Using Sentinel-2 and canopy height models to derive a landscape-level biomass map covering multiple vegetation types

Vegetation biomass is a globally important climate-relevant terrestrial carbon pool and also drives local hydrological systems via evapotranspiration. Vegetation biomass of individual vegetation types has been successfully estimated from active and passive remote sensing data. However, for many tasks, landscape-level biomass maps across several vegetation types are more suitable than biomass maps of individual vegetation types. For example, the validation of ecohydrological models and carbon budgeting typically requires spatially continuous biomass estimates, independent from vegetation type. Studies that derive biomass estimates across multiple vegetation or land-cover types to merge them into a single landscape-level biomass map are still scarce, and corresponding workflows must be developed. Here, we present a workflow to derive biomass estimates on landscape-level for a large watershed in central Chile. Our workflow has three steps: First, we combine field plotbased biomass estimates with spectral and structural information collected from Sentinel-2, TanDEM-X and airborne LiDAR data to map grassland, shrubland, native forests and pine plantation biomass using random forest regressions with an automatic feature selection. Second, we predict all models to the entire landscape. Third, we derive a land-cover map including the four considered vegetation types. We then use this land-cover map to assign the correct vegetation type-specific biomass estimate to each pixel according to one of the four considered vegetation types. Using a single repeatable workflow, we obtained biomass predictions comparable to earlier studies focusing on only one of the four vegetation types (Spearman correlation between 0.80 and 0.84; normalized-RMSE below 16 % for all vegetation types). For all woody vegetation types, height metrics were amongst the selected predictors, while for grasslands, only Sentinel-2 bands were selected. The land-cover was also mapped with high accuracy (OA = 83.1 %). The final landscape-level biomass map spatially agrees well with the known biomass distribution patterns in the watershed. Progressing from vegetation-type specific maps towards landscape-level biomass maps is an essential step towards integrating remote-sensing based biomass estimates into models for water and carbon management

Identifying driving processes of drought recovery in the southern Andes natural catchments

Study region: The natural river basins of Chile. Study focus: Drought effects on terrestrial ecosystems produce hydroclimatic stress with variable extensions. Particularly, hydrological drought duration can provide a better understanding of recovery together with catchment characteristics and climatology. This study focuses on the impacts of the multi-year drought experienced in Chile for more than a decade. The recovery of relevant catchment variables to quantify the drought termination (DT) and drought termination duration (DTD) after the hydrological drought is presented. A composite analysis of natural catchments using the CAMELS-CL data set discharge (1988–2020), k-NDVI (2000–2020), and soil moisture (1991–2020) provides the average response of the recovery after severe droughts. New hydrological insights for the region: This study demonstrates that local catchment properties can explain the recovery of studied variables after a hydrological drought. Explanatory variables from CAMELS-CL to derive the DT using random forest regression (RFR) were used with a strong correlation of 0.92, 0.84, and 0.89 for discharge, vegetation productivity, and soil moisture, respectively. The discharge patterns show longer recovery over environments dominated by shrublands with less precipitation and higher temperatures, in central Chile, while higher latitudes with higher vegetation cover, increasing precipitation, and lower temperatures present shorter recovery times. The vegetation productivity shows longer recovery over highly vegetated mountains in central Chile. The soil moisture recovery spatial distribution presented patterns that connect them with the discharge recovery. This work enables the identification of drought vulnerability, which is valuable for managing water resources and ecosystems and is helping to predict drought recovery periods in regions with a lack of observations

The CAMELS-CL dataset: catchment attributes and meteorology for large sample studies – Chile dataset

We introduce the first catchment dataset for large sample studies in Chile. This dataset includes 516 catchments; it covers particularly wide latitude (17.8 to 55.0∘ S) and elevation (0 to 6993 m a.s.l.) ranges, and it relies on multiple data sources (including ground data, remote-sensed products and reanalyses) to characterise the hydroclimatic conditions and landscape of a region where in situ measurements are scarce. For each catchment, the dataset provides boundaries, daily streamflow records and basin-averaged daily time series of precipitation (from one national and three global datasets), maximum, minimum and mean temperatures, potential evapotranspiration (PET; from two datasets), and snow water equivalent. We calculated hydro-climatological indices using these time series, and leveraged diverse data sources to extract topographic, geological and land cover features. Relying on publicly available reservoirs and water rights data for the country, we estimated the degree of anthropic intervention within the catchments. To facilitate the use of this dataset and promote common standards in large sample studies, we computed most catchment attributes introduced by Addor et al. (2017) in their Catchment Attributes and MEteorology for Large-sample Studies (CAMELS) dataset, and added several others. We used the dataset presented here (named CAMELS-CL) to characterise regional variations in hydroclimatic conditions over Chile and to explore how basin behaviour is influenced by catchment attributes and water extractions. Further, CAMELS-CL enabled us to analyse biases and uncertainties in basin-wide precipitation and PET. The characterisation of catchment water balances revealed large discrepancies between precipitation products in arid regions and a systematic precipitation underestimation in headwater mountain catchments (high elevations and steep slopes) over humid regions. We evaluated PET products based on ground data and found a fairly good performance of both products in humid regions (r>0.91) and lower correlation (r<0.76) in hyper-arid regions. Further, the satellite-based PET showed a consistent overestimation of observation-based PET. Finally, we explored local anomalies in catchment response by analysing the relationship between hydrological signatures and an attribute characterising the level of anthropic interventions. We showed that larger anthropic interventions are correlated with lower than normal annual flows, runoff ratios, elasticity of runoff with respect to precipitation, and flashiness of runoff, especially in arid catchments. CAMELS-CL provides unprecedented information on catchments in a region largely underrepresented in large sample studies. This effort is part of an international initiative to create multi-national large sample datasets freely available for the community. CAMELS-CL can be visualised from http://camels.cr2.cl and downloaded from https://doi.pangaea.de/10.1594/PANGAEA.894885

Draft genome sequence of chloride-tolerant Leptospirillum ferriphilum Sp-Cl from industrial bioleaching operations in northern Chile

Indexación: Web of Science; PubMedLeptospirillum ferriphilum Sp-Cl is a Gram negative, thermotolerant, curved, rod- shaped bacterium, isolated from an industrial bioleaching operation in northern Chile, where chalcocite is the major copper mineral and copper hydroxychloride atacamite is present in variable proportions in the ore. This strain has unique features as compared to the other members of the species, namely resistance to elevated concentrations of chloride, sulfate and metals. Basic microbiological features and genomic properties of this biotechnologically relevant strain are described in this work. The 2,475,669 bp draft genome is arranged into 74 scaffolds of 74 contigs. A total of 48 RNA genes and 2,834 protein coding genes were predicted from its annotation; 55 % of these were assigned a putative function. Release of the genome sequence of this strain will provide further understanding of the mechanisms used by acidophilic bacteria to endure high osmotic stress and high chloride levels and of the role of chloride-tolerant iron-oxidizers in industrial bioleaching operations.https://standardsingenomics.biomedcentral.com/articles/10.1186/s40793-016-0142-

Forest hydrology in Chile: Past, present, and future

This paper reviews the current knowledge of hydrological processes in Chilean temperate forests which extend along western South America from latitude 29° S to 56 ° S. This geographic region includes a diverse range of natural and planted forests and a broad sweep of vegetation, edaphic, topographic, geologic, and climatic settings which create a unique natural laboratory. Many local communities, endangered freshwater ecosystems, and downstream economic activities in Chile rely on water flows from forested catchments. This review aims to (i) provide a comprehensive overview of Chilean forest hydrology, to (ii) review prior research in forest hydrology in Chile, and to (iii) identify knowledge gaps and provide a vision for future research on forest hydrology in Chile. We reviewed the relation between native forests, commercial plantations, and other land uses on water yield and water quality from the plot to the catchment scale. Much of the global understanding of forests and their relationship with the water cycle is in line with the findings of the studies reviewed here. Streamflow from forested catchments increases after timber harvesting, native forests appear to use less water than plantations, and streams draining native forest yield less sediment than streams draining plantations or grassland/shrublands. We identified 20 key knowledge gaps such as forest groundwater systems, soil–plant-atmosphere interactions, native forest hydrology, and the effect of forest management and restoration on hydrology. Also, we found a paucity of research in the northern geographic areas and forest types (35-36 ° S); most forest hydrology studies in Chile (56 %) have been conducted in the southern area (Los Rios Region around 39-40 ° S). There is limited knowledge of the geology and soils in many forested areas and how surface and groundwater are affected by changes in land cover. There is an opportunity to advance our understanding using process-based investigations linking field studies and modeling. Through the establishment of a forest hydrology science “society” to coordinate efforts, regional and national-scale land use planning might be supported. Our review ends with a vision to advance a cross-scale collaborative effort to use new nation-wide catchment-scale networks Long-term Ecosystem Research (LTER) sites, to promote common and complementary techniques in these studies, and to conduct transdisciplinary research to advance sound and integrated planning of forest lands in Chile

Retos y soluciones tecnológicas en logística y transporte refrigerado de frutas y hortalizas

La presente Monografía, integrada en las publicaciones de la Red Temática FRUTURA, de CYTED, recoge las aportaciones de sus miembros en su tercera reunión científico-técnica, dando continuidad a las celebradas en Madrid y Sao Paulo en 2009. Se denominó “Situación actual, retos y soluciones en logística y transporte refrigerado internacional de frutas y hortalizas” y se celebró en la Universidad Politécnica de Cartagena, España, en junio de 2010. El evento se desarrolló durante tres jornadas, incluyendo el III Seminario Internacional de Transporte Frigorífico Marítimo, el I Seminario Internacional de Transporte Frigorífico Terrestre y Aéreo y el Foro Empresarial: Desafíos y Oportunidades del Intercambio Comercial Hortofrutícola España-Iberoamérica. La temática se enmarcó dentro del principal objetivo de la Red, el desarrollo de un sistema integral de mejora de la calidad y seguridad de las frutas durante la manipulación, el transporte y la comercialización, mediante nuevas tecnologías de inspección y monitorización. Las frutas y hortalizas frescas se producen frecuentemente en lugares alejados de los centros de consumo. Grandes volúmenes de productos, con frecuencia muy perecederos, se transportan diariamente a pequeñas o grandes distancias, tanto dentro de los propios países productores, como entre las naciones y Continentes. Paralelamente, los consumidores exigen de ellos una calidad cada día más elevada, no solo organoléptica, sino también nutricional, con especial garantía de la seguridad y el respeto del medio ambiente. Esto implica una alta exigencia al planificar el transporte y las operaciones omplementarias, para optimizar la calidad global y minimizar las pérdidas. Los aspectos asociados al transporte hortofrutícola en fresco, tanto en España como en Iberoamérica se abordaron a través de conferencias relacionadas con la situación en cada país participante. Así, se trataron los principales problemas y desafíos del transporte terrestre en Argentina y Uruguay, y de la exportación marítima desde Brasil, desde España (incluyendo tratamientos cuarentenarios) y desde Chile (con la modelización del envasado en atmósfera modificada a escala de pallet, los atributos de calidad en el transporte terrestre y aéreo y el seguimiento de la calidad de la fruta cortada mediante imágenes hiperespectrales). La calidad de las contribuciones recogidas en esta monografía, son un buen indicador del alto nivel científico de los miembros de la Red, cuyas aportaciones se vieron enriquecidas con el debate entre ponentes y participantes. Ello facilitó el intercambio de experiencias, la discusión de las temáticas en los diferentes ámbitos, la ampliación de conocimientos y la posibilidad de colaborar para llevar adelante nuevos avances tecnológicos. Asimismo, permitió identificar las limitaciones, problemas y desafíos que presenta el sector. Son aún muchos los condicionantes que surgen durante el transporte de productos perecederos, en especial de frutas y hortalizas, que requieren una solución técnica y económica. Durante las jornadas se realizaron diversas vistitas técnicas al Puerto de Cartagena, en sus áreas de logística, terminales y sistemas operativos de carga y descarga, contenedores isotermos y frigoríficos y cámaras frigoríficas de almacenamiento, organizadas por la Agencia Marítima Erhardt, S.A., Consignataria de buques de Cartagena (Murcia); la sede de la Autoridad Portuaria de Cartagena, donde se analizaron el desarrollo y previsiones de crecimiento de sus instalaciones portuarias en el futuro inmediato; la plataforma logística de exportación del Grupo Caliche S.A., ubicada en San Javier (Murcia) y la central hortofrutícola exportadora de cítricos y hortalizas de SAT San Cayetano, también en San Javier (Murcia). El interés por la temática de esta reunión quedó demostrado por la elevada participación durante las jornadas de empresarios, técnicos, investigadores y profesionales iberoamericanos. Pensamos que el fin último, que fue conocer en más profundidad la realidad presente del transporte terrestre, marítimo y aéreo en Iberoamérica mediante el acercamiento entre Universidades y Centros de Investigación y las Empresas del sector (exportadoras, importadoras y transportistas), se alcanzó plenamente. Deseamos agradecer al Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (AC2010-00017-00-00), a la Comunidad Autónoma de la Región de Murcia, a la Fundación Séneca de la Región de Murcia (14506/OC/10) y al Ayuntamiento de Cartagena su valiosa colaboración para la realización de este evento. Igualmente destacamos la ayuda desinteresada de los miembros del Grupo de Postrecolección y Refrigeración y del Instituto de Biotecnología Vegetal de la UPCT, quienes contribuyeron enormemente al éxito de la reunión