- INTRANET (Reserved access)
| Date and place | Participant(s) | Content |
|---|---|---|
| 01/07/2019 from 11h00 to 12h00 PS 2, salle 201 |
Santiago TRUEBA | Jeudi de l'AMAP (Résultats & Programmes) Understanding the effect of plant-water relations on the distribution and survival of species using a nanometers-to-landscape approach Read the summary AMAP's ThursdayOn 01/07/2019 , from 11h00 to 12h00, PS 2, salle 201 Santiago TRUEBA will present Understanding the effect of plant-water relations on the distribution and survival of species using a nanometers-to-landscape approachIncreasing frequency and severity of drought events are triggering the dieback of plant communities across the world. Understanding how vegetation responds to water deficit is therefore a major goal in current ecological research. Using a functional approach, we have found that, amongst other commonly measured traits, the drought-induced dysfunction of the xylem hydraulic system is a major driver of the distribution of tropical species. Consequently, xylem embolism vulnerability is significantly related to environmental variables across the landscape. However, to understand the fate of plant communities under climate change, it is important to study the levels of dehydration that impact major physiological processes at the organ level. In a second part of this presentation, I will show a sequence of leaf functional damage over increasing dehydration. Our findings suggest that stomatal and leaf hydraulic declines are impacted early during dehydration. Damage to the photochemical apparatus, which functional decline is commonly used as a marker of drought stress, seems to occur only under extreme dehydration. By analysing a large set of anatomical features, we have found that the thickness of the membrane covering the lateral pits of the xylem conduits is correlated with the drought tolerance of the hydraulic apparatus. This finding highlights the influence of a nanometrical anatomical feature on the drought resistance of plant species with different anatomical organizations. In order to further understand how anatomical structure influence the hydraulic function of the plant, I am currently using cutting-edge imaging techniques such as x-ray microtomography. We will discuss how this technique can help us to understand the hydraulic function of the plant in vivo, and how this knowledge can be used to predict the survival of plant communities under global climate change. Joined File : 20190701_Santiago_Trueba_JeudiAMAP.pdf Joined File : 20190701_Santiago_Trueba_JeudiAMAP.pdf |
| 11/07/2019 from 11h00 to 12h00 PS 2, salle 201 |
Nicolas GROSS | Jeudi de l'AMAP (Résultats & Programmes) Biodiversity and Ecosystem Multifunctionality: Lesson from drylands Read the summary AMAP's ThursdayOn 11/07/2019 , from 11h00 to 12h00, PS 2, salle 201 Nicolas GROSS will present Biodiversity and Ecosystem Multifunctionality: Lesson from drylandsFunctional traits are often invoked to explain species coexistence and ecosystem functioning. However, the hypothesis that trait differences determine the ability of ecosystems to maintain multiple functions simultaneously (multifunctionality) remains largely untested at a global scale. In a survey of 124 dryland plant communities, we found a unique scaling relationship between trait diversity of specific leaf area and maximum plant height and multifunctionality (productivity and surrogates of carbon, nitrogen and phosphorus cycling). Across a variety of species pools and environmental conditions, trait diversity within communities was strikingly high and maximized multifunctionality. Trait diversity had a much stronger impact on multifunctionality than other multifunctionality drivers (e.g. species richness, aridity). We uncovered a general scaling relationship that quantifies how much plant diversity is required to maximize multifunctionality in global drylands. Joined File : 20190711_Nicolas_Gorss_JeudiAMAP.pdf Joined File : 20190711_Nicolas_Gorss_JeudiAMAP.pdf |
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