Nathalie Cassagne

Groupe ESA Higher education and research in life sciences · Laboratory of Plant Ecophysiology and Agroecology (LEVA)

Winter oilseed rape (OSR) can be grown intercropped with frost-sensitive service plant mixtures. This practice may reduce weed pressure and contribute to providing N for OSR after service plant freezing. However, there is little knowledge of how plants interact together and with the soil in diverse annual crop mixtures. To assess these interactions...

Intercrops and crop mixtures are considered to be a way to increase nitrogen use efficiency by promoting niche complementarity and facilitation, reducing the input of fertilizers and herbicides, which are important factors when considering the effects of climate change. However, interactions between crop communities and soil functional diversity al...

Both aboveground and belowground biodiversity and their interactions can play an important role in crop productivity. Plant functional diversity, such as legume based intercrops have been shown to improve yields through plant complementarity for nitrogen use (Corre-Hellou et al., 2006). Moreover, plant species or plant genotype may influence the st...

Biological indicators of agricultural soil quality. Within a context of agroecological transition, the Agrinnov project validated a set of indicators of the biological quality of agricultural soils to enable farmers to grasp the impact of their practices. AgrInnov project brought researchers and farmers to work together. To accompany the set of ind...

Functional diversity within plant communities may enhance productivity (Díaz et al. 2007). Among soil organisms, earthworms can positively affect plant growth (Scheu 2003, Brown et al. 2004). Biodiversity may also influence productivity of the plant cover through above- and belowground interactions (De Deyn and Van der Putten 2005, Eisenhauer 2012)...

Functional diversity within plant communities may enhance productivity (Díaz et al. 2007). Among soil organisms, earthworms can positively affect plant growth (Scheu 2003, Brown et al. 2004). Biodiversity may also influence productivity of the plant cover through above- and belowground interactions (De Deyn and Van der Putten 2005, Eisenhauer 2012)...

Past fire recurrence impacts the vegetation structure, and it is consequently hypothesized to alter its future fire behaviour. We examined the fire behaviour in shrubland-forest mosaics of southeastern France, which were organized along a range of fire frequency (0 to 3-4 fires along the past 50 years) and had different time intervals between fires...

Résumé Les associations végétales, par la complexité du couvert végétal qu’elles créent, sont le siège d’interactions biotiques particulières avec les ravageurs, les prédateurs, les champignons pathogènes, les adventices ou encore les organismes non pathogènes du sol. Cet article traite de la diversité des mécanismes en jeu (modification de paramèt...

Résumé Les associations végétales, par la complexité du couvert végétal qu’elles créent, sont le siège d’interactions biotiques particulières avec les ravageurs, les prédateurs, les champignons pathogènes, les adventices ou encore les organismes non pathogènes du sol. Cet article traite de la diversité des mécanismes en jeu (modification de paramèt...

We examined how fire hazard was affected by prescribed burning and fuel recovery over the first six years following treatment. Eight common Mediterranean fuel complexes managed by means of prescribed burning in limestone Provence (South-Eastern France) were studied, illustrating forest and woodland, garrigue and grassland situations. The coupled at...

Height and intensity information derived from Airborne Laser Scanning (ALS) was used to obtain a quantitative vertical stratification of vegetation in a multi-layered Mediterranean ecosystem. A new methodology for the separation of different vegetation strata was implemented using supervised classification of a two-dimensional feature space spanned...

Maintenance and monitoring of soil fertility is a key issue for sustainable forest management. Vital ecosystem processes may be affected by management practices which change the physical, chemical and biological properties of the soil. This study is the first in Europe to use electrical resistivity (ER) as a non-invasive method to rapidly determine...

Pourquoi mesurer la résistivité électrique des sols ? L'hétérogénéité spatiale des sols forestiers doit être prise en compte tant par le gestionnaire que par le scientifique, notamment lorsqu'il s'agit d'étudier d'éventuelles modifications sur le long terme. Actuellement, les méthodes qui permettent de rendre compte de cette hétérogénéité sont peu...

We investigated the power of near infrared (NIR) analysis for the quantitative assessment of soil quality in a wildfire chronosequence. The effect of wildfire disturbance and soil engineering activity of earthworms on soil organic matter quality was first assessed with principal component analysis of NIR spectra. Three soil quality indices were fur...

Impacts of repeated forest fires on the environment and the soil: looking for indicators. IRISE project, Final report RESUME Mots clefs: Incendie de forêt; biodiversité; sol; indicateurs; flore; physique du sol; chimie du sol; structure de végétation; dépérissement des forêts; vers de terre; bactéries; cycle de l'azote; cycle du carbone; nitrificat...

We examine the effect of natural differences in soil temperature at two locations distant by approximately 500 m in the frozen scree of La Plagne en Chartreuse (Savoy, France). We determined humus properties, soil organisms and biologically mediated soil-forming processes in screes from a low part dominated by an open pine forest (OF, 1100 m asl) a...

Near infrared reflectance spectroscopy (NIRS) was used to predict six biological properties of soil and earthworm casts including extracellular soil enzymes, microbial carbon, potential nitrification and denitrification. Partial least squares regression (PLSR) models were developed with a selection of the most important near infrared wavelengths. T...

Our study compared the soil collembolan community at three semi-natural sites (a beech forest, a beech–fir forest and a fir stand) and three managed sites (Norway spruce, beech–fir and fir). Collembola were extracted from a total of 60 samples with a Berlese–Tullgren funnel, counted and identified to species level. A total of 7187 specimens, repres...

Differences of collembolan communities within the organo-mineral A layer were studied in relation to physico-chemical changes in humus at nine sites of beech forests (Fagus sylvatica L.) and first generation spruce stands (Picea abies (L.) Karst.), planted on former beech forest 30 years ago (Central Pyrenees, France). Changes in humus form were ca...

Soil samples were taken under four tree species in various forest sites located in southern France. For each sampled A horizon of the soil profile, pH, organic matter content, C:N ratio and amounts of exchangeable cations (K, Ca, Mg) were measured, and collembolan fauna was extracted using Berlese-Tullgren funnels. A total of 78 species representin...

Soil phosphorus in different depths or horizons of two Inceptisols and four Spodosols was fractionated using the Hedley, Stewart and Chauhan method. The soils were sampled at altitudes between 2000 and 2400 m in the Eastern Pyrenees (France). The total phosphorus content varied considerably between soils and between horizons in the soils. The total...