Browsing by Autor "Marlene Soriano"

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Commercial Logging of Timber Species Enhances Amazon (Brazil) Nut Populations: Insights from Bolivian Managed Forests
(Multidisciplinary Digital Publishing Institute, 2021) Marlene Soriano; Pieter A. Zuidema; Cristina Barber; G.M.J. Mohren; Nataly Ascarrunz; Juan Carlos Licona; Marielos Peña‐Claros
A typical case of multiple-use forest management (MFM) in Southwestern Amazon is the commercial harvesting of Amazon or Brazil nut (Bertholletia excelsa) seeds and of timber of other tree species. Although the Amazon nut is the most important non-timber forest product (NTFP) in the Amazon basin, the species is under serious threat due to deforestation and may also be affected by overharvesting. However, selective logging of other tree species coexisting with Bertholletia may positively affect Bertholletia populations, thus enabling a special case for MFM. For this research, we investigated the impact of the intensity of Amazon nut harvesting and timber logging on Bertholletia populations in the Bolivian Amazon. We used demographic data from 72 two-hectare transects located within 24 community-based household forests varying in the intensity of nut collection (0–100%) and timber logging (0–15% of logging-disturbed forest area). Simulated Bertholletia population size increased with logging intensity but decreased with Amazon nut harvesting intensity. Bertholletia populations were projected to grow at the average MFM harvesting scenario tested: 57.4% of nut harvesting, 5.3% of logging-disturbed area (λ100 = 1.011). Our simulations also revealed that up to 89% of Amazon nut seeds can be harvested while sustaining Bertholletia populations, under 15% of logging-disturbed area, and applying liana cutting. Modest levels of timber logging and application of liana cutting may compensate for the negative effect of Amazon nut collection on Bertholletia populations for the next century. Our study demonstrates that Amazon nut and timber production could be combined in a sustainable MFM scheme, thus increasing the economic value of managed tropical forests and its promotion to reduce the increasing pressure by deforestation.
Implementing multiple forest management in Brazil nut-rich community forests: Effects of logging on natural regeneration and forest disturbance
(Elsevier BV, 2011) Marlene Soriano; Karen A. Kainer; Christina L. Staudhammer; Eduardo Sone Soriano
Integrating Stand and Soil Properties to Understand Foliar Nutrient Dynamics during Forest Succession Following Slash-and-Burn Agriculture in the Bolivian Amazon
(Public Library of Science, 2014) Eben N. Broadbent; Angélica M. Almeyda Zambrano; Gregory P. Asner; Marlene Soriano; Christopher B. Field; Harrison Ramos de Souza; Marielos Peña‐Claros; Rachel I. Adams; Rodolfo Dirzo; Larry Giles
Secondary forests cover large areas of the tropics and play an important role in the global carbon cycle. During secondary forest succession, simultaneous changes occur among stand structural attributes, soil properties, and species composition. Most studies classify tree species into categories based on their regeneration requirements. We use a high-resolution secondary forest chronosequence to assign trees to a continuous gradient in species successional status assigned according to their distribution across the chronosequence. Species successional status, not stand age or differences in stand structure or soil properties, was found to be the best predictor of leaf trait variation. Foliar δ(13)C had a significant positive relationship with species successional status, indicating changes in foliar physiology related to growth and competitive strategy, but was not correlated with stand age, whereas soil δ(13)C dynamics were largely constrained by plant species composition. Foliar δ(15)N had a significant negative correlation with both stand age and species successional status, - most likely resulting from a large initial biomass-burning enrichment in soil (15)N and (13)C and not closure of the nitrogen cycle. Foliar %C was neither correlated with stand age nor species successional status but was found to display significant phylogenetic signal. Results from this study are relevant to understanding the dynamics of tree species growth and competition during forest succession and highlight possibilities of, and potentially confounding signals affecting, the utility of leaf traits to understand community and species dynamics during secondary forest succession.
Socio-ecological costs of Amazon nut and timber production at community household forests in the Bolivian Amazon
(Public Library of Science, 2017) Marlene Soriano; G.M.J. Mohren; Nataly Ascarrunz; Wolfram Dressler; Marielos Peña‐Claros
The Bolivian Amazon holds a complex configuration of people and forested landscapes in which communities hold secure tenure rights over a rich ecosystem offering a range of livelihood income opportunities. A large share of this income is derived from Amazon nut (Bertholletia excelsa). Many communities also have long-standing experience with community timber management plans. However, livelihood needs and desires for better living conditions may continue to place these resources under considerable stress as income needs and opportunities intensify and diversify. We aim to identify the socioeconomic and biophysical factors determining the income from forests, husbandry, off-farm and two keystone forest products (i.e., Amazon nut and timber) in the Bolivian Amazon region. We used structural equation modelling tools to account for the complex inter-relationships between socioeconomic and biophysical factors in predicting each source of income. The potential exists to increase incomes from existing livelihood activities in ways that reduce dependency upon forest resources. For example, changes in off-farm income sources can act to increase or decrease forest incomes. Market accessibility, social, financial, and natural and physical assets determined the amount of income community households could derive from Amazon nut and timber. Factors related to community households' local ecological knowledge, such as the number of non-timber forest products harvested and the number of management practices applied to enhance Amazon nut production, defined the amount of income these households could derive from Amazon nut and timber, respectively. The (inter) relationships found among socioeconomic and biophysical factors over income shed light on ways to improve forest-dependent livelihoods in the Bolivian Amazon. We believe that our analysis could be applicable to other contexts throughout the tropics as well.
Spatial partitioning of biomass and diversity in a lowland Bolivian forest: Linking field and remote sensing measurements
(Elsevier BV, 2008) Eben N. Broadbent; Gregory P. Asner; Marielos Peña‐Claros; Michael Palace; Marlene Soriano
The legally allowable versus the informally practicable in Bolivia’s domestic timber market
(Elsevier BV, 2014) Wil de Jong; Walter Cano; Mario Zenteno; Marlene Soriano
Understanding the role of youth in Indigenous territorial governance
(Frontiers Media, 2023) Maria Paula Sarigumba; Marlene Soriano; James P. Robson; Ignacio Quiviquivi; Olga Lidia Cabrera
Indigenous territories cover more than one-fourth of the world’s land surface, overlap with distinct ecological areas, and harbour significant cultural and biological diversity; their stewardship provides critical contributions to livelihood, food security, conservation, and climate action. How these territories are accessed, used, and managed is an important question for owner communities, state governments, development agencies, and researchers alike. This extends to how broad community memberships remain invested in territorial use and management, with young people comprising one sub-group often underrepresented in decision-making spaces. We know that internal community norms and structures–often dominated by older, adult males–can limit opportunities for youth to contribute their energy and ideas. We also know that youth can and do leave their home communities to pursue life, work, or education goals and aspirations. Drawing on insights from 5 years of collaborative research with the Indigenous Territory of Lomerío (ITL), Bolivia, we explore the roles that youth play in territorial governance, their perceptions of current structures and novel engagement strategies, and consider what lessons from this case could be applied more broadly. Our findings point to the ITL as an instructive example of how Indigenous (and other rural and remote) communities might enable young people to participate more fully in territorial governance, highlighting the importance of an enabling, underlying socio-cultural context. Based on our work in Bolivia, and lessons from other places, we discuss ways to enhance youth-community-territory linkages to support Indigenous land sovereignty and stewardship and reflect on how research co-design and knowledge co-production can help deliver more robust, inclusive, and useful (in an applied sense) empirical insights in support of such efforts.