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Item type:Publication, Spatial variation in specific sediment yield along the Peruvian western Andes(Elsevier BV, 2022-10-22)The tropical Andes has been less studied in terms of erosion processes in comparison to other major mountain ranges in the world. Environmental gradients are steepest along the western flank of the Andes that is characterized by marked differences in vegetation, rough topography with deeply incised canyons, and highly variable and extreme precipitation patterns. Previous efforts mostly focused on sediment fluxes in large rivers draining to e.g. the Amazon basin while small to medium-sized rivers such as the ones flowing towards the Pacific Ocean have been relegated. They highlighted the link between sediment yield, anthropogenic and natural factors, e.g. climate, topography, river runoff, lithology and vegetation cover. In this study, we identified the spatial patterns of specific sediment yield along the western slopes of the Peruvian Andes between 3° and 13° S latitude for 21 catchments. We collected and analysed data from 22 environmental factors to elucidate their importance on spatially varying sediment yield. The sediment load was derived from gauging stations, reservoir sedimentation and water turbidity over a 30-yr period. The specific sediment yield varies strongly along the Peruvian western Andes as a consequence of the spatial variation in climate, topography and land cover controlling sediment production and transport. We reported higher-than-average specific sediment yields for the central part (6°-11°S) with values of 2130 and 2300 t km−2 yr−1 and low and uniform yields of 39 to 551 t km−2 yr−1 in the southern part (11° − 14.5° S). Given the scarcity of data on sediment yield, we included an uncertainty assessment based on bootstrapping approaches as to get a better grasp on the potential range of specific sediment yields in the study region. Using statistical techniques including Spearman correlation rank, univariate and multivariate regression analyses, we were able to determine the importance of the 22 environmental variables on the specific sediment yield. About 55 % of the observed variance can be explained by river discharge (Q90) and river steepness index (ks50). By adding an anthropogenic variable based on land cover, the explained variance in SSY increases up to 63 %, however, the effects of land cover on specific sediment yield are not clear because of spurious correlation between land cover, river discharge and topography. Our study therefore provides important new insights in the ongoing scientific debate on sediment yield variability in the western Andes. - Some of the metrics are blocked by yourconsent settings
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Item type:Publication, The Impact of Sustained Malaria Control in the Loreto Region of Peru: A Retrospective, Observational, Spatially-Varying Interrupted Time Series Analysis of the PAMAFRO Program(Elsevier Ltd, 2023-04-01)Background: Although malaria control investments worldwide have resulted in dramatic declines in transmission since 2000, progress has stalled. In the Amazon, malaria resurgence has followed withdrawal of Global Fund support of the Project for Malaria Control in Andean Border Areas (PAMAFRO). We estimate intervention-specific and spatially-explicit effects of the PAMAFRO program on malaria incidence across the Loreto region of Peru, and consider the influence of the environmental risk factors in the presence of interventions. Methods: We conducted a retrospective, observational, spatial interrupted time series analysis of malaria incidence rates among people reporting to health posts across Loreto, Peru between the first epidemiological week of January 2001 and the last epidemiological week of December 2016. Model inference is at the smallest administrative unit (district), where the weekly number of diagnosed cases of Plasmodium vivax and Plasmodium falciparum were determined by microscopy. Census data provided population at risk. We include as covariates weekly estimates of minimum temperature and cumulative precipitation in each district, as well as spatially- and temporally-lagged malaria incidence rates. Environmental data were derived from a hydrometeorological model designed for the Amazon. We used Bayesian spatiotemporal modeling techniques to estimate the impact of the PAMAFRO program, variability in environmental effects, and the role of climate anomalies on transmission after PAMAFRO withdrawal. Findings: During the PAMAFRO program, incidence of P. vivax declined from 42.8 to 10.1 cases/1000 people/year. Incidence for P. falciparum declined from 14.3 to 2.5 cases/1000 people/year over this same period. The effects of PAMAFRO-supported interventions varied both by geography and species of malaria. Interventions were only effective in districts where interventions were also deployed in surrounding districts. Further, interventions diminished the effects of other prevailing demographic and environmental risk factors. Withdrawal of the program led to a resurgence in transmission. Increasing minimum temperatures and variability and intensity of rainfall events from 2011 onward and accompanying population displacements contributed to this resurgence. Interpretation: Malaria control programs must consider the climate and environmental scope of interventions to maximize effectiveness. They must also ensure financial sustainability to maintain local progress and commitment to malaria prevention and elimination efforts, as well as to offset the effects of environmental change that increase transmission risk. Funding: National Aeronautics and Space Administration, National Institutes of Health, Bill and Melinda Gates Foundation. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Hydrology, Water Resources Availability and Management in the Andes Under Climate Change and Human Impacts(Elsevier B.V., 2023-10-01)• This Special Issue investigates water availability and management across the Andes. • It includes novel approaches to couple climate and hydrology with human water needs. • The collection enables an integrated analysis to reduce future risk of water scarcity. • Andean water research requires improved data collection and plausible future scenarios. • Adaptive water management needs to foster science-policy dialogue processes. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Long read, high-coverage reference genome of the Nymphalid butterfly <i>Catonephele acontius</i> (Nymphalidae: Biblidinae)(Genetics Society of America, 2026-07-02)BACKGROUND: Catonephele acontius (Nymphalidae:Biblidinae:Epicalinii) is a butterfly species with a wide distribution across the Neotropics including the Amazon. Here, we present a long-read high-coverage reference genome for this species to serve as a genomic resource for future studies on Biblidinae butterflies, a group that is the subject of ongoing studies of seasonal adaptation under climate change. RESULTS: We used PacBio HiFi and Isoseq reads to generate a highly contiguous and well-annotated reference genome. Five libraries were constructed, four using RNA from different tissues and one using High Molecular Weight (HMW) DNA from a wild-caught female. The DNA was sequenced using PacBio HiFi technology and the RNA was sequenced using long read PacBio IsoSeq technology. 20Gb of raw HiFi data was generated and assembled to an initial size of 520.7Mb (39x homozygous coverage) in 90 contigs. The assembly was then polished and decontaminated into 40 contigs with an N50 of 19.927Mb (BUSCO completeness: 99.0%, duplication 0.5%, fragmentation 0.7% and missing 0.3%). Final assembly size was 519.2Mb. Repeats were annotated, showing that the genome consisted of 40.4% transposable elements. IsoSeq transcriptome data from antennae, leg, ovary and digestive tissue was then used to structurally and functionally annotate gene models for the softmasked genome, uncovering ∼18,500 genes, with 70% of them given functional annotation. CONCLUSIONS: This reference assembly joins many published genomes in the Nymphalidae family but represents one of the first high-quality genomes from the Biblidinae subfamily. It provides a valuable resource to study the evolution of plastic and seasonal traits and will help investigate the genetic processes that may influence this species responses to rapid climate change. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Drivers of drought and its propagation in the Southern Peruvian Andes(2026-02-01)The southern Peruvian Andes is vulnerable to droughts, with impacts on agriculture and hydropower production, and wildfire frequency. Previous research has focussed on the processes controlling precipitation variability in the region, while the drivers of drought propagation, from meteorological drought to soil moisture, vegetation and hydrological drought, remain unconstrained. We analyse large-scale climate variability and daily atmospheric circulation patterns to gain new insights into the spatial-temporal variation of the processes that enhance or inhibit the development of drought and its propagation during the period 1985-2020. Across all seasons, meteorological drought is broadly driven by an upper tropospheric westerly wind anomaly and weaker convection in the western Amazon. However, the climatic processes that cause these anomalies vary in time and space. During the onset of the wet season drought is driven by La Niña, while during the termination of the wet season drought typically occurs under El Niño. Droughts are more likely when the Pacific Decadal Oscillation is in phase with the El Niño-Southern Oscillation, while the influence of tropical Atlantic sea surface temperature is variable and often weak. The propagation to soil moisture drought occurs on short timescales, typically less than a month, and is enhanced by favourable climatic conditions, while hydrological drought is buffered by catchment-scale processes. The modulation of drought propagation by vegetation cover and local hydrological processes in the southern Peruvian Andes suggests that the region may see notable benefits from a localised impact-focussed drought forecasting system.1