Browsing by Author "Cayuela, Luis"

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    Natural forests loss and tree plantations: large-scale tree cover loss differentiation in a threatened biodiversity hotspot
    (2020) Altamirano, Adison; Miranda, Alejandro; Aplin, Paul; Carrasco, Jaime; Catalan, German; Cayuela, Luis; Fuentes-Castillo, Taryn; Hernandez, Angela; Martinez-Harms, Maria J.; Peluso, Franco; Prado, Marco; Reyes-Riveros, Rosa; Van Holt, Tracy; Vergara, Cristian; Zamorano-Elgueta, Carlos; Di Bella, Carlos
    Distinguishing between natural forests from exotic tree plantations is essential to get an accurate picture of the world's state of forests. Most exotic tree plantations support lower levels of biodiversity and have less potential for ecosystem services supply than natural forests, and differencing them is still a challenge using standard tools. We use a novel approach in south-central of Chile to differentiate tree cover dynamics among natural forests and exotic tree plantations. Chile has one of the world's most competitive forestry industry and the region is a global biodiversity hotspot. Our collaborative visual interpretation method combined a global database of tree cover change, remote sensing from high-resolution satellite images and expert knowledge. By distinguishing exotic tree plantation and natural forest loss, we fit spatially explicit models to estimate tree-cover loss across 40 millions of ha between 2000 and 2016. We were able to distinguish natural forests from exotic tree plantations with an overall accuracy of 99% and predicted forest loss. Total tree cover loss was continuous over time, and the disaggregation revealed that 1 549 909 ha of tree plantations were lost (mean = 96 869 ha year(-1)), while 206 142 ha corresponded to natural forest loss (mean = 12 884 ha year(-1)). Mostly of tree plantations lost returned to be plantation (51%). Natural forests were converted mainly (75%) to transitional land covers (e.g. shrubland, bare land, grassland), and an important proportion of these may finish as tree plantation. This replacement may undermine objectives of increasedcarbon storage and biodiversity. Tree planting as a solution has gained increased attention in recen years with ambitious commitments to mitigate the effects of climate change. However, negative outcomes for the environment could result if strategies incentivize the replacement of natural forests into other land covers. Initiatives to reduce carbon emissions should encourage differentiating natural forests from exotic tree plantations and pay more attention on protecting and managing sustainably the former.
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    Toward Integrated Analysis of Human Impacts on Forest Biodiversity: Lessons from Latin America
    (2009) Newton, Adrian C.; Cayuela, Luis; Echeverria, Cristian; Armesto, Juan J.; Del Castillo, Rafael F.; Golicher, Duncan; Geneletti, Davide; Gonzalez-Espinosa, Mario; Huth, Andreas; Lopez-Barrera, Fabiola; Malizia, Lucio; Manson, Robert; Premoli, Andrea; Ramirez-Marcial, Neptali; Benayas, Jose-Maria Rey; Rueger, Nadja; Smith-Ramirez, Cecilia; Williams-Linera, Guadalupe
    Although sustainable forest management (SFM) has been widely adopted as a policy and management goal, high rates of forest loss and degradation are still occurring in many areas. Human activities such as logging, livestock husbandry, crop cultivation, infrastructural development, and use of fire are causing widespread loss of biodiversity, restricting progress toward SFM. In such situations, there is an urgent need for tools that can provide an integrated assessment of human impacts on forest biodiversity and that can support decision making related to forest use. This paper summarizes the experience gained by an international collaborative research effort spanning more than a decade, focusing on the tropical montane forests of Mexico and the temperate rain forests of southern South America, both of which are global conservation priorities. The lessons learned from this research are identified, specifically in relation to developing an integrated modeling framework for achieving SFM. Experience has highlighted a number of challenges that need to be overcome in such areas, including the lack of information regarding ecological processes and species characteristics and a lack of forest inventory data, which hinders model parameterization. Quantitative models are poorly developed for some ecological phenomena, such as edge effects and genetic diversity, limiting model integration. Establishment of participatory approaches to forest management is difficult, as a supportive institutional and policy environment is often lacking. However, experience to date suggests that the modeling toolkit approach suggested by Sturvetant et al. (2008) could be of value in such areas. Suggestions are made regarding desirable elements of such a toolkit to support participatory-research approaches in domains characterized by high uncertainty, including Bayesian Belief Networks, spatial multi-criteria analysis, and scenario planning.