Cacao flower visitation: Low pollen deposition, low fruit set and dominance of herbivores

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 pollen deposition in limiting fruit set. Here, we aimed to improve understanding of cacao pollination by studying limiting factors of fruit set in Peru, part of the centre of origin of cacao. Flower visitors were sampled with sticky insect glue in 20 cacao agroforests in two biogeographically distinct regions of Peru, across gradients of shade cover and forest distance. Further, we assessed pollen quantities and compared fruit set between naturally and manually pollinated flowers. The most abundant flower visitors were aphids, ants and thrips in the north and thrips, midges and parasitoid wasps in the south of Peru. We present some evidence of increasing visitation rates from medium to high shade (40%–95% canopy closure) in the dry north, and opposite patterns in the semi-humid south, during the wet season. Natural pollination resulted in remarkably low fruit set rates (2%), and very low pollen deposition. After hand pollination, fruit set more than tripled (7%), but was still low. The diversity and high relative abundances of herbivore flower visitors limit our ability to draw conclusions on the functional role of different flower visitors. The remarkably low fruit set of naturally and even hand pollinated flowers indicates that other unaddressed factors limit cacao fruit production. Such factors could be, amongst others, a lack of effective pollinators, genetic incompatibility or resource limitation. Revealing efficient pollinator species and other causes of low fruit set rates is therefore key to establish location-specific management strategies and develop high yielding native cacao agroforestry systems in regions of origin of cacao. © 2022 The Authors. Ecological Solutions and Evidence published by John Wiley & Sons Ltd on behalf of British Ecological Society

Efectos del cambio climático en la distribución de 20 especies de aves de la región amazónica del Perú

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, se colectaron los puntos de presencia de todas las especies de aves en la Amazonía peruana según eBird/Clements Checklist (Clements et al., 2019). Los puntos de presencia fueron obtenidos de las siguientes bases de datos: GBIF (Global Biodiversity Information Facility; www.gbif.org), e Inventario Nacional Forestal y de Fauna Silvestre del SERFOR. Luego de colectar los datos, se procedió con la selección de las especies para el modelamiento de acuerdo a los siguientes criterios: (i) que las especies estén amenazadas según el Libro Rojo de la Fauna Silvestre Amenazada del Perú (SERFOR, 2018), (ii) que existan como mínimo 15 puntos de presencia, y (iii) que por lo menos la mitad de los puntos de presencia se encuentren ubicados en la Amazonía. Las siguientes 20 especies cumplieron los criterios y fueron utilizadas para el modelamiento

Socio-ecological benefits of fine-flavor cacao in its center of origin

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 region, interest is growing to achieve premium prices with the conversion of high-yielding, but mostly bulk-quality cacao to native fine-flavor cacao varieties, culturally important since pre-Columbian times. Conversion to native cacao can be expected to favor adaptation to regional climate and growth conditions, and to enhance native biodiversity and ecosystem services such as biological pest control and pollination, but possibly also imply susceptibility to diseases. Experience from successful conversion of non native cacao plantations to fine-flavor cacao agroforestry with rejuvenation by grafting and under medium-canopy cover levels (30%–40%) can ensure a smooth transition with only minor temporary productivity gaps. This includes ongoing selection programs of high yielding and disease resistant native fine-flavor cacao genotypes and organizing in cooperatives to buffer the high market volatility. In conclusion, the recent interest on converting bulk cacao to a diversity of native fine-flavor varieties in countries like Peru is a challenge, but offers promising socio-ecological perspectives

Birds and bats enhance cacao yield despite suppressing arthropod mesopredation

Bird- and bat-mediated biocontrol benefits the productivity of tropicalcommodity crops such as cacao, but the ecological interactions drivingthese ecosystem services remain poorly understood. Whereas birds and batsprey on herbivorous arthropods, they may also prey on arthropodmesopredators such as ants, with poorly understood consequences for pestbiocontrol. We used a full-factorial experiment excluding birds, bats, andants to assess their effects on (a) the abundanceof multiple arthropodgroups; (b) predation pressure on arthropods evaluated through artificialsentinel caterpillars; and (c) cacao yield over 1 year in shaded agroforestrysystems of native cacao varieties in Peru. Birds and bats increasedcacao yield by 118%, which translates in smallholder benefits of ca.US $959 ha−1year−1. Birds and bats decreased predation by ants and otherarthropods, but contributed to thecontrol of phytophagous taxa such asaphids and mealybugs. By contrast, ant presence increased the abundanceof these sap-sucking insects, with negative impacts for cacao yield.Notably, high abundances of the dominant antNylanderiasp., known toattend sap-sucking insects, were associated with lower cacao yield along adistance gradient from the closest forest edge. According to these results,arthropod predation by birds and bats, rather than mesopredation byarthropods, was most responsible forincreases in cacao yield. Moving for-ward, detailed research about their trophic interactions will be necessary toidentify the cause of such benefits. Retaining and restoring the large bene-fits of birds and bats as well as minimizing disservices by other taxa incacao agroforests can benefit from management schemes that prioritizepreservation of shade trees and adjacent forests within agroforestrylandscapes

Quantifying services and disservices provided by insects and vertebrates in cacao agroforestry landscapes

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 exper- iment in northwestern Peru, we excluded flying insects, ants, birds and bats from cacao trees and assessed several productivity indicators. We quan- tified the contribution of each group to fruit set, fruit loss and marketable yield and evaluated how forest distance and canopy closure affected pro- ductivity. Fruit set dropped (from 1.7% to 0.3%) when flying insects were excluded and tripled at intermediate (40%) compared to high (greater than 80%) canopy cover in the non-exclusion treatment. Fruit set also dropped with bird and bat exclusion, potentially due to increased abundances of arthropods preying on pollinators or flower herbivores. Overall, cacao yields more than doubled when birds and bats had access to trees. Ants were generally associated with fruit loss, but also with yield increases in agroforests close to forest. We also evidenced disservices generated by squir- rels, leading to significant fruit losses. Our findings show that several functional groups contribute to high cacao yield, while trade-offs between services and disservices need to be integrated in local and landscape-scale sustainable cacao agroforestry managemen

Global South leadership towards inclusive tropical ecology and conservation

Strengthening participation of Global South researchers in tropical ecology and conservation is a target of our scientific community, but strategies for fostering increased engagement are mostly directed at Global North institutions and researchers. Whereas such approaches are crucial, there are unique challenges to addressing diversity, equity and inclusion (DEI) within the Global South given its socio-economic, cultural and scientific contexts. Sustainable solutions protecting biodiversity in the tropics depend on the leadership of Global South communities, and therefore DEI improvements in the Global South are paramount in our field. Here, we propose ten key actions towards equitable international collaborations in tropical ecology, which, led by Global South researchers, may improve DEI at institutional, national and international levels. At an institutional level, we recommend (1) becoming role models for DEI, (2) co-developing research with local stakeholders, and (3) promoting transparent funding management favouring local scientists. At a national level, we encourage (4) engagement in political actions protecting scientists and their research in tropical countries, (5) participation in improving biodiversity research policies, and (6) devising research that reaches society. At an international level, we encourage Global South researchers in international collaborations to (7) lead and direct funding applications, (8) ensure equitable workloads, and (9) procure equal benefits among national and foreign collaborators. Finally, (10) we propose that Global South leadership in DEI efforts has the most potential for worldwide improvements, supporting positive long-lasting changes in our entire scientific community. Supplementary materials provide this abstract in 18 other languages spoken in the Global South

Occurrence thresholds of African ant-following birds in an agroforestry mosaic = Umbrales de extinción de aves africanas seguidoras de hormigas en un mosaico agroforestal

A review of the main issues that affect the livelihoods of non timber forest products (NTFP) focusing on the commercialisation issues of gatherers/producers and traders, was made for Colombia. It aimed to investigate broadly which are some of the cultural, economic, social, environmental, marketing and legislative issues that affect the outcomes for NTFP livelihoods. The sustainable rural livelihood framework was used to understand the main issues affecting NTFP livelihoods and to propose alternatives to improve the constraints found in NTFP development and commercialisation. The study identify the great importance of NTFP local and regional markets for rural development, and some data was given for international markets in order to understand the magnitude of the commerce and the possibilities that might arise for some promissory products. The review of some institutional and organisation incentives influencing NTFP production and commercialisation was undertaken by reviewing the forestry policies and some of its instruments. The study used secondary data of reports made mainly in Latin-America. The report concludes that the policies and norms that influence NTFP, such as the forestry policy and plans do not consider the importance of NTFP for social and environmental objectives. For NTFP research, the analysis of the commercialisation process is strongly co-related to social networks, ecology, cultural taboos, norms for management of NTFP and effectiveness of support organisations. NTFP livelihoods can be seriously affected by government organisations and NGO’s if they are treated as traditional commodities because of the fragility and uniqueness of their ecology, economy and social structures. The report gives some recommendations to government agencies and researchers that wish to mend the constraints found for NTFP successful development