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  • Fine-scale processes shape ecosystem service provision by an Amazonian hyperdominant tree species

Fine-scale processes shape ecosystem service provision by an Amazonian hyperdominant tree species

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FTA COMMUNICATIONS TEAM

Conspecific distance and density-dependence is a key driver of tree diversity in natural forests, but the extent to which this process may influence ecosystem service provision is largely unknown. Drawing on a dataset of >135,000 trees from the Peruvian Amazon, we assessed its manifestation in biomass accumulation and seed production of Brazil nut (Bertholletia excelsa) which plays a keystone role in carbon sequestration and NTFP harvesting in Amazonia. For the first time, we find both negative and positive effects of conspecific proximity on seed production and above ground biomass at small and large nearest neighbour distances, respectively. Plausible explanations for negative effects at small distances are fine-scale genetic structuring and competition for shared resources, whereas positive effects at large distances are likely due to increasing pollen limitation and suboptimal growth conditions. Finally, findings suggest that most field plots in Amazonia used for estimating carbon storage are too small to account for distance and density-dependent effects and hence may be inadequate for measuring species-centric ecosystem services.

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  • Genetic diversity of Ceiba pentandra in Colombian seasonally dry tropical forest: implications for conservation and management

Genetic diversity of Ceiba pentandra in Colombian seasonally dry tropical forest: implications for conservation and management

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FTA COMMUNICATIONS TEAM

Seasonally dry tropical forests (SDTFs) are one of the most degraded vegetation types worldwide and in Colombia<10% of the original cover remains. This calls for urgent conservation measures and restoration efforts. Understanding the genetic diversity and structure of tree species is crucial to inform not only conservation measures, but also sourcing of planting materials to ensure the long-term success of tree planting efforts, particularly in light of climate change. We assessed the genetic diversity distribution and structure of Ceiba pentandra from twelve representative locations of SDTF in Colombia, and how they may have been shaped by past climatic changes and human influence. We found three different genetic groups which may be the result of differentiation due to isolation of the Caribbean region, the Upper Cauca River Valley and the Patía River Valley in pre-glacial times. Range expansion of SDTF during the last glacial period, followed by more recent range contraction during the Holocene can explain the current distribution and mixture of genetic groups across contemporary STDF fragments. Most of the sampled localities showed heterozygosity scores close to Hardy–Weinberg expectations. Only two sites, among which the Patía River valley, an area with high conservation value, displayed significantly positive values of inbreeding coefficient, potentially affecting their survival and use as seed sources. While the effects of climate change might threaten C. pentandra populations across their current distribution ranges, opportunities remain for the in situ persistence of the most genetically diverse and unique ones. Based on our findings we identify priority areas for the in situ conservation of C. pentandra in Colombian SDTF and propose a pragmatic approach to guide the selection of appropriate planting material for use in restoration.

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  • Forest restoration needs to become climate-smart

Forest restoration needs to become climate-smart

A native tree nursery promotes restoration in Colombia. Photo by C. Alcazar Caisedo/Bioversity International
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FTA COMMUNICATIONS TEAM

A gaharu tree nursery in the Hutan Harapan forest, Indonesia. Photo by R. Jalonen/Bioversity International

As the world leaders gather in Bonn for the UN climate summit, a new study shows that forest restoration needs a mindset change to reach its potential in mitigating climate change.

All forest and landscape restoration projects require access to land and seed. International agreements and guidelines now broadly recognize the need to consider both the biophysical and political dimensions of land during restoration planning, from erosion control to tenure issues.

By contrast, the quality, availability of, and access to tree seed has received little attention in high-level policy and planning. And yet, restoring just a million hectares of degraded forest land – a fraction of recent unprecedented global restoration commitments – can easily require a billion seedlings.

What these seedlings are, where they come from, how they are selected, produced and delivered and by whom, are neither trivial nor merely technical issues for forest and landscape restoration to be effective and provide expected benefits, including for climate.

A new study that surveyed restoration projects from more than 50 countries shows that most projects struggle in selecting and accessing suitable tree seed for meeting their objectives. For example, half of the projects did not have any seed selection criteria to ensure that seed is viable and adequately diverse – and yet, four of five projects often could not find what they were looking for in seed markets.

Lack of genetic diversity or unsuitable origin of seed has profound impacts on restoration success, reducing seedling growth and survival, productivity, resistance to pests and diseases, and capacity to adapt to environmental change. Survey respondents described the practical implications for their projects: 47% of them had often experienced higher costs, 41% delays and 35% ended up restoring the same site again because of problems with planting material. Carbon credits quickly pick up cost.

Read more: FTA at COP23 

A native tree nursery promotes restoration in Colombia. Photo by C. Alcazar Caisedo/Bioversity International

Alarmingly, the projects that specifically aim at mitigating climate change are often the ones giving least attention to what they plant, and, therefore, at highest risk of failure.

Additional bad news for mitigation targets is that restoration practitioners often strongly prefer ‘local’ seed, typically sourced from within a few kilometers from the restoration site. They commonly assume that such seed sources are best adapted to the site conditions – a view that has little support from research, especially in light of changing climate.

Moreover, in target landscapes for restoration, remaining forests are often degraded and likely producing inbred seed with poor growth and survival. It would be prudent to expand the area within which seed is sourced, emphasizing the genetic viability of seed sources rather than arbitrary cut-off distances from the restoration site.

What can countries do to reduce the rates of failure and help make forest and landscape restoration climate-smart?

“Unfortunately, there are no quick fixes: trees typically take several years, in some cases up to decades, to start to produce seed”, says Riina Jalonen, the study’s lead author and Associate Scientist at Bioversity International. “Therefore, seed supply for tomorrow’s restoration needs really has to be planned today”.

“Countries should initiate national assessments of seed supply and demand for meeting restoration targets as a priority. If seed needs are assessed only at project level, the gaps in supply continue to go unnoticed and can’t be dealt with effectively,” Jalonen says.

Currently, growing restoration pledges worldwide are not accompanied by growing commitments to developing and protecting seed sources. That spells increasing trouble for restoration practitioners in the years ahead. Can we change the tide?

Read more: Gender Research Fellowship’s second round kicks off in Kenya

Originally published on the website of Bioversity International


This research is part of the CGIAR Research Program on Forests, Trees and Agroforestry and is supported by CGIAR Fund Donors.

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  • Forest restoration needs to become climate-smart

Forest restoration needs to become climate-smart

A native tree nursery promotes restoration in Colombia. Photo by C. Alcazar Caisedo/Bioversity International
Posted by

FTA COMMUNICATIONS TEAM

A gaharu tree nursery in the Hutan Harapan forest, Indonesia. Photo by R. Jalonen/Bioversity International

As the world leaders gather in Bonn for the UN climate summit, a new study shows that forest restoration needs a mindset change to reach its potential in mitigating climate change.

All forest and landscape restoration projects require access to land and seed. International agreements and guidelines now broadly recognize the need to consider both the biophysical and political dimensions of land during restoration planning, from erosion control to tenure issues.

By contrast, the quality, availability of, and access to tree seed has received little attention in high-level policy and planning. And yet, restoring just a million hectares of degraded forest land – a fraction of recent unprecedented global restoration commitments – can easily require a billion seedlings.

What these seedlings are, where they come from, how they are selected, produced and delivered and by whom, are neither trivial nor merely technical issues for forest and landscape restoration to be effective and provide expected benefits, including for climate.

A new study that surveyed restoration projects from more than 50 countries shows that most projects struggle in selecting and accessing suitable tree seed for meeting their objectives. For example, half of the projects did not have any seed selection criteria to ensure that seed is viable and adequately diverse – and yet, four of five projects often could not find what they were looking for in seed markets.

Lack of genetic diversity or unsuitable origin of seed has profound impacts on restoration success, reducing seedling growth and survival, productivity, resistance to pests and diseases, and capacity to adapt to environmental change. Survey respondents described the practical implications for their projects: 47% of them had often experienced higher costs, 41% delays and 35% ended up restoring the same site again because of problems with planting material. Carbon credits quickly pick up cost.

Read more: FTA at COP23 

A native tree nursery promotes restoration in Colombia. Photo by C. Alcazar Caisedo/Bioversity International

Alarmingly, the projects that specifically aim at mitigating climate change are often the ones giving least attention to what they plant, and, therefore, at highest risk of failure.

Additional bad news for mitigation targets is that restoration practitioners often strongly prefer ‘local’ seed, typically sourced from within a few kilometers from the restoration site. They commonly assume that such seed sources are best adapted to the site conditions – a view that has little support from research, especially in light of changing climate.

Moreover, in target landscapes for restoration, remaining forests are often degraded and likely producing inbred seed with poor growth and survival. It would be prudent to expand the area within which seed is sourced, emphasizing the genetic viability of seed sources rather than arbitrary cut-off distances from the restoration site.

What can countries do to reduce the rates of failure and help make forest and landscape restoration climate-smart?

“Unfortunately, there are no quick fixes: trees typically take several years, in some cases up to decades, to start to produce seed”, says Riina Jalonen, the study’s lead author and Associate Scientist at Bioversity International. “Therefore, seed supply for tomorrow’s restoration needs really has to be planned today”.

“Countries should initiate national assessments of seed supply and demand for meeting restoration targets as a priority. If seed needs are assessed only at project level, the gaps in supply continue to go unnoticed and can’t be dealt with effectively,” Jalonen says.

Currently, growing restoration pledges worldwide are not accompanied by growing commitments to developing and protecting seed sources. That spells increasing trouble for restoration practitioners in the years ahead. Can we change the tide?

Read more: Gender Research Fellowship’s second round kicks off in Kenya

Originally published on the website of Bioversity International


This research is part of the CGIAR Research Program on Forests, Trees and Agroforestry and is supported by CGIAR Fund Donors.

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  • Celebrating and rewarding excellence in producing high-quality cocoa: The 2017 International Cocoa Award winners

Celebrating and rewarding excellence in producing high-quality cocoa: The 2017 International Cocoa Award winners

Cacao pods lie on the ground after harvesting. Photo by J. Raneri/Bioversity International
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FTA COMMUNICATIONS TEAM

Cacao pods lie on the ground after harvesting. Photo by J. Raneri/Bioversity International

As the only event in the world celebrating the work of producers and the richness of expression of cocoa, a unique cocoa initiative is helping to further mutual awareness and reinforce collaborations between producers and chocolate makers.

Every two years, the Cocoa of Excellence Programme spearheaded by Bioversity International and Event International recognizes the quality, flavor and diversity of cocoas according to their origin, with the participation of countries that can directly present the fruits of their labors to chocolate makers and the press.

The Cocoa of Excellence Programme is the entry point for the International Cocoa Awards (ICA). It aims to increase awareness and promote education along the cocoa supply chain on the opportunity to produce high quality cocoa and preserve flavors resulting from genetic diversity, terroir and know-how of the farmers who prepare cocoa.

Cacao diversity is also vital for production, as it provides not only different flavors, but also resistance to pests and disease outbreaks, and resilience in changing climatic conditions. Providing opportunities and incentives for safeguarding diversity to farmers and national organizations ensures that a portfolio of options remain available for future needs.

Celebrating the shortlisted entrants at the 2017 International Cocoa Awards at the Salon du Chocolat. Photo by Bioversity International

Following the selection and evaluation of 166 cocoa samples submitted from 40 countries, the wait was finally over on Oct. 30, 2017, for the 50 entrants shortlisted for the 2017 Edition of the ICA. The 18 ICA winners were celebrated at the Salon du Chocolat in Paris, shining an international spotlight on the work of cocoa farmers and cocoa diversity around the world.

“It is the highest reward for the Salon du Chocolat to be with Bioversity International at the origin of this unique program that gathered so many great and indisputable international experts in the world of cacao. Our initial wish was to create a direct link between chocolate makers and producers for reciprocal enrichment, in the qualitative aspects of chocolate and cocoa with all the benefits they entail,” said Francois Jeantet, Creator of the Salon du Chocolat.

“Today our wishes are fulfilled. A big thank you to all the team and all those that participate with passion,” he added.

“The program facilitates communication and linkages between the producers of this wonderful crop that is cocoa that delights the bean buyers and chocolate makers. This communication needs to be standardized so that all the actors along the value chain understand each other, from the farmers to the chocolate makers,” explained Brigitte Laliberté, Expert on Cacao Genetic Resources at Bioversity International.

“We are coordinating an effort on the development of international standards for the assessment of cocoa quality and flavor, for which we convened a consultation at the Salon just this morning,” Laliberté continued. “The meeting led to some very exciting group decisions and innovations in this important area.”

The Cocoa of Excellence Programme is the entry point for the International Cocoa Awards.

After a physical quality evaluation, the beans were carefully processed into liquor and untempered chocolate for blind sensory evaluation by a panel of international experts who are part of the Cocoa of Excellence Technical Committee.

Following the evaluation, the best 50 samples were selected and processed into tempered and molded chocolate (following the same recipe of 66 percent cocoa) for sensory evaluation by a broader panel of 41 chocolate professionals.

“Never before has there been such an assemblage of superb cocoas as we have had expressed as chocolates in these 2017 Edition of Cocoa of Excellence. The flavor evaluation has been both daunting as well as exhilarating. There is more outstanding flavor and diversity from more countries than ever before. The Technical Committee and the additional jury have performed superbly,” said Ed Seguine, Cacao Cocoa and Chocolate Advisors/Guittard Chocolate.

“We continue to believe that the Cocoa of Excellence as well as the International Cocoa Awards will shine the spotlight of flavors, craftsmanship and diversity on these farmers and bring real, meaningful value to them for their beans,” he added.

The 18 International Cocoa Awards for 2017 are:

Africa & the Indian Ocean

  • Ghana Simon Marfo – associated with Cocoa Abrabopa Association
  • Madagascar Mava Sa – Ferme D’ottange
  • Sierra Leone Sahr Bangura – associated with Kasiyatama
  • Tanzania Kokoa Kamili Limited

Asia, Pacific & Australia

  • Australia Australian Chocolate Pty Ltd
  • Hawaii Jeanne Bennett and Bruce Clements – Nine Fine Mynahs Estates
  • Hawaii University of Hawaii
  • India Regal plantations
  • Malaysia Teo Chun Hoon

Central America & Caribbean

  • Dominica Stewart Paris – Paris Family – associated with North East Cocoa Growers Cooperative
  • El Salvador José Eduardo Zacapa Campos
  • Guatemala Asociación Waxaquib Tzikin
  • Guatemala Mariel Ponce – Kacaou
  • Martinique Kora Bernabe and Elizabeth Pierre-Louis – associated with Valcaco – Association des Producteurs de Cacao de Martinique

South America

  • Bolivia Chocoleco
  • Brazil Emir De Macedo Gomes Filho
  • Ecuador Asociacion Quiroga
  • Peru Cooperativa Agraria APPROCAP Ltda.

Adapted from the press release originally published by Bioversity International. For more information, contact Ines Drouault at the Cocoa of Excellence Programme: i.drouault(at)cgiar.org.


The Cocoa of Excellence (CoEx) Programme is the entry point for cocoa-producers to participate in the International Cocoa Awards (ICA). The programme is coordinated by Bioversity International, and jointly organized with Event International in partnership with the CGIAR Research Program on Forests, Trees and Agroforestry (FTA), Guittard Chocolate, Seguine Cacao, Cocoa and Chocolate, Barry Callebaut, Puratos and the International Cocoa Organization (ICCO) with sponsorship from the European Cocoa Association (ECA), the Association of Chocolate, Biscuit and Confectionery Industries of Europe (Caobisco), the Federation of Cocoa Commerce (FCC), Nestlé, the Lutheran World Relief (LWR), Mars UK, Valrhona and with in-kind contributions from the Cocoa Research Centre of the University of the West Indies (CRC/UWI), Valrhona, Weiss Chocolate and CocoaTown.

This work contributes to the CGIAR Research Program on Forests for Trees and Agroforestry, supported by CGIAR Fund Donors.

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  • Celebrating and rewarding excellence in producing high-quality cocoa: The 2017 International Cocoa Award winners

Celebrating and rewarding excellence in producing high-quality cocoa: The 2017 International Cocoa Award winners

Cacao pods lie on the ground after harvesting. Photo by J. Raneri/Bioversity International
Posted by

FTA COMMUNICATIONS TEAM

Cacao pods lie on the ground after harvesting. Photo by J. Raneri/Bioversity International

As the only event in the world celebrating the work of producers and the richness of expression of cocoa, a unique cocoa initiative is helping to further mutual awareness and reinforce collaborations between producers and chocolate makers.

Every two years, the Cocoa of Excellence Programme spearheaded by Bioversity International and Event International recognizes the quality, flavor and diversity of cocoas according to their origin, with the participation of countries that can directly present the fruits of their labors to chocolate makers and the press.

The Cocoa of Excellence Programme is the entry point for the International Cocoa Awards (ICA). It aims to increase awareness and promote education along the cocoa supply chain on the opportunity to produce high quality cocoa and preserve flavors resulting from genetic diversity, terroir and know-how of the farmers who prepare cocoa.

Cacao diversity is also vital for production, as it provides not only different flavors, but also resistance to pests and disease outbreaks, and resilience in changing climatic conditions. Providing opportunities and incentives for safeguarding diversity to farmers and national organizations ensures that a portfolio of options remain available for future needs.

Celebrating the shortlisted entrants at the 2017 International Cocoa Awards at the Salon du Chocolat. Photo by Bioversity International

Following the selection and evaluation of 166 cocoa samples submitted from 40 countries, the wait was finally over on Oct. 30, 2017, for the 50 entrants shortlisted for the 2017 Edition of the ICA. The 18 ICA winners were celebrated at the Salon du Chocolat in Paris, shining an international spotlight on the work of cocoa farmers and cocoa diversity around the world.

“It is the highest reward for the Salon du Chocolat to be with Bioversity International at the origin of this unique program that gathered so many great and indisputable international experts in the world of cacao. Our initial wish was to create a direct link between chocolate makers and producers for reciprocal enrichment, in the qualitative aspects of chocolate and cocoa with all the benefits they entail,” said Francois Jeantet, Creator of the Salon du Chocolat.

“Today our wishes are fulfilled. A big thank you to all the team and all those that participate with passion,” he added.

“The program facilitates communication and linkages between the producers of this wonderful crop that is cocoa that delights the bean buyers and chocolate makers. This communication needs to be standardized so that all the actors along the value chain understand each other, from the farmers to the chocolate makers,” explained Brigitte Laliberté, Expert on Cacao Genetic Resources at Bioversity International.

“We are coordinating an effort on the development of international standards for the assessment of cocoa quality and flavor, for which we convened a consultation at the Salon just this morning,” Laliberté continued. “The meeting led to some very exciting group decisions and innovations in this important area.”

The Cocoa of Excellence Programme is the entry point for the International Cocoa Awards.

After a physical quality evaluation, the beans were carefully processed into liquor and untempered chocolate for blind sensory evaluation by a panel of international experts who are part of the Cocoa of Excellence Technical Committee.

Following the evaluation, the best 50 samples were selected and processed into tempered and molded chocolate (following the same recipe of 66 percent cocoa) for sensory evaluation by a broader panel of 41 chocolate professionals.

“Never before has there been such an assemblage of superb cocoas as we have had expressed as chocolates in these 2017 Edition of Cocoa of Excellence. The flavor evaluation has been both daunting as well as exhilarating. There is more outstanding flavor and diversity from more countries than ever before. The Technical Committee and the additional jury have performed superbly,” said Ed Seguine, Cacao Cocoa and Chocolate Advisors/Guittard Chocolate.

“We continue to believe that the Cocoa of Excellence as well as the International Cocoa Awards will shine the spotlight of flavors, craftsmanship and diversity on these farmers and bring real, meaningful value to them for their beans,” he added.

The 18 International Cocoa Awards for 2017 are:

Africa & the Indian Ocean

  • Ghana Simon Marfo – associated with Cocoa Abrabopa Association
  • Madagascar Mava Sa – Ferme D’ottange
  • Sierra Leone Sahr Bangura – associated with Kasiyatama
  • Tanzania Kokoa Kamili Limited

Asia, Pacific & Australia

  • Australia Australian Chocolate Pty Ltd
  • Hawaii Jeanne Bennett and Bruce Clements – Nine Fine Mynahs Estates
  • Hawaii University of Hawaii
  • India Regal plantations
  • Malaysia Teo Chun Hoon

Central America & Caribbean

  • Dominica Stewart Paris – Paris Family – associated with North East Cocoa Growers Cooperative
  • El Salvador José Eduardo Zacapa Campos
  • Guatemala Asociación Waxaquib Tzikin
  • Guatemala Mariel Ponce – Kacaou
  • Martinique Kora Bernabe and Elizabeth Pierre-Louis – associated with Valcaco – Association des Producteurs de Cacao de Martinique

South America

  • Bolivia Chocoleco
  • Brazil Emir De Macedo Gomes Filho
  • Ecuador Asociacion Quiroga
  • Peru Cooperativa Agraria APPROCAP Ltda.

Adapted from the press release originally published by Bioversity International. For more information, contact Ines Drouault at the Cocoa of Excellence Programme: i.drouault(at)cgiar.org.


The Cocoa of Excellence (CoEx) Programme is the entry point for cocoa-producers to participate in the International Cocoa Awards (ICA). The programme is coordinated by Bioversity International, and jointly organized with Event International in partnership with the CGIAR Research Program on Forests, Trees and Agroforestry (FTA), Guittard Chocolate, Seguine Cacao, Cocoa and Chocolate, Barry Callebaut, Puratos and the International Cocoa Organization (ICCO) with sponsorship from the European Cocoa Association (ECA), the Association of Chocolate, Biscuit and Confectionery Industries of Europe (Caobisco), the Federation of Cocoa Commerce (FCC), Nestlé, the Lutheran World Relief (LWR), Mars UK, Valrhona and with in-kind contributions from the Cocoa Research Centre of the University of the West Indies (CRC/UWI), Valrhona, Weiss Chocolate and CocoaTown.

This work contributes to the CGIAR Research Program on Forests for Trees and Agroforestry, supported by CGIAR Fund Donors.

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  • A review of research on the effects of drought and temperature stress and increased CO2 on Theobroma cacao L., and the role of genetic diversity to address climate change

A review of research on the effects of drought and temperature stress and increased CO2 on Theobroma cacao L., and the role of genetic diversity to address climate change

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FTA COMMUNICATIONS TEAM

The global status of research on the effects of drought, temperature and elevated carbon dioxide (CO2) levels on the cacao plant, and the role of genetic diversity in producing more resilient cacao, are presented in this report. With the aim to enhance what we know about the resilience of cacao to climate change, and generate a comprehensive understanding of the questions that remain, this report highlights significant advances in published and ongoing research on drought and temperature tolerance in cacao.

Most of the information about ongoing or unpublished work was obtained from personal communications and surveys involving research institutes around the globe. Organizations were selected to participate in the survey based on their presence in the relevant literature, referrals from other organizations, or personal communications from individuals attesting to their involvement in research related to drought and temperature tolerance, or increased CO2 response, in cacao. A vast network of public and private sector partners including research institutes, producer organizations, and industry representatives around the world participated and were involved to collect additional information on unpublished and on-going research work in this area.

Over 100 scientists from 50 institutes across 29 countries participated. Additional information was gathered from personal communications, surveys carried out in collaboration with WCF and its USAID-supported Feed the Future Partnership for the Climate-Smart Cocoa Program, the Global Network for Cacao Genetic Resources (CacaoNet), the International Network for Cacao Genetic Improvement (INGENIC), the Regional Breeders Working Groups, and the research team on cacao and climate change at the University of Reading, UK. Fundamentally, the literature compiled in this report serves as a basis to understand the questions that still remain regarding cacao’s responses to abiotic stresses, highlight the resources that are available to answer them, and identify synergies and complementarities.

The report also helps to identify key research questions and partners for the development of a proposal for an international/multi-institutional research programme, to be implemented over the next three to five years, as part of the Collaborative Framework for Cacao Evaluation (CFCE). Although future climatic predictions are worrisome, the genetic materials held within national and international collections offer much potential in the development of improved planting material. The objective of the report is to gather as much information as possible, so that we can aim to maximize the resilience of cacao through the discovery and use of improved planting material, in combination with improved management practices.

The authors express gratitude to all of those who provided details of thier research on cacao genetic resources and abiotic stress and acknowledge financial support of WCF and its Feed the Future Partnership for Climate Smart Cocoa, through a grant to Bioversity International from USDA-FAS, the ECA/CAOBISCO/FCC Joint Working Group on Cocoa Quality and Productivity; and the CGIAR Research Program on Forests, Trees and Agroforestry (FTA).

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  • Fruit tree genetic diversity in Central Asia: a spatial threat analysis

Fruit tree genetic diversity in Central Asia: a spatial threat analysis

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FTA COMMUNICATIONS TEAM

Our spatial analysis framework aims to predict, at the population level, where multiple threats (overexploitation, overgrazing, landslides, fragmentation and predicted climate change), superimposed on patterns of genetic and nutritional diversity, are likely to have negative impact on important indigenous fruit and nut tree species.

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  • Relationships between population density, fine-scale genetic structure, mating system and pollen dispersal in a timber tree from African rainforest

Relationships between population density, fine-scale genetic structure, mating system and pollen dispersal in a timber tree from African rainforest

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FTA

Also published at Bioversity International

Authors: Duminil, J.; Dainou, K.; Kaviriri, D.K.; Gillet, P.; Loo, J.; Doucet, J.L.; Hardy, O.J.

The reproductive biology and genetic diversity of trees in the Congo Basin don’t seem to be affected by current logging practices. However, researcher recommend further investigations in low-density populations to evaluate (1) whether pollen limitation may reduce seed production and (2) the regeneration potential of the species.

This is the result from a study of genetic diversity, mating system and gene flow in three Central African populations of the self-compatible legume timber species Erythrophleum suaveolens with contrasting densities (0.11, 0.68 and 1.72 adults per ha).

Comparing reproductive biology processes and genetic diversity of populations at different densities can provide indirect evidence of the potential impacts of logging.

Selective logging could affect the demography, reproductive biology and evolutionary potential of forest trees. This is particularly relevant in tropical forests where natural population densities can be low and isolated trees may be subject to outcross pollen limitation and/or produce low-quality selfed seeds that exhibit inbreeding depression.

Researchers found that inbred individuals are eliminated between seedling and adult stages. Levels of genetic diversity, selfing rates (~16%) and patterns of spatial genetic structure (Sp ~0.006) were similar in all three populations.

However, the extent of gene dispersal differed markedly among populations: the average distance of pollen dispersal increased with decreasing density (from 200 m in the high-density population to 1000 m in the low-density one). In other words, at lower population densities, trees are still connected as a result of larger pollen dispersal distances.

The study was conducted by Bioversity International, the Université Libre de Bruxelles, Brussels, Belgium; Université de Liège, Gembloux, Belgium; Nature+ asbl, Wavre, Belgium; Université de Kisangani, Kisangani, Democratic Republic of Congo.


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