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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    Efficient sampling for geostatistical surveys
    Wadoux, A.M.J.C. ; Marchant, B.P. ; Lark, R.M. - \ 2019
    European Journal of Soil Science (2019). - ISSN 1351-0754 - 34 p.
    A geostatistical survey for soil requires rational choices regarding the sampling strategy. If the variogram of the property of interest is known then it is possible to optimize the sampling scheme such that an objective function related to the survey error is minimized. However, the variogram is rarely known prior to sampling. Instead it must be approximated by using either a variogram estimated from a reconnaissance survey or a variogram estimated for the same soil property in similar conditions. For this reason, spatial coverage schemes are often preferred, because they rely on the simple dispersion of sampling units as uniformly as possible, and are similar to those produced by minimizing the kriging variance. If extra sampling locations are added close to those in a spatial coverage scheme then the scheme might be broadly similar to one produced by minimizing the total error (i.e. kriging variance plus the prediction error due to uncertainty in the covariance parameters). We consider the relative merits of these different sampling approaches by comparing their mean total error for different specified random functions. Our results showed the considerable benefit of adding close‐pairs to a spatial coverage scheme, and that optimizing with respect to the total error generally gave a small further advantage. When we consider the example of sampling for geostatistical survey of clay content of the soil, an optimized scheme based on the average of previously reported clay variograms was fairly robust compared to the spatial coverage plus close‐pairs scheme. We conclude that the direct optimization of spatial surveys was only rarely worthwhile. For most cases, it is best to apply a spatial coverage scheme with a proportion of additional sampling locations to provide some closely spaced pairs. Furthermore, our results indicated that the number of observations required for an effective geostatistical survey depend on the variogram parameters.
    Scenarios of Land Use and Land Cover Change and Their Multiple Impacts on Natural Capital in Tanzania
    Capitani, Claudia ; Soesbergen, Arnout van; Mukama, Kusaga ; Malugu, Isaac ; Mbilinyi, Boniface ; Chamuya, Nurdin ; Kempen, Bas ; Malimbwi, Rogers ; Mant, Rebecca ; Munishi, Panteleo ; Njana, Marco Andrew ; Ortmann, Antonia ; Platts, Philip J. ; Runsten, Lisen ; Sassen, Marieke ; Sayo, Philippina ; Shirima, Deo ; Zahabu, Elikamu ; Burgess, Neil D. ; Marchant, Rob - \ 2019
    Environmental Conservation 46 (2019)1. - ISSN 0376-8929 - p. 17 - 24.
    Reducing emissions from deforestation and forest degradation plus the conservation of forest carbon stocks, sustainable management of forests and enhancement of forest carbon stocks in developing countries (REDD+) requires information on land-use and land-cover changes (LULCCs) and carbon emission trends from the past to the present and into the future. Here, we use the results of participatory scenario development in Tanzania to assess the potential interacting impacts on carbon stock, biodiversity and water yield of alternative scenarios where REDD+ is or is not effectively implemented by 2025, a green economy (GE) scenario and a business as usual (BAU) scenario, respectively. Under the BAU scenario, LULCCs will cause 296 million tonnes of carbon (MtC) national stock loss by 2025, reduce the extent of suitable habitats for endemic and rare species (mainly in encroached protected mountain forests) and change water yields. In the GE scenario, national stock loss decreases to 133 MtC. In this scenario, consistent LULCC impacts occur within small forest patches with high carbon density, water catchment capacity and biodiversity richness. Opportunities for maximizing carbon emission reductions nationally are largely related to sustainable woodland management, but also contain trade-offs with biodiversity conservation and changes in water availability.
    REDD+, hype, hope and disappointment : The dynamics of expectations in conservation and development pilot projects
    Massarella, Kate ; Sallu, Susannah M. ; Ensor, Jonathan E. ; Marchant, Rob - \ 2018
    World Development 109 (2018). - ISSN 0305-750X - p. 375 - 385.
    East Africa - International forest conservation and development intervention - Pilot projects - REDD+ - Sociology of expectations - Tanzania

    We explore the dynamics of expectations in international forest conservation and development programs, and the impacts and implications of (unfulfilled) expectations for actors involved. Early stages of new international conservation and development programs, often involving pilot projects designed to test intervention concepts at village level, are characterized by large amounts of resources and attention, along with high expectations of success. However, evidence shows that these early expectations are rarely fulfilled. Despite this repeated pattern and growing engagement with expectations in critical conservation and development literature, little is known about the dynamics of expectations in conservation and development pilot projects. We address this knowledge gap first by exploring concepts from the sociology of expectations. We then unpack expectations in a case study of REDD+ pilot projects in Tanzania, using extensive qualitative data reflecting the perspectives and experiences of a wide range of actors involved. Our study finds that expectations play a performative role, mobilizing actors and resources, despite uncertainty identified among policy-makers and practitioners. We also find that once raised, expectations are dynamic and continually mediated by actors and social contexts, which conflicts with attempts to ‘manage’ them. We argue therefore that a trade-off exists between fully piloting new initiatives and raising expectations. We also argue that failure to address this trade-off has implications beyond pilot project objectives and timelines, which are experienced most acutely by village communities. We argue for more critical engagement with expectations and the embedding of accountability for expectations in conservation and development practice. Our findings also challenge the discourse of ‘needing’ to pilot, which prioritizes awareness, impact and innovation without fully considering the potential negative impact of unfulfilled expectations.

    Rejoinder to Comments on Minasny et al., 2017 Soil carbon 4 per mille Geoderma 292, 59–86
    Minasny, Budiman ; Arrouays, Dominique ; McBratney, Alex B. ; Angers, Denis A. ; Chambers, Adam ; Chaplot, Vincent ; Chen, Zueng Sang ; Cheng, Kun ; Das, Bhabani S. ; Field, Damien J. ; Gimona, Alessandro ; Hedley, Carolyn ; Hong, Suk Young ; Mandal, Biswapati ; Malone, Brendan P. ; Marchant, Ben P. ; Martin, Manuel ; McConkey, Brian G. ; Mulder, Vera Leatitia ; O'Rourke, Sharon ; Richer-de-Forges, Anne C. ; Odeh, Inakwu ; Padarian, José ; Paustian, Keith ; Pan, Genxing ; Poggio, Laura ; Savin, Igor ; Stolbovoy, Vladimir ; Stockmann, Uta ; Sulaeman, Yiyi ; Tsui, Chun Chih ; Vågen, Tor Gunnar ; Wesemael, Bas van; Winowiecki, Leigh - \ 2018
    Geoderma 309 (2018). - ISSN 0016-7061 - p. 124 - 129.
    Forest gaps, edge, and interior support different ant communities in a tropical peat-swamp forest in Borneo
    Schreven, Stijn ; Perlett, Eric D. ; Jarrett, Benjamin J.M. ; Marchant, Nicholas C. ; Harsanto, Franciskus Agus ; Purwanto, Ari ; Sýkora, K.V. ; Harrison, Mark E. - \ 2018
    Asian Myrmecology 10 (2018). - ISSN 1985-1944 - 13 p.
    Southeast Asia’s tropical peat-swamp forests (TPSF) are globally important for carbon storage and biodiversity conservation, but are at risk from multiple threats and urgently require improved management. Ants are often used as ecological indicators in monitoring programmes to guide adaptive management, but data on TPSF ants are scarce. We conducted a twelve-month study on ants in the Sabangau TPSF in Indonesian Borneo using baited traps, to compare community composition across three disturbance categories (forest gaps, forest edge and relatively undisturbed interior forest) and between dry and wet season. The three disturbance categories supported distinct ant communities across seasons. Differences in canopy cover likely underlie these changes in ant community composition. Surveying was more effective in the dry season, because ant capture rates were higher and more indicator taxa were identified than in the wet season, but overall ant community composition did not differ significantly between seasons. These findings suggest a potentially useful role of ants as ecological indicators in TPSF. Further surveys should be conducted in Sabangau and other TPSFs to test the transferability of our findings.
    Tropical forest canopies and their relationships with climate and disturbance: results from a global dataset of consistent field-based measurements
    Pfeifer, Marion ; Gonsamo, Alemu ; Woodgate, William ; Cayuela, Luis ; Marshall, Andrew R. ; Ledo, Alicia ; Paine, Timothy C.E. ; Marchant, Rob ; Burt, Andrew ; Calders, Kim ; Courtney-mustaphi, Colin ; Cuni-sanchez, Aida ; Deere, Nicolas J. ; Denu, Dereje ; Gonzalez De Tanago Meñaca, J. ; Hayward, Robin ; Lau Sarmiento, A.I. ; Macía, Manuel J. ; Olivier, Pieter I. ; Pellikka, Petri ; Seki, Hamidu ; Shirima, Deo ; Trevithick, Rebecca ; Wedeux, Beatrice ; Wheeler, Charlotte ; Munishi, Pantaleo K.T. ; Martin, Thomas ; Mustari, Abdul ; Platts, Philip J. - \ 2018
    Forest Ecosystems 5 (2018). - ISSN 2095-6355 - 14 p.
    Background: Canopy structure, defined by leaf area index (LAI), fractional vegetation cover (FCover) and fraction of absorbed photosynthetically active radiation (fAPAR), regulates a wide range of forest functions and ecosystem services. Spatially consistent field-measurements of canopy structure are however lacking, particularly for the tropics. Methods: Here, we introduce the Global LAI database: a global dataset of field-based canopy structure measurements spanning tropical forests in four continents (Africa, Asia, Australia and the Americas). We use these measurements to test for climate dependencies within and across continents, and to test for the potential of anthropogenic disturbance and forest protection to modulate those dependences. Results: Using data collected from 887 tropical forest plots, we show that maximum water deficit, defined across the most arid months of the year, is an important predictor of canopy structure, with all three canopy attributes declining significantly with increasing water deficit. Canopy attributes also increase with minimum temperature, and with the protection of forests according to both active (within protected areas) and passive measures (through topography). Once protection and continent effects are accounted for, other anthropogenic measures (e.g. human population) do not improve the model. Conclusions: We conclude that canopy structure in the tropics is primarily a consequence of forest adaptation to the maximum water deficits historically experienced within a given region. Climate change, and in particular changes in drought regimes may thus affect forest structure and function, but forest protection may offer some resilience against this effect.
    Soil carbon 4 per mille
    Minasny, Budiman ; Malone, Brendan P. ; McBratney, Alex B. ; Angers, Denis A. ; Arrouays, Dominique ; Chambers, Adam ; Chaplot, Vincent ; Chen, Zueng Sang ; Cheng, Kun ; Das, Bhabani S. ; Field, Damien J. ; Gimona, Alessandro ; Hedley, Carolyn B. ; Hong, Suk Young ; Mandal, Biswapati ; Marchant, Ben P. ; Martin, Manuel ; McConkey, Brian G. ; Mulder, Vera Leatitia ; O'Rourke, Sharon ; Richer-de-Forges, Anne C. ; Odeh, Inakwu ; Padarian, José ; Paustian, Keith ; Pan, Genxing ; Poggio, Laura ; Savin, Igor ; Stolbovoy, Vladimir ; Stockmann, Uta ; Sulaeman, Yiyi ; Tsui, Chun Chih ; Vågen, Tor Gunnar ; Wesemael, Bas van; Winowiecki, Leigh - \ 2017
    Geoderma 292 (2017). - ISSN 0016-7061 - p. 59 - 86.
    Climate change - Greenhouse gases - Soil carbon - Soil carbon sequestration

    The ‘4 per mille Soils for Food Security and Climate’ was launched at the COP21 with an aspiration to increase global soil organic matter stocks by 4 per 1000 (or 0.4 %) per year as a compensation for the global emissions of greenhouse gases by anthropogenic sources. This paper surveyed the soil organic carbon (SOC) stock estimates and sequestration potentials from 20 regions in the world (New Zealand, Chile, South Africa, Australia, Tanzania, Indonesia, Kenya, Nigeria, India, China Taiwan, South Korea, China Mainland, United States of America, France, Canada, Belgium, England & Wales, Ireland, Scotland, and Russia). We asked whether the 4 per mille initiative is feasible for the region. The outcomes highlight region specific efforts and scopes for soil carbon sequestration. Reported soil C sequestration rates globally show that under best management practices, 4 per mille or even higher sequestration rates can be accomplished. High C sequestration rates (up to 10 per mille) can be achieved for soils with low initial SOC stock (topsoil less than 30 t C ha− 1), and at the first twenty years after implementation of best management practices. In addition, areas which have reached equilibrium will not be able to further increase their sequestration. We found that most studies on SOC sequestration only consider topsoil (up to 0.3 m depth), as it is considered to be most affected by management techniques. The 4 per mille number was based on a blanket calculation of the whole global soil profile C stock, however the potential to increase SOC is mostly on managed agricultural lands. If we consider 4 per mille in the top 1m of global agricultural soils, SOC sequestration is between 2-3 Gt C year− 1, which effectively offset 20–35% of global anthropogenic greenhouse gas emissions. As a strategy for climate change mitigation, soil carbon sequestration buys time over the next ten to twenty years while other effective sequestration and low carbon technologies become viable. The challenge for cropping farmers is to find disruptive technologies that will further improve soil condition and deliver increased soil carbon. Progress in 4 per mille requires collaboration and communication between scientists, farmers, policy makers, and marketeers.

    Predicting the HMA-LMA status in marine sponges by machine learning
    Moitinho-Silva, Lucas ; Steinert, Georg ; Nielsen, Shaun ; Hardoim, Cristiane C.P. ; Wu, Yu Chen ; McCormack, Grace P. ; López-Legentil, Susanna ; Marchant, Roman ; Webster, Nicole ; Thomas, Torsten ; Hentschel, Ute - \ 2017
    Frontiers in Microbiology 8 (2017). - ISSN 1664-302X - 14 p.
    16S rRNA gene - Marine sponges - Microbial diversity - Microbiome - Random forest - Symbiosis

    The dichotomy between high microbial abundance (HMA) and low microbial abundance (LMA) sponges has been observed in sponge-microbe symbiosis, although the extent of this pattern remains poorly unknown. We characterized the differences between the microbiomes of HMA (n = 19) and LMA (n = 17) sponges (575 specimens) present in the Sponge Microbiome Project. HMA sponges were associated with richer and more diverse microbiomes than LMA sponges, as indicated by the comparison of alpha diversity metrics. Microbial community structures differed between HMA and LMA sponges considering Operational Taxonomic Units (OTU) abundances and across microbial taxonomic levels, from phylum to species. The largest proportion of microbiome variation was explained by the host identity. Several phyla, classes, and OTUs were found differentially abundant in either group, which were considered "HMA indicators" and "LMA indicators." Machine learning algorithms (classifiers) were trained to predict the HMA-LMA status of sponges. Among nine different classifiers, higher performances were achieved by Random Forest trained with phylum and class abundances. Random Forest with optimized parameters predicted the HMA-LMA status of additional 135 sponge species (1,232 specimens) without a priori knowledge. These sponges were grouped in four clusters, from which the largest two were composed of species consistently predicted as HMA (n = 44) and LMA (n = 74). In summary, our analyses shown distinct features of the microbial communities associated with HMA and LMA sponges. The prediction of the HMA-LMA status based on the microbiome profiles of sponges demonstrates the application of machine learning to explore patterns of host-associated microbial communities.

    Animals and us: history, exciting developments, cross-pollination and new directions for applied ethology research
    Brown, J. ; Seddon, Y. ; Rault, J.L. ; Doyle, R. ; Jensen, P. ; Rodenburg, T.B. ; Marchant-Forde, J. - \ 2016
    In: Proceedings of the 50th congress of the International Society for Applied Ethology. - Wageningen : Wageningen Academic Publishers - ISBN 9789086862870 - p. 112 - 112.
    Applied ethology is a relatively new eld, which has grown rapidly in scope, geographical distribution and in€uence since the inception of the SVE/ISAE in 1966. There has been limited historical documentation of the eld, and students new to the area have little information available to understand the history of this science beyond what is found in journal publications.
    To address this gap, several ISAE members and a‚liated researchers have compiled a book, ‘Animals and us: 50 years and more of applied ethology’ which documents and celebrates the rst 50 years of the ISAE. The book is written in four parts, including: (1) the history of the society and early pioneers; (2) research advances in behaviour; (3) global perspectives;
    and (4) future directions for applied ethology research. Contributing authors include many leading researchers in the field- too numerous to mention here. This presentation will explore highlights from the text related to achievements, trends in research, collaborative studies with other elds, and new directions for both basic and applied research, all in an attempt to explain why ethologists are so passionate about their work, and why this eld remains more exciting now than ever before. �emes include human-animal interaction, personality, play
    behaviour, cognition, multi-level selection, polyvagal theory, and the relationship between applied ethology and animal welfare science. We conclude that other animals, with their amazing and various forms and habits, may be the perfect human enrichment.
    Future directions for applied ethology
    Marchant-Forde, J. ; Rodenburg, T.B. - \ 2016
    In: Animals and Us Wageningen Academic Publishers - ISBN 9789086862825 - p. 297 - 318.
    It is the expectation that the world population will grow to 9 billion people by 2050. There is no doubt that this dramatic increase will impact all of the animals with which we share this planet. A global population growing in size and affluence will greatly increase demand for food from animal sources, meaning global growth in livestock production. More livestock production means changes in land use, with more land being converted to grazing or animal feedstuff production, and more production of waste to be applied back to the land, together impacting natural habitats and wildlife species diversity. Greater affluence also means greater companion animal ownership, further increasing demand for food from animal sources, increasing feral populations with potential impacts on human health and wildlife diversity. In this chapter, we will attempt to gaze into the crystal ball and identify some future directions for applied ethology and for our Society. There is no doubt that applied ethologists can have exciting roles to play in shaping and safeguarding the welfare of domestic animals and wild animals in captivity, and also feral and wild animals living in their natural habitat, either impacting or being impacted by humans
    Continental-scale variability in browser diversity is a major driver of diversity patterns in acacias across
    Greve, M. ; Lykke, A.M. ; Fagg, C. ; Bogaert, J. ; Friis, I. ; Marchant, R. ; Marshall, A.R. ; Ndayishimiye, J. ; Sandel, B.S. ; Sandom, C. ; Schmidt, M. ; Timberlake, J.R. ; Wieringa, J.J. ; Zizka, G. ; Svenning, J. - \ 2012
    Journal of Ecology 100 (2012)5. - ISSN 0022-0477 - p. 1093 - 1104.
    plant-species richness - climate-change - spatial autocorrelation - autoregressive models - savanna - distributions - tree - determinants - herbivores - gradients
    1. It has been proposed that, across broad spatial scales, climatic factors are the main drivers of ecological patterns, while biotic factors are mainly important at local spatial scales. However, few tests of the effect of biotic interactions on broad-scale patterns have been conducted; conclusions about the scale-dependence of the importance of biotic interactions thus seem premature. 2. We developed an extensive database of locality records of one of Africa’s most conspicuous groups, the acacias (the genera Senegalia and Vachellia), and used species distribution models (SDMs) to estimate the distribution of all African acacias. 3. African acacias are particularly well adapted against mammalian herbivory; therefore, we hypothesized that browser diversity could be an important driver of acacia richness. Species richness maps for the two genera were created from SDM-generated maps. Ordinary least square (OLS) regressions and, to consider spatial autocorrelation, simultaneous autoregressive (SAR) analyses were used to model richness of the two genera in relation to mammalian browser richness, current environment (including climate), and climate history since the Last Glacial Maximum (LGM). We used variation partitioning to determine what percentage of variation could be explained by these three groups of factors. 4. Both genera showed centres of richness in East Africa and the Limpopo Basin of southern Africa. Browser richness was the best explanatory variable for richness of both genera. Environmental factors explained negligible variation in the richness of Senegalia, but some variation in Vachellia. For both genera, the residuals of the species richness model of one genus also explained much variation in the richness of the other genus, indicating that common factors not considered in the richness analyses here may additionally be driving the richness of both genera. 5. Mechanisms that could generate a correlation between browser and acacia richness are proposed, and differences in the determinants of richness patterns of Senegalia and Vachellia discussed in the light of the two genera’s history of colonization of Africa. 6. Synthesis. This is the first study that demonstrates that consumer diversity can influence richness patterns at continental scales and demonstrates that biotic factors can drive richness even at broad spatial scales.
    Behavior in natural and captive environments compared to assess and enhance welfare of zoo animals
    Koene, P. - \ 2011
    In: Proceedings of the 45th Congress of the International Society for Applied Ethology (ISAE), Indianapolis, USA, 31 July - 4 August 2011. - Wageningen, The Netherlands : Wageningen Academic Publishers - p. 6 - 6.
    How do different amounts of solid feed in the diet affect time spent performing abnormal oral behaviours in veal calves?
    Webb, L.E. ; Bokkers, E.A.M. ; Reenen, C.G. van - \ 2011
    In: Proceedings of the 45th Congress of the International Society for Applied Ethology (ISAE), 30 July - 4 August 2011, Indianapolis, USA. - Wageningen Academic Publishers - p. 67 - 67.
    Maternal care and selection for low mortality affect immune competence of laying hens
    Rodenburg, T.B. ; Bolhuis, J.E. ; Ellen, E.D. ; Vries Reilingh, G. de; Nieuwland, M.G.B. ; Koopmanschap, R.E. ; Parmentier, H.K. - \ 2011
    In: Proceedings of the 45th Congress of the International Society for Applied Ethology (ISAE), 31 July - 4 August 2011, Indianapolis, USA. - Wageningen, The Netherlands : Wageningen Academic Publishers - ISBN 9789086861798 - p. 30 - 30.
    Feather pecking and serotonin: 'the chicken or the egg?'
    Kops, M. ; Bolhuis, J.E. ; Haas, E.N. de; Korte-Bouws, G.A.H. ; Rodenburg, T.B. ; Olivier, B. ; Korte, S.M. - \ 2011
    In: Proceedings of the 45th Congress of the International Society for Applied Ethology (ISAE), 31 July - 4 August 2011, Indianapolis, USA. - Wageningen, The Netherlands : Wageningen Academic Publishers - ISBN 9789086861798 - p. 49 - 49.
    The relationship between fearfulness at a young age and stress responses in the later life of laying hens
    Haas, E.N. de; Kops, M. ; Bolhuis, J.E. ; Rodenburg, T.B. - \ 2011
    In: Proceedings of the 45th Congress of the International Society for Applied Ethology (ISAE), 31 July - 4 August 2011, Indianapolis, USA. - Wageningen, The Netherlands : Wageningen Academic Publishers - ISBN 9789086861798 - p. 19 - 19.
    Learning how to eat like a pig: effectiveness of mechanisms for vertical social learning in piglets
    Oostindjer, M. ; Bolhuis, J.E. ; Mendl, M. ; Held, S. ; Brand, H. van den; Kemp, B. - \ 2011
    In: Proceedings of the 45th Congress of the International Society for Applied Ethology (ISAE), 31 July - 4 August 2011. - Wageningen, The Netherlands : Wageningen Academic Publishers - ISBN 9789086861798 - p. 33 - 33.
    Wildlife management in Gonarezhou National Park, southeast Zimbabwe: Climate change and implications for management
    Gandiwa, E. ; Zisadza, P. - \ 2010
    Nature and Faune 25 (2010)1. - ISSN 2026-5611 - p. 95 - 104.
    Climate change is not a new phenomenon; the only constant about climate throughout Earth’s history is that it has changed (Marchant, 2010). An earlier study in Africa indicated that some Southern African ecosystems are highly sensitive to climate change (e.g., Magadza, 1994). Climate change in Africa is expected to lead to higher occurrence of severe droughts in semiarid and arid ecosystems (Foley et al., 2008). For instance, a severe drought associated with the El Niño-Southern Oscillation phenomenon was recorded in 1991–92 in Southern Africa. In Zimbabwe, the most affected areas in terms of wildlife and ecological systems in the 1991–92 drought were recorded in the southeastern parts of the country (Magadza, 1994).
    Pollen-based biome reconstructions for Latin America at 0, 6000 and 18 000 radiocarbon years
    Marchant, R. ; Harrison, S.P. ; Hooghiemstra, H. ; Cleef, A.M. ; Hammen, T. van der; Wille, M. - \ 2009
    Climate of the Past Discussions 5 (2009)1. - ISSN 1814-9340 - p. 369 - 461.
    The biomisation method is used to reconstruct Latin American vegetation at 6000±500 and 18 000±1000 radiocarbon years before present (14C yr BP) from pollen data. Tests using modern pollen data from 381 samples derived from 287 locations broadly reproduce potential natural vegetation. The strong temperature gradient associated with the Andes is recorded by a transition from high altitude cool grass/shrubland and cool mixed forest to mid-altitude cool temperate rain forest, to tropical dry, seasonal and rain forest at low altitudes. Reconstructed biomes from a number of sites do not match the potential vegetation due to local factors such as human impact, methodological artefacts and mechanisms of pollen representivity of the parent vegetation. At 6000±500 14C yr BP 255 samples are analysed from 127 sites. Differences between the modern and the 6000±500 14C yr BP reconstruction are comparatively small. Patterns of change relative to the modern reconstruction are mainly to biomes characteristic of drier climate in the north of the region with a slight more mesic shift in the south. Cool temperate rain forest remains dominant in western South America. In northwestern South America a number of sites record transitions from tropical seasonal forest to tropical dry forest and tropical rain forest to tropical seasonal forest. Sites in Central America also show a change in biome assignment to more mesic vegetation, indicative of greater plant available moisture, e.g. on the Yucatán peninsula sites record warm evergreen forest, replacing tropical dry forest and warm mixed forest presently recorded. At 18 000±1000 14C yr BP 61 samples from 34 sites record vegetation that reflects a generally cool and dry environment. Cool grass/shrubland prevalent in southeast Brazil, Amazonian sites record tropical dry forest, warm temperate rain forest and tropical seasonal forest. Southernmost South America is dominated by cool grass/shrubland, a single site retains cool temperate rain forest indicating that forest was present at some locations at the LGM. Some sites in Central México and lowland Colombia remain unchanged in their biome assignments, although the affinities that these sites have to different biomes do change between 18 000±1000 14C yr BP and present. The "unresponsive" nature of these sites results from their location and the impact of local edaphic influence
    Distribution and ecology of pollen lodged within the Latin American Pollen Database
    Marchant, R. ; Almeida, L. ; Behling, H. ; Berrío, J.C. ; Bush, M. ; Cleef, A.M. ; Duivenvoorden, J. ; Kappelle, M. ; Oliveira, P. de; Texeira de Oliviera-Filho, A. ; Lozano-García, S. ; Hooghiemstra, H. - \ 2002
    Review of Palaeobotany and Palynology 121 (2002)1. - ISSN 0034-6667 - p. 1 - 75.
    The cornerstone of palaeoecological research, concerned with vegetation dynamics over the recent geological past, is a good understanding of the present-day ecology and distribution of the taxa. This is particularly necessary in areas of high floral diversity such as Latin America. Vegetation reconstructions, based on numerous pollen records, now exist with respect to all major vegetation associations from Latin America. With this ever-increasing number of sedimentary records becoming available, there is a need to collate this information and to provide information concerning ecology and distribution of the taxa concerned. The existing Latin American Pollen Database (LAPD) meets the first of these needs. Information concerning the ecology and distribution of the parent taxa responsible for producing the pollen, presently lodged within the LAPD, is the focus of this paper. The `dictionary' describes the ecology and distribution of the parent taxa responsible for producing pollen identified within sedimentary records. These descriptions are based on a wide range of literature and extensive discussions with members of the palaeoecological community working in different parts of Latin America investigating a range of different vegetation types.
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