Laurent Augusto

Bio: Laurent Augusto is an academic researcher from International Sleep Products Association. The author has contributed to research in topics: Soil water & Topsoil. The author has an hindex of 35, co-authored 97 publications receiving 4238 citations. Previous affiliations of Laurent Augusto include Institut national de la recherche agronomique.

Impact of several common tree species of European temperate forests on soil fertility

Abstract: The aim of the present work was to provide a synopsis of the scientific literature concerning the effects of different tree spe- cies on soil and to quantify the effect of common European temperate forest species on soil fertility. The scientific literature dealing with the tree species effect on soil has been reviewed. The composition of forest overstory has an impact on the chemical, physical and biolo- gical characteristics of soil. This impact was highest in the topsoil. Different tree species had significantly different effects on water ba- lance and microclimate. The physical characteristics of soils also were modified depending on the overstory species, probably through modifications of the soil fauna. The rates of organic matter mineralization and nitrification seem to be dependent on tree species. A coni- ferous species, Picea abies, had negative input-output budgets for some nutrients, such as Ca and Mg. This species promoted a higher soil acidification and a decrease in pH. Thus, it should not be planted in very poor soils in areas affected by acidic atmospheric deposi- tions. Nevertheless, the effect of the canopy species on soil fertility was rarely significant enough to promote forest decline. The impact of a tree species on soil fertility varied depending on the type of bedrock, climate and forest management. forest soils / tree species / fertility / sustainability / resiliency

Effects of tree species on understory vegetation and environmental conditions in temperate forests

Abstract: L'objectif de cette etude etait de comparer l'effet sur la vegetation et le sol de six essences forestieres. Quatre-vingts peuplements repartis sur 26 sites ont ete selectionnes. Sur chacun des sites, les peuplements etaient d'essence differente mais comparables en termes de sol, de topographie et de passe cultural. Dans chaque peuplement, le sol a ete echantillonne et la vegetation a ete determinee. Les essences etaient : l'epicea commun (Picea abies Karsten.), le pin sylvestre (Pinus sylvestris L.), le sapin Douglas (Pseudotsuga menziesii (Mirb.) Franco), le sapin pectine (Abies alba Miller), le hetre (Fagus sylvatica L.) et le chene (Quercus robur L., Quercus petraea (Matt.) Liebl.). Les caracteristiques geographiques et geologiques des sites ont plus influence la vegetation et la chimie des sols que les essences. La gestion sylvicole a plus d'impact sur la flore accompagnatrice que les essences. La richesse specifique et l'equitabilite vegetales different peu selon les essences. La strate muscinale des pessieres est plus abondante que sous les autres essences, sauf le sapin pectine. La vegetation sous l'epicea est plus typique de conditions oligotrophes et acides que celle sous le hetre. Les sols sous les coniferes, notamment l'epicea commun, etaient plus acides et riches en aluminium que les sols sous les feuillus. L'effet des essences sur les sols etait essentiellement significatif dans les dix centimetres les plus superficiels.

Influences of evergreen gymnosperm and deciduous angiosperm tree species on the functioning of temperate and boreal forests

Abstract: It has been recognized for a long time that the overstorey composition of a forest partly determines its biological and physical-chemical functioning. Here, we review evidence of the influence of evergreen gymnosperm (EG) tree species and deciduous angiosperm (DA) tree species on the water balance, physical-chemical soil properties and biogeochemical cycling of carbon and nutrients. We used scientific publications based on experimental designs where all species grew on the same parent material and initial soil, and were similar in stage of stand development, former land use and current management. We present the current state of the art, define knowledge gaps, and briefly discuss how selection of tree species can be used to mitigate pollution or enhance accumulation of stable organic carbon in the soil. The presence of EGs generally induces a lower rate of precipitation input into the soil than DAs, resulting in drier soil conditions and lower water discharge. Soil temperature is generally not different, or slightly lower, under an EG canopy compared to a DA canopy. Chemical properties, such as soil pH, can also be significantly modified by taxonomic groups of tree species. Biomass production is usually similar or lower in DA stands than in stands of EGs. Aboveground production of dead organic matter appears to be of the same order of magnitude between tree species groups growing on the same site. Some DAs induce more rapid decomposition of litter than EGs because of the chemical properties of their tissues, higher soil moisture and favourable conditions for earthworms. Forest floors consequently tend to be thicker in EG forests compared to DA forests. Many factors, such as litter lignin content, influence litter decomposition and it is difficult to identify specific litter-quality parameters that distinguish litter decomposition rates of EGs from DAs. Although it has been suggested that DAs can result in higher accumulation of soil carbon stocks, evidence from field studies does not show any obvious trend. Further research is required to clarify if accumulation of carbon in soils (i.e. forest floor + mineral soil) is different between the two types of trees. Production of belowground dead organic matter appears to be of similar magnitude in DA and EG forests, and root decomposition rate lower under EGs than DAs. However there are some discrepancies and still are insufficient data about belowground pools and processes that require further research. Relatively larger amounts of nutrients enter the soil-plant biogeochemical cycle under the influence of EGs than DAs, but recycling of nutrients appears to be slightly enhanced by DAs. Understanding the mechanisms underlying forest ecosystem functioning is essential to predicting the consequences of the expected tree species migration under global change. This knowledge can also be used as a mitigation tool regarding carbon sequestration or management of surface waters because the type of tree species affects forest growth, carbon, water and nutrient cycling.

Biochar and its effects on plant productivity and nutrient cycling: a meta‐analysis

Abstract: Biochar is a carbon-rich coproduct resulting from pyrolyzing biomass. When applied to the soil it resists decomposition, effectively sequestering the applied carbon and mitigating anthropogenic CO2 emissions. Other promoted benefits of biochar application to soil include increased plant productivity and reduced nutrient leaching. However, the effects of biochar are variable and it remains unclear if recent enthusiasm can be justified. We evaluate ecosystem responses to biochar application with a meta-analysis of 371 independent studies culled from 114 published manuscripts. We find that despite variability introduced by soil and climate, the addition of biochar to soils resulted, on average, in increased aboveground productivity, crop yield, soil microbial biomass, rhizobia nodulation, plant K tissue concentration, soil phosphorus (P), soil potassium (K), total soil nitrogen (N), and total soil carbon (C) compared with control conditions. Soil pH also tended to increase, becoming less acidic, following the addition of biochar. Variables that showed no significant mean response to biochar included belowground productivity, the ratio of aboveground : belowground biomass, mycorrhizal colonization of roots, plant tissue N, and soil P concentration, and soil inorganic N. Additional analyses found no detectable relationship between the amount of biochar added and aboveground productivity. Our results provide the first quantitative review of the effects of biochar on multiple ecosystem functions and the central tendencies suggest that biochar holds promise in being a win-win-win solution to energy, carbon storage, and ecosystem function. However, biochar's impacts on a fourth component, the downstream nontarget environments, remain unknown and present a critical research gap.

Soil Microorganisms Mediating Phosphorus Availability Update on Microbial Phosphorus

Abstract: Microorganisms are integral to the soil phosphorus (P) cycle and as such play an important role in mediating the availability of P to plants. Understanding the microbial contribution to plant P nutrition and opportunities for manipulating specific microorganisms to enhance P availability in soil has

Chapter One – Mineral–Organic Associations: Formation, Properties, and Relevance in Soil Environments

Abstract: Minerals and organic matter (OM) may form intricate associations via myriad interactions. In soils, the associations of OM with mineral surfaces are mainly investigated because of their role in determining the long-term retention of OM. OM “must decay in order to release the energy and nutrients that drive live processes all over the planet” ( Janzen, 2006 ). Thus, the processes and mechanisms that retain OM in soil are a central concern to very different branches of environmental research. An agronomist may want to synchronize periods of high nutrient and energy release with the growth stages of a crop. An environmental chemist may wish to either immobilize an organic soil contaminant or enhance its decomposition into less harmful metabolites, while climate scientists need to understand the processes that mediate the production of potent greenhouse gases from decomposing OM. Associations of OM with pedogenic minerals (henceforth termed mineral–organic associations (MOAs)) are known to be key controls in these and many other processes. Here we strive to present an overview of the current knowledge on MOAs and identify key questions and future research needs.