Discriminating impacts of geomorphological and human factors on vineyard soil erosion (Burgundy, France)

International audienceThe Burgundy vineyards have been recognized for the high diversity of Terroirs, controlled by complex interactions between natural features, historical parameters and soil management practices. Vineyards are known to undergo substantial soil loss in comparison with other types of agricultural land. Hydric erosion on vineyards is controlled by complex interactions of natural and anthropogenic factors leading to intra-plot spatial heterogeneities of topsoil at a scale of a metre. Studying the relationship between soils and their degradation is crucial in this situation where soil sustainability is threatened. This study explores the relative influences of historical and present-day anthropogenic factors and geomorphological processes controlling soil erosion on vineyard hillslopes. The selected area was located in the Monthelie vineyard (Côte de Beaune, France) where intensive erosion occurred during high-intensity rainfall events. Soil erosion quantification was performed at a square-metre scale using dendrogeomorphology. This method is based on the measurement of the unearthing of the stock located on the vine plants, considered as a passive marker of soil-surface vertical displacement since the year of plantation. The obtained maps, together with various complementary datasets, such as geological and geomorphological data, but also historical documents (cadastral plans, cadastral matrices and old aerial photographs) allow landscape evolution to be assessed. The combination of all these data shows that spatial distribution and intensity of erosion are controlled mainly by lithology and slope value. However, our study highlights that the sediment dynamics in this vineyard plot is highly related to historical former plot limits and present-day management practices. Nonetheless, quantification of sediment dynamic for the last decade reveals that the impacts of historical structures are disappearing gradually, in response to present-day management practices and geomorphological factors. Finally, this study shows that it is crucial to take into account the pre-plantation history of vineyard plots in order to increase our understanding of sediment dynamics on vineyard hillslopes

Mapping soil and substratum at a very high spatial resolution in the hillslope of Couchey (France)

International audienceIn this work, we present a method based on very high spatial resolution (VHSR) aerial images acquired in the visible domain and that map soil surface diversity at the hillslope scale with a spatial resolution of a few centimeters. This method combines aerial VHSR image classification with local soil sampling. Principal component analysis (PCA) and non-supervised classification was performed on image characteristics to define soil surface characteristic classes (SSC). Then soil surface mapping was combined with soil surface descriptions and soil profiles to define soil types by physical and chemical characteristics. As soil results from parent material alteration, identifying the geological substratum can help to explain the diversity of vineyard soils. The confrontation between soil map and geological map at a 1:10000 scale highlights a good correlation between the geological substratum and soils classes for this hillslope

Spatial analysis of within-vineyard grapevine sensitivity to solar irradiance patterns. A case study using Pinot noir in a complex terrain

Communication orale, texte intégralWe analyze how the patterns of the solar irradiance affect the growth of Pinot noir grapevines at stand-scale over a hilly terrain bounded by a coniferous forest. Results show that the patterns of irradiance deficit are the primary driving force of the growth. Linear trends display good correlation between the total deficit of irradiance, and the developed growth index (R2 up to 0.96 ). This result also suggests the impact of low minimum temperature due to cold air drainage and stagnation. Results lead to propose a model able to capture at stand-scale 90% of the whole spatial variability of the growth. The model accounts for the diffuse component of the deficit of irradiance and the squared temperature anomalies. Combining such models through the use of GIS enables to better understand the driving mechanisms of grapevine growth over complex terrain, towards a better management of the “terroir” potential whithin climate change

Structural Basis for the Association of MAP6 Protein with Microtubules and Its Regulation by Calmodulin: Microtubule and calmodulin binding on Mn modules of MAP6

International audienceMicrotubules are highly dynamic αβ-tubulin polymers. In vitro and in living cells, microtubules are most often cold- and nocodazole-sensitive. When present, the MAP6/STOP family of proteins protects microtubules from cold- and nocodazole-induced depolymerization but the molecular and structure determinants by which these proteins stabilize microtubules remain under debate. We show here that a short protein fragment from MAP6-N, which encompasses its Mn1 and Mn2 modules (MAP6(90-177)), recapitulates the function of the full-length MAP6-N protein toward microtubules, i.e. its ability to stabilize microtubules in vitro and in cultured cells in ice-cold conditions or in the presence of nocodazole. We further show for the first time, using biochemical assays and NMR spectroscopy, that these effects result from the binding of MAP6(90-177) to microtubules with a 1:1 MAP6(90-177):tubulin heterodimer stoichiometry. NMR data demonstrate that the binding of MAP6(90-177) to microtubules involve its two Mn modules but that a single one is also able to interact with microtubules in a closely similar manner. This suggests that the Mn modules represent each a full microtubule binding domain and that MAP6 proteins may stabilize microtubules by bridging tubulin heterodimers from adjacent protofilaments or within a protofilament. Finally, we demonstrate that Ca(2+)-calmodulin competes with microtubules for MAP6(90-177) binding and that the binding mode of MAP6(90-177) to microtubules and Ca(2+)-calmodulin involves a common stretch of amino acid residues on the MAP6(90-177) side. This result accounts for the regulation of microtubule stability in cold condition by Ca(2+)-calmodulin

Earthworm communities in organic and conventional coffee cultivation

O objetivo deste trabalho foi avaliar o efeito do cultivo de café orgânico e convencional sobre a biomassa, densidade populacional e diversidade de minhocas em Lerroville, distrito de Londrina, Paraná. A comunidade de minhocas foi avaliada em três áreas de cultivo orgânico (CO1, CO2, CO3), duas áreas em cultivo convencional (CC1 e CC2) e um fragmento de mata nativa (MT). O solo das áreas CO1, CC1 e MT foi classificado como Nitossolo Vermelho e o solo das áreas CO2, CO3 e CC2 como Latossolo Vermelho. Oito amostras foram coletadas em cada área, em dois períodos, inverno e verão, pelo método do Tropical Soil Biology and Fertility (TSBF), na camada 0–20 cm. As minhocas foram separadas manualmente e preservadas em formol 4%, e, depois, foram pesadas, contadas e identificadas. A biomassa das minhocas, nas amostragens de inverno e de verão, foi maior na área CO3. A densidade populacional foi maior nas áreas CO1 e CO3. O maior número de espécies foi identificado nos cultivos orgânicos. A adoção de práticas orgânicas, no cultivo do café, favoreceu a diversidade, densidade populacional e biomassa das comunidades de minhocas.The objective of this work was to evaluate the effect of organic and conventional coffee crops on biomass, population density and diversity of earthworms, in Lerroville, district of Londrina County, Paraná state, Brazil. Earthworm communities were sampled in three areas with organic coffee cultivation (CO1, CO2 and CO3), two with conventional coffee (CC1 and CC2), and a native forest fragment (MT). The soil of the areas CO1, CC1, and MT was classified as Nitossolo Vermelho (Rhodic Kandiudox), while CO2, CO3, and CC2 were on Latossolo Vermelho (Rhodic Hapludox). Eight samples were taken in each area on two occasions, winter and summer, using the Tropical Soil Biology and Fertility (TSBF) method in the 0–20 cm soil layer. The earthworms were handsorted and preserved in 4% formaldehyde, and were later weighed, counted and identified. The highest earthworm biomass, both in winter and summer, occurred in the CO3 area. For population density, the higher numbers of individuals were found in CO1 and CO3. The highest number of species was identified in the organic cultivation. The adoption of organic practices in coffee cultivation favored the diversity, density and biomass of earthworm communities

Генетический алгоритм балансировки нагрузки в сети

Предложен генетический алгоритм решения задачи балансировки нагрузки на каналы связи в компьютерных и транспортных сетях как многопараметрической задачи оптимизации. Обоснованы особенности представления хромосом и генетических операций кроссовера, мутации и отбора. Сформированы подходы использования описанного алгоритма в существующих сетях с использованием современных протоколов маршрутизации.A genetic algorithm is suggested of solving the problem of a balancing of the load on the communication channels in computer and transport networks as a multi-parametric problem of optimization. The peculiarities of the representation of chromosomes and genetic operations of a crossover. Mutation and a selection are substantiated. The approaches of using the described algorithm in the existing networks are formulated with the use of contemporary protocols of the routing.Запропоновано генетичний алгоритм розв'язання задачі балансування навантаження на канали зв’язку в комп’ютерних та транспортних мережах як багатопараметричної задачі оптимізації. Обґрунтовано особливості представлення хромосом та генетичних операцій кросоверу, мутації та відбору. Сформовано підходи використання описаного алгоритму в існуючих мережах із використанням сучасних протоколів маршрутизації

ALTÉRATION ET DIFFÉRENCIATION PÉDOLOGIQUE SUR GRANITE EN BRETAGNE. ETUDE D'UNE TOPOSÉQUENCE

Cette thèse est une contribution à l'étude des arènes granitiques et dessols qui leurs sont associés, dans le Massif Armoricain. Cette étude concerne en effet, l'analysed'une arène formée par l'altération des minéraux primaires et la perte de la structure(l)originelle du granite. Puis l'analyse des sols eux-mêmes, et de leur variation le long d'unepente.L'accent sera mis sur la description détaillée des structures, qui serontobservées à des niveaux croissants de complexité, depuis l'assemblage élémentaire des constituants,jusqu'à la répartition des sols dans les bassins versants. L'interprétation génétiquede ces structures permettra ensuite d'approcher la dynamique du sol passée et actuelle.No abstrac