Browsing by Autor "Oswaldo Maillard"

Now showing 1 - 15 of 15

A potential turning point for Bolivia’s biodiversity conservation
(Nature Portfolio, 2025) Mónica Moraes R.; Álvaro Fernández‐Llamazares; Luís F. Aguirre; Oswaldo Maillard; Alfredo Romero‐Muñoz
Bolivia must prioritize biodiversity
(American Association for the Advancement of Science, 2025) Oswaldo Maillard
Bolivian forests hold carbon storage potential
(American Association for the Advancement of Science, 2025) Oswaldo Maillard; Roberto Vides-Almonacid
Diagnóstico biológico preliminar y prioridades de investigación en el área protegida municipal Parabanó
(2004) Kathia Rivero; Damián I. Rumiz; Juan Carlos Catari; Huáscar Azurduy; Oswaldo Maillard; L. Acosta; Miguel Angel Aponte; Karina Osinaga; Grimaldo Soto; Humberto Saavedra
Effect of Deforestation on Land Surface Temperature in the Chiquitania Region, Bolivia
(Multidisciplinary Digital Publishing Institute, 2022) Oswaldo Maillard; Roberto Vides-Almonacid; Álvaro Salazar; Daniel M. Larrea‐Alcázar
Neotropical forests offer alternatives to surface cooling and their conservation is an effective solution for mitigating the effects of climate change. Little is known about the importance of tropical dry forests for temperature regulation in Chiquitania, a region with increasing deforestation rates. The impact that deforestation processes are having on the surface temperature in Chiquitania remains an open question. This study evaluated trends in forest cover loss based on land surface temperatures (°C) in forested and deforested areas in Chiquitania. We hypothesized a positive relationship between higher deforestation and a temperature increase, which would decrease the resilience of highly disturbed Chiquitano forests. We evaluated ten sampling sites (10 × 10 km), including five in forested areas with some type of protection and the other five in areas with populated centers and accelerated forest loss. We developed scripts on the Google Earth Engine (GEE) platform using information from the Normalized Difference Vegetation Index (NDVI, MOD13A2) and the daytime and nighttime Land Surface Temperature (LST, MYD11A1) from MODIS products for the period 2001–2021. The statistical significance of the trends of the time series averages of the MODIS products was analyzed using a nonparametric Mann–Kendall test and the degree of the relationship between the variables was determined using the Pearson statistic. Our results based on NDVI analysis showed consistent vegetation growth in forested areas across the study period, while the opposite occurred in deforested lands. Regarding surface temperature trends, the results for daytime LST showed a positive increase in the four deforested areas. Comparatively, daytime LST averages in deforested areas were warmer than those in forested areas, with a difference of 3.1 °C. Additionally, correlation analyses showed a significant relationship between low NDVI values due to deforestation in three sites and an increase in daytime LST, while for nighttime LST this phenomenon was registered in two deforested areas. Our results suggest a significant relationship between the loss of forest cover and the increase in land surface temperature in Chiquitania. This study could be the first step in designing and implementing an early climate–forest monitoring system in this region.
Enact reforms to protect Bolivia’s forests from fire
(American Association for the Advancement of Science, 2025) Yifan He; Stasiek Czaplicki Cabezas; Oswaldo Maillard; Robert Müller; Alfredo Romero‐Muñoz; Laurenz Feliciano Romero Pimentel; Alcides Vadillo; Vincent Antoine Vos
Estado de conservación de los ecosistemas de las serranías chiquitanas: Un caso de estudio de la Lista Roja de Ecosistemas de la UICN en Bolivia
(2018) Oswaldo Maillard; Ruth Anívarro; Roberto Vides-Almonacid; Weimar Torres
Impact of Fires on Key Biodiversity Areas (KBAs) and Priority Bird Species for Conservation in Bolivia
(Multidisciplinary Digital Publishing Institute, 2022) Oswaldo Maillard; Sebastián K. Herzog; Rodrigo Wilber Soria-Auza; Roberto Vides-Almonacid
Key Biodiversity Areas (KBAs) are sites that contribute significantly to the protection of the planet’s biodiversity. In this study, we evaluated the annual burned areas and the intensity of the fires that affected Bolivia and its 58 KBAs (23.3 million ha) over the last 20 years (2001–2020). In particular, we analyzed the impact of wildfires on the distribution of Bolivian birds at the levels of overall species richness, endemic species and threatened species (Critically Endangered, Endangered, Vulnerable). We found that at the KBA level, the cumulative area of wildfires was 21.6 million ha, while the absolute area impacted was 5.6 million ha. The KBAs most affected by the wildfires are located in the departments of Beni and Santa Cruz; mainly in the KBAs Área Natural de Manejo Integrado San Matías, Oeste del río Mamoré, Este del río Mamoré, Noel Kempff Mercado and Área Natural de Manejo Integrado Otuquis. The wildfires impacted the distribution of 54 threatened species and 15 endemic species in the KBAs. Based on the results of this study, it is a priority to communicate to Bolivian government authorities the importance of KBAs as a strategy for the conservation of the country’s biodiversity and the threats resulting from anthropogenic fires.
Integridad del paisaje y riesgos de degradación del hábitat del jaguar (Panthera onca) en áreas ganaderas de las tierras bajas de Santa Cruz, Bolivia
(2020) Oswaldo Maillard; Sixto Angulo; Roberto Vides-Almonacid; Damián I. Rumiz; Peter Vogt; Octavio Monroy‐Vilchis; Hermes Justiniano; Huáscar Azurduy; Roger Coronado; Claudia Venegas
Multi-Criteria Prioritization of Watersheds for Post-Fire Restoration Using GIS Tools and Google Earth Engine: A Case Study from the Department of Santa Cruz, Bolivia
(Multidisciplinary Digital Publishing Institute, 2023) J. C. Giménez Fernández; Oswaldo Maillard; Gerson Uyuni; Mónica Guzmán-Rojo; Marisa Escobar
The Santa Cruz department in Bolivia is characterized by a wide range of ecosystems and by its richness in water resources. In recent years, extended drought caused by climate change has led to extensive fire events. Combined with deforestation, this is resulting in the degradation of the region’s ecosystems and water resources. To address restoration needs from both a land- and water-management perspective, this study proposes to prioritize restoration areas by applying a multi-criteria analysis (MCA) based on two main principles: (1) using the watershed as the main study unit and (2) involving stakeholders in the definition of priority watersheds. Local stakeholders selected criteria representing water resources, biophysical characteristics, land management, productive areas, and fire disaster threats, and reclassified the spatial information based on perceived importance. Different prioritization scenarios were developed and compared in a Google Earth Engine (GEE) application. Priority restoration areas largely depend on the weighting scheme. Focusing solely on past fires leads to prioritizing the south-east basins, while the conservation of the western watersheds becomes more important when increasing the weight of the water resources criteria. This study represents the first step in developing a participatory MCA tool at the watershed scale in Santa Cruz. Highlighting the impact of different prioritization criteria can support collective decision-making around land and watershed restoration.
Perception from a Public Survey of the Social–Ecological Effects of Wildfires in the Chiquitania Region of Bolivia
(Multidisciplinary Digital Publishing Institute, 2025) Oswaldo Maillard; P. Herrera; Nicolas Mielich; Claudia Venegas
In recent years, large-scale wildfires have become a serious threat to terrestrial ecosystems and people in the Chiquitania region of Bolivia. Understanding public perceptions is fundamental to designing comprehensive and effective wildfire management strategies. The objectives of the study were to learn perception on the main causes of wildfires, to understand their perceptions of the impacts of these events, and to explore the most viable solutions to preventing future wildfires in the Chiquitania region of Bolivia. We developed a 15-questions online survey and disseminated it through social media platforms, mobile messaging service groups, and at two workshops held in two locations. A total of 597 people participated in the survey with a balanced sex distribution. The participants were mainly young people aged 18–24 (45.40%) and 25–34 (21.40%), representing university students (42.6%) and professionals (42.6%). The data came from seven departments, but Santa Cruz was more strongly represented (75.9%). In addition, although only 65% considered themselves part of the general population, the data shows that 76% had personal experience of wildfires. Respondents indicated that fires were caused by human activities (95.9%), mainly due to traditional agricultural practices. The most important perceived impacts included landscape and vegetation quality, fauna habitat and ecosystem regeneration. In addition, participants have prioritized the reinforcement of patrols and surveillance, the hiring of forest firefighters and the purchase of aerial firefighting units. For prevention, the most chosen was to change policies that promote fires, changing the vision for economic development and stricter penalties. The findings can be used to formulate public policies aimed at preventing wildfires, mitigating their impacts and promoting environmental conservation.
Riesgos ambientales en las unidades hidrográficas de las serranías chiquitanas, departamento de Santa Cruz, Bolivia
(2019) Oswaldo Maillard; Julio Cesar Salinas; Sixto Angulo; Roberto Vides-Almonacid
Seasonal spatial-temporal trends of vegetation recovery in burned areas across Africa
(Public Library of Science, 2025) Oswaldo Maillard; Natasha Ribeiro; Amanda Armstrong; Ana I. Ribeiro‐Barros; Samora M. Andrew; Lucy Amissah; Zeinab Shirvani; Jonathan Ilunga Muledi; Omid Abdi; Huáscar Azurduy
Africa is entering a new fire paradigm, with climate change and increasing anthropogenic pressure shifting the patterns of frequency and severity. Thus, it is crucial to use available information and technologies to understand vegetation dynamics during the post-fire recovery processes. The main objective of this study was to evaluate the seasonal spatio-temporal trends of vegetation recovery in response to fires across Africa, from 2001 to 2020. Non-parametric tests were used to analyze MODIS Normalized Difference Vegetation Index (NDVI) products comparing the following three-month seasonal periods: December-February (DJF), March-May (MAM), June-August (JJA), and September-November (SON). We evaluated the seasonal spatial trends of NDVI in burned areas by hemisphere, territory, or country, and by land cover types, and fire recurrences, with a focus on forested areas. The relationships between the seasonal spatial trend and three climatic variables (i.e. maximum air temperature, precipitation, and vapor pressure deficit) were then analyzed. For the 8.7 million km2 burned in Africa over the past 22 years, we observed several seasonal spatial trends of NDVI. The highest proportions of areas with increasing trend (p < 0.05) was recorded in MAM for both hemispheres, with 22.0% in the Northern Hemisphere and 17.4% in the Southern Hemisphere. In contrast, areas with decreasing trends (p < 0.05), showed 4.8-5.5% of burned area in the Northern Hemisphere, peaking in JJA, while the Southern Hemisphere showed a range of 7.1 to 10.9% with the highest proportion also in JJA. Regarding land cover types, 48.0% of fires occurred in forests, 24.1% in shrublands, 16.6% in agricultural fields, and 8.9% in grasslands/savannas. Consistent with the overall trend, the area exhibiting an increasing trend in NDVI values (p < 0.05) within forested regions had the highest proportion in MAM, with 19.9% in the Northern Hemisphere and 20.6% in the Southern Hemisphere. Conversely, the largest decreasing trend (p < 0.05) was observed in DJF in the Northern Hemisphere (2.7-2.9%) and in JJA in the Southern Hemisphere (7.2-10.4%). Seasonally, we found a high variability of regeneration trends of forested areas based on fire recurrences. In addition, we found that of the three climatic variables, increasing vapor pressure deficit values were more related to decreasing NDVI levels. These results indicate a strong component of seasonality with respect to fires, trends of vegetation increase or decrease in the different vegetation covers of the African continent, and they contribute to the understanding of climatic conditions that contribute to vegetation recovery. This information is helpful for researchers and decision makers to act on specific sites during restoration processes.
Spatio-Temporal Evaluation of MSWEP, CHIRPS and ERA5-Land Reveals Regional-Specific Responses Across Complex Topography in Bolivia
(Multidisciplinary Digital Publishing Institute, 2025) Álvaro Salazar; Daniel M. Larrea‐Alcázar; Angéline Bertin; Nicolás Gouin; Alejandro Pareja; Luis Miguel Morales; Oswaldo Maillard; Diego Ocampo Melgar; Francisco A. Squeo
Reliable precipitation estimates are critical for climate analysis and ecosystem management in regions with complex topography and limited ground-based observations. Bolivia, where the Andes, inter-Andean valleys, and Amazonian lowlands converge, presents sharp climatic heterogeneity that challenges both satellite retrievals and reanalysis products. This study evaluated three widely used datasets, MSWEP V2.2, CHIRPS V2, and ERA5-Land, against monthly station records from 1980 to 2022 to identify the most reliable precipitation estimations for hydrological and climate applications in five distinct regions. We applied a robust validation framework that integrates continuous and categorical performance metrics into a Combined Accuracy Index (CAI), providing a balanced measure of magnitude and event detection skill. Additionally, we implemented a conservative trend analysis with explicit correction for serial autocorrelation to ensure reliable identification of long-term changes. The results showed that MSWEP V2.2 consistently outperforms CHIRPS V2 and ERA5-Land across most regions, achieving the highest combined skill. In the Altiplano, MSWEP reached a CAI of 0.91, compared to CHIRPS (0.80) AND ERA5-Land (0.68). In the Valles region, MSWEP also led with 0.85, outperforming CHIRPS (0.79) and ERA5-Land (0.51). By contrast, CHIRPS V2 performed better in the Llanos (0.85) relative to MSWEP (0.82) and ERA5-Land (0.79). In the Chaco, MSWEP and CHIRPS performed similarly (0.80 and 0.81, respectively), while ERA5-Land scored 0.70. In the Amazonian lowlands, all three products performed well, with MSWEP ranking first (0.93), followed by ERA5-Land (0.88) and CHIRPS (0.86). ERA5-Land systematically overestimated precipitation across Bolivia, with annual biases above 36 mm month−1. Trend analysis revealed significant precipitation declines, particularly in the Llanos (MSWEP: −0.88 mm year−1; CHIRPS: −1.19 mm year−1; ERA5-Land: −0.90 mm year−1), while changes in the Altiplano, Valles and Amazonia were weaker or nonsignificant. These findings highlight MSWEP V2.2 as the most reliable dataset for Bolivia. The methodological framework proposed here offers a transferable approach to validate gridded products in other data-scarce and environmentally diverse regions.
Temperatura de la superficie terrestre y escenarios climáticos por el cambio de uso de suelo en los municipios metropolitanos del departamento de Santa Cruz, Bolivia
(2021) Boris Hinojosa Guzmán; Oswaldo Maillard; Diego Saucedo