Search results for "Écologie végétale"
showing 4 items of 4 documents
Temperature and pH define the realised niche space of arbuscular mycorrhizal fungi
2021
Made available in DSpace on 2021-06-25T11:52:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-04 European Regional Development Fund (Centre of Excellence EcolChange) University of Tartu (Estonian Research Council ) Moscow State University Natural Sciences and Engineering Research Council of Canada Discovery Grant Russian Science Foundation Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Swedish Research Council (Vetenskapsradet) The arbuscular mycorrhizal (AM) fungi are a globally distributed group of soil organisms that play critical roles in ecosystem function. However, the ecological niches of individual AM fungal taxa are poorly understood. We collected > 300 s…
Data synergy between leaf area index and clumping index Earth Observation products using photon recollision probability theory
2018
International audience; Clumping index (CI) is a measure of foliage aggregation relative to a random distribution of leaves in space. The CI can help with estimating fractions of sunlit and shaded leaves for a given leaf area index (LAI) value. Both the CI and LAI can be obtained from global Earth Observation data from sensors such as the Moderate Resolution Imaging Spectrometer (MODIS). Here, the synergy between a MODIS-based CI and a MODIS LAI product is examined using the theory of spectral invariants, also referred to as photon recollision probability ('p-theory'), along with raw LAI-2000/2200 Plant Canopy Analyzer data from 75 sites distributed across a range of plant functional types.…
Vegetation structure and greenness in Central Africa from Modis multi-temporal data.
2013
African forests within the Congo Basin are generally mapped at regional scale as broad-leaved evergreen forests, with a main distinction between terra-firme and swamp forests types. At the same time, commercial forest inventories, as well as national maps, have highlighted a strong spatial heterogeneity of forest types. A detailed vegetation map generated using consistent methods is needed to inform decision makers about spatial forest organisation and theirs relationships with environmental drivers in the context of global change. We propose a multi-temporal remotely sensed data approach to characterize vegetation types using vegetation index annual profiles. The classifications identified…
Conséquences écologiques et évolutives du flux de gènes entre Brassica napus transgénique et ses apparentés sauvages
2010
In the framework of commercial release for transgenic crops with novel traits, consequences of gene flow and introgression are still one main concern. I explored the ecological and evolutionary consequences of gene flow between oilseed rape (Brassica napus) and its wild relatives, brown mustard (B. juncea) and wild radish (Raphanus raphanistrum), through several experiments carried out in greenhouse, common garden and field in Beijing and Dijon. First, I revised a comprehensive review of the literature about gene flow and its effect on plant fitness in the Brassiceae. Second, I investigated the effects on gene flow of seed size of hybrids between Bt-transgenic oilseed rape and mustard. Smal…