerative Life Support Systems) as food producers and bio-regenerators of environmental resources such as oxygen and water, and, plant resistance to IR is undoubtedly one of the first trait to consider. Indeed, IR may influence plants growth and development, potentially affecting their bioregenerative performance, jeopardizing astronaut survival and in turn the success of future Space missions. Notwithstanding, available information on plants' responses to IR remain unclear, and intrinsic IR and plant factors (e.g., type of radiation, dose, plant species, cultivar, and developmental stage at the time of irradiation) interactions must be considered.
The purpose of this study was to test the radio resistance of the Salanova® lettuce (Lactuca sativa L. var. capitata) to different doses of high-LET (Linear Energy Transfer) radiation, in terms of morpho-anatomical and nutritional traits. At the GSI Helmholtzzentrum für Schwerionenforschung GmbH, dry seeds were exposed to increasing doses (0-control, 0.3, 1, 10, 20, and 25 Gy) of iron ions (56Fe) (one of the most damaging ions in the galactic cosmic ray spectrum). Following irradiation, plants were grown in a growth chamber under controlled light, temperature, and relative humidity conditions.
Seed germination percentage, as well as plant growth and leaf photosynthesis performances were monitored during cultivation.
Morpho-biometric parameters such as plant total leaf area, number of leaves, and fresh and dry biomass were quantified at harvest. Leaf functional anatomical traits (e.g., lamina thickness, stomatal frequency and size, vein density) were also analyzed using light and epifluorescence microscopy and digital image analysis. Finally, to assess the phytochemical and nutritional profile, the antioxidant capacity, chlorophylls, carotenoid, and mineral composition content were determined.
Results showed that responses of Salanova lettuce from irradiated seeds changed depending on the IR dose delivered, with the occurrence of both hormetic and detrimental outcomes, as well as possible plant radioprotective strategies. This information will be helpful to unveil the mechanisms behind plant radiotolerance and to define the shielding requirements for Space cultivation facilities.
Part of the results presented here is based on the experiment Bio_08_DeMicco, which was performed at the SIS18 at the GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany) in the frame of FAIR Phase-0.
How to cite: De Francesco, S., Amitrano, C., Tinganelli, W., Durante, M., De Pascale, S., Arena, C., and De Micco, V.: Morpho-anatomical and biochemical modifications in Lactuca sativa L. plants in response to increasing doses of High-LET ionizing radiation, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-8395, https://doi.org/10.5194/egusphere-egu23-8395, 2023.
Although evidence of the incidence of foliar water uptake has previously been documented in white spruce (Picea glauca), its eco-physiological importance remains unclear. Our aim was to evaluate the ecological significance of functional differences in foliar water uptake between populations relative to their climate of origin, foliar anatomy, and aquaporin expression.
To investigate needle radial anatomies, micrographs were made using new growth needles collected from 11 provenances growing in a range-wide common garden experiment near Athabasca Alberta. Correlations were then performed to determine relationships between the anatomies and climatic parameters of origin. A foliar water uptake experiment was then conducted on twigs with new growth needles from 6 representative provenances, 3 pairs, each from a different climatic ecozone to best capture a gradient of differences in latitude and marked differences in climate of origin and needle anatomy. The experiment was run using two initial desiccation levels on the 3 ecozones selected—mild, and severe—and mass measurements and tissue samples for RT-qPCR of PIP aquaporins were taken before dehydration, and at t=0, 30, 60, and 240 minutes.
Provenances with thinner Casparian strips and hypodermis layers lost more water during needle dehydration but were also able to take up water faster when wet. Dry climate, Boreal Plains provenances, were anatomically maladapted to drought but had a greater water influx than the others over the first 30 minutes of wetting, which may be explained by their greater aquaporin expression levels during uptake. Expression rates of PIP aquaporins 1;1, and 2;2 were strongly positively correlated with RWC and 1;2 was negatively correlated with the hypodermis thickness.
We conclude that population level differences in foliar water uptake are facilitated by needle anatomy and mediated by aquaporin expression. Our results suggest that there are inherent trade-offs between productivity maintenance in cold climates, drought tolerance, and foliar water uptake. Colder climate populations are anatomically maladapted to drought, but some may be able to compensate with foliar water uptake.
How to cite: Fleurial, K. G., Sebastián Azcona, J., Hamann, A., and Zwiazek, J. J.: Threading the white spruce needle: hydraulic foliar adaptive traits stitch a story of diffusion trade-offs between growth maintenance, drought resistance, and needle water uptake, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-13695, https://doi.org/10.5194/egusphere-egu23-13695, 2023.
Extraordinary changes in alpine fire regimes have been often associated with heat waves, which are generally regarded as an indication of a changing climate that will lead to new fire regimes in the Alps. Fine roots function of absorbing water and nutrients is crucial to plant survival and their traits such as biomass, length, specific root length, production, death, and decomposition can inform how trees interact with their environments and provide ecological functions in response to exogenous stresses. After an unusual, late-fall wildfire in a European beech (Fagus sylvatica L.) forest in the pre-Alps of northern Italy, the response of fine roots (< 2 mm diameter) was analysed and appeared more evident when fine roots were further subdivided by diameter size and soil depth. The finest roots (0‒0.3 mm diameter) were generally the most responsive to fire, with the effect more pronounced at the shallowest soil depth. While roots 0.3‒1 mm in diameter had their length and biomass at the shallowest soil depth reduced by fire, fire stimulated more length and biomass at the deepest soil depth compared to the control. Fire elevated the total length of dead roots and their biomass immediately and this result persisted through the first spring, after which control and fire-impacted trees had similar fine root turnover. Our results add to the paucity of data concerning fire impacts on beech roots in a natural condition and provide the basis for understanding fine-root morphological traits approach to assess plant species vulnerability and resilience to unusual fire occurrence due to climate changes. Changes in disturbance regimes might be most realized by distribution of the finest of fine roots at differing soil depths, and the dynamics of these roots may provide the most resilience to disturbance.
How to cite: Montagnoli, A., Terzaghi, M., Miali, A., Chiatante, D., and Dumroese, K.: Fine-root morphological traits may improve understanding of the vulnerability of Fagus sylvatica natural forests to late-fall unusual wildfire, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-17297, https://doi.org/10.5194/egusphere-egu23-17297, 2023.
In the current scenario of decreasing in precipitation and water resources, and increasing in temperature, it is pivotal to define multiple strategies to cope with the negative consequences on the crop production and food security. Hazelnut (Corylus avellana L.) is an important nut tree crop grown in several countries all over the world and mainly in the Mediterranean Basin area. Among the producer countries Italy is the second main worldwide producer, soon after Turkey. Despite the long-lasting and traditional cultivation of hazelnut in the hilly areas and a recent wider spread of its orchards to newly cultivated fertile plains, hazelnut is well known as a very sensitive species to both water stress and high temperatures. The main aim of this study was to evaluate growth performances and morpho-physiological adaptive responses to prolonged water stress in potted young hazelnut plants. Secondarily, the effect of biostimulant treatments in mitigating the effects of water and heat stresses were evaluated. The research was conducted on one-year-old cultivar micro propagated plants of cv “Tonda di Giffoni” grown in a cold polycarbonate greenhouse at the Department of Agricultural Sciences of the University of Naples “Federico II” during two consecutive growing seasons. Three irrigation levels (i.e. 100, 80, and 60% of the daily water requirement) were applied in combination with two different biostimulant treatments. In particular, they consisted in the application near the roots of protein hydrolysate or mycorrhizae inoculation. The first one was applied every two weeks with a dosage of 2.5 ml/l according to the chemical characteristics of the product, during the whole growing season; instead, the second one was applied with a single-dose of 15 g per plant at the beginning of each growing season. During the two seasons, growth rate (i.e. basal diameter, branch length, leaf number, leaf area, and buds), eco-physiological behaviour (i.e. gas exchanges measurements, Chlorophyll a fluorescence emission, SPAD index, and leaf water potential), and leaf functional traits were investigated. Results showed that the use of biostimulant and mycorrhizae positively influenced physiological behaviour and growth of plants by counteracting deficit irrigation stress effects. In conclusion, our study demonstrate how these type of treatments help to improve the quality of plants.
How to cite: Vanacore, L., Modarelli, G. C., El-Nakhel, C., Pannico, A., Rouphael, Y., and Cirillo, C.: Biostimulant applications to mitigate multiple summer stress effects on potted Corylus avellana L. young plants , EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-9556, https://doi.org/10.5194/egusphere-egu23-9556, 2023.
Posters on site: Fri, 28 Apr, 16:15–18:00 | Hall A
Deep roots play a major role in plant water uptake. During dry periods, they can be the decisive factor for plant survival. In agricultural production systems, survival is not enough. Crops must thrive to sustain high yields.
While deep water uptake by deep roots is well documented it is puzzling that drought symptoms can be observed in deep-rooted species with access to deep stored soil moisture. Something limits the deep water uptake.
Today breeding for deeper roots in crops is intensifying to ensure food production facing more frequent and more severe droughts in the world’s major crop-producing areas. I argue that the investment in deeper roots is not likely to reach its full potential unless limitations to deep water uptake are identified and targeted by breeders. I hypothesize that the limitation is caused by 1) limited hydraulic conductivity in the deeper part of the root system, and/or 2) a hormonal response to a dry topsoil forcing stomates to close.
How to cite: Ruø Rasmussen, C.: The mystery of the lazy deep roots, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-2287, https://doi.org/10.5194/egusphere-egu23-2287, 2023.
Vanuatu as one of Small Island Developing States (SIDS) in the Pacific region is one of the most vulnerable countries to climate impacts including climate-related natural disasters. In order to build the adaptive capacity of vulnerable communities and users of climate information and services. The Climate Information Services for Resilient Development Planning in Vanuatu (Van-CISRDP; Vanuatu Klaemet Infomesen blong Redy, Adapt mo Protekt (Van-KIRAP) in Bislama) project was approved at the Green Climate Fund (GCF) 15th meeting of the board in Apia, Samoa in December 2016 (FP 035). The two implementing entities: Secretariat of the Pacific Environment Program (SPREP) and Geo-Hazard Department (VMGD) and three delivery partners: APEC Climate Center (APCC), Commonwealth Scientific and Industrial Research Organization (CSIRO) and Australia Bureau of Meteorology are collaboratively conducted the Van-KIRAP project. In the Van-KIRAP project, the major activities of APCC consist of (1) Develop Agro met information portal including new on line IT infrastructure and software (OSCAR prototype), (2) Collecting, modelling, analysis and reporting of agro-met data to determine optimal agriculture crop planning options, (3) Undertaking field trials and validation prior to incorporation into DSS delivery platforms, ground truthing and outreach with target Next/End Users, and (4) Develop the crop-climate diary (CCD) customised for agro-met data collection. In this presentation, we will introduce the APCC portion of the Van-KIRAP project including experimental field trials for major staple crops, various training and education programs in both on-line and on-site, and the development of the OSCAR system incorporating various Artificial Intelligence techniques and modelling approaches. These will provide relevant climate information applied to the agriculture sector. The CCD will serve as a tool to collect data in an efficient streamlined manner from different areas of Vanuatu. Utilizing the data from CCD, OSCAR will be a hub for the interaction of climate information and agriculture.
How to cite: Chun, J. A., Park, S., Jung, I., Lee, S., and Park, K.: Developing Tailored Agro-met Predictions for Target Cropping Systems in Vanuatu: tailOred System of Climate services for AgRiculutre (OSCAR), EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-3743, https://doi.org/10.5194/egusphere-egu23-3743, 2023.
In the upcoming years, agriculture will have a central role not only in feeding a growing population worldwide, but also in Space-related research, through the implementation of protected cultivation systems. To make it possible, it is fundamental to understand plants’ ability to cope with a dynamic environment, made worst by harsh Space conditions including microgravity and ionizing radiation.
Plant plasticity in adaptation relies on the development of both structural and physiological traits, which are deeply influenced by the environment; therefore, leaf morpho-anatomical traits are critical for balancing plant water and CO2 exchange and determine the efficiency of CO2 diffusion within the mesophyll. Their relationship has been widely studied; however, it remains unclear at what extent leaf anatomical traits may drive leaf hydraulic and photosynthetic acclimation to Space environmental stressors.
Previous studies have proven that ionizing radiation can induce positive, null or negative effects depending on the radiation type, dose and exposure (acute or chronic) as well as plant developmental stage and species.
In this study, we compared functional, anatomical (e.g., leaf area, leaf dry matter content, leaf mass per area, stomatal and vein size and density, mesophyll organization, chloroplast distribution) and biochemical traits (e.g. chlorophyll and carotenoids content, polyphenols, ascorbic acid) of brassica microgreens (Brassica rapa L. subsp. sylvestris var. esculenta) exposed to three different types of radiation (X-rays, Carbon ion 12C, Iron ion 56Fe) at the same doses (0-control, 0.3, 1, 10, 20, and 25 Gy). Irradiation took place at the GSI Helmholtzzentrum für Schwerionenforschung GmbH, and then microgreens were cultivated in a growth chamber under controlled condition. Microgreens were chosen as study model for two main reasons. First, microgreens are good candidates for the diet integration of astronauts because they are rich in nutraceutical compounds and can be cultivated directly in Space with very low input resources. From a fundamental science viewpoint, understanding the morpho-functional responses of microgreens is needed because at this stage of development plants are very vulnerable: overcoming the microgreens stage may represent a bottleneck in the cultivation of adult plants in bioregenerative life support systems.
The results suggest the different radiation type and doses determined alterations in morpo-anatomical and biochemical traits which may determine the limits of crop responses and biomass production. These findings should be considered when studying plant adaptation to Space environment, trying to optimize plant growth in controlled environment to achieve the sustainability of the system.
Part of the results presented here is based on the experiment Bio_08_DeMicco, which was performed at the SIS18 at the GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany) in the frame of FAIR Phase-0.
How to cite: Amitrano, C., De Francesco, S., Tinganelli, W., Durante, M., Vitale, E., Arena, C., and De Micco, V.: The study of morpho-anatomical and biochemical traits on irradiated microgreens to unlock crop potential in Space , EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-7239, https://doi.org/10.5194/egusphere-egu23-7239, 2023.
With climate change increasing the severity and duration of droughts, ecosystems may not be able to withstand such droughts causing a rapid collapse. However, at present we lack a quantitative understanding of this ‘buffer capacity’ of ecosystems to these deteriorating droughts. Here, we established continental-scale models to quantify the ecosystem vulnerability and associated drought characteristics impacts for different ecosystems in Europe using high spatial and temporal resolution drought and traits data from remote sensing. Specifically, we observed varying vulnerabilities across ecosystems where vegetation damage increases with earlier, longer and more intense droughts. However, we also found that vulnerability of most ecosystems increases disproportionally when drought severity begins to increase. Collectively, the results suggest that the intensified drought under future climate change could threaten a vast range of ecosystem types. The multi-characteristics assessment of ecosystem vulnerability based on traits in our study will help to forecast and quantify vegetation damage to future global climate change challenges and inform drought mitigation policies.
How to cite: Chen, Q., Timmermans, J., Wen, W., and van Bodegom, P.: Ecosystems threatened by intensified drought with varied vulnerability in Europe, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-10375, https://doi.org/10.5194/egusphere-egu23-10375, 2023.
The accumulation of fragmented extracellular DNA in decomposing plant litter reduces conspecific seed germination and plantlet growth in a concentration-dependent manner. An inverse relationship between DNA inhibition magnitude and taxonomic distance between the DNA source and the target species has been reported. This phenomenon bears important implications in plant ecology, as the accumulation or removal of DNA in litter can play a fundamental role in determining biodiversity patterns in different ecosystems and could represent a further explanatory process underlying negative plant–soil feedback. In this context, self-DNA has been suggested to act as a stress signaling molecule, possibly as damage-associated molecular pattern (DAMP), triggering plant resistance and growth inhibition in response to environmental stressors (e.g., herbivory, pathogens attack, intraspecific competition) causing death and subsequent release of conspecific DNA in the soil. The underlying mechanisms at cellular and molecular levels are not yet fully clarified, but previous studies reported the induction, in plants, of early innate immune response, ROS production, MAPK activation, extra-floral nectar production, increased intracellular [Ca2+] and plasma membrane depolarization. Moreover, a recent whole-plant transcriptome profiling and confocal microscopy analyses in Arabidopsis thaliana suggested that cells are capable of discriminating self from non-self DNA by specific sensing and highlighted an association between self-DNA exposure and abiotic stress gene response. In the present work we investigated, for the first time, the species-specificity of self-DNA inhibition in cultivated vs. weed congeneric species (respectively, Setaria italica and S. pumila) and carried out a targeted real-time qPCR analysis, under the hypothesis that self-DNA elicits molecular pathways responsive to abiotic stressors. The results of a first cross-factorial experiment on root elongation of plantlets exposed to self-DNA, congeneric DNA and heterospecific DNA from Brassica napus and Salmon salar questioned the species-specificity of the inhibitory effect, possibly related to the confounding effect of contaminants in the treatment solutions. A repeated test after ultra-purification of the treatment solutions confirmed a significantly higher inhibition by self-DNA as compared to non-self treatments, the latter showing a magnitude of the effect consistent with the phylogenetic distance between the DNA source and the target species. Targeted gene expression analysis highlighted an early activation of genes involved in ROS degradation and management (FSD2, ALDH22A1, CSD3, MAPK17) and deactivation of scaffolding molecules acting as negative regulators of stress signaling pathways (WD40-155). While being the first exploration of early response to self-DNA inhibition at molecular level on C4 model plants, our study highlights the need for further investigation of the relationships between DNA exposure and stress signaling pathways, discussing potential applications for species-specific sustainable weed control in agriculture.
How to cite: Ronchi, A., Foscari, A., Zaina, G., De Paoli, E., and Incerti, G.: Self-DNA early exposure in cultivated and weedy Setaria triggers ROS degradation signaling pathways and root growth inhibition, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-12429, https://doi.org/10.5194/egusphere-egu23-12429, 2023.
The relative importance or the abundance of plant species in ecosystems shows large spatio-temporal variability due to habitat- and species-related factors. What is more, in Hungary, climate change is accompanied by an increased probability of droughts and heat waves with further consequences on community attributes both in time and space.
The finely undulating (no more than 1.5 m elevation differences within the study site) surface in our sandy grassland study site was formed through the combined effects of wind, water erosion, and drought, and resulted in uneven soil nutrient and water distributions. We surveyed the vegetation of an ~ 1 ha area along 15 campaigns covering spring, summer, and autumn aspects for 7 years in 80 × 60 m grids where the surface cover of plant species within 78 patches of 0.5 × 0.5 m quadrates was recorded. The large spatial and temporal dataset (n=78 × 15=1170 quadrates with an overall species number of 114) enabled us to follow both species-wise (abundances) and community-level (e.g., diversity) patterns along with different terrain attributes for years.
During the study period, the grassland functioned as a carbon sink with a balanced physiological performance with year-to-year variability. The yearly sum of precipitation was very variable without any statistically significant change since the establishment of the study station (2002); however, significant warming was observable since then.
Within the study area, vegetation differentiation was detectable along with the terrain attributes. This vegetation differentiation was temporally variable following the patterns of how species with different environmental requirements split available places/resources through time. At hotter, dryer, more elevated positions, and more on the ridges, we could differentiate a larger ratio and diversity of a group of species favoring such conditions, while another group was more abundant in areas with opposite conditions. The presence of such different species groups and functional types within this relatively small area with a slight surface undulation may have been responsible for the observed balanced physiological performance of the grassland. However, although the diversity of the community as a whole didn’t change significantly during the study period, one of the ecological group diversities, that of species favoring cooler, wetter positions, decreased. So, not only temporal variability but also trend-like shifts were observable in the vegetation composition through time, and the stability of the diversity was found to show a terrain-related pattern.
How to cite: Fóti, S., Balogh, J., Bartha, S., Pintér, K., and Nagy, Z.: Trends in plant species-wise abundances with parallel maintenance of community-level diversity in a Hungarian sandy pasture, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-12765, https://doi.org/10.5194/egusphere-egu23-12765, 2023.
Plants often experience adverse or stressful environments that might have an impact on their growth and development, thus, phenotype. Visible symptoms of stress had been long studied, but their manual scrutiny can be challenging, time-consuming, and error-prone. However, there are currently very few instances of machine learning (ML) models that can automatically predict plant stresses, especially abiotic ones, from image-derived morphological traits. This study aims to fill this gap using digital phenotyping tools for stress detection based on automated image analysis and to further compare them with standard analytical procedures commonly carried out in laboratories. Two preliminary models for classifying salt stress levels have been developed to achieve this goal on Arabidopsis thaliana plants. Seedlings were grown on different substrates (soil and perlite) and exposed to “medium” and “high” salinity stress levels (50 mM and 150 mM NaCl) for 10 days. Biochemical parameters – Electrolyte Leakage (EL), Relative Water Content (RWC), and Dry weight (DW) – were measured, along with morphological traits – colorimetrical and geometrical – obtained from RGB images using both manual and automated approaches. The resulting data was then used to evaluate the performance of decision trees on 2-classes (presence or absence of stress) and 3-classes models (absence, medium, and high-stress levels). We noticed that plants’ development was influenced both by the growing environment and substrate type. Visible symptoms of stress included a reduction in leaf number and rosette size, as opposed to a chlorosis increment. RWC and DW decreased in response to high NaCl concentration, whereas EL increased. Nevertheless, while differences were significant among high-stressed plants and control ones, medium-stressed plants were hard to discern from both conditions. The Principal Component Analysis, which grouped the two levels of stress, also supported this conclusion. These results were further validated by classification algorithms tested: the 3-classes model only achieved 73% accuracy, compared to the binary model’s 90%. EL appears to be one of the key features for stress detection, but other important image-derived functional traits have also emerged from this preliminary study that can be used as indicators of plant health status and to study plant strategy to cope with environmental stressors, thus predicting their vulnerability/resilience to extreme climate conditions. With these findings, we demonstrate the great potential of image analysis methods and we highlight the positive impacts of automation, including increased analysis speed and decreased error rates. Moreover, we emphasize the importance of explainable ML models that can be easily interpreted and indicate essential traits needed for the model’s deployment and improvement. Given the modest size of our dataset, an integrated strategy is still necessary to obtain an adequate degree of classification accuracy. Therefore, in the future, by increasing the number of instances, we aim to enhance the model’s robustness and reliability and generalize it for the detection of various abiotic stresses in diverse species.
How to cite: Del Cioppo, G., Scalabrino, S., Simiele, M., Scippa, G. S., and Trupiano, D.: Understanding plant vulnerability to stressors with automated image analysis, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-15576, https://doi.org/10.5194/egusphere-egu23-15576, 2023.
Climate change projections indicate that significant areas of the current cocoa cultivation areas in West Africa are likely to experience unfavorable climatic conditions by 2050. Water use efficient agroforestry systems are considered to be an important option to adapt cocoa to climate change. Water use efficiency and complementary soil water use between cocoa and shade trees have been reported in previous studies in Indonesia but in our previous study in Ghana, popular native shade tree species Albizia ferruginea and Antiaris toxicaria were found to have a strong competitive water use advantage over cocoa plants during an extreme drought experienced during 2015/16. Cocoa plants under no shade were relatively more resilient with higher survival rate and post drought recovery.
While past research studies were each limited to few selected shade tree species being investigated despite the huge numbers within cocoa landscapes. To overcome this limitation, an approach based on functional traits of trees in terms of water use is proposed to understand their effect on water use efficiency and drought resilience in cocoa agroforestry systems rather than describing individual species. We apply this concept across temporal and spatial scales in a marginally suitable cocoa climate in Ghana. Shade tree species have been categorized into phenological trait groups (evergreen, deciduous, or brevi-deciduous) under which detailed above- and belowground traits interactions with cocoa plant and effect on water use has been evaluated.
The following hypotheses are being tested: (i) shade trees in the three phenological trait groups exhibit significant difference in their root and water uptake depth, and, thus, affect environmental conditions relevant for cocoa, (ii) cocoa plant above- and belowground morphological and physiological traits are influenced by shade tree phenological and morphological traits and their modification by micro-climatic (light, temperature, relative humidity and VPD), and soil (water and nutrients) conditions over different seasons.
Replicated plots of 19 shade tree species distributed across the three phenological trait groups have been established for analysis of functional traits interactions in such a multi-species agroforestry system. We determine root specific traits through direct sampling, stable isotope analysis for assessment of water use portioning between the various shade tree groups and cocoa plants. Soil moisture, temperature and relative humidity and light sensors were installed in each plot. Cocoa plants under different micro-climatic impact zones of the shade trees have been monitored for a full production cycle. The shade trees impact on the cocoa plant productivity (morphology and yield traits) has been evaluated. Complementary and non-complementary shade tree species with respect to their trait interactions and effect on cocoa plant productivity have been identified.
How to cite: Abdulai, I., Hoffman, M., Dippold, M., Asare, R., and Rötter, R.: Managing climatic risk in cocoa by designing resilient agroforestry systems based on a functional trait approach , EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-16069, https://doi.org/10.5194/egusphere-egu23-16069, 2023.
Posters virtual: Fri, 28 Apr, 16:15–18:00 | vHall BG
Phenology reflect the influences of climate change on individual plant biodiversity. Meteorological factors (temperature, precipitation, sunshine period) are reported to have major influence for determining variation of time phenophases through changes in biological activities.
Functional traits are morphological, physiological, and phenological features that show the plant functional response to a specific environmental condition. Traits are therefore connected to physiological functions and mechanisms that allow species to face the climatic changes.
Phenological traits can help explaining variation in plant growth strategies as it is closely associated with carbon gain and nutrient conservation. The beginning of leaf emergence and senescence can maximize plant survival and productivity, as the duration of stages are closely related to resource acquisition and distribution. Intraspecific trait variation, complementarity, and environmental stress are investigated at several hierarchical levels with the final goal of identify the mechanisms through which individuals and species interact and coexist for the use of resources. Therefore, it is fundamental to understanding how species modulate their phenological traits.
In this work, phenological traits for 12 forest species are monitored and studied. The research was conducted on an experimental site in Sardinia, Italy. A selection of monocultures and mixed communities, with different levels of species richness and functional diversity, were under observation over a 2-years period.
Phenological traits were investigated by using automated monitoring systems for recording high-resolution digital images in the visible spectrum. Start and duration of the growing season were monitored to acquire information regarding the plant status in relation to environmental conditions (temperature/drought). The images were collected at daily interval during the period 2017-2019. Six systems were set-up and installed on a metal pole, at 2.5 m height above ground.
The phenological traits for each individual were determined by analysing images visually. Moreover, a digital image processing, for deriving colour vegetation indices, was performed using a routine specifically developed under the software application MATLAB. RGB color channel information were recorded as digital numbers (DN) in a region of interest (ROI). To reduce the effects of scene illumination, the DNs are converted in to chromatic coordinates. Daily values of vegetation indices (ExG, REI, GRVI, etc) were then calculated.
The pattern of vegetation indices during the growing season were analysed for each species, showing how the color index performance works in capturing vegetation phenological change, and the performance of species growing under different levels of richness and functional diversity.
Information from this study can provide a valid contribution to a more detailed understanding on how plant responds to different environmental conditions, in particular in relation to phenological behaviour in response to climatic changes in Mediterranean regions.
How to cite: Cesaraccio, C., Piga, A., Mereu, S., Ventura, A., Masia, P., and Duce, P.: Monitoring of plant phenological traits in a mixed Mediterranean forest species based on colour vegetation indices, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-12407, https://doi.org/10.5194/egusphere-egu23-12407, 2023.
