Evert Thomas

Consultative Group on International Agricultural Research | CGIAR · Alliance of Bioversity International and CIAT

At the start of the UN Decade of Ecosystem Restoration (2021–2030), the restoration of degraded ecosystems is more than ever a global priority. Tree planting will make up a large share of the ambitious restoration commitments made by countries around the world, but careful planning is needed to select species and seed sources that are suitably adap...

Peru is the eighth largest producer of cacao beans globally, but high cadmium contents are constraining access to international markets which have set upper thresholds for permitted concentrations in chocolate and derivatives. Preliminary data have suggested that high cadmium concentrations in cacao beans are restricted to specific regions in the c...

El principal objetivo de este catálogo es dar a conocer la gran diversidad de cacaos que existen en el Perú para promover tanto su uso como su conservación. El primer capítulo muestra que la mayoría de los diferentes cultivares tradicionales y grupos genéticos silvestres tienen una coherencia geográfica que permitirá la implementación de una sist...

Climate change is expected to impact cacao cultivation in Ecuador, the fifth largest cacao producing country in the world and largest exporter of fine flavour cacao. The objective of this study was to evaluate the future impact of climate change on the suitable distribution of cultivated and wild cacao and identify areas where climate change tolera...

El principal objetivo de este catálogo es dar a conocer la gran diversidad de cacaos que existen en el Ecuador para promover tanto su uso como su conservación. Está claro que el Instituto Nacional de Investigaciones Agropecuarias (INIAP) lidera los esfuerzos de caracterización, selección y mejoramiento de los recursos genéticos de cacao en el país...

El cacao (Theobroma cacao L.) es una planta originaria de América tropical y constituye uno de los cultivos más importantes y con mayor comercialización en el mundo. La producción mundial está distribuida en la región tropical, en países de América del Sur, América Central, el Caribe, África, Asia y Oceanía. En América Latina el cultivo de cacao ti...

Artisanal and Small‐Scale Gold Mining (ASGM) carried out by individual miners or small enterprises with limited capital, significantly contribute to land degradation and loss of biodiversity‐rich forests in the Amazon. Due to limited information on the edaphic conditions crucial for restoring these degraded areas, a soil evaluation method was emplo...

En este primer capítulo introductorio presentamos los diferentes grupos genéticos que tengan presencia en el Ecuador, sea de origen nativo, o como consecuencia de introducción humana. Consideramos que esta información ayudará a interpretar la composición genética de los diferentes genotipos caracterizados en fincas de agricultores y en colecciones...

El principal objetivo de este catálogo es dar a conocer la diversidad de cacaos que existen en colecciones en Honduras para promover tanto su uso como su conservación. La Fundación Hondureña de Investigación Agrícola (FHIA) lidera la investigación de cacao en el país y mantiene un banco de germoplasma de más de cuarenta clones seleccionadas y d...

Diversity and functionality of bird communities in tropical agroforests are shaped by their surrounding landscape, particularly the extent and type of natural forest. However, most evidence comes from tropical rainforest landscapes, whereas the bearing of such trends in other forest types remains understudied. We compared functional and beta divers...

Artisanal and small-scale gold mining (ASGM) in the Amazon has degraded tropical forests and escalated mercury (Hg) pollution, affecting biodiversity, ecological processes and rural livelihoods. In the Peruvian Amazon, ASGM annually releases some 181 tons of Hg into the environment. Despite some recent advances in understanding the spatial distribu...

Persistent gender inequalities challenge theory and praxis of community-based collective action. Here we adopt an innovative approach which integrates environmental justice, value chain inclusion and collective action theory to diagnose inequalities in community-based organizations (CBOs) and identify strategies to address them. Drawing on the find...

Biodiversity in all its dimensions is being threatened by climate change and the impact of human activities. Genetic diversity is a key dimension of biodiversity underlying adaptation to global changes. Here we assess the impact of climate change on plant genetic diversity in a region located in the southernmost portion of Argentina and Chile range...

Plant diversity has long been linked to an increase in ecosystem productivity and function, but concrete examples in which ecosystem services are linked to diversity at the scale at which management decisions are taken are rare. We specifically tested for a correlation between plant diversity and provision-ing ecosystem services estimated via the p...

In the last 25 years, almost 50 million hectares of primary forest have been lost due to deforestation. Numerous international initiatives such as the Bonn Challenge and the New York Declaration on Forests have set ambitious goals to restore degraded and deforested lands by 2030. Realizing global commitments on forest and landscape restoration (FLR...

In the last 25 years, almost 50 million hectares of primary forest have been lost due to deforestation. Numerous international initiatives such as the Bonn Challenge and the New York Declaration on Forests have set ambitious goals to restore degraded and deforested lands by 2030. Realizing global commitments on forest and landscape restoration (FLR...

The quality and origin of tree seeds and seedlings affect the survival, growth, productivity, ecosystem services and adaptive capacity of restored forests and landscapes. The availability of seeds and seedlings directly influences the delivery of benefits to land users from restoration efforts. Yet, despite more than a decade of global restoration...

The IUCN Red List of Threatened Species is an extinction risk assessment tool that has guided species conservation over the last five decades. However, as wildlife scientists and conservationists, we argue that its influence on the global conservation agenda can hinder effective species conservation efforts. Here, we review the limitations of the R...

Versión en alta resolución / high-resolution version: https://www.dropbox.com/scl/fo/kwc3erumfs3nqu3z061e3/h?rlkey=477vijhlp3tnd1oksimawapkg&dl=0

XXX download here: https://authors.elsevier.com/a/1hTtNcA-Inxce XXXX The cacao tree (Theobroma cacao) is a billion-dollar crop species of which the yields are greatly constrained by, amongst others, pollination limitation. Manual pollen supplementation has been proposed to counter pollination deficits, thus improving yield quantity and potentially...

El principal objetivo de este capitulo es dar a conocer la gran diversidad de cacaos que existen en el Perú para promover tanto su uso como su conservación. El capítulo demuestra que la mayoría de los diferentes cultivares tradicionales y grupos genéticos silvestres tienen una coherencia geográfica que permitirá la implementación de una sistema de...

Bird‐ and bat‐mediated biocontrol benefits the productivity of tropical commodity crops such as cacao, but the ecological interactions driving these ecosystem services remain poorly understood. Whereas birds and bats prey on herbivorous arthropods, they may also prey on arthropod mesopredators such as ants, with poorly understood consequences for p...

Certification of sustainability standards is an important governance strategy aimed at enhancing the human well-being outcomes of agri-food value chains. While the impacts of certification on well-being are positive for some farmers under certain conditions, they are insignificant or adverse for others. Many barriers can impede positive impacts of...

The intraspecific diversity of cacao has traditionally been preserved in genebanks. However, these establishments face various challenges, notably insufficient funding, accession redundancy, misidentification and lack of wild cacao population samples. In natural environments, it is expected that unknown varieties of cacao may still be found, but wi...

In the tropics, combining food security with biodiversity conservation remains a major challenge. Tropical agroforestry systems are among the most biodiversity‐friendly and productive land‐use systems, and 70% of cocoa is grown by >6 million smallholder farmers living on <2$ per day. In cacao's main centre of diversification, the western Amazon reg...

Durante las últimas 2 décadas, la producción y el área sembrada de cacao en el país han aumentado sustancialmente, en gran parte debido a los programas de sustitución de cultivos de uso ilícito. Actualmente, el sector cacaotero del Perú reúne cerca de 90 mil familias productoras con unidades agrícolas de 1,9 hectáreas en promedio, pues a diferencia...

Animals provide services such as pollination and pest control in cacao agro-forestry systems, but also disservices. Yet, their combined contributions to crop yield and fruit loss are mostly unclear. In a full-factorial field experiment in northwestern Peru, we excluded flying insects, ants, birds and bats from cacao trees and assessed several produ...

Societal Impact Statement Modern food systems push agriculture to focus on a small number of commercial crops, while there is a very large diversity of untapped edible plants that could be used to address food security and nutrition. Poor and monotonous diets are closely linked to the complex burden of multiple forms of malnutrition and dietary ris...

p>In the original publication of the article, under the case study “Case study 3: Participatory guarantee system to stimulate agroecological transition in Cuba”, the reference “Fernández León 2016” should read “Fernández and León 2016”. Further, the correct reference should read as below, Díaz Fernández I, León DE (2016) Gestión Empresarial y Géner...

Esta guía práctica denominada Recuperación de la salud del suelo para la restauración de áreas degradadas por la minería aurífera aluvial en la Amazonía peruana, pretende ilustrar de forma sencilla y práctica el proceso y los fundamentos de restauración de áreas degradadas por la minería de oro aluvial en la Amazonía. En este aspecto, es necesario...

Governments are updating national strategies to meet global goals on biodiversity, climate change and food systems proposed in the Convention on Biological Diversity post-2020 framework and agreed at the United Nation’s Climate Change Conference (COP26) and Food Systems Summit (UNFSS). This represents a unique and crucial opportunity to integrate a...

Climate change and other anthropogenic threats are increasingly imperilling the diverse biomes of Central Africa, which are globally important for biodiversity, carbon storage and people's livelihoods. The objectives of this paper were to: (i) map the vulnerability of 100 socio-ecologically important priority tree species in Central Africa to clima...

Remote sensing-based approaches are important for evaluating ecosystem degradation and the efficient planning of ecosystem restoration efforts. However, the large majority of remote sensing-based degradation assessments are trend-based, implying that they can only detect degradation that occurred after medium or high-resolution satellite imagery be...

El cacao (Theobroma cacao L.) es un cultivo perenne de importancia económica por sus granos utilizadas en la fabricación de chocolates y productos derivados. Es una fuente importante de ingresos para cientos de miles de productores que conforman la cadena productiva a lo largo de zonas tropicales. A nivel mundial, Perú es posiblemente el país que a...

Enhancing water use efficiency in urban green spaces is an increasing concern in hyper-arid megacities. Here we aimed to compare the efficacy of species selection vs. soil management as strategies for reducing water demand of ornamental trees in irrigated green spaces of the city of Lima, Peru. We compared the performance of a popular exotic shrub...

Pollination services of cacao are crucial for global chocolate production, yet remain critically understudied, particularly in regions of origin of the species. Notably, uncertainties remain concerning the identity of cacao pollinators, the influence of landscape (forest distance) and management (shade cover) on flower visitation and the role of po...

Cacao (Theobroma cacao L.) is among the most important cash crops in tropical countries. The existing cacao genetic diversity represents a key resource to ensure the long-term sustainability of cacao cultivation but it remains vastly underused. The objective of this paper is to describe the current state of conservation and use of cacao genetic mat...

Tree diversity in Asia's tropical and subtropical forests is central to nature-based solutions. Species vulnerability to multiple threats, which affects the provision of ecosystem services, is poorly understood. We conducted a region-wide, spatially explicit vulnerability assessment (including overexploitation, fire, overgrazing, habitat conversion...

Agricultural expansion and intensification increasingly threaten birds and bats, especially insectivorous species from the tropics. Cacao agroforests in tropical rainforest areas have been shown to support higher bird and bat biodiversity than other land-use systems, but their suitability for tropical dry forest biodiversity remains unclear. We pre...

The work of the CGIAR Research Program on Forests, Trees and Agroforestry (FTA) on tree seed systems — the authors’ shorthand for the means through which growers obtain access to tree-planting materials, either seeds or seedlings — has sought to address significant constraints in the diversity and genetic quality of the tree seeds and seedlings tha...

Forests and trees are critical for the survival of life on earth. They conserve a tremendous biodiversity and fulfill essential ecosystem services such as climate regulation, cycling of nutrients and water. They contribute to food and nutrition security, are a major source of raw materials and offer countless livelihood opportunities. However, fore...

High-quality, suitably adapted tree seed at volume is a key component for the implementation and long-term success of forest landscape restoration (FLR). We analysed the tree seed systems in four Asian countries—the Philippines, Indonesia, Malaysia and India—which have committed to restore in total over 47.5 million hectares of degraded lands by 20...

The Amazon is an important reservoir of biodiversity and carbon but it is under pressure by multiple threats such as artisanal and small‐scale gold mining (ASGM). In Peru ASGM has degraded 90,000 ha of old growth forest since the eighties, leaving vast areas as wastelands. As most ASGM in the region is illegal, efforts to recover degraded areas hav...

Seasonally Dry Tropical Forest (SDTF) is one of the most threatened ecosystems worldwide and in Colombia it is considered critically endangered according to the national red list of ecosystems. Ongoing processes of fragmentation and degradation of SDTFs are expected to be accompanied by a loss of genetic diversity of the tree populations contained...

Latin America boasts an enormous diversity of nutritionally important and potentially economically valuable fruit trees. The majority have limited national and regional markets, with only a few traded internationally. This chapter explores why native fruit trees remain neglected and underutilized species (NUS) despite their potential to diversify d...

Achieving multi-million-hectare commitments from countries around the world to restore degraded lands in resilient and sustainable ways requires, among other things, huge volumes of tree planting material. Seed systems encompassing all forest reproductive material (e.g., seeds, cuttings, stakes, and wildings), are key to ensuring that sufficient pl...

At its creation in 2008, the United Nations REDD (‘reducing emissions from degradation and deforestation’) programme was hailed as a way to finance conservation with tools such as carbon offsets. Thirteen years on, little of that promise has been realized. A REDD transaction signed in March for the Cordillera Azul National Park, in the foothills of...

Gold mining is the largest source of mercury (Hg) pollution worldwide. The discharge of mercury in the environment bears direct human health risks and is likely to increase cascading effects throughout local food chains. In the Peruvian Amazon the mining process consists of slashing and burning trees, followed by extraction of gold-bearing sediment...

Aim Cacao (Theobroma cacao L.) is expected to be vulnerable to climate change. The objectives of this study were to (a) assess the future impact of climate change on cacao in Peru and (b) identify areas where climate change‐tolerant genotypes are potentially present. Location Peru. Methods Drawing on 19,700 to and1,200 presence points of cultivat...

OBJETIVO El objetivo del estudio es evaluar los efectos del cambio climático en la distribución de las poblaciones silvestres de 20 especies de árboles amenazadas. ÁREA DE ESTUDIO El área de estudio es el bosque de las regiones amazónicas de Huánuco, Amazonas, Junín, Loreto, Madre de Dios, Pasco, San Martín y Ucayali. SELECCIÓN DE LAS 20 ESPECIES I...

OBJETIVO El objetivo del estudio es evaluar los efectos del cambio climático en la distribución de las poblaciones silvestres de 20 especies de aves. ÁREA DE ESTUDIO El área de estudio es el bosque de las regiones Amazónicas de Huánuco, Amazonas, Junín, Loreto, Madre de Dios, Pasco, San Martín y Ucayali. SELECCIÓN DE LAS 20 ESPECIES Inicialmente, s...

In the 12,000 years preceding the Industrial Revolution, human activities led to significant changes in land cover, plant and animal distributions, surface hydrology, and biochemical cycles. Earth system models suggest that this anthropogenic land cover change influenced regional and global climate. However, the representation of past land use in e...

Ecosystem services of Amazonian forests are disproportionally produced by a limited set of hyperdominant tree species. Yet the spatial variation in the delivery of ecosystem services by individual hyperdominant species across their distribution ranges and corresponding environmental gradients is poorly understood. Here, we use the concept of habita...

Tree-based forest landscape restoration interventions require knowledge on the suitability and origin of seed sources and planting material. A common recommendation is to select locally sourced material based on the assumption that it is well adapted to local environmental conditions and to avoid introduction of maladapted genes. However, faced wit...

El cacao Peruano chuncho de Cusco se destaca por tener una diversidad de sabores y aromas sin par en el mundo, que sin duda es el resultado de largos procesos de domesticación a cargo de grupos indígenas, hoy en día representados por los Matsigenka, concentrados en la Región de Cusco, que utilizaban el cacao para rituales y también para realizar in...

Forest restoration projects involving active planting should prioritize species that are useful to local communities, while also considering species' threat status and resistance to local stress factors, but scientific knowledge on these criteria is scarce, especially in understudied tropical ecosystems. We hypothesized that local ecological knowle...

1. At the start of the UN Decade of Ecosystem Restoration (2021-2030), the restoration of degraded ecosystems is more than ever a global priority. Tree planting will make up a large share of the ambitious restoration commitments made by countries around the world, but careful planning is needed to select species and seed sources that are suitably a...

The global decline in invertebrate diversity requires urgent conservation interventions. However, identifying priority conservation areas for invertebrates remains a significant challenge. We hypothesized that aligning the conservation of invertebrate biodiversity with climate change mitigation offers a solution. As both soil carbon storage and inv...

Growing evidence suggests that constraints to the availability and quality of tree seed can undermine the success of forest and landscape restoration efforts and the delivery of associated benefits such as mitigating climate change and halting biodiversity loss. Past experiences to promote tree seed supply have frequently shown limited outcomes ove...

The Brazil nut is a highly valuable non-timber forest product from a wild, hyper-dominant, emergent tree species that is increasingly vulnerable and exposed to habitat degradation. We provide evidence for how Brazil nut genetic resources are negatively affected by forest degradation and discuss the consequences of this for reproductive success. To...

La minería de oro es la mayor fuente de contaminación por mercurio (Hg) en todo el mundo. La emisión de mercurio conlleva graves riesgos directos a la salud humana y el ambiente. En la Amazonía peruana, la minería aurífera consiste en la tala y quema de árboles, extracción de sedimentos, la amalgamación con Hg y la recuperación de oro, lo que conll...

In this article we highlight the challenges involved in delivering seeds at a large scale and the policy initiatives that could be put in place to ensure functional, well-tracked tree-seed delivery. We discuss the need to link the conservation of tree genetic resources (TGR) with their sustainable use and livelihoods in FLR and provide case studies...

Growing demand for tropical commodities that are socially and environmentally more sustainable is changing the global market for agroforestry products such as coffee and cocoa. Transforming mass production of cash crops towards higher socio-ecological standards includes challenges, but also novel opportunities to protect ecosystem services and hum...