Biology subjects

Beillouin, D.

Publications and source records attributed to Beillouin, D..

3 recordsLinked to original sources

bioRxiv2026

Biochar reduces soil thermal conductivity, diffusivity and volumetric heat storage: A global meta-analysis

Biochar amendments are increasingly applied to improve soil physical functioning and support carbon dioxide removal, but their effects on intrinsic soil thermal properties remain poorly characterised. We conducted the first global systematic meta-analysis of 19 independent studies, 231 control-biochar comparisons, and 529 property-specific effect sizes to test how biochar changes soil heat transfer and storage. Biochar reduced thermal conductivity by 17.6% (95% CI, -22.7 to -12.2), thermal diffusivity by 11.0% (-14.5 to -7.3), and volumetric heat capacity by 8.3% (-12.3 to -4.1). Gravimetric heat capacity showed no significant overall response (+3.3%; -7.6 to 15.4) but was supported by fewer studies. Negative responses were directionally consistent for thermal conductivity, diffusivity, and volumetric heat capacity. Moderator analyses showed that responses were most consistently associated with post-application bulk density and changes in bulk density, while application rate modulated response magnitude and soil texture constrained context dependence. Co-variation among thermal conductivity, thermal diffusivity, and volumetric heat capacity matched expected physical dependencies, indicating coordinated structural reorganisation rather than independent shifts in isolated parameters. These estimates describe intrinsic conductive and storage properties; field-scale soil temperature responses may also be modified by albedo, evaporation, vegetation, and surface energy balance. Improved integration of soil thermal measurements with moisture dynamics, structural changes, and carbon cycling is essential to accurately represent biochar effects in soil and land-surface models. Significance StatementBiochar is increasingly used to store carbon while improving soils, but its effects on how soils conduct, transmit, and store heat remain poorly understood. By synthesising 19 studies and 529 property-specific effect sizes, we show that biochar consistently reduces soil thermal conductivity, diffusivity, and volumetric heat capacity, primarily through structural changes in bulk density and pore architecture. These findings identify soil thermal behaviour as an overlooked component of biochar-soil interactions, with implications for soil temperature buffering, water-energy coupling, plant and microbial processes, and land-surface and carbon-cycle modelling.

ecology↗

bioRxiv2024

Global review of meta-analyses reveals key data gaps in agricultural impact studies on biodiversity in croplands

AimAgriculture depends heavily on biodiversity, yet unsustainable management practices continue to affect a wide range of organisms and ecosystems at unprecedented levels worldwide. Addressing the global challenge of biodiversity loss requires access to consolidated knowledge across management practices, spatial levels, and taxonomic groups. LocationGlobal Time period1994 to 2022 Major taxa studiedAnimals, microorganisms, plants. MethodsWe conducted a comprehensive literature review synthesising data from all meta-analyses about the impacts of agricultural management practices on biodiversity in croplands, covering field, farm, and landscape levels. From 200 retained meta-analyses, we extracted 1,885 mean effect sizes (from 69,850 comparisons between a control and treatment) assessing the impact of management practices on biodiversity, alongside characterising over 9,000 primary papers. ResultsSeven high-income countries, notably the USA, China, and Brazil dominate agricultural impact studies with fertiliser use, phytosanitary interventions and crop diversification receiving widespread attention. The focus on individual practices overshadows research at the farm and landscape level. Taxonomically, Animalia, especially arthropods, are heavily studied while taxa such as annelids and plants receive comparatively less attention. Effect sizes are predominantly calculated from averaged abundance data. Significant gaps persist in terms of studies on the effects of agricultural interventions on specific taxonomic groups (e.g. annelids, mammals) and studies analysing functional traits. Main conclusionsOur study highlights the importance of analysing the effects of combined practices to accurately reflect real-world farming contexts. While abundance metrics are common, reflecting several biodiversity facets and adopting a more balanced research approach across taxa are crucial for understanding biodiversity responses to agricultural changes and informing conservation strategies. Given the unbalanced evidence on impacts of agricultural practices on biodiversity, caution is required when utilising meta-analytical findings for informing public policies or integrating them into global assessment models like life-cycle assessments or global flux models.

ecology↗

bioRxiv2020

Benefits of crop diversification for biodiversity and ecosystem services

Ecological theory suggests that biodiversity has a positive and stabilizing effect on the delivery of ecosystem services. Yet, the impacts of increasing the diversity of cultivated crop species or varieties in agroecosystems are still under scrutiny. The empirical evidence available is scattered in scope, agronomic and geographical contexts and impacts on ecosystem services may depend on the type of diversification strategy used. To robustly assess the effects of crop diversification in agroecosystems, we compiled the results of 95 meta-analyses integrating 5,156 experiments conducted over 84 experimental years and representing more than 54,500 paired observations on 120 crop species in 85 countries. Overall, our synthesis of experimental data from across the globe shows that crop diversification enhances not only crop production (median effect +14%), but also the associated biodiversity (+24%, i.e. the biodiversity of non-cultivated plants and animals), and several supporting and regulating ecosystem services including water quality (+51%), pest and disease control (+63%) and soil quality (+11%). However, there was substantial variability in the results for each individual ecosystem service between different diversification strategies like agroforestry, intercropping, cover-crops, crop rotation or variety mixtures. Agroforestry is particularly effective in delivering multiple ecosystem services, i.e. water use and quality, pest and diseases regulation, associated biodiversity, long-term soil productivity and quality. Variety mixtures, instead, provide the lowest benefits, while the other strategies show intermediate results. Our results highlight that while increasing the diversity of cultivated crop species or varieties in agroecosystems represents a very promising strategy for more sustainable land management, contributing to enhanced yields, enhanced biodiversity and ecosystem services, some crop diversification strategies are more effective than others in supporting key ecosystem services.

ecology↗