Exploring the branch wood supply potential of an agroforestry system with strategically designed harvesting interventions based on terrestrial LiDAR data

Agroforestry systems hold potential for wood and tree biomass production without the need of felling trees. Branch wood harvesting provides access to considerable amounts of lignocellulosic biomass while leaving the tree standing. Aiming at alternatives for wood provision, we assessed the actual woody structure of a silvopastoral system in the African Savannah ecoregion, utilising terrestrial LiDAR technology and quantitative structure models to simulate branch removals and estimate harvesting yields. In addition, the stand structure and harvested wood were examined for the provision of four types of assortments meeting local needs, and operational metrics for each treatment were derived. The stand had large variability in woody structures. Branch harvesting interventions removed up to 18.2% of total stand volume, yielded 5.9 m3 ha−1 of branch wood, and delivered 2.54 m3 ha−1 of pole wood quality, retaining on average more than 75% of the original tree structures. Among the most intense simulations, a mean of 54.7 litres (L) of branch wood was provided per tree, or approximately 34.2 kg of fresh biomass. The choice of an ideal harvesting treatment is subject to practitioners’ interests, while the discussion on aspects of the operation, and stand and tree conditions after treatment, together with outputs, assist decision making. The partitioning of tree structures and branch removal simulations are tools to support the design of tending operations aiming for wood and tree biomass harvesting in agroforestry systems while retaining different functional roles of trees in situ.Supplementary File S1. Figure S1: Individual tree point clouds identified by colours (up), leaf-on mode evidenced by intensity values (middle), and the leaf-off point clouds (bottom); Figure S2: Stand-level wood assortments available in linear meters for each simulated harvesting treatment; Figure S3: Boxplots of the absolute branch volume removal in each harvesting simulation with the red crosses representing treatment means; Table S1: QSM-derived tree parameters for trees in the stand (n = 66); Table S2: Optimised QSM input parameters for each tree; Table S3: Summary of available assortments and yields per harvesting treatment.Supplementary File S2 contains the assessment of assortments on a tree basis for each harvesting simulation.The German Federal Ministry of Education and Research (BMBF). The article processing charge was funded by the Baden-Württemberg Ministry of Science, Research and Art and the University of Freiburg in the funding programme Open Access Publishing.https://www.mdpi.com/journal/forestsdm2022Plant Production and Soil Scienc

Post-harvest use of banana in Uganda and Tanzania: Product characteristics and cultivar preferences of male and female farmers.

Understanding user preferred traits is important for the successful development and adoption of improved banana cultivars. This article provides an overview of different banana products, cultivars used to make those products and the preferred characteristics as reported by men and women farmers in different regions of Uganda and Tanzania. Qualitative data from 23 focus group discussions (FGDs) conducted in six districts (Mbarara and Luwero in Uganda; and Bukoba, Meru, Moshi and Rungwe in Tanzania) were coded and analysed. Results show that farmers process banana to make a range of products that include staple foods such as steamed matooke, mbalaga and machalari; alcoholic beverages and snacks. Different cultivars are preferred for an assortment of products. There are minimal differences in the cultivar preferences for specific products and product utilization patterns by men and women farmers. Differences only occurred when men and women described reasons why products are important or preferred, and in the roles of men, women and children in the preparation and processing of products from different banana types. Both men and women mentioned socio-economic, cultural, consumption and health-related attributes of the different products. However, women (73% of women only FGDs) specifically highlighted health benefits attached to women, for example after giving birth, during pregnancy, during lactation and for children; compared to 44% for men. Men pointed out more the socio-cultural importance of the products and provided detailed descriptions on market-related traits and the corresponding value chain actors (88.9% of men only FGDs). A myriad of factors that include variety of products, cultivar attributes before processing, characteristics of the processed product and location differences are identified, highlighting the need for further assessments and physicochemical characterisation of the traits to gauge the feasibility of considering this valuable information in the product development process. Some of the products and attributes of cultivars cited by farmers are generalized descriptions lacking sufficient detail (e.g. ‘tastes nice’, ‘good flavour’, ‘long shelf life’). Farmers have tacit knowledge of these attributes. Hence, researchers need to probe further and use a range of methods to extract this knowledge. There is a need for social scientists to collect data on trait prioritisation and for food scientists to do biochemical analyses to ensure information collected is well defined, comprehensive, quantifiable and measurable to effectively guide breeding and other agricultural research and development

Low N2_{2}O and variable CH4_{4} fluxes from tropical forest soils of the Congo Basin

Globally, tropical forests are assumed to be an important source of atmospheric nitrous oxide (N$_{2}$O) and sink for methane (CH$_{4}$). Yet, although the Congo Basin comprises the second largest tropical forest and is considered the most pristine large basin left on Earth, in situ N$_{2}$O and CH$_{4}$ flux measurements are scarce. Here, we provide multi-year data derived from on-ground soil flux (n = 1558) and riverine dissolved gas concentration (n = 332) measurements spanning montane, swamp, and lowland forests. Each forest type core monitoring site was sampled at least for one hydrological year between 2016 - 2020 at a frequency of 7-14 days. We estimate a terrestrial CH$_{4}$ uptake (in kg CH$_{4}$-C ha$^{-1}$ yr$^{-1}$) for montane (−4.28) and lowland forests (−3.52) and a massive CH$_{4}$ release from swamp forests (non-inundated 2.68; inundated 341). All investigated forest types were a N$_{2}$O source (except for inundated swamp forest) with 0.93, 1.56, 3.5, and −0.19 kg N$_{2}$O-N ha$^{-1}$ yr$^{-1}$ for montane, lowland, non-inundated swamp, and inundated swamp forests, respectively

TARIBAN1, TARIBAN2, TARIBAN3, and TARIBAN4 'Matooke' cooking banana cultivars for the Great Lakes Region of Africa

Open Access Journal; Published online: 23 Nov 202

Sterol 14α-demethylase mutation leads to amphotericin B resistance in Leishmania mexicana

Amphotericin B has emerged as the therapy of choice for use against the leishmaniases. Administration of the drug in its liposomal formulation as a single injection is being promoted in a campaign to bring the leishmaniases under control. Understanding the risks and mechanisms of resistance is therefore of great importance. Here we select amphotericin B-resistant Leishmania mexicana parasites with relative ease. Metabolomic analysis demonstrated that ergosterol, the sterol known to bind the drug, is prevalent in wild-type cells, but diminished in the resistant line, where alternative sterols become prevalent. This indicates that the resistance phenotype is related to loss of drug binding. Comparing sequences of the parasites’ genomes revealed a plethora of single nucleotide polymorphisms that distinguish wild-type and resistant cells, but only one of these was found to be homozygous and associated with a gene encoding an enzyme in the sterol biosynthetic pathway, sterol 14α-demethylase (CYP51). The mutation, N176I, is found outside of the enzyme’s active site, consistent with the fact that the resistant line continues to produce the enzyme’s product. Expression of wild-type sterol 14α-demethylase in the resistant cells caused reversion to drug sensitivity and a restoration of ergosterol synthesis, showing that the mutation is indeed responsible for resistance. The amphotericin B resistant parasites become hypersensitive to pentamidine and also agents that induce oxidative stress. This work reveals the power of combining polyomics approaches, to discover the mechanism underlying drug resistance as well as offering novel insights into the selection of resistance to amphotericin B itself

Metabolic Variation during Development in Culture of Leishmania donovani Promastigotes

The genome sequencing of several Leishmania species has provided immense amounts of data and allowed the prediction of the metabolic pathways potentially operating. Subsequent genetic and proteomic studies have identified stage-specific proteins and putative virulence factors but many aspects of the metabolic adaptations of Leishmania remain to be elucidated. In this study, we have used an untargeted metabolomics approach to analyze changes in the metabolite profile as promastigotes of L. donovani develop during in vitro cultures from logarithmic to stationary phase. The results show that the metabolomes of promastigotes on days 3–6 of culture differ significantly from each other, consistent with there being distinct developmental changes. Most notable were the structural changes in glycerophospholipids and increase in the abundance of sphingolipids and glycerolipids as cells progress from logarithmic to stationary phase