Fabrice Bureau

Bio: Fabrice Bureau is an academic researcher from University of Rouen. The author has contributed to research in topics: Humus & Ecosystem. The author has an hindex of 27, co-authored 57 publications receiving 2531 citations. Previous affiliations of Fabrice Bureau include École Polytechnique.

Patterns of denitrification rates in European alluvial soils under various hydrological regimes

Abstract: 1. Denitrification in floodplain soils is one of the main biological processes emitting and reducing nitrous oxide, a greenhouse gas, and the main process responsible for the buffering capacity of riparian zones against diffuse nitrate pollution. 2. The aim of this study was to measure denitrification rates under a wide range of current climatic conditions and hydrological regimes in Europe (from latitude 64°N to latitude 42°N and from longitude 2°W to longitude 25°E), in order to determine the response patterns of this microbial process under different climatic and hydrological conditions, and to identify denitrification proxies robust enough to be used at the European scale. 3. Denitrification activity was significant in all the floodplain soils studied whatever the latitude. However, we found an increase in rates of an order of magnitude from high to mid latitudes. Maximum rates (above 30 g N m?2 month?1) were measured in the maritime conditions of the Trent floodplain. These rates are similar to mineralisation rates measured in alluvial soils and of the same order of magnitude as the amount of N stored in herbaceous plants in alluvial soils. 4. We used Multivariate Adaptative Regression Splines to relate the response variable denitrification with five relevant predictors, namely soil moisture, temperature, silt plus clay, nitrate content and herbaceous plant biomass. 5. Soil moisture, temperature, and nitrate were the three main control variables of microbial denitrification in alluvial soils in decreasing order of importance. 6. The model developed for denitrification with interaction effects outperformed a pure additive model. Soil moisture was involved in all interactions, emphasising its importance in predicting denitrification. 7. These results are discussed in the context of scenarios for future change in European hydrological regimes.

Effect of tree mixture on the humic epipedon and vegetation diversity in managed beech forests (Normandy, France)

Abstract: Using a space-for-time substitution procedure, we assessed the patterns of variation during stand develop- ment of the humic epipedon and vegetation diversity in a pure European beech (Fagus sylvatica L.) forest and in a mixed beech-hornbeam (Carpinus betulus L.) forest. The humic epipedon was investigated through macromorpho- logical characteristics (thickness of the OL, OF, OH, and A horizons) and pH measurements (pHKCl, pH HO 2 , and ∆pH). Vegetation diversity was assessed using correspondence analysis and hierarchical cluster analysis to identify the main plant community succession groups. The groups were compared using three diversity measures (species richness, Shan- non index, and evenness index) and three indices describing the community composition (similarity index between stands and index of heterogeneity at the stand and herbaceous layer levels). The pH measurements revealed an acidifi- cation of the A horizon during pure beech stand maturation. Macromorphological characteristics showed an alternation of an organic matter accumulation phase and organic matter disappearance along the two silvicultural cycles. Vegeta- tion diversity measures showed small differences between the two forests. Indices accounting for community composi- tion revealed a homogenizing effect of the pure beech silvicultural type on species composition of plant communities occurring during stand development. They also revealed a strong heterogeneity at the herbaceous level. Comparison of species composition indicated an increasing occurrence of acidophilous species in the pure beech forest. We discuss the interest of these results for future sustainable management decisions.

Soil quality – A critical review

Abstract: Sampling and analysis or visual examination of soil to assess its status and use potential is widely practiced from plot to national scales. However, the choice of relevant soil attributes and interpretation of measurements are not straightforward, because of the complexity and site-specificity of soils, legacy effects of previous land use, and trade-offs between ecosystem services. Here we review soil quality and related concepts, in terms of definition, assessment approaches, and indicator selection and interpretation. We identify the most frequently used soil quality indicators under agricultural land use. We find that explicit evaluation of soil quality with respect to specific soil threats, soil functions and ecosystem services has rarely been implemented, and few approaches provide clear interpretation schemes of measured indicator values. This limits their adoption by land managers as well as policy. We also consider novel indicators that address currently neglected though important soil properties and processes, and we list the crucial steps in the development of a soil quality assessment procedure that is scientifically sound and supports management and policy decisions that account for the multi-functionality of soil. This requires the involvement of the pertinent actors, stakeholders and end-users to a much larger degree than practiced to date.

Ecosystem Ecology: The links between biodiversity, ecosystem services and human well-being

Abstract: No matter who we are, or where we live, our well-being depends on the way ecosystems work. Most obviously, ecosystems can provide us with material things that are essential for our daily lives, such as food, wood, wool and medicines. Although the other types of benefit we get from ecosystems are easily overlooked, they can, for example, also play an important role in regulating the environments in which we live. They can help ensure the flow of clean water and protect us from flooding or other hazards like soil erosion, land-slips and tsunamis. They can even contribute to our spiritual well-being, through their cultural or religious significance or the opportunities they provide for recreation or the enjoyment of nature.

A review of earthworm impact on soil function and ecosystem services

Abstract: Summary Biodiversity is responsible for the provision of many ecosystem services; human well-being is based on these services, and consequently on biodiversity. In soil, earthworms represent the largest component of the animal biomass and are commonly termed ‘ecosystem engineers’. This review considers the contribution of earthworms to ecosystem services through pedogenesis, development of soil structure, water regulation, nutrient cycling, primary production, climate regulation, pollution remediation and cultural services. Although there has been much research into the role of earthworms in soil ecology, this review demonstrates substantial gaps in our knowledge related in particular to difficulties in identifying the effects of species, land use and climate. The review aims to assist people involved in all aspects of land management, including conservation, agriculture, mining or other industries, to obtain a broad knowledge of earthworms and ecosystem services.