Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Disentangling the genetics of lean mass
Karasik, David ; Zillikens, M.C. ; Hsu, Yi Hsiang ; Aghdassi, Ali ; Akesson, Kristina ; Amin, Najaf ; Barroso, Inês ; Bennett, David A. ; Bertram, Lars ; Bochud, Murielle ; Borecki, Ingrid B. ; Broer, Linda ; Buchman, Aron S. ; Byberg, Liisa ; Campbell, Harry ; Campos-Obando, Natalia ; Cauley, Jane A. ; Cawthon, Peggy M. ; Chambers, John C. ; Chen, Zhao ; Cho, Nam H. ; Choi, Hyung Jin ; Chou, Wen Chi ; Cummings, Steven R. ; Groot, Lisette C.P.G.M. De; Jager, Phillip L. De; Demuth, Ilja ; Diatchenko, Luda ; Econs, Michael J. ; Eiriksdottir, Gudny ; Enneman, Anke W. ; Eriksson, Joel ; Eriksson, Johan G. ; Estrada, Karol ; Evans, Daniel S. ; Feitosa, Mary F. ; Fu, Mao ; Gieger, Christian ; Grallert, Harald ; Gudnason, Vilmundur ; Lenore, Launer J. ; Hayward, Caroline ; Hofman, Albert ; Homuth, Georg ; Huffman, Kim M. ; Husted, Lise B. ; Illig, Thomas ; Ingelsson, Erik ; Ittermann, Till ; Jansson, John Olov ; Johnson, Toby ; Biffar, Reiner ; Jordan, Joanne M. ; Jula, Antti ; Karlsson, Magnus ; Khaw, Kay Tee ; Kilpeläinen, Tuomas O. ; Klopp, Norman ; Kloth, Jacqueline S.L. ; Koller, Daniel L. ; Kooner, Jaspal S. ; Kraus, William E. ; Kritchevsky, Stephen ; Kutalik, Zoltán ; Kuulasmaa, Teemu ; Kuusisto, Johanna ; Laakso, Markku ; Lahti, Jari ; Lang, Thomas ; Langdahl, Bente L. ; Lerch, Markus M. ; Lewis, Joshua R. ; Lill, Christina ; Lind, Lars ; Lindgren, Cecilia ; Liu, Yongmei ; Livshits, Gregory ; Ljunggren, Östen ; Loos, Ruth J.F. ; Lorentzon, Mattias ; Luan, Jian An ; Luben, Robert N. ; Malkin, Ida ; McGuigan, Fiona E. ; Medina-Gomez, Carolina ; Meitinger, Thomas ; Melhus, Håkan ; Mellström, Dan ; Michaëlsson, Karl ; Mitchell, Braxton D. ; Morris, Andrew P. ; Mosekilde, Leif ; Nethander, Maria ; Newman, Anne B. ; Oconnell, Jeffery R. ; Oostra, Ben A. ; Orwoll, Eric S. ; Palotie, Aarno ; Peacock, Munro ; Perola, Markus ; Peters, Annette ; Prince, Richard L. ; Psaty, Bruce M. ; Räikkönen, Katri ; Ralston, Stuart H. ; Ripatti, Samuli ; Rivadeneira, Fernando ; Robbins, John A. ; Rotter, Jerome I. ; Rudan, Igor ; Salomaa, Veikko ; Satterfield, Suzanne ; Schipf, Sabine ; Shin, Chan Soo ; Smith, Albert V. ; Smith, Shad B. ; Soranzo, Nicole ; Spector, Timothy D. ; StanÄ Áková, Alena ; Stefansson, Kari ; Steinhagen-Thiessen, Elisabeth ; Stolk, Lisette ; Streeten, Elizabeth A. ; Styrkarsdottir, Unnur ; Swart, Karin M.A. ; Thompson, Patricia ; Thomson, Cynthia A. ; Thorleifsson, Gudmar ; Thorsteinsdottir, Unnur ; Tikkanen, Emmi ; Tranah, Gregory J. ; Uitterlinden, André G. ; Duijn, Cornelia M. Van; Schoor, Natasja M. Van; Vandenput, Liesbeth ; Vollenweider, Peter ; Völzke, Henry ; Wactawski-Wende, Jean ; Walker, Mark ; J Wareham, Nicholas ; Waterworth, Dawn ; Weedon, Michael N. ; Wichmann, H.E. ; Widen, Elisabeth ; Williams, Frances M.K. ; Wilson, James F. ; Wright, Nicole C. ; Yerges-Armstrong, Laura M. ; Yu, Lei ; Zhang, Weihua ; Zhao, Jing Hua ; Zhou, Yanhua ; Nielson, Carrie M. ; Harris, Tamara B. ; Demissie, Serkalem ; Kiel, Douglas P. ; Ohlsson, Claes - \ 2019
American Journal of Clinical Nutrition 109 (2019)2. - ISSN 0002-9165 - p. 276 - 278.
body composition - body fat - meta-Analysis of genome-wide association studies - metabolic profile - skeletal muscle

Background Lean body mass (LM) plays an important role in mobility and metabolic function. We previously identified five loci associated with LM adjusted for fat mass in kilograms. Such an adjustment may reduce the power to identify genetic signals having an association with both lean mass and fat mass. Objectives To determine the impact of different fat mass adjustments on genetic architecture of LM and identify additional LM loci. Methods We performed genome-wide association analyses for whole-body LM (20 cohorts of European ancestry with n = 38,292) measured using dual-energy X-ray absorptiometry) or bioelectrical impedance analysis, adjusted for sex, age, age 2, and height with or without fat mass adjustments (Model 1 no fat adjustment; Model 2 adjustment for fat mass as a percentage of body mass; Model 3 adjustment for fat mass in kilograms). Results Seven single-nucleotide polymorphisms (SNPs) in separate loci, including one novel LM locus (TNRC6B), were successfully replicated in an additional 47,227 individuals from 29 cohorts. Based on the strengths of the associations in Model 1 vs Model 3, we divided the LM loci into those with an effect on both lean mass and fat mass in the same direction and refer to those as "sumo wrestler" loci (FTO and MC4R). In contrast, loci with an impact specifically on LM were termed "body builder" loci (VCAN and ADAMTSL3). Using existing available genome-wide association study databases, LM increasing alleles of SNPs in sumo wrestler loci were associated with an adverse metabolic profile, whereas LM increasing alleles of SNPs in "body builder" loci were associated with metabolic protection. Conclusions In conclusion, we identified one novel LM locus (TNRC6B). Our results suggest that a genetically determined increase in lean mass might exert either harmful or protective effects on metabolic traits, depending on its relation to fat mass.

Using agent-based modelling to simulate social-ecological systems across scales
Lippe, Melvin ; Bithell, Mike ; Gotts, Nick ; Natalini, Davide ; Barbrook-Johnson, Peter ; Giupponi, Carlo ; Hallier, Mareen ; Hofstede, Gert Jan ; Page, Christophe Le; Matthews, Robin B. ; Schlüter, Maja ; Smith, Peter ; Teglio, Andrea ; Thellmann, Kevin - \ 2019
Geoinformatica : an international journal on advances of computer science for geographic information systems 23 (2019)7. - ISSN 1384-6175 - p. 269 - 298.
ABM - Agent-based modelling - Cross-scale - SESs - Social-ecological systems

Agent-based modelling (ABM) simulates Social-Ecological-Systems (SESs) based on the decision-making and actions of individual actors or actor groups, their interactions with each other, and with ecosystems. Many ABM studies have focused at the scale of villages, rural landscapes, towns or cities. When considering a geographical, spatially-explicit domain, current ABM architecture is generally not easily translatable to a regional or global context, nor does it acknowledge SESs interactions across scales sufficiently; the model extent is usually determined by pragmatic considerations, which may well cut across dynamical boundaries. With a few exceptions, the internal structure of governments is not included when representing them as agents. This is partly due to the lack of theory about how to represent such as actors, and because they are not static over the time-scales typical for social changes to have significant effects. Moreover, the relevant scale of analysis is often not known a priori, being dynamically determined, and may itself vary with time and circumstances. There is a need for ABM to cross the gap between micro-scale actors and larger-scale environmental, infrastructural and political systems in a way that allows realistic spatial and temporal phenomena to emerge; this is vital for models to be useful for policy analysis in an era when global crises can be triggered by small numbers of micro-level actors. We aim with this thought-piece to suggest conceptual avenues for implementing ABM to simulate SESs across scales, and for using big data from social surveys, remote sensing or other sources for this purpose.

Responses of forest ecosystems in Europe to decreasing nitrogen deposition
Schmitz, Andreas ; Sanders, Tanja G.M. ; Bolte, Andreas ; Bussotti, Filippo ; Dirnböck, Thomas ; Johnson, Jim ; Peñuelas, Josep ; Pollastrini, Martina ; Prescher, Anne Katrin ; Sardans, Jordi ; Verstraeten, Arne ; Vries, Wim de - \ 2019
Environmental Pollution 244 (2019). - ISSN 0269-7491 - p. 980 - 994.
Air pollution - Emission reduction - Forest monitoring - Nitrogen deposition - Recovery

Average nitrogen (N) deposition across Europe has declined since the 1990s. This resulted in decreased N inputs to forest ecosystems especially in Central and Western Europe where deposition levels are highest. While the impact of atmospheric N deposition on forests has been receiving much attention for decades, ecosystem responses to the decline in N inputs received less attention. Here, we review observational studies reporting on trends in a number of indicators: soil acidification and eutrophication, understory vegetation, tree nutrition (foliar element concentrations) as well as tree vitality and growth in response to decreasing N deposition across Europe. Ecosystem responses varied with limited decrease in soil solution nitrate concentrations and potentially also foliar N concentrations. There was no large-scale response in understory vegetation, tree growth, or vitality. Experimental studies support the observation of a more distinct reaction of soil solution and foliar element concentrations to changes in N supply compared to the three other parameters. According to the most likely scenarios, further decrease of N deposition will be limited. We hypothesize that this expected decline will not cause major responses of the parameters analysed in this study. Instead, future changes might be more strongly controlled by the development of N pools accumulated within forest soils, affected by climate change and forest management. We find limited indication for response of Europe's forests to declining N deposition. Reactions have been reported for soil solution NO3 and potentially foliar N concentrations but not for other indicators.

Roots, Tubers and Bananas: Contributions to Food Security
Kennedy, G. ; Raneri, Jessica ; Stoian, Dietmar ; Attwood, S. ; Burgos, Gabriela ; Ceballos, Herman ; Ekesa, Beatrice ; Johnson, V. ; Low, Jan W. ; Talsma, E.F. - \ 2019
In: Encyclopedia of Food Security and Sustainability / Ferranti, Pasquale, Anderson, Jack R., Berry, Elliot M., Elsevier - ISBN 9780128126882 - p. 231 - 256.
The class of root, tuber and banana (RTB) crops encompasses banana and plantain, cassava, potato, sweet potato, taro, yam and a number of lesser cultivated and consumed root and tuber crops. RTB are the second most important group of crops in LDCs after cereals. RTB are vital for food security, with parts of sub-Saharan Africa, Asia and Latin America relying on RTB as main staple foods in their diets. They provide up to 15% or more of the daily per capita dietary energy for the 763 million people living in the least developed countries. Production, yield and area planted for most RTB are showing increasing trends. While most RTB are used for food, feed and biofuel uses are growing. With vast genetic diversity RTB play an important role in the food systems of countries worldwide. The CGIAR has been actively working within this genetic diversity to improve the nutritional content of some RTB. Most notably varieties of banana, cassava and sweet potato have been successfully identified for higher pro-vitamin A content, while potatoes with higher iron and zinc content are also available. The use of varieties with higher pro-vitamin A, iron and zinc will contribute to reductions in micronutrient deficiencies. Many of the leaves of RTB, most notably cassava and sweet potato are also consumed, sometimes in large amounts and contribute to both diversity of the diet as well as increased intake of essential micronutrients. Threats from pests and disease to which these crops are susceptible are among the largest concerns. The impact of changing climate on resistance to disease/pest threats as well as yield and longer-term sustainability issues is also of concern. Finally, greater research and development on propagation and post-harvest storage and processing is needed for some of the lesser RTB crops.
A protocol for an intercomparison of biodiversity and ecosystem services models using harmonized land-use and climate scenarios
Kim, Hyejin ; Rosa, Isabel M.D. ; Alkemade, Rob ; Leadley, Paul ; Hurtt, George ; Popp, Alexander ; Vuuren, Detlef P. van; Anthoni, Peter ; Arneth, Almut ; Baisero, Daniele ; Caton, Emma ; Chaplin-Kramer, Rebecca ; Chini, Louise ; Palma, Adriana De; Fulvio, Fulvio Di; Marco, Moreno Di; Espinoza, Felipe ; Ferrier, Simon ; Fujimori, Shinichiro ; Gonzalez, Ricardo E. ; Gueguen, Maya ; Guerra, Carlos ; Harfoot, Mike ; Harwood, Thomas D. ; Hasegawa, Tomoko ; Haverd, Vanessa ; Havlík, Petr ; Hellweg, Stefanie ; Hill, Samantha L.L. ; Hirata, Akiko ; Hoskins, Andrew J. ; Janse, Jan H. ; Jetz, Walter ; Johnson, Justin A. ; Krause, Andreas ; Leclère, David ; Martins, Ines S. ; Matsui, Tetsuya ; Merow, Cory ; Obersteiner, Michael ; Ohashi, Haruka ; Poulter, Benjamin ; Purvis, Andy ; Quesada, Benjamin ; Rondinini, Carlo ; Schipper, Aafke M. ; Sharp, Richard ; Takahashi, Kiyoshi ; Thuiller, Wilfried ; Titeux, Nicolas - \ 2018
Geoscientific Model Development 11 (2018)11. - ISSN 1991-959X - p. 4537 - 4562.

To support the assessments of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the IPBES Expert Group on Scenarios and Models is carrying out an intercomparison of biodiversity and ecosystem services models using harmonized scenarios (BES-SIM). The goals of BES-SIM are (1) to project the global impacts of land-use and climate change on biodiversity and ecosystem services (i.e., nature's contributions to people) over the coming decades, compared to the 20th century, using a set of common metrics at multiple scales, and (2) to identify model uncertainties and research gaps through the comparisons of projected biodiversity and ecosystem services across models. BES-SIM uses three scenarios combining specific Shared Socio-economic Pathways (SSPs) and Representative Concentration Pathways (RCPs)-SSP1xRCP2.6, SSP3xRCP6.0, SSP5xRCP8.6-to explore a wide range of land-use change and climate change futures. This paper describes the rationale for scenario selection, the process of harmonizing input data for land use, based on the second phase of the Land Use Harmonization Project (LUH2), and climate, the biodiversity and ecosystem services models used, the core simulations carried out, the harmonization of the model output metrics, and the treatment of uncertainty. The results of this collaborative modeling project will support the ongoing global assessment of IPBES, strengthen ties between IPBES and the Intergovernmental Panel on Climate Change (IPCC) scenarios and modeling processes, advise the Convention on Biological Diversity (CBD) on its development of a post-2020 strategic plans and conservation goals, and inform the development of a new generation of nature-centred scenarios.

State of the world's raptors : Distributions, threats, and conservation recommendations
McClure, Christopher J.W. ; Westrip, James R.S. ; Johnson, Jeff A. ; Schulwitz, Sarah E. ; Virani, Munir Z. ; Davies, Robert ; Symes, Andrew ; Wheatley, Hannah ; Thorstrom, Russell ; Amar, Arjun ; Buij, Ralph ; Jones, Victoria R. ; Williams, Nick P. ; Buechley, Evan R. ; Butchart, Stuart H.M. - \ 2018
Biological Conservation 227 (2018). - ISSN 0006-3207 - p. 390 - 402.
Bird of prey - Important Bird and Biodiversity Areas - IUCN Red List - Ornithology - Raptors MoU - United Nations Convention on the Conservation of Migratory Species of Wild Animals

Raptors provide critical ecosystem services, yet there is currently no systematic, global synthesis of their conservation status or threats. We review the International Union for the Conservation of Nature's Red List to examine the conservation status, distributions, threats, and conservation recommendations for all 557 raptor species. We further assess the significance of Important Bird and Biodiversity Areas (IBAs) for raptor conservation. We also determine which countries contain the most species listed under the Memorandum of Understanding on the Conservation of Migratory Birds of Prey in Africa and Eurasia (Raptors MoU). Raptors, especially Old World vultures, are more threatened than birds in general. Eighteen percent of raptors are threatened with extinction and 52% of raptors have declining global populations. South and Southeast Asia have the highest richness and the largest number of threatened raptor species. By country, Indonesia has the highest richness of raptor species (119) and most declining species (63). China and Russia contain the most Raptors MoU species, although they are not yet signatories to the agreement. Raptor species that require forest are more likely to be threatened and declining than those that do not. Agriculture and logging are the most frequently identified threats, although poisoning is especially detrimental to Old World vultures. Of the 10 most important IBAs for raptors, six are in Nepal. Highest priority conservation actions to protect raptors include preventing mortality and conserving key sites and priority habitats. Improved long-term monitoring would allow for conservation to be appropriately targeted and effectiveness of interventions to be assessed.

The burden of cardiovascular diseases among us states, 1990-2016
Roth, Gregory A. ; Johnson, Catherine O. ; Abate, Kalkidan Hassen ; Abd-Allah, Foad ; Ahmed, Muktar ; Alam, Khurshid ; Alam, Tahiya ; Alvis-Guzman, Nelson ; Ansari, Hossein ; Ärnlöv, Johan ; Atey, Tesfay Mehari ; Awasthi, Ashish ; Awoke, Tadesse ; Barac, Aleksandra ; Bärnighausen, Till ; Bedi, Neeraj ; Bennett, Derrick ; Bensenor, Isabela ; Biadgilign, Sibhatu ; Castañeda-Orjuela, Carlos ; Catalá-López, Ferrán ; Davletov, Kairat ; Dharmaratne, Samath ; Ding, Eric L. ; Dubey, Manisha ; Faraon, Emerito Jose Aquino ; Farid, Talha ; Farvid, Maryam S. ; Feigin, Valery ; Fernandes, João ; Frostad, Joseph ; Gebru, Alemseged ; Geleijnse, Johanna M. ; Gona, Philimon Nyakauru ; Griswold, Max ; Hailu, Gessessew Bugssa ; Hankey, Graeme J. ; Hassen, Hamid Yimam ; Havmoeller, Rasmus ; Hay, Simon ; Heckbert, Susan R. ; Irvine, Caleb Mackay Salpeter ; James, Spencer Lewis ; Jara, Dube ; Kasaeian, Amir ; Khan, Abdur Rahman ; Khera, Sahil ; Khoja, Abdullah T. ; Khubchandani, Jagdish ; Kim, Daniel ; Kolte, Dhaval ; Lal, Dharmesh ; Larsson, Anders ; Linn, Shai ; Lotufo, Paulo A. ; Razek, Hassan Magdy Abd El; Mazidi, Mohsen ; Meier, Toni ; Mendoza, Walter ; Mensah, George A. ; Meretoja, Atte ; Mezgebe, Haftay Berhane ; Mirrakhimov, Erkin ; Mohammed, Shafiu ; Moran, Andrew Edward ; Nguyen, Grant ; Nguyen, Minh ; Ong, Kanyin Liane ; Owolabi, Mayowa ; Pletcher, Martin ; Pourmalek, Farshad ; Purcell, Caroline A. ; Qorbani, Mostafa ; Rahman, Mahfuzar ; Rai, Rajesh Kumar ; Ram, Usha ; Reitsma, Marissa Bettay ; Renzaho, Andre M.N. ; Rios-Blancas, Maria Jesus ; Safiri, Saeid ; Salomon, Joshua A. ; Sartorius, Benn ; Sepanlou, Sadaf Ghajarieh ; Shaikh, Masood Ali ; Silva, Diego ; Stranges, Saverio ; Tabarés-Seisdedos, Rafael ; Atnafu, Niguse Tadele ; Thakur, J.S. ; Topor-Madry, Roman ; Truelsen, Thomas ; Tuzcu, E.M. ; Tyrovolas, Stefanos ; Ukwaja, Kingsley Nnanna ; Vasankari, Tommi ; Vlassov, Vasiliy ; Vollset, Stein Emil ; Wakayo, Tolassa ; Weintraub, Robert ; Wolfe, Charles ; Workicho, Abdulhalik ; Xu, Gelin ; Yadgir, Simon ; Yano, Yuichiro ; Yip, Paul ; Yonemoto, Naohiro ; Younis, Mustafa ; Yu, Chuanhua ; Zaidi, Zoubida ; Sayed Zaki, Maysaa El; Zipkin, Ben ; Afshin, Ashkan ; Gakidou, Emmanuela ; Lim, Stephen S. ; Mokdad, Ali H. ; Naghavi, Mohsen ; Vos, Theo ; Murray, Christopher J.L. - \ 2018
JAMA Cardiology 3 (2018)5. - ISSN 2380-6583 - p. 375 - 389.
Importance: Cardiovascular disease (CVD) is the leading cause of death in the United States, but regional variation within the United States is large. Comparable and consistent state-level measures of total CVD burden and risk factors have not been produced previously. Objective: To quantify and describe levels and trends of lost health due to CVD within the United States from 1990 to 2016 as well as risk factors driving these changes. Design, setting, and participants: Using the Global Burden of Disease methodology, cardiovascular disease mortality, nonfatal health outcomes, and associated risk factors were analyzed by age group, sex, and year from 1990 to 2016 for all residents in the United States using standardized approaches for data processing and statistical modeling. Burden of disease was estimated for 10 groupings of CVD, and comparative risk analysis was performed. Data were analyzed from August 2016 to July 2017. Exposures: Residing in the United States. Main outcomes ans measures: Cardiovascular disease disability-Adjusted life-years (DALYs). Results: Between 1990 and 2016, age-standardized CVD DALYs for all states decreased. Several states had large rises in their relative rank ordering for total CVD DALYs among states, including Arkansas, Oklahoma, Alabama, Kentucky, Missouri, Indiana, Kansas, Alaska, and Iowa. The rate of decline varied widely across states, and CVD burden increased for a small number of states in the most recent years. Cardiovascular disease DALYs remained twice as large among men compared with women. Ischemic heart disease was the leading cause of CVD DALYs in all states, but the second most common varied by state. Trends were driven by 12 groups of risk factors, with the largest attributable CVD burden due to dietary risk exposures followed by high systolic blood pressure, high body mass index, high total cholesterol level, high fasting plasma glucose level, tobacco smoking, and low levels of physical activity. Increases in risk-deleted CVD DALY rates between 2006 and 2016 in 16 states suggest additional unmeasured risks beyond these traditional factors. Conclusions and relevance: Large disparities in total burden of CVD persist between US states despite marked improvements in CVD burden. Differences in CVD burden are largely attributable to modifiable risk exposures.
Crop pests and predators exhibit inconsistent responses to surrounding landscape composition
Karp, Daniel S. ; Chaplin-Kramer, Rebecca ; Meehan, Timothy D. ; Martin, Emily A. ; Declerck, Fabrice ; Grab, Heather ; Gratton, Claudio ; Hunt, Lauren ; Larsen, Ashley E. ; Martínez-Salinas, Alejandra ; O’Rourke, Megan E. ; Rusch, Adrien ; Poveda, Katja ; Jonsson, Mattias ; Rosenheim, Jay A. ; Schellhorn, Nancy A. ; Tscharntke, Teja ; Wratten, Stephen D. ; Zhang, Wei ; Iverson, Aaron L. ; Adler, Lynn S. ; Albrecht, Matthias ; Alignier, Audrey ; Angelella, Gina M. ; Zubair Anjum, Muhammad ; Avelino, Jacques ; Batáry, Péter ; Baveco, Johannes M. ; Bianchi, Felix J.J.A. ; Birkhofer, Klaus ; Bohnenblust, Eric W. ; Bommarco, Riccardo ; Brewer, Michael J. ; Caballero-López, Berta ; Carrière, Yves ; Carvalheiro, Luísa G. ; Cayuela, Luis ; Centrella, Mary ; Ćetković, Aleksandar ; Henri, Dominic Charles ; Chabert, Ariane ; Costamagna, Alejandro C. ; La Mora, Aldo De; Kraker, Joop De; Desneux, Nicolas ; Diehl, Eva ; Diekötter, Tim ; Dormann, Carsten F. ; Eckberg, James O. ; Entling, Martin H. ; Fiedler, Daniela ; Franck, Pierre ; Veen, F.J.F. van; Frank, Thomas ; Gagic, Vesna ; Garratt, Michael P.D. ; Getachew, Awraris ; Gonthier, David J. ; Goodell, Peter B. ; Graziosi, Ignazio ; Groves, Russell L. ; Gurr, Geoff M. ; Hajian-Forooshani, Zachary ; Heimpel, George E. ; Herrmann, John D. ; Huseth, Anders S. ; Inclán, Diego J. ; Ingrao, Adam J. ; Iv, Phirun ; Jacot, Katja ; Johnson, Gregg A. ; Jones, Laura ; Kaiser, Marina ; Kaser, Joe M. ; Keasar, Tamar ; Kim, Tania N. ; Kishinevsky, Miriam ; Landis, Douglas A. ; Lavandero, Blas ; Lavigne, Claire ; Ralec, Anne Le; Lemessa, Debissa ; Letourneau, Deborah K. ; Liere, Heidi ; Lu, Yanhui ; Lubin, Yael ; Luttermoser, Tim ; Maas, Bea ; Mace, Kevi ; Madeira, Filipe ; Mader, Viktoria ; Cortesero, Anne Marie ; Marini, Lorenzo ; Martinez, Eliana ; Martinson, Holly M. ; Menozzi, Philippe ; Mitchell, Matthew G.E. ; Miyashita, Tadashi ; Molina, Gonzalo A.R. ; Molina-Montenegro, Marco A. ; O’Neal, Matthew E. ; Opatovsky, Itai ; Ortiz-Martinez, Sebaastian ; Nash, Michael ; Östman, Örjan ; Ouin, Annie ; Pak, Damie ; Paredes, Daniel ; Parsa, Soroush ; Parry, Hazel ; Perez-Alvarez, Ricardo ; Perović, David J. ; Peterson, Julie A. ; Petit, Sandrine ; Philpott, Stacy M. ; Plantegenest, Manuel ; Plećaš, Milan ; Pluess, Therese ; Pons, Xavier ; Potts, Simon G. ; Pywell, Richard F. ; Ragsdale, David W. ; Rand, Tatyana A. ; Raymond, Lucie ; Ricci, Benoît ; Sargent, Chris ; Sarthou, Jean-Pierre ; Saulais, Julia ; Schäckermann, Jessica ; Schmidt, Nick P. ; Schneider, Gudrun ; Schüepp, Christof ; Sivakoff, Frances S. ; Smith, Henrik G. ; Stack Whitney, Kaitlin ; Stutz, Sonja ; Szendrei, Zsofia ; Takada, Mayura B. ; Taki, Hisatomo ; Tamburini, Giovanni ; Thomson, Linda J. ; Tricault, Yann ; Tsafack, Noelline ; Tschumi, Matthias ; Valantin-Morison, Muriel ; Trinh, Mai Van; Werf, Wopke Van Der; Vierling, Kerri T. ; Werling, Ben P. ; Wickens, Jennifer B. ; Wickens, Victoria J. ; Woodcock, Ben A. ; Wyckhuys, Kris ; Xiao, Haijun ; Yasuda, Mika ; Yoshioka, Akira - \ 2018
Proceedings of the National Academy of Sciences of the United States of America 115 (2018)33. - ISSN 0027-8424 - p. E7863 - E7870.
The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies.
Ability tracking and social trust in China’s rural secondary school system
Li, Fan ; Loyalka, Prashant ; Yi, Hongmei ; Shi, Yaojiang ; Johnson, Natalie ; Rozelle, Scott - \ 2018
School Effectiveness and School Improvement 29 (2018)4. - ISSN 0924-3453 - p. 545 - 572.
Ability tracking - confidence in public institutions - interpersonal trust - rural secondary schooling - social trust

The goal of this paper is to describe and analyze the relationship between ability tracking and student social trust, in the context of low-income students in developing countries. Drawing on the results from a longitudinal study among 1,436 low-income students across 132 schools in rural China, we found a significant lack of interpersonal trust and confidence in public institutions among poor rural young adults. We also found that slow-tracked students have a significantly lower level of social trust, comprised of interpersonal trust and confidence in public institutions, relative to their fast-tracked peers. This disparity might further widen the gap between relatively privileged students who stay in school and less privileged students who drop out of school. These results suggest that making high school accessible to more students may improve social trust among rural low-income young adults.

Global-change effects on early-stage decomposition processes in tidal wetlands-implications from a global survey using standardized litter
Mueller, Peter ; Schile-Beers, Lisa M. ; Mozdzer, Thomas J. ; Chmura, Gail L. ; Dinter, Thomas ; Kuzyakov, Yakov ; Groot, Alma V. de; Esselink, Peter ; Smit, Christian ; Alpaos, Andrea D'; Ibáñez, Carles ; Lazarus, Magdalena ; Neumeier, Urs ; Johnson, Beverly J. ; Baldwin, Andrew H. ; Yarwood, Stephanie A. ; Montemayor, Diana I. ; Yang, Zaichao ; Wu, Jihua ; Jensen, Kai ; Nolte, Stefanie - \ 2018
Biogeosciences 15 (2018)10. - ISSN 1726-4170 - p. 3189 - 3202.

Tidal wetlands, such as tidal marshes and mangroves, are hotspots for carbon sequestration. The preservation of organic matter (OM) is a critical process by which tidal wetlands exert influence over the global carbon cycle and at the same time gain elevation to keep pace with sea-level rise (SLR). The present study assessed the effects of temperature and relative sea level on the decomposition rate and stabilization of OM in tidal wetlands worldwide, utilizing commercially available standardized litter. While effects on decomposition rate per se were minor, we show strong negative effects of temperature and relative sea level on stabilization, as based on the fraction of labile, rapidly hydrolyzable OM that becomes stabilized during deployment. Across study sites, OM stabilization was 29% lower in low, more frequently flooded vs. high, less frequently flooded zones. Stabilization declined by ∼ 75% over the studied temperature gradient from 10.9 to 28.5°C. Additionally, data from the Plum Island long-term ecological research site in Massachusetts, USA, show a pronounced reduction in OM stabilization by > 70% in response to simulated coastal eutrophication, confirming the potentially high sensitivity of OM stabilization to global change. We therefore provide evidence that rising temperature, accelerated SLR, and coastal eutrophication may decrease the future capacity of tidal wetlands to sequester carbon by affecting the initial transformations of recent OM inputs to soil OM.

Agroecological integration of shade- and drought-tolerant food/feed crops for year-round productivity in banana-based systems under rain-fed conditions in Central Africa
Blomme, G. ; Ocimati, W. ; Groot, J.C.J. ; Ntamwira, J. ; Bahati, L. ; Kantungeko, D. ; Remans, R. ; Tittonell, P. - \ 2018
In: 10th International Symposium on Banana. - International Society for Horticultural Science (Acta Horticulturae ) - ISBN 9789462611924 - p. 41 - 54.
Intensification - Resilience - Small-scale farming - Year-round productivity - Yield gaps
Yield gaps in banana-based production systems have increased in the past two decades due to declining soil fertility, drought and biotic stresses. Sustainable, environmentally sound and economically viable strategies for intensification in these systems are urgently needed. Agroecological practices, such as the integration of shade- and drought-tolerant crops, nitrogen-fixing and cover crops could potentially improve soil fertility and moisture retention, reduce the weed burden, narrow yield gaps and increase overall plot/farm productivity in these systems. In Malaysia, leguminous crops like Pueraria phaseoloides, Calopogonium caeruleum and Centrosema pubescens are often cultivated as cover crops (to suppress weeds, and reduce moisture loss and soil erosion) in young rubber and oil palm plantations with low shade levels. Even in mature oil palm plantations with less than 30% light intensity, various shade-tolerant crops are grown, e.g., elephant foot yam, turmeric and arrow root. In humid tropical Africa, Colocasia (taro) and Xanthosoma (cocoyam) are reported to tolerate shade conditions and hence often planted under perennial banana/plantain plantations. Drought tolerance is a less common feature of most annual crops grown in the humid tropics. A few root and tuber crops (e.g., cassava, taro, yam and sweetpotato) remain in the field during the dry season in Central Africa and are then harvested according to household needs. This paper also reports on crops (Mucuna, lablab and chickpea) with potential for integration into banana-based systems during the dry season, if planted during the last month of the rainy season. These crops are reported to use the residual soil moisture content for continued growth during the dry season months. The paper concludes with detailed descriptions (from a literature review) on drought- and shade-tolerance characteristics of various crops which have long been integrated in Central African banana-based cropping systems, crops with a more recent cultivation history and crops with potential for system integration.
Managing the interactions between soil abiotic factors to alleviate the effect of Fusarium wilt in bananas
Segura, R.A. ; Stoorvogel, J.J. ; Samuels, J.Z. ; Sandoval, J.A. - \ 2018
In: 10th International Symposium on Banana. - International Society for Horticultural Science (Acta Horticulturae ) - ISBN 9789462611924 - p. 163 - 168.
Biomass - Micronutrients - Panama disease - Plant disease - Soil fertility
Soil management offers various options to alleviate the effects of Fusarium wilt caused by Fusarium oxysporum f. sp. cubense (Foc) in bananas. Nevertheless, it receives little attention as a strategy in Fusarium wilt management. Literature provides ample evidence linking soil conditions such as soil texture and fertility to the spread and severity of plant diseases. However, the inconsistency of results between case studies limits the attention of soil management in crop disease management. The present study aimed at unravelling the role of soil abiotic factors on nutrient concentrations in plant tissue, biomass production and the incidence of Fusarium wilt (Foc race 1) in bananas (‘Gros Michel’, AAA) under field conditions. A large field trial was established in which the effects of soil pH and nutrients (N, Ca, Mg and Mn) were studied. Around 30% of the plants showed symptoms of Fusarium wilt at flowering in the first season. However, Fusarium wilt incidence did not vary between treatments. Soil pH showed significant interactions with soil N and Mn concentrations resulting in a lower bunch weight and increased micronutrient concentrations in the pseudostem. With a higher pH, bunch weight increased, although higher Mn concentrations suppressed this positive effect. Interactions between a high soil pH and Ca and Mg resulted in a higher bunch weight and lower micronutrient concentrations in the pseudostem. The results can be used to develop soil management strategies for improving banana productivity in infected plantations.
Effects of Xanthomonas wilt and other banana diseases on ecosystem services in banana-based agroecosystems
Ocimati, W. ; Groot, J.C.J. ; Tittonell, P. ; Taulya, G. ; Blomme, G. - \ 2018
In: 10th International Symposium on Banana. - International Society for Horticultural Science (Acta Horticulturae ) - ISBN 9789462611924 - p. 19 - 32.
Drought tolerance - Landscape - Multiple functions - Provisioning - Regulatory - Shade tolerance - Supporting
Banana plantations are multifunctional agroecosystems that besides their main provisioning service also deliver a range of supporting, regulatory and cultural services that are largely unvalorized. Banana is perennial in nature with plantations as old as 50 years reported in the African Great Lakes region. Banana is cultivated in a wide range of agroecologies (from sea level to 2400 m a.s.l.) and cropping systems, where it contributes to various ecosystem services (ES). These include regulating soil erosion, water cycles and quality, and nutrient recycling. However, the outbreak of Xanthomonas wilt of banana (XW) along with some of its management practices, such as uprooting mats/entire fields, is devastating banana production and rendering landscapes bare and prone to degradation. Yet this process is also leading to diversification of agroecosystems in over 70% of farms in the African Great Lakes region with unknown but potentially positive consequences for resilience and adaptation, as well as for local diets. The sustainability of these alternative land-uses is variable. This study reviews the different services offered by banana plantations and the impacts, positive or negative, that XW-driven diversification may have on these services. It suggests the need to consider explicitly the consequences of pests and diseases for the full range of ES provided by the crop and an ES-broad framework for estimation of losses, and planning resources and strategies for disease management. The study also suggests strategies, such as incorporation of shade- and drought-tolerant cover crops, hedges and agroforestry trees, to augment the supply of key ES within XW-affected agroecosystems/landscapes.
Next generation microbiological risk assessment—Potential of omics data for hazard characterisation
Haddad, Nabila ; Johnson, Nick ; Kathariou, Sophia ; Métris, Aline ; Phister, Trevor ; Pielaat, Annemarie ; Tassou, Chrysoula ; Wells-Bennik, Marjon H.J. ; Zwietering, Marcel H. - \ 2018
International Journal of Food Microbiology 287 (2018). - ISSN 0168-1605 - p. 28 - 39.
Dose-response - Food safety - Functional genomics - Pathogenicity - Public health - Quantitative transcriptomics and proteomics - Risk analysis - Virulence
According to the World Health Organization estimates in 2015, 600 million people fall ill every year from contaminated food and 420,000 die. Microbial risk assessment (MRA) was developed as a tool to reduce and prevent risks presented by pathogens and/or their toxins. MRA is organized in four steps to analyse information and assist in both designing appropriate control options and implementation of regulatory decisions and programs. Among the four steps, hazard characterisation is performed to establish the probability and severity of a disease outcome, which is determined as function of the dose of toxin and/or pathogen ingested. This dose-response relationship is subject to both variability and uncertainty. The purpose of this review/opinion article is to discuss how Next Generation Omics can impact hazard characterisation and, more precisely, how it can improve our understanding of variability and limit the uncertainty in the dose-response relation. The expansion of omics tools (e.g. genomics, transcriptomics, proteomics and metabolomics) allows for a better understanding of pathogenicity mechanisms and virulence levels of bacterial strains. Detection and identification of virulence genes, comparative genomics, analyses of mRNA and protein levels and the development of biomarkers can help in building a mechanistic dose-response model to predict disease severity. In this respect, systems biology can help to identify critical system characteristics that confer virulence and explain variability between strains. Despite challenges in the integration of omics into risk assessment, some omics methods have already been used by regulatory agencies for hazard identification. Standardized methods, reproducibility and datasets obtained from realistic conditions remain a challenge, and are needed to improve accuracy of hazard characterisation. When these improvements are realized, they will allow the health authorities and government policy makers to prioritize hazards more accurately and thus refine surveillance programs with the collaboration of all stakeholders of the food chain.
Habitat heterogeneity promotes intraspecific trait variability of shrub species in Australian granite inselbergs
Smedt, P. de; Ottaviani, G. ; Wardell-Johnson, G. ; Sýkora, K.V. ; Mucina, L. - \ 2018
Folia Geobotanica 53 (2018)2. - ISSN 1211-9520 - p. 133 - 145.
Fire-refugia - Functional traits - Global biodiversity hotspot - Mediterranean-type climate - Plant resource strategies - Proteaceae
The role of intraspecific trait variability is increasingly recognized as a key factor shaping plant fitness and community assembly worldwide. Studying the direct effects of habitat heterogeneity on trait expression of individual plants of the same species is a useful tool to quantify intraspecific trait variability locally. We investigated how habitat heterogeneity on granite inselbergs affected intraspecific trait variability of 19 functional traits in three shrub species of the family Proteaceae in south western Australia, a global biodiversity hotspot. We used pairwise comparison (single trait) and multivariate analysis (multiple traits, functional space) to detect shifts in trait patterns. Consistent with our predictions, we found that individuals developing in putatively more stressful habitats (highly sun-irradiated, shallow-soil patches on the outcrops) were characterized by trait expressions indicative of more conservative resource-related strategies when compared with plants occurring in the surrounding woodlands that were experiencing more benign ecological conditions. These results were significant for two out of three species. Granite inselbergs promoted plant longevity, a signal that these granite inselbergs might offer refugial conditions defined as protection against fire.
Bardocz, Tamas ; Jansen, H.M. ; Cai, Junning ; Aguilar-Manjarrez, Jose ; Barrento, Sara ; Hunter, Shane A. ; Poelman, M. - \ 2018
In: Building Industries at Sea: 'Blue Growth' and the New Maritime Economy / Johnson, Kate, Dalton, Gordon, Masters, Ian, River Publishers (River Publishers Series in Renewable Energy ) - ISBN 9788793609266 - p. 11 - 38.
Seabed Mining
Rozemeijer, M.J.C. ; Burg, S.W.K. van den; Jak, R.G. ; Lallier, Laura E. ; Craenenbroeck, Karel van - \ 2018
In: Building Industries at Sea: 'Blue Growth' and the New Maritime Economy / Johnson, Katie, Dalton, Gordon, Masters, Ian, River Publishers (River Publishers Series in Renewable Energy ) - ISBN 9788793609266 - p. 73 - 136.
Regulation and Planning in the Mediterranean Sea
Rockmann, C. ; Vega Fernández, Tomás ; Pipitone, Carlo - \ 2018
In: Building Industries at Sea: 'Blue Growth' and the New Maritime Economy / Johnson, Kate, Dalton, Gordon, Masters, Ian, River Publishers (River Publishers Series in Renewable Energy ) - ISBN 9788793609266 - p. 365 - 402.
The Sphagnome Project : enabling ecological and evolutionary insights through a genus-level sequencing project
Weston, David J. ; Turetsky, Merritt R. ; Johnson, Matthew G. ; Granath, Gustaf ; Lindo, Zoë ; Belyea, Lisa R. ; Rice, Steven K. ; Hanson, David T. ; Engelhardt, Katharina A.M. ; Schmutz, Jeremy ; Dorrepaal, Ellen ; Euskirchen, Eugénie S. ; Stenøien, Hans K. ; Szövényi, Péter ; Jackson, Michelle ; Piatkowski, Bryan T. ; Muchero, Wellington ; Norby, Richard J. ; Kostka, Joel E. ; Glass, Jennifer B. ; Rydin, Håkan ; Limpens, Juul ; Tuittila, Eeva Stiina ; Ullrich, Kristian K. ; Carrell, Alyssa ; Benscoter, Brian W. ; Chen, Jin Gui ; Oke, Tobi A. ; Nilsson, Mats B. ; Ranjan, Priya ; Jacobson, Daniel ; Lilleskov, Erik A. ; Clymo, R.S. ; Shaw, A.J. - \ 2018
New Phytologist 217 (2018)1. - ISSN 0028-646X - p. 16 - 25.
ecological genomics - ecosystem engineering - evolutionary genetics - genome sequencing - niche construction - peatlands - Sphagnome - Sphagnum
Considerable progress has been made in ecological and evolutionary genetics with studies demonstrating how genes underlying plant and microbial traits can influence adaptation and even ‘extend’ to influence community structure and ecosystem level processes. Progress in this area is limited to model systems with deep genetic and genomic resources that often have negligible ecological impact or interest. Thus, important linkages between genetic adaptations and their consequences at organismal and ecological scales are often lacking. Here we introduce the Sphagnome Project, which incorporates genomics into a long-running history of Sphagnum research that has documented unparalleled contributions to peatland ecology, carbon sequestration, biogeochemistry, microbiome research, niche construction, and ecosystem engineering. The Sphagnome Project encompasses a genus-level sequencing effort that represents a new type of model system driven not only by genetic tractability, but by ecologically relevant questions and hypotheses.
A comparative history of commercial transition in three West African slave trading economies, 1630 to 1860
Dalrymple-Smith, Angus - \ 2017
Wageningen University. Promotor(en): Ewout Frankema; Elise van Nederveen Meerkerk, co-promotor(en): M. van Rossum. - Wageningen : Wageningen University - ISBN 9789463436199 - 283
slavery - history - colonialism - trade - commodities - gold - law - social change - economic change - west africa - slavernij - geschiedenis - kolonialisme - handel - basisproducten - goud - recht - sociale verandering - economische verandering - west-afrika

The nineteenth century ‘commercial transition’ from export economies based on slaves to ones dominated by commodities like palm oil has been a central theme in West African history. However, most studies have tended to focus on the impact of the change and assumed that its causes were largely a result of the British decision to abolish their transatlantic slave trade in 1807 and subsequently persuading or forcing other nations to do the same. This thesis makes two principal contributions to this debate. Firstly, it reviews new evidence which shows that the commercial transition in West Africa’s most important slave exporting regions, the Gold Coast, the Bight of Biafra and the Bight of Benin, can be predicted by the patterns of trade established in previous centuries. It then presents a model of analysis which sets out which interrelated factors shaped their export economies and ultimately determined how they responded to the changing political and economic environment of the Atlantic world from the seventeenth to the nineteenth centuries. This study offers an important comparative, long term quantitative perspective on the transition from slave exports to so-called ‘legitimate commerce’.

Chapter 1 shows that the speed and timing of the nineteenth century commercial transition differed considerably across the case study regions. Along the Gold Coast there was a sudden, and effectively total end to transatlantic slave trading after 1807. In the Bight of Biafra slave exports gradually declined until largely ceasing in the 1830s. Lastly in the Bight of Benin export slavery continued until the 1850s. The chapter argues that earlier studies have tended to ignore long term trends and also lack a comparative approach, as many are focused on individual regions. It then suggests a new model of analysis and dismisses two factors as irrelevant; the British slave trade patrol and changing demands for, or changing supply of, African slaves. The chapter argues that regional variations can be explained by five key factors: 1) the nature and duration of long-term trade relations; 2) the identity of the principal European trade partner; 3) certain aspects of the ecology of the different regions; 4) the regional political contexts; and 5) the development of institutions that either encouraged or discouraged elite participation in non-slave exports.

Chapter 2 provides a broad overview of each case study region’s patterns of trade from the fifteenth to the eighteenth Centuries based on secondary and primary qualitative sources. It then reviews quantitative evidence of commodity trading patterns from the earlier eighteenth century from British and Dutch commodity traders and slaving vessels that bought commodities. It argues that the expansion of slavery in the Bight of Biafra did not crowd out other forms of commerce. On the Gold Coast the early eighteenth century saw continued engagement in commodity exports while the slave trade expanded. However, by the 1780s, both slave and commodity exports seem to have begun to decline. In the Dahomean-controlled area of the Bight of Benin, there is no evidence of slavery crowding out other forms of commerce, as captives were always the only item of trade with the Atlantic world.

Chapter 3 investigates the extent to which the 18th century intensification of the trans-Atlantic slave trade boosted commercial agriculture in the coastal areas of West Africa and in particular in the case study regions. It explores the provisioning strategies of 187 British, French, Dutch and Danish slave voyages conducted between 1681 and 1807, and calls for a major downward adjustment of available estimates of the slave trade induced demand impulse. It shows that during the 18th century, an increasing share of the foodstuffs required to feed African slaves were taken on board in Europe instead of West Africa. However, there was considerable variation in provisioning strategies among slave trading nations and across main regions of slave embarkation. The Bight of Benin never significantly engaged in provisioning trade. Traders along the Gold Coast provided relatively large quantities of food to slaving vessels, but in the Bight of Biafra, British demand stimulated a considerable trade in foodstuffs. The chapter explains these trends and variation in terms of the relative (seasonal) security of European versus African food supplies, the falling relative costs of European provisions and the increasing risks in the late 18th century trade, putting a premium on faster embarkation times.

Chapter 4 uses a newly constructed dataset on the quantities and prices of African commodities on the coast and in British markets over the long eighteenth century and provides new insights into the changing nature of Britain’s non-slave trade. It improves on previous work by Johnson et al. (1990) and finds that earlier estimates of the volume and value of commodity trade have been underestimates and fail to account for regional changes in output. The data suggests that from the 1770s the focus of Britain’s commodity trade shifted from Senegambia to the Bight of Biafra and that in the later eighteenth century non-slave goods were primarily purchased by slave ships, not specialist bi-lateral traders. The chapter argues that these changes were motivated by a number of factors; conflicts between Atlantic powers, the prices of British trade goods and African imports, increasing levels of risk faced by British slave merchants and the fact that traders in the Bight of Biafra were both willing and able to supply desirable commodities.

Part 1 establishes that the Gold Coast had a far long history of commodity trading and seemed to have been moving away from the slave trade at the end of the eighteenth century. The region of the Bight of Benin controlled by Dahomey always focused exclusively on slaves. The Bight of Biafra had a considerable non-slave export economy that was growing at the end of the eighteenth century. Part 2 of the thesis applies the model of analysis to the case study regions.

Chapter 5 argues that that for the Gold Coast and more particularly the Asante empire British abolition policies and the slave forts can explain the timing of the end of transatlantic slavery but not why it ended. Following the model of analysis, the chapter shows that the presence of gold determined both long term political development and the nature of the region’s trade relationship with the Atlantic. In addition, gold became essential as a means of marking status and wealth at all levels of society and for domestic exchange. This meant that slaves were always essential for the production of gold, meaning that there was an important competing domestic market for coerced labour. Over the eighteenth-century gold became scarcer leading to slaves being pulled out of the Atlantic market to focus on production. In addition, well-developed trade relations with the interior and a rise in demand from the Islamic states in the Sokoto caliphate led to an expansion of kola exports which demanded yet more labour. Most importantly, the chapter argues that both households and elite groups could profit more from commodity than slave exports which explains the rapid move away from the transatlantic slavery and towards the production of commodities.

In Chapter 6 it is argued that in the Bight of Biafra, the slave and commodity trades were not only compatible but complementary. The region’s riverine transport networks, long established coastal-interior trade relations and suitability for the growing of yams, palm oil and tropical hardwoods meant that the provisioning and commodity trades could function alongside slave exports. The relatively late opening of central Igboland to the Atlantic slave markets meant that the region did not see the influx of wealth in the seventeenth century that spurred the development of states in the other case study areas. Instead the region followed a different institutional path which saw the development small political entities linked together through the Aro trade network. Elites in the interior and at the coast were reliant on trade for both power and status, but not specifically the slave trade. As a result, abolition was not a serious economic shock as commodities and slaves had always been traded side by side. As in Gold Coast both commoners and elites benefited from commodity trading. Atlantic goods allowed many more people to purchase goods to improve their standards of living, while elites benefitted from the less volatile commodity trade. Furthermore, the British state also perhaps unintentionally supported the development of the palm oil trade through its customs policies. Eventually, this led to palm oil crowding out slave exports through greater demands for domestic labour.

Chapter 7 investigates why the region of the Bight of Benin controlled by Dahomey only ever exported slaves. It shows that this region possessed no gold and had less favourable geography for commodity exports than the Bight of Biafra. The early expansion of export slavery in the seventeenth century spurred the development of states and elites who were entirely dependent on slave exports to maintain their wealth and power. It led to the development of a militaristic culture and institutions based on large scale slave raiding that were highly effective as a means of controlling and harnessing elite violence, generating wealth and defending the state from powerful external threats and economic competition. The demands of the army and elites took much of the kingdom’s potential labour away from households. In addition, constant warfare led to a serious demographic decline across the region further reducing the amount of available labour. The chapter argues that it was never in the interests of elites to switch to an alternative economic system and there was, until the 1850s, always sufficient external demand. In the end abolition efforts were a necessary condition to ending the slave trade.

Chapter 8 concludes with a summary of the main contributions of thesis; the importance of long term patterns of trade in determining nineteenth century commercial transition and a modified model of analysis to explain the diverging trajectories of the different case study regions. It also argues that the impact of Britain’s abolition campaign should be reassessed. In the Gold Coast and the Bight of Biafra it was not an important factor in ending transatlantic slavery, while in the Bight of Benin it was. The chapter ends with suggestions for future research.

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