Interplay of Cultures Studio – Sámi: Architecture that leaves no trace in the environment, Master's level course in Architecture

Who are the Sámi? What is Sámi culture? What is Sápmi? What can be called Sámiarchitecture? Who has the right to design in Sápmi? What is cultural appropriation? How can one experience Sápmi? Who has the right to own the land? How can we learn about indigenous culture, here Sámi, without perpetuating colonization? What have we learned about the way Sámi cultures relate to our material reality and how could this inform the way we build today in Western culture as we strive for a sustainable way to live on the planet? During the beginning of the year 2022 the multidisciplinary architecture master studio,Interplay of Culture introduced 16 students to Sámi culture. Here are a few questions that we asked ourselves, and tried to answer with more questions than definite answers. The focus of this course is on the thematic area of Global Sustainability and Cultural Locality. The aim was to gain insight on sustainable building solutions and culturally sensitive architecture in indigenous northern cultures context. This publication is the summary of our exploration on the extremely broad and fascinatingSámi cultures. It gives diversified insight on what students explored, learned and understood of Sámi culture and building knowledge.Peer reviewe

Monitoreo de servicios ecosistémicos en un observatorio de cafetales agroforestales. Recomendaciones para el sector cafetalero

Ocho años de estudio de la ecofisiología del café, a través de experimentación y de modelación y el monitoreo de los servicios del ecosistema (SE) en una gran finca cafetalera en Costa Rica, revelaron varias recomendaciones prácticas para los agricultores y los formuladores de políticas. El sistema de cultivo estudiado dentro de nuestro observatorio colaborativo (Coffee-Flux), corresponde a un sistema agroforestal (SAF) a base de café bajo la sombra de grandes árboles de Erythrina poeppigiana (16% de la cubierta del dosel). Una gran cantidad de SE y limitantes dependen de las propiedades locales del suelo (en este caso Andisoles), especialmente de la erosión/infiltración, el agua/carbono y la capacidad de almacenamiento de nutrientes. Por lo tanto, para la evaluación de SE, el tipo de suelo es crucial. Una densidad adecuada de árboles de sombra (bastante baja aquí por la condición de libre crecimiento), redujo la severidad de las enfermedades de las hojas con la posibilidad de reducir el uso de plaguicidas y fungicidas. Un inventario simple del área basal en el collar de las plantas de café permitió estimar la biomasa subterránea y la edad promedio de la plantación, para juzgar su valor de mercado y decidir cuándo reemplazarla. Las fincas de café probablemente estén mucho más cerca de la neutralidad de C que lo indicado en el protocolo actual de C-neutralidad, que solo considera árboles de sombra, no los cafetos ni el suelo. Se proponen evaluaciones más completas, que ncluyen árboles, café, hojarasca, suelo y raíces en el balance C del SAF. Los árboles de sombra ofrecen muchos SE si se gestionan adecuadamente en el contexto local. En comparación con las condiciones a pleno sol, los árboles de sombra pueden (i) reducir la erosión laminar en un factor de 2; (ii) aumentar la fijación de N y el % de N reciclado en el sistema, reduciendo así los requisitos de fertilizantes; (iii) reducir la severidad de enfermedades de las hojas; (iv) aumentar el secuestro de C; (v) mejorar el microclima y (vi) reducir sustancialmente los efectos del cambio climático. En nuestro estudio de caso, no se encontró ningún efecto negativo sobre el rendimiento del café

Quelles représentations les enfants ont-ils du SIDA ? Contribution d’une recherche-action en éducation pour la santé auprès de classes de CM1 et CM2

International audienc

Fine root lifespan depending on their diameter and soil depth

International audienceIntroduction Fine root dynamics control plant growth and development and play a major role in the global carbon cycle through the uptake of water and nutrients as well as respiration and decomposition processes. Fine root elongation rates and lifespan are in direct relation with soil water availability and soil temperature likely depending on seasonal variations and soil depth. Most of the studies dealing with fine root dynamics have been performed in relatively shallow soil horizons ( 2.5 m) mainly occurred not only at bud break in spring but also throughout the winter, after leaf fall. By contrast, shallow roots grew mainly during the spring-summer period. While the studies carried out by Hendrick and Pregitzer (2006) suggested that fine root production occurred mainly in spring and early summer at all soil depths, a significant fine root growth during winter at great depth (> 2 m) was evidenced in our study. Our results suggest that carbon and nutrient remobilizations might also occur in winter to support fine root growth in deep soil layers. Many studies in temperate forests have evidenced that the majority of annual fine root production occurs in the topsoil (Mao et al. 2013). By contrast, our study shows that fine roots below a depth of 4 m accounted for more than one fourth of the total root production in the whole soil rooting profile down to a depth of 4.7 m. In Mediterranean agroforestry systems, the competition with winter intercrops induces tree roots to explore deep soil layers (Mulia and Dupraz 2006; Cardinael et al. 2015). We think that proliferation of fine roots in very deep soil layers during the winter could be an adaptive mechanism to ensure tree survival, enhancing the access to water during long summer drought periods in this region. Root mortality occurred mainly in upper soil layers and only 10% of the fine roots that appeared over the study period below 4 m died. Lifespan of the finest roots (0.0-0.5 mm) increased from 129 days (turnover 2.8 yr-1) in the topsoil to 190 (turnover 1.9 yr-1) at depths > 2.5 m. Fine root lifespan was longer with increasing root diameter and soil depth. Therefore, more organic matter was added into shallow layers through root mortality, whereas carbon injected deeper through root growth may improve C storage during longer periods in this ecosystem. Conclusion Our study revealed the unexpected growth of very deep fine roots during the winter months, which is unusual for a deciduous tree species, especially under a Mediterranean climate. Our results have major implications for our understanding of tree physiological processes. The high fine root turnover rates observed in this agroforestry system will provide novel data for the estimation of soil organic carbon dynamic

How to better describe spatial heterogeneity of fine root distribution in tree ecosystems?

In tree ecosystems, tree fine roots (defined as those of diameter ≤ 2 mm) comprise only a small proportion of total biomass, but play the most active and fundamental role in both tree functioning (via water and nutrition uptakes) and carbon flux dynamics (via respiration, exudation and high turn-over rate). These processes have a beneficial effect on the promotion of underground biodiversity, as fine roots with their rhizospheres can provide “cradle effect” for sheltering and nourishing soil micro- and macro-organisms in both direct (e.g. mycorrhizal fungi growth on roots) and indirect (e.g. creating soil organic matter) manners. As a result, in order to better explore underground biodiversity repartition and evaluate its service, a reliable characterisation of the spatial distribution of fine roots is indispensable. The spatial distribution of fine root can be served either as a proxy of repartition of certain fauna or as an environmental factor to be correlated with biodiversity indicators. However, our knowledge concerning fine roots distribution is still limited, partially due to the lack of effective root modelling and data analysis methods. This proposal aims to introduce and highlight a set of methodologies suitable to quantitatively describe root spatial distribution. The methods are statistically based and easy to use in conjunction with conventional root sampling techniques (e.g. root trench, coring). Fine root density from trees at a given point can be modelled by a modified logistic function parametrised by tree dimension and position, presence of obstacles between a tree and the given point, and root competition level with roots from understory species. For fine root vertical distribution, by introducing a recently published piecewise linear model’, namely “hockey stick model,” an ecological threshold served to distinguish shallow rooting zone and deep rooting zone, might be thus detected with statistical diagnostic. Applying a log-normal function and Gompertz function allows us to better fit the shape of root diameter spectrum (cumulative root density with increasing diameter). Regarding the phenomenon that fine root distribution exhibits a pattern of patchiness (or namely root nuggets), application of geo-statistical approaches allows us to better quantify aggregation and dispersion rate of roots within/amongst nuggets.In the ongoing projects ANR ECOSFIX (Ecosystem Services of Roots – Hydraulic Redistribution, Carbon Sequestration and Soil Fixation) and ARANGE FP7 (Advanced multifunctional management of European mountain forests), these above methods have been successfully applied to several French tree ecosystems, varying from heterogeneous mixed mountain forests (with low intervention intensity), to homogenous agroforests and plantations (with high intervention intensity). In the framework of Cost Action Biolink, it might be therefore particularly interesting to have these novel root analysis methods applied toward new root data, in order to better evaluate the state and roles of belowground soil biodiversity

Linking rooting depth and fine root turnover to soil organic carbon stocks in a Mediterranean agroforestry system

Introduction :Much attention has been paid to agroforestry systems these last decades as they combine food production and provide different ecosystem services such as erosion control, biodiversity enhancement, and climate change mitigation. However, the functioning of these systems and the services they provide mainly depends on belowground processes, which are poorly known. We hypothesized that a deep rooting of trees below the crop roots would increase the organic C inputs to soil and therefore affect soil organic carbon (SOC) stocks. Our goals were therefore to quantify tree fine root distribution in an agroforestry plot, to estimate turnover of shallow and deep fine roots, and to measure SOC stocks. Methods : Our study site was located in the Mediterranean region of France, 15 km North of Montpellier. This 18-year-old experimental site comprised an agricultural control plot (AC), where durum wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.) is cultivated, an agroforestry plot (AF) where hybrid walnut (Juglans regia × nigra L.) trees are intercropped with durum wheat, and a tree monoculture (TM) where only walnut trees are grown. A 2 m deep pit was dug in both the AF and TM plots, as well as an additional 4 m deep × 5 m long pit in the AF plot (Cardinael et al. 2015). Fine root impacts were mapped to measure root intersection density, and soil cubes were sampled at different depths to measure root length density. In the deep AF pit, 16 minirhizotrons were installed at four depths (0, 1, 2.5, 4 m) and two distances from the trees (2 and 5 m). Tree fine root dynamics were monitored during one year. To assess soil organic carbon storage between the AC and AF plots, 100 soil cores were sampled in both plots down to 2 m soil depth, at different distances from the trees. Results and Discussion : In the TM plot, about 70% of tree fine root density was concentrated in the first 0.6 m of soil. In the AF plot, root density was significantly smaller in the topsoil than in the TM plot, but was still high at 1.0-1.5 m deep. In the AF plot, 50% of total fine root density was below 1 m, and about 35% was between 2 and 4 m. This deeper rooting of walnut trees in the AF plot due to the competition with winter crops may explain the good performances observed in this system, as trees are able to reach the watertable (Mulia and Dupraz 2006). Fine root turnover ranged from 1.5 to 2.6 year-1 and decreased with increasing soil depth and root diameter. Down to 2 m soil depth, organic carbon inputs to the soil were increased by 30% in the AF plot compared to the AC plot, and about 70% of this increase was due to fine root mortality (walnut, and herbaceous vegetation in the tree rows). A positive additional SOC storage was found in the AF plot compared to the AC plot down to 1 m soil depth (+ 6.3 ± 1.6 Mg C ha-1). However, 75% of this additional storage was located in 0-30 cm. Conclusion : This work provides new insights on belowground functioning of agroforestry systems with a novel focus in deep soil layers. Additional SOC storage in the agroforestry system seems to be mainly due to more organic inputs to soil from root mortality, but it could also partly be explained by a change in soil organic matter stabilization, which is currently investigated. Linking rooting depth and fine root turnover to soil organic carbon stocks in a Mediterranean agroforestry system