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127 results on '"Siebert, Stefan J."'

1. The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Author

Clements, Hayley S., Do Linh San, Emmanuel, Hempson, Gareth, Linden, Birthe, Maritz, Bryan, Monadjem, Ara, Reynolds, Chevonne, Siebert, Frances, Stevens, Nicola, Biggs, Reinette, De Vos, Alta, Blanchard, Ryan, Child, Matthew, Esler, Karen J., Hamann, Maike, Loft, Ty, Reyers, Belinda, Selomane, Odirilwe, Skowno, Andrew L., Tshoke, Tshegofatso, Abdoulaye, Diarrassouba, Aebischer, Thierry, Aguirre-Gutiérrez, Jesús, Alexander, Graham J., Ali, Abdullahi H., Allan, David G., Amoako, Esther E., Angedakin, Samuel, Aruna, Edward, Avenant, Nico L., Badjedjea, Gabriel, Bakayoko, Adama, Bamba-kaya, Abraham, Bates, Michael F., Bates, Paul J. J., Belmain, Steven R., Bennitt, Emily, Bradley, James, Brewster, Chris A., Brown, Michael B., Brown, Michelle, Bryja, Josef, Butynski, Thomas M., Carvalho, Filipe, Channing, Alan, Chapman, Colin A., Cohen, Callan, Cords, Marina, Cramer, Jennifer D., Cronk, Nadine, Cunneyworth, Pamela M. K., Dalerum, Fredrik, Danquah, Emmanuel, Davies-Mostert, Harriet T., de Blocq, Andrew D., De Jong, Yvonne A., Demos, Terrence C., Denys, Christiane, Djagoun, Chabi A. M. S., Doherty-Bone, Thomas M., Drouilly, Marine, du Toit, Johan T., Ehlers Smith, David A., Ehlers Smith, Yvette C., Eiseb, Seth J., Fashing, Peter J., Ferguson, Adam W., Fernández-García, José M., Finckh, Manfred, Fischer, Claude, Gandiwa, Edson, Gaubert, Philippe, Gaugris, Jerome Y., Gibbs, Dalton J., Gilchrist, Jason S., Gil-Sánchez, Jose M., Githitho, Anthony N., Goodman, Peter S., Granjon, Laurent, Grobler, J. Paul, Gumbi, Bonginkosi C., Gvozdik, Vaclav, Harvey, James, Hauptfleisch, Morgan, Hayder, Firas, Hema, Emmanuel M., Herbst, Marna, Houngbédji, Mariano, Huntley, Brian J., Hutterer, Rainer, Ivande, Samuel T., Jackson, Kate, Jongsma, Gregory F. M., Juste, Javier, Kadjo, Blaise, Kaleme, Prince K., Kamugisha, Edwin, Kaplin, Beth A., Kato, Humphrey N., Kiffner, Christian, Kimuyu, Duncan M., Kityo, Robert M., Kouamé, N’goran G., Kouete T, Marcel, le Roux, Aliza, Lee, Alan T. K., Lötter, Mervyn C., Lykke, Anne Mette, MacFadyen, Duncan N., Macharia, Gacheru P., Madikiza, Zimkitha J. K., Mahlaba, Themb’alilahlwa A. M., Mallon, David, Mamba, Mnqobi L., Mande, Claude, Marchant, Rob A., Maritz, Robin A., Markotter, Wanda, McIntyre, Trevor, Measey, John, Mekonnen, Addisu, Meller, Paulina, Melville, Haemish I., Mganga, Kevin Z., Mills, Michael G. L., Minnie, Liaan, Missoup, Alain Didier, Mohammad, Abubakr, Moinde, Nancy N., Moise, Bakwo Fils E., Monterroso, Pedro, Moore, Jennifer F., Musila, Simon, Nago, Sedjro Gilles A., Namoto, Maganizo W., Niang, Fatimata, Nicolas, Violaine, Nkenku, Jerry B., Nkrumah, Evans E., Nono, Gonwouo L., Norbert, Mulavwa M., Nowak, Katarzyna, Obitte, Benneth C., Okoni-Williams, Arnold D., Onongo, Jonathan, O’Riain, M. Justin, Osinubi, Samuel T., Parker, Daniel M., Parrini, Francesca, Peel, Mike J. S., Penner, Johannes, Pietersen, Darren W., Plumptre, Andrew J., Ponsonby, Damian W., Porembski, Stefan, Power, R. John, Radloff, Frans G. T., Rambau, Ramugondo V., Ramesh, Tharmalingam, Richards, Leigh R., Rödel, Mark-Oliver, Rollinson, Dominic P., Rovero, Francesco, Saleh, Mostafa A., Schmiedel, Ute, Schoeman, M. Corrie, Scholte, Paul, Serfass, Thomas L., Shapiro, Julie Teresa, Shema, Sidney, Siebert, Stefan J., Slingsby, Jasper A., Sliwa, Alexander, Smit-Robinson, Hanneline A., Sogbohossou, Etotepe A., Somers, Michael J., Spawls, Stephen, Streicher, Jarryd P., Swanepoel, Lourens, Tanshi, Iroro, Taylor, Peter J., Taylor, William A., te Beest, Mariska, Telfer, Paul T., Thompson, Dave I., Tobi, Elie, Tolley, Krystal A., Turner, Andrew A., Twine, Wayne, Van Cakenberghe, Victor, Van de Perre, Frederik, van der Merwe, Helga, van Niekerk, Chris J. G., van Wyk, Pieter C. V., Venter, Jan A., Verburgt, Luke, Veron, Geraldine, Vetter, Susanne, Vorontsova, Maria S., Wagner, Thomas C., Webala, Paul W., Weber, Natalie, Weier, Sina M., White, Paula A., Whitecross, Melissa A., Wigley, Benjamin J., Willems, Frank J., Winterbach, Christiaan W., and Woodhouse, Galena M.

Published
2024
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2. Specific leaf area is lower on ultramafic than on neighbouring non-ultramafic soils

Author

Samojedny, Thomas J, Garnica-Díaz, Claudia, Grossenbacher, Dena L, Adamidis, George C, Dimitrakopoulos, Panayiotis G, Siebert, Stefan J, Spasojevic, Marko J, Hulshof, Catherine M, and Rajakaruna, Nishanta

Subjects
Agricultural, Veterinary and Food Sciences, Agriculture, Land and Farm Management, Biological Sciences, Edaphic, extreme environments, functional trait, leaf economic spectrum, serpentine syndrome, stress resistance syndrome, specific leaf area, Ecological Applications, Ecology, Plant Biology, Forestry sciences, Plant biology
Published
2022

3. Global Plant Ecology of Tropical Ultramafic Ecosystems

Author

Garnica-Diaz, Claudia, Iturralde, Rosalina Berazain, Cabrera, Betsaida, Calderon-Morales, Erick, Felipe, Fermin L., Garcia, Ricardo, Hechavarria, Jose Luis Gomez, Guimaraes, Aretha Franklin, Medina, Ernesto, Paul, Adrian L.D., Rajakaruna, Nishanta, Restrepo, Carla, Siebert, Stefan J., van den Berg, Eduardo, van der Ent, Antony, Velasquez, Grisel, and Hulshof, Catherine M.

Subjects
Tropical plants -- Distribution -- Growth, Soil ecology, Botanical research, Company growth, Company distribution practices, Biological sciences
Abstract

Ultramafic ecosystems are renowned for high endemism and habitat specialization. However, most of our understanding of ultramafic plant ecology comes from Mediterranean and temperate climes, raising questions about the generalizability of plant responses to ultramafic soils. This is especially apparent in tropical ultramafic ecosystems which exhibit a wide range of endemism and differentiation between ultramafic and adjacent non-ultramafic soils. Our objectives were two-fold: 1) synthesize our understanding of tropical ultramafic plant ecology, paying particular attention to generalities that may explain variation in endemism and habitat specialization among tropical ultramafic ecosystems; and 2) define an interdisciplinary research agenda using tropical ultramafic ecosystems as a macroecological model. We demonstrate that tropical ultramafic floras are diverse and variable in plant form and function due to the interactive effects of biogeography, climate, and edaphic properties. The variable rates of endemism, specialization, and stress tolerance traits across tropical ultramafic ecosystems have implications for the management and conservation of these diverse systems. Los ecosistemas ultramaficos son reconocidos por su endemismo y especializacion del habitat. Sin embargo, la mayor parte de nuestra comprension de la ecologia vegetal ultramafica proviene de climas mediterraneos y templados, lo que plantea dudas sobre la generalizacion de las respuestas de las plantas a los suelos ultramaficos. Esto es especialmente evidente en los ecosistemas tropicales ultramaficos que exhiben una amplia gama de endemismo y diferenciacion entre suelos tropicales ultramaficos y no ultramaficos adyacentes. Nosotros teniamos dos objetivos: 1) sintetizar nuestra comprension actual de la ecologia de las plantas tropicales ultramaficas, prestando especial atencion a las generalidades que pueden explicar la variacion en el endemismo y la especializacion del habitat entre los ecosistemas tropicales ultramaficos; y 2) definir una agenda de investigacion interdisciplinaria utilizando ecosistemas ultramaficos tropicales como modelo macroecologico. Las floras tropicales ultramaficas son diversas y variables en la forma y funcion de las plantas debido a los efectos interactivos de la biogeografia, el clima y las propiedades edaficas. Las tasas variables de endemismo, especializacion y rasgos de tolerancia al estres en los ecosistemas tropicales ultramaficos tienen implicaciones para el manejo y conservacion de estos diversos sistemas. Keywords Edaphic * Endemism * Hyperaccumulator * Metallophyte * Serpentine * Unusual soil, Introduction Ultramafic (serpentine) soils have long attracted scientific attention due to their specialized flora and ecological and evolutionary implications. However, our understanding of ultramafic plant ecology remains dominated by research [...]

Published
2023
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8. Crinum bulbispermum , a Medicinal Geophyte with Phytostabilization Properties in Metal-Enriched Mine Tailings.

Author

Clarke, Vincent C., Marcelo-Silva, João, Claassens, Sarina, and Siebert, Stefan J.

Subjects
INDUCTIVELY coupled plasma mass spectrometry, PHYTOREMEDIATION, HEAVY metals, GRASSLAND restoration, MINE soils, ACID mine drainage, HYPERACCUMULATOR plants, PLATEAUS, METAL tailings
Abstract

Ancient grasslands are lost through transformation to agriculture, mining, and urban expansion. Land-use change leads to ecosystem degradation and a subsequent loss of biodiversity. Globally, degraded grasslands have become a priority for restoration efforts to recover lost ecosystem services. Although the ecological and social benefits of woody species and grasses are well documented, limited research has considered the use of forbs for restoration purposes despite their benefits (e.g., C sequestration and medicinal uses). The aim of this study was to determine if Crinum bulbispermum (Burm.f.) Milne-Redh. & Schweick., a medicinal geophyte, could form part of restoration initiatives to restore mine soils in grasslands of the South African Highveld. A pot experiment was conducted to assess the performance of C. bulbispermum in a random design, with three soil treatments varying in level of degradation and metal contamination. The plants were monitored for 12 months, and the morphological characters were measured monthly to assess performance and survival. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the soil and plant tissue concentration of potentially toxic metals. The results indicated that mine tailings negatively affected the growth and development of C. bulbispermum. Although the survival rates indicated that it could survive on tailings, its below-par productivity indicated that the species is not ideal for restoration purposes unless the tailings are ameliorated with topsoil. Although there was root accumulation of metals (Co, Cd, Cu, Mo, and Zn), there was no translocation to the bulbs and leaves, which makes C. bulbispermum suitable for medicinal use even when grown on metal-enriched soil. This species may not be viable for phytoremediation but is a contender to be used in phytostabilization due to its ecological advantages and the fact that it does not accumulate or store metals. These findings underscore the importance of considering geophytes in grassland restoration strategies, expanding their ecological and societal benefits beyond conventional approaches. [ABSTRACT FROM AUTHOR]

Published
2024
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13. The effect of rainfall amount and timing on annual transpiration in a grazed savanna grassland

Author

Räsänen, Matti, primary, Aurela, Mika, additional, Vakkari, Ville, additional, Beukes, Johan P., additional, Tuovinen, Juha-Pekka, additional, Van Zyl, Pieter G., additional, Josipovic, Miroslav, additional, Siebert, Stefan J., additional, Laurila, Tuomas, additional, Kulmala, Markku, additional, Laakso, Lauri, additional, Rinne, Janne, additional, Oren, Ram, additional, and Katul, Gabriel, additional

Published
2022
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16. Global Plant Ecology of Tropical Ultramafic Ecosystems

Author

Garnica-Díaz, Claudia, primary, Berazaín Iturralde, Rosalina, additional, Cabrera, Betsaida, additional, Calderón-Morales, Erick, additional, Felipe, Fermín L., additional, García, Ricardo, additional, Hechavarría, José Luis Gómez, additional, Guimarães, Aretha Franklin, additional, Medina, Ernesto, additional, Paul, Adrian L. D., additional, Rajakaruna, Nishanta, additional, Restrepo, Carla, additional, Siebert, Stefan J., additional, van den Berg, Eduardo, additional, van der Ent, Antony, additional, Velasquez, Grisel, additional, and M. Hulshof, Catherine, additional

Published
2022
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21. Supplementary material to "The effect of rainfall amount and timing on annual transpiration in a grazed savanna grassland"

Author

Räsänen, Matti, primary, Aurela, Mika, additional, Vakkari, Ville, additional, Beukes, Johan P., additional, Tuovinen, Juha-Pekka, additional, Van Zyl, Pieter G., additional, Josipovic, Miroslav, additional, Siebert, Stefan J., additional, Laurila, Tuomas, additional, Kulmala, Markku, additional, Laakso, Lauri, additional, Rinne, Janne, additional, Oren, Ram, additional, and Katul, Gabriel, additional

Published
2021
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22. The effect of rainfall amount and timing on annual transpiration in a grazed savanna grassland

Author

Räsänen, Matti, primary, Aurela, Mika, additional, Vakkari, Ville, additional, Beukes, Johan P., additional, Tuovinen, Juha-Pekka, additional, Van Zyl, Pieter G., additional, Josipovic, Miroslav, additional, Siebert, Stefan J., additional, Laurila, Tuomas, additional, Kulmala, Markku, additional, Laakso, Lauri, additional, Rinne, Janne, additional, Oren, Ram, additional, and Katul, Gabriel, additional

Published
2021
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24. A research agenda for the restoration of tropical and subtropical grasslands and savannas

Author

Buisson, Elise, primary, Fidelis, Alessandra, additional, Overbeck, Gerhard E., additional, Schmidt, Isabel B., additional, Durigan, Giselda, additional, Young, Truman P., additional, Alvarado, Swanni T., additional, Arruda, André J., additional, Boisson, Sylvain, additional, Bond, William, additional, Coutinho, André, additional, Kirkman, Kevin, additional, Oliveira, Rafael S., additional, Schmitt, Melissa H., additional, Siebert, Frances, additional, Siebert, Stefan J., additional, Thompson, Dave I., additional, and Silveira, Fernando A. O., additional

Published
2020
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26. Rehabilitation of kimberlite tailings in the afro‐alpine zone of Lesotho: seed germination and plant performance of native grassland species across different topsoil mixtures.

Author

Ntloko, Bongani R., Siebert, Stefan J., and Mokotjomela, Thabiso M.

Subjects
*PLANT performance, *KIMBERLITE, *GERMINATION, *TOPSOIL, *NATIVE plants, *DIAMOND mining
Abstract

Environmental rehabilitation is mandatory for mining operations in many countries, including Lesotho. At Letšeng Diamond Mine in Lesotho, waste residues of kimberlite tailings create a hostile environment for the establishment of plant species during vegetation restoration. In this study, we investigated seed germination of native grassland species and tested the best performing species on different topsoil mixtures with kimberlite tailings in the Afro‐alpine zone in Lesotho. Rapid germination tests showed highly significant differences in the number of seedlings that emerged for different plant species: the grass Tenaxia disticha (% mean ± SE: 80 ± 17%; n = 36) and the forb Hesperantha schelpeana (56 ± 14%) were highest but nonsignificantly different to each other, while other species were significantly lower and nonsignificantly different to each other. In all treatments, seed germination of T. disticha was significantly higher than the experimental control, while the treatments that were covered with topsoil did not differ significantly. In addition, T. disticha seedling height and basal width varied significantly over time with seedlings in all the treatments growing significantly taller than those in the experimental control. Also, seedling basal width showed significant increase during the third growing season while height remained constant. We concluded that kimberlite tailings ameliorated with topsoil encourage plant establishment and performance of T. disticha, and this medium could be used to stabilize disturbed mine landscapes in the Afro‐alpine zone of Lesotho. [ABSTRACT FROM AUTHOR]

Published
2022
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27. Myth‐busting tropical grassy biome restoration

Author

Silveira, Fernando A. O., primary, Arruda, André J., additional, Bond, William, additional, Durigan, Giselda, additional, Fidelis, Alessandra, additional, Kirkman, Kevin, additional, Oliveira, Rafael S., additional, Overbeck, Gerhard E., additional, Sansevero, Jerônimo B. B, additional, Siebert, Frances, additional, Siebert, Stefan J., additional, Young, Truman P., additional, and Buisson, Elise, additional

Published
2020
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29. The effect of rainfall amount and timing on annual transpiration in grazed savanna grassland

Author

Räsänen, Matti, primary, Aurela, Mika, additional, Vakkari, Ville, additional, Beukes, Johan P., additional, Tuovinen, Juha-Pekka, additional, Van Zyl, Pieter G., additional, Josipovic, Miroslav, additional, Siebert, Stefan J., additional, Laurila, Tuomas, additional, Kulmala, Markku, additional, Laakso, Lauri, additional, Rinne, Janne, additional, Oren, Ram, additional, and Katul, Gabriel, additional

Published
2020
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30. Supplementary material to "The effect of rainfall amount and timing on annual transpiration in grazed savanna grassland"

Author

Räsänen, Matti, primary, Aurela, Mika, additional, Vakkari, Ville, additional, Beukes, Johan P., additional, Tuovinen, Juha-Pekka, additional, Van Zyl, Pieter G., additional, Josipovic, Miroslav, additional, Siebert, Stefan J., additional, Laurila, Tuomas, additional, Kulmala, Markku, additional, Laakso, Lauri, additional, Rinne, Janne, additional, Oren, Ram, additional, and Katul, Gabriel, additional

Published
2020
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32. The effect of rainfall amount and timing on annual transpiration in a grazed savanna grassland.

Author

Rasanen, Matti, Aurela, Mika, Vakkari, Ville, Beukes, Johan P., Tuovinen, Juha-Pekka, Zyl, Pieter G. Van, Josipovic, Miroslav, Siebert, Stefan J., Laurila, Tuomas, Kulmala, Markku, Laakso, Lauri, Rinne, Janne, Oren, Ram, and Katul, Gabriel

Abstract

The role of precipitation (P) variability on evapotranspiration (ET) and its two components, transpiration (T) and evaporation (E) from savannas, continues to draw significant research interest given its relevance to a number of eco-hydrological applications. Our study reports on six years of measured ET and estimated T and E from a grazed savanna grassland in Welgegund, South Africa. Annual P varied significantly in amount (508 to 672 mm yr-1), with dry years characterized by infrequent early-season rainfall. T was determined using annual water-use efficiency and gross primary production estimates derived from eddy covariance measurements of latent heat flux and net ecosystem CO2 exchange rates. The computed annual T was nearly constant, 331 ± 11 mm yr-1 (T/ET=0.52), for the four wet years with frequent early wet-season rainfall, whereas annual T was 268 and 175 mm yr-1 during the dry years. Annual T/ET was linearly related to the early wet-season storm frequency. The constancy of annual T during wet years is explained by the moderate water stress of C4 grass and constant annual tree transpiration covering 15% of the landscape. However, grass transpiration declines during dry spells. Moreover, grasses respond to water availability with a dieback-regrowth pattern, reducing leaf area and transpiration during drought. These changes lead to an anomalous monthly T/ET relation to leaf-area index (LAI). The results highlight the role of the C4 grass layer in the hydrological balance and suggest that the grass response to dry spells and drought is reasonably described by precipitation timing. [ABSTRACT FROM AUTHOR]

Published
2021
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33. The price of collecting life

Author

Smith, Gideon F., Steenkamp, Yolande, Klopper, Ronell R., Siebert, Stefan J., and Arnold, Trevor H.

Published
2003

34. A research agenda for the restoration of tropical and subtropical grasslands and savannas.

Author

Buisson, Elise, Fidelis, Alessandra, Overbeck, Gerhard E., Schmidt, Isabel B., Durigan, Giselda, Young, Truman P., Alvarado, Swanni T., Arruda, André J., Boisson, Sylvain, Bond, William, Coutinho, André, Kirkman, Kevin, Oliveira, Rafael S., Schmitt, Melissa H., Siebert, Frances, Siebert, Stefan J., Thompson, Dave I., and Silveira, Fernando A. O.

Subjects
GRASSLANDS, WILDLIFE reintroduction, SAVANNAS, CHEATGRASS brome, PRESCRIBED burning, VEGETATIVE propagation
Abstract

Despite growing recognition of the conservation value of grassy biomes, our understanding of how to restore biodiverse tropical and subtropical grassy biomes (grasslands and savannas; TGB) remains limited. Several tools have recently been identified for TGB restoration, including prescribed fires, appropriate management of livestock and wild herbivores, tree cutting and shrub removal, invasive species control, and the reintroduction of native grasses and forbs via seeding or transplants. However, additional research for improved TGB restoration is needed. This article aims to identify ecological research priorities for TGB restoration. The following points are crucial to scale up TGB restoration and meet the challenges of the UN Restoration Decade. Research should focus on: disentangling the reasons why TGB are often undervalued and misunderstood; mapping TGB restoration opportunities; identifying regions where TGB and other biomes naturally exist as alternative stable states; recognizing areas with natural regeneration potential to avoid unnecessary intervention; restoring soil conditions; disentangling factors driving low seed quality, determining germination requirements and developing vegetative propagation techniques for TGB species; disentangling the limiting factors and key ecological processes underlying seedling establishment and community assembly; improving and validating long‐term management to mimic natural disturbance regimes; setting the minimum attributes of desirable TGB in terms of structure, composition, functioning, and resilience; and improving monitoring of restoration outcomes. Such research has the potential to advance theory, policy, and practice in TGB restoration, ultimately resulting in long‐term benefits for people and nature in some of the more neglected ecosystems of our planet. [ABSTRACT FROM AUTHOR]

Published
2021
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35. Celtis sinensis Pers. (Ulmaceae) naturalised in northern South Africa and keys to distinguish between Celtis species commonly cultivated in urban environments

Author

Siebert, Stefan J., Struwig, Madeleen, Knoetze, Leandra, Komape, Dennis M., 12204145 - Siebert, Stefan John, 24676748 - Komape, Dennis Mmakgabo, 21215294 - Knoetze, Leandra, and 12516309 - Struwig, Madeleen

Subjects
naturalised, lcsh:QH1-199.5, Invasive, Urban open space, Highveld, Garden, Celtis sinensis, garden, urban open space, lcsh:General. Including nature conservation, geographical distribution, invasive, Naturalised
Abstract

BACKGROUND: Alien Celtis species are commonly cultivated in South Africa. They are easily confused with indigenous C. africana Burm.f. and are often erroneously traded as such. Celtis australis L. is a declared alien invasive tree. Celtis sinensis Pers. is not, but has become conspicuous in urban open spaces. OBJECTIVES: This study investigates the extent to which C. sinensis has become naturalised, constructs keys to distinguish between indigenous and cultivated Celtis species, and provides a descriptive treatment of C. sinensis. METHODS: Land-cover types colonised by C. sinensis were randomly sampled with 16 belt transects. Woody species were identified, counted and height measured to determine the population structure. C. africana and the three alien Celtis species were cultivated for 2 years and compared morphologically. RESULTS: Celtis sinensis, Ligustrum lucidum and Melia azedarach were found to be alien species, most abundant in urban areas. The population structure of C. sinensis corresponds to that of the declared invasive alien, M. azedarach. Although C. africana occurs naturally, it is not regularly cultivated. This is ascribed to erroneous plantings because of its resemblance to juvenile plants of C. sinensis. Keys are provided to identify Celtis species based on leaf shape and margin, and drupe characters. CONCLUSION: Celtis sinensis is naturalised in central South Africa, especially in urban open spaces and beginning to colonise natural areas. It is flagged as a species with invasive potential. Characteristics of the leaves and fruits allow for accurate identification of indigenous and alien Celtis species, both as juvenile or adult trees.

Published
2018

39. DATA Aggregation effects in regional yield simulations

Author

Hoffmann, Holger, Kersebaum, Kurt Christian, Zhao, Gang, Asseng, Senthold, Bindi, Marco, Cammarano, Davide, Constantin, Julie, Coucheney, Elsa, Dechow, Rene, Doro, Luca, Eckersten, Henrik, Gaiser, Thomas, Grosz, Balazs, Haas, Edwin, Kassie, Belay T., Kiese, Ralf, Klatt, Steffen, Kuhnert, Matthias, Lewan, Elisabet, Moriondo, Marco, Nendel, Claas, Raynal, Helene, Roggero, Pier Paolo, Rötter, Reimund Paul, Siebert, Stefan J., Sosa, Carmen, Specka, Xenia, Tao, Fulu, Teixeira, Edmar, Trombi, Giacomo, Yeluripati, Jagadeesh, Vanuytrecht, Eline, Wallach, Daniel, Wang, Enli, Weihermueller, Lutz, Zhao, Zhigan, Ewert, Frank, Institute of Crop Science and Resource Conservation, University of Bonn-Division of Plant Nutrition, Leibniz-Zentrum für Agrarlandschaftsforschung = Leibniz Centre for Agricultural Landscape Research (ZALF), INRES, Rheinische Friedrich-Wilhelms-Universität Bonn, University of Florida [Gainesville], University of Florence (UNIFI), The James Hutton Institute, UMR : AGroécologie, Innovations, TeRritoires, Ecole Nationale Supérieure Agronomique de Toulouse, Department of Soil and Environment, Swedish University of Agricultural Sciences (SLU), Thünen Institute of Climate Smart Agriculture, Texas A&M University System, Department of Crop Production Ecology, Institut für Meteorologie und Klimaforschung (IMK), Karlsruher Institut für Technologie (KIT), Agricultural and Biological Engineering, Institut für Meteorologie und Klimaforschung - Atmosphärische Umweltforschung (IMK-IFU), Biological and Environmental Sciences, University of Stirling, Unité de Mathématiques et Informatique Appliquées de Toulouse (MIAT INRA), Institut National de la Recherche Agronomique (INRA), Università degli Studi di Sassari, Department of Crop Sciences, University of Goettingen, Instutute of Landscape Biogeochemistry, Climate Impacts Group, New Zealand Institute for Plant and Food Research Limited, Department of Agri-Food Production and Environmental Sciences, University delgi Studi di Firenze, Information and Computational Sciences Group, Department of Earth and Environmental Sciences [Leuven] (EES), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), CSIRO, Institute of Bio- and Geosciences Agrosphere (IBG-3), China Agricultural University, Institute of Crop Science and Resource Conservation [Bonn] (INRES), University of Florida [Gainesville] (UF), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), AGroécologie, Innovations, teRritoires (AGIR), Institut National de la Recherche Agronomique (INRA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Departement of Soil and Environment, Institute for Meteorology and Climate Research (IMK), Karlsruhe Institute of Technology (KIT), Department of Agricultural and Biological Engineering [Gainesville] (UF|ABE), Institute of Food and Agricultural Sciences [Gainesville] (UF|IFAS), University of Florida [Gainesville] (UF)-University of Florida [Gainesville] (UF), University of Göttingen - Georg-August-Universität Göttingen, Plant & Food Research, and China Agricultural University (CAU)

Subjects
[SDV]Life Sciences [q-bio]
Abstract

Session: AgMIP: Advances in Crop & Soil Model Intercomparison and Improvement Oral; Regional yield simulations with process-based models often rely on input data of coarse spatial resolution (Ewert et al., 2015; Zhao et al., 2015). Using aggregated data as input for process-based models entails the risks of introducing so-called aggregation errors (AE). Such AE depend on the model structure in combination with the aggregation method, the type of aggregated data as well as its spatial heterogeneity. While the regional crop yield bias is usually

Published
2016

40. The effect of rainfall amount and timing on annual transpiration in grazed savanna grassland.

Author

Räsänen, Matti, Aurela, Mika, Vakkari, Ville, Beukes, Johan P., Tuovinen, Juha-Pekka, Van Zyl, Pieter G., Josipovic, Miroslav, Siebert, Stefan J., Laurila, Tuomas, Kulmala, Markku, Laakso, Lauri, Rinne, Janne, Oren, Ram, and Katul, Gabriel

Abstract

The role of precipitation (P) variability on evapotranspiration (ET) and its two components transpiration (T) and evaporation (E) rates from savannas continues to draw significant research interest given its relevance to a number of eco-hydrological applications. The work here reports on six years of measured ET and energy flux components, and estimated T from a grazed savanna grassland collected at a research site situated in Welgegund, South Africa. During this period, annual P varied considerably in amount (421 mm to 614 mm), rainy season length and precipitation intensity. T was estimated using annual water use efficiency and gross primary production determined from eddy-covariance measurements of net ecosystem CO2 exchange rates. The computed annual T was highly constrained to 352 ± 8 mm (T/ET = 0.55) for four wet years when rainfall was near or above the long-term mean. This is explained by the near constant annual tree transpiration and moderate water stress of C4 grasses during these years. In a drought year with intermittent rainfall, the annual ecosystem T was reduced due to grass dieback-regrowth that alters the temporal dynamics of bare soil cover and infiltration, and complicates monthly T/ET relation to leaf-area index (LAI). However, annual ET remains approximately equal to annual precipitation (P) even during the drought year due to increased soil evaporation. Indeed, at annual scales, ET ≈ P and annual T is conservative despite variation in amount and timing in rainfall, due to constant water use of mature trees, and the ability of C4 grasses to maintain transpiration at moderate water stress and effectively use pulsed rainfall. [ABSTRACT FROM AUTHOR]

Published
2020
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43. Carbon balance of a grazed savanna grassland ecosystem in South Africa

Author

Räsänen, Matti, primary, Aurela, Mika, additional, Vakkari, Ville, additional, Beukes, Johan P., additional, Tuovinen, Juha-Pekka, additional, Van Zyl, Pieter G., additional, Josipovic, Miroslav, additional, Venter, Andrew D., additional, Jaars, Kerneels, additional, Siebert, Stefan J., additional, Laurila, Tuomas, additional, Rinne, Janne, additional, and Laakso, Lauri, additional

Published
2017
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44. Measurements of biogenic volatile organic compounds at a grazed savannah grassland agricultural landscape in South Africa

Author

Jaars, Kerneels, primary, van Zyl, Pieter G., additional, Beukes, Johan P., additional, Hellén, Heidi, additional, Vakkari, Ville, additional, Josipovic, Micky, additional, Venter, Andrew D., additional, Räsänen, Matti, additional, Knoetze, Leandra, additional, Cilliers, Dirk P., additional, Siebert, Stefan J., additional, Kulmala, Markku, additional, Rinne, Janne, additional, Guenther, Alex, additional, Laakso, Lauri, additional, and Hakola, Hannele, additional

Published
2016
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45. The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project

Author

Hudson, Lawrence N., primary, Newbold, Tim, additional, Contu, Sara, additional, Hill, Samantha L. L., additional, Lysenko, Igor, additional, De Palma, Adriana, additional, Phillips, Helen R. P., additional, Alhusseini, Tamera I., additional, Bedford, Felicity E., additional, Bennett, Dominic J., additional, Booth, Hollie, additional, Burton, Victoria J., additional, Chng, Charlotte W. T., additional, Choimes, Argyrios, additional, Correia, David L. P., additional, Day, Julie, additional, Echeverría‐Londoño, Susy, additional, Emerson, Susan R., additional, Gao, Di, additional, Garon, Morgan, additional, Harrison, Michelle L. K., additional, Ingram, Daniel J., additional, Jung, Martin, additional, Kemp, Victoria, additional, Kirkpatrick, Lucinda, additional, Martin, Callum D., additional, Pan, Yuan, additional, Pask‐Hale, Gwilym D., additional, Pynegar, Edwin L., additional, Robinson, Alexandra N., additional, Sanchez‐Ortiz, Katia, additional, Senior, Rebecca A., additional, Simmons, Benno I., additional, White, Hannah J., additional, Zhang, Hanbin, additional, Aben, Job, additional, Abrahamczyk, Stefan, additional, Adum, Gilbert B., additional, Aguilar‐Barquero, Virginia, additional, Aizen, Marcelo A., additional, Albertos, Belén, additional, Alcala, E. L., additional, del Mar Alguacil, Maria, additional, Alignier, Audrey, additional, Ancrenaz, Marc, additional, Andersen, Alan N., additional, Arbeláez‐Cortés, Enrique, additional, Armbrecht, Inge, additional, Arroyo‐Rodríguez, Víctor, additional, Aumann, Tom, additional, Axmacher, Jan C., additional, Azhar, Badrul, additional, Azpiroz, Adrián B., additional, Baeten, Lander, additional, Bakayoko, Adama, additional, Báldi, András, additional, Banks, John E., additional, Baral, Sharad K., additional, Barlow, Jos, additional, Barratt, Barbara I. P., additional, Barrico, Lurdes, additional, Bartolommei, Paola, additional, Barton, Diane M., additional, Basset, Yves, additional, Batáry, Péter, additional, Bates, Adam J., additional, Baur, Bruno, additional, Bayne, Erin M., additional, Beja, Pedro, additional, Benedick, Suzan, additional, Berg, Åke, additional, Bernard, Henry, additional, Berry, Nicholas J., additional, Bhatt, Dinesh, additional, Bicknell, Jake E., additional, Bihn, Jochen H., additional, Blake, Robin J., additional, Bobo, Kadiri S., additional, Bóçon, Roberto, additional, Boekhout, Teun, additional, Böhning‐Gaese, Katrin, additional, Bonham, Kevin J., additional, Borges, Paulo A. V., additional, Borges, Sérgio H., additional, Boutin, Céline, additional, Bouyer, Jérémy, additional, Bragagnolo, Cibele, additional, Brandt, Jodi S., additional, Brearley, Francis Q., additional, Brito, Isabel, additional, Bros, Vicenç, additional, Brunet, Jörg, additional, Buczkowski, Grzegorz, additional, Buddle, Christopher M., additional, Bugter, Rob, additional, Buscardo, Erika, additional, Buse, Jörn, additional, Cabra‐García, Jimmy, additional, Cáceres, Nilton C., additional, Cagle, Nicolette L., additional, Calviño‐Cancela, María, additional, Cameron, Sydney A., additional, Cancello, Eliana M., additional, Caparrós, Rut, additional, Cardoso, Pedro, additional, Carpenter, Dan, additional, Carrijo, Tiago F., additional, Carvalho, Anelena L., additional, Cassano, Camila R., additional, Castro, Helena, additional, Castro‐Luna, Alejandro A., additional, Rolando, Cerda B., additional, Cerezo, Alexis, additional, Chapman, Kim Alan, additional, Chauvat, Matthieu, additional, Christensen, Morten, additional, Clarke, Francis M., additional, Cleary, Daniel F.R., additional, Colombo, Giorgio, additional, Connop, Stuart P., additional, Craig, Michael D., additional, Cruz‐López, Leopoldo, additional, Cunningham, Saul A., additional, D'Aniello, Biagio, additional, D'Cruze, Neil, additional, da Silva, Pedro Giovâni, additional, Dallimer, Martin, additional, Danquah, Emmanuel, additional, Darvill, Ben, additional, Dauber, Jens, additional, Davis, Adrian L. V., additional, Dawson, Jeff, additional, de Sassi, Claudio, additional, de Thoisy, Benoit, additional, Deheuvels, Olivier, additional, Dejean, Alain, additional, Devineau, Jean‐Louis, additional, Diekötter, Tim, additional, Dolia, Jignasu V., additional, Domínguez, Erwin, additional, Dominguez‐Haydar, Yamileth, additional, Dorn, Silvia, additional, Draper, Isabel, additional, Dreber, Niels, additional, Dumont, Bertrand, additional, Dures, Simon G., additional, Dynesius, Mats, additional, Edenius, Lars, additional, Eggleton, Paul, additional, Eigenbrod, Felix, additional, Elek, Zoltán, additional, Entling, Martin H., additional, Esler, Karen J., additional, de Lima, Ricardo F., additional, Faruk, Aisyah, additional, Farwig, Nina, additional, Fayle, Tom M., additional, Felicioli, Antonio, additional, Felton, Annika M., additional, Fensham, Roderick J., additional, Fernandez, Ignacio C., additional, Ferreira, Catarina C., additional, Ficetola, Gentile F., additional, Fiera, Cristina, additional, Filgueiras, Bruno K. C., additional, Fırıncıoğlu, Hüseyin K., additional, Flaspohler, David, additional, Floren, Andreas, additional, Fonte, Steven J., additional, Fournier, Anne, additional, Fowler, Robert E., additional, Franzén, Markus, additional, Fraser, Lauchlan H., additional, Fredriksson, Gabriella M., additional, Freire, Geraldo B., additional, Frizzo, Tiago L. M., additional, Fukuda, Daisuke, additional, Furlani, Dario, additional, Gaigher, René, additional, Ganzhorn, Jörg U., additional, García, Karla P., additional, Garcia‐R, Juan C., additional, Garden, Jenni G., additional, Garilleti, Ricardo, additional, Ge, Bao‐Ming, additional, Gendreau‐Berthiaume, Benoit, additional, Gerard, Philippa J., additional, Gheler‐Costa, Carla, additional, Gilbert, Benjamin, additional, Giordani, Paolo, additional, Giordano, Simonetta, additional, Golodets, Carly, additional, Gomes, Laurens G. L., additional, Gould, Rachelle K., additional, Goulson, Dave, additional, Gove, Aaron D., additional, Granjon, Laurent, additional, Grass, Ingo, additional, Gray, Claudia L., additional, Grogan, James, additional, Gu, Weibin, additional, Guardiola, Moisès, additional, Gunawardene, Nihara R., additional, Gutierrez, Alvaro G., additional, Gutiérrez‐Lamus, Doris L., additional, Haarmeyer, Daniela H., additional, Hanley, Mick E., additional, Hanson, Thor, additional, Hashim, Nor R., additional, Hassan, Shombe N., additional, Hatfield, Richard G., additional, Hawes, Joseph E., additional, Hayward, Matt W., additional, Hébert, Christian, additional, Helden, Alvin J., additional, Henden, John‐André, additional, Henschel, Philipp, additional, Hernández, Lionel, additional, Herrera, James P., additional, Herrmann, Farina, additional, Herzog, Felix, additional, Higuera‐Diaz, Diego, additional, Hilje, Branko, additional, Höfer, Hubert, additional, Hoffmann, Anke, additional, Horgan, Finbarr G., additional, Hornung, Elisabeth, additional, Horváth, Roland, additional, Hylander, Kristoffer, additional, Isaacs‐Cubides, Paola, additional, Ishida, Hiroaki, additional, Ishitani, Masahiro, additional, Jacobs, Carmen T., additional, Jaramillo, Víctor J., additional, Jauker, Birgit, additional, Hernández, F. Jiménez, additional, Johnson, McKenzie F., additional, Jolli, Virat, additional, Jonsell, Mats, additional, Juliani, S. Nur, additional, Jung, Thomas S., additional, Kapoor, Vena, additional, Kappes, Heike, additional, Kati, Vassiliki, additional, Katovai, Eric, additional, Kellner, Klaus, additional, Kessler, Michael, additional, Kirby, Kathryn R., additional, Kittle, Andrew M., additional, Knight, Mairi E., additional, Knop, Eva, additional, Kohler, Florian, additional, Koivula, Matti, additional, Kolb, Annette, additional, Kone, Mouhamadou, additional, Kőrösi, Ádám, additional, Krauss, Jochen, additional, Kumar, Ajith, additional, Kumar, Raman, additional, Kurz, David J., additional, Kutt, Alex S., additional, Lachat, Thibault, additional, Lantschner, Victoria, additional, Lara, Francisco, additional, Lasky, Jesse R., additional, Latta, Steven C., additional, Laurance, William F., additional, Lavelle, Patrick, additional, Le Féon, Violette, additional, LeBuhn, Gretchen, additional, Légaré, Jean‐Philippe, additional, Lehouck, Valérie, additional, Lencinas, María V., additional, Lentini, Pia E., additional, Letcher, Susan G., additional, Li, Qi, additional, Litchwark, Simon A., additional, Littlewood, Nick A., additional, Liu, Yunhui, additional, Lo‐Man‐Hung, Nancy, additional, López‐Quintero, Carlos A., additional, Louhaichi, Mounir, additional, Lövei, Gabor L., additional, Lucas‐Borja, Manuel Esteban, additional, Luja, Victor H., additional, Luskin, Matthew S., additional, MacSwiney G, M Cristina, additional, Maeto, Kaoru, additional, Magura, Tibor, additional, Mallari, Neil Aldrin, additional, Malone, Louise A., additional, Malonza, Patrick K., additional, Malumbres‐Olarte, Jagoba, additional, Mandujano, Salvador, additional, Måren, Inger E., additional, Marin‐Spiotta, Erika, additional, Marsh, Charles J., additional, Marshall, E. J. P., additional, Martínez, Eliana, additional, Martínez Pastur, Guillermo, additional, Moreno Mateos, David, additional, Mayfield, Margaret M., additional, Mazimpaka, Vicente, additional, McCarthy, Jennifer L., additional, McCarthy, Kyle P., additional, McFrederick, Quinn S., additional, McNamara, Sean, additional, Medina, Nagore G., additional, Medina, Rafael, additional, Mena, Jose L., additional, Mico, Estefania, additional, Mikusinski, Grzegorz, additional, Milder, Jeffrey C., additional, Miller, James R., additional, Miranda‐Esquivel, Daniel R., additional, Moir, Melinda L., additional, Morales, Carolina L., additional, Muchane, Mary N., additional, Muchane, Muchai, additional, Mudri‐Stojnic, Sonja, additional, Munira, A. Nur, additional, Muoñz‐Alonso, Antonio, additional, Munyekenye, B. F., additional, Naidoo, Robin, additional, Naithani, A., additional, Nakagawa, Michiko, additional, Nakamura, Akihiro, additional, Nakashima, Yoshihiro, additional, Naoe, Shoji, additional, Nates‐Parra, Guiomar, additional, Navarrete Gutierrez, Dario A., additional, Navarro‐Iriarte, Luis, additional, Ndang'ang'a, Paul K., additional, Neuschulz, Eike L., additional, Ngai, Jacqueline T., additional, Nicolas, Violaine, additional, Nilsson, Sven G., additional, Noreika, Norbertas, additional, Norfolk, Olivia, additional, Noriega, Jorge Ari, additional, Norton, David A., additional, Nöske, Nicole M., additional, Nowakowski, A. Justin, additional, Numa, Catherine, additional, O'Dea, Niall, additional, O'Farrell, Patrick J., additional, Oduro, William, additional, Oertli, Sabine, additional, Ofori‐Boateng, Caleb, additional, Oke, Christopher Omamoke, additional, Oostra, Vicencio, additional, Osgathorpe, Lynne M., additional, Otavo, Samuel Eduardo, additional, Page, Navendu V., additional, Paritsis, Juan, additional, Parra‐H, Alejandro, additional, Parry, Luke, additional, Pe'er, Guy, additional, Pearman, Peter B., additional, Pelegrin, Nicolás, additional, Pélissier, Raphaël, additional, Peres, Carlos A., additional, Peri, Pablo L., additional, Persson, Anna S., additional, Petanidou, Theodora, additional, Peters, Marcell K., additional, Pethiyagoda, Rohan S., additional, Phalan, Ben, additional, Philips, T. Keith, additional, Pillsbury, Finn C., additional, Pincheira‐Ulbrich, Jimmy, additional, Pineda, Eduardo, additional, Pino, Joan, additional, Pizarro‐Araya, Jaime, additional, Plumptre, A. J., additional, Poggio, Santiago L., additional, Politi, Natalia, additional, Pons, Pere, additional, Poveda, Katja, additional, Power, Eileen F., additional, Presley, Steven J., additional, Proença, Vânia, additional, Quaranta, Marino, additional, Quintero, Carolina, additional, Rader, Romina, additional, Ramesh, B. R., additional, Ramirez‐Pinilla, Martha P., additional, Ranganathan, Jai, additional, Rasmussen, Claus, additional, Redpath‐Downing, Nicola A., additional, Reid, J. Leighton, additional, Reis, Yana T., additional, Rey Benayas, José M., additional, Rey‐Velasco, Juan Carlos, additional, Reynolds, Chevonne, additional, Ribeiro, Danilo Bandini, additional, Richards, Miriam H., additional, Richardson, Barbara A., additional, Richardson, Michael J., additional, Ríos, Rodrigo Macip, additional, Robinson, Richard, additional, Robles, Carolina A., additional, Römbke, Jörg, additional, Romero‐Duque, Luz Piedad, additional, Rös, Matthias, additional, Rosselli, Loreta, additional, Rossiter, Stephen J., additional, Roth, Dana S., additional, Roulston, T'ai H., additional, Rousseau, Laurent, additional, Rubio, André V., additional, Ruel, Jean‐Claude, additional, Sadler, Jonathan P., additional, Sáfián, Szabolcs, additional, Saldaña‐Vázquez, Romeo A., additional, Sam, Katerina, additional, Samnegård, Ulrika, additional, Santana, Joana, additional, Santos, Xavier, additional, Savage, Jade, additional, Schellhorn, Nancy A., additional, Schilthuizen, Menno, additional, Schmiedel, Ute, additional, Schmitt, Christine B., additional, Schon, Nicole L., additional, Schüepp, Christof, additional, Schumann, Katharina, additional, Schweiger, Oliver, additional, Scott, Dawn M., additional, Scott, Kenneth A., additional, Sedlock, Jodi L., additional, Seefeldt, Steven S., additional, Shahabuddin, Ghazala, additional, Shannon, Graeme, additional, Sheil, Douglas, additional, Sheldon, Frederick H., additional, Shochat, Eyal, additional, Siebert, Stefan J., additional, Silva, Fernando A. B., additional, Simonetti, Javier A., additional, Slade, Eleanor M., additional, Smith, Jo, additional, Smith‐Pardo, Allan H., additional, Sodhi, Navjot S., additional, Somarriba, Eduardo J., additional, Sosa, Ramón A., additional, Soto Quiroga, Grimaldo, additional, St‐Laurent, Martin‐Hugues, additional, Starzomski, Brian M., additional, Stefanescu, Constanti, additional, Steffan‐Dewenter, Ingolf, additional, Stouffer, Philip C., additional, Stout, Jane C., additional, Strauch, Ayron M., additional, Struebig, Matthew J., additional, Su, Zhimin, additional, Suarez‐Rubio, Marcela, additional, Sugiura, Shinji, additional, Summerville, Keith S., additional, Sung, Yik‐Hei, additional, Sutrisno, Hari, additional, Svenning, Jens‐Christian, additional, Teder, Tiit, additional, Threlfall, Caragh G., additional, Tiitsaar, Anu, additional, Todd, Jacqui H., additional, Tonietto, Rebecca K., additional, Torre, Ignasi, additional, Tóthmérész, Béla, additional, Tscharntke, Teja, additional, Turner, Edgar C., additional, Tylianakis, Jason M., additional, Uehara‐Prado, Marcio, additional, Urbina‐Cardona, Nicolas, additional, Vallan, Denis, additional, Vanbergen, Adam J., additional, Vasconcelos, Heraldo L., additional, Vassilev, Kiril, additional, Verboven, Hans A. F., additional, Verdasca, Maria João, additional, Verdú, José R., additional, Vergara, Carlos H., additional, Vergara, Pablo M., additional, Verhulst, Jort, additional, Virgilio, Massimiliano, additional, Vu, Lien Van, additional, Waite, Edward M., additional, Walker, Tony R., additional, Wang, Hua‐Feng, additional, Wang, Yanping, additional, Watling, James I., additional, Weller, Britta, additional, Wells, Konstans, additional, Westphal, Catrin, additional, Wiafe, Edward D., additional, Williams, Christopher D., additional, Willig, Michael R., additional, Woinarski, John C. Z., additional, Wolf, Jan H. D., additional, Wolters, Volkmar, additional, Woodcock, Ben A., additional, Wu, Jihua, additional, Wunderle, Joseph M., additional, Yamaura, Yuichi, additional, Yoshikura, Satoko, additional, Yu, Douglas W., additional, Zaitsev, Andrey S., additional, Zeidler, Juliane, additional, Zou, Fasheng, additional, Collen, Ben, additional, Ewers, Rob M., additional, Mace, Georgina M., additional, Purves, Drew W., additional, Scharlemann, Jörn P. W., additional, and Purvis, Andy, additional

Published
2016
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47. Diversity patterns of selected predaceous arthropod groups in maize fields and margins in South African Highveld grassland.

Author

Botha, Monique, Siebert, Stefan J., van den Berg, Johnnie, Ellis, Suria, and Greyvenstein, Bianca M.

Subjects
*PHYSIOLOGICAL control systems, *BIODIVERSITY conservation, *GRASSLANDS, *SPECIES diversity, *CROPPING systems, ENVIRONMENTAL aspects
Abstract

Abstract: Conservation biological control focuses on enhancing arthropod predator habitats by increasing the natural resources required for survival and reproduction. However, this requires knowledge about the specific requirements of these predators, which can only be acquired from species‐level data. We provide a description of species‐level diversity patterns of the arthropod predator groups Araneae, Coccinellidae, Mantodea and Neuroptera from maize agro‐ecosystems in South Africa. Predators were sampled by sweep‐net at regional and local scales within the Dry Highveld Grassland Bioregion. A list is provided of predators that occurred naturally inside maize agro‐ecosystems, which may be good candidates for the biological control of pests. Diversity indices displayed significantly lower values in maize fields compared with uncultivated vegetation. Marginal and rangeland vegetation had similar diversity levels. Predator diversity of maize was probably dependent on source populations from uncultivated vegetation, highlighting the importance of field margins with respect to maintaining predator diversity in pest management regimes for maize fields. Some predators frequented maize fields, suggesting adaptability to agricultural disturbance. Generalists including Cheilomenes lunata, Chrysoperla congrua and Enoplognatha molesta may be suitable for conservation biocontrol because they can persist in annual agro‐ecosystems year‐round provided that they have access to field margins. [ABSTRACT FROM AUTHOR]

Published
2018
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49. Carbon balance of a grazed savanna grassland ecosystem in South Africa

Author

Räsänen, Matti, primary, Aurela, Mika, additional, Vakkari, Ville, additional, Beukes, Johan P., additional, Van Zyl, Pieter G., additional, Josipovic, Miroslav, additional, Venter, Andrew D., additional, Jaars, Kerneels, additional, Siebert, Stefan J., additional, Laurila, Tuomas, additional, Tuovinen, Juha-Pekka, additional, Rinne, Janne, additional, and Laakso, Lauri, additional

Published
2016
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50. Stuifmeelmorfologie van Prototulbaghia Vosa: 'n vergelykende palinologiese studie van die Alliaceae in Suider–Afrika

Author

Andriessen, Melissa, Struwig, Madeleen, Siebert, Stefan J., 22089225 - Andriessen, Melissa, and 12204145 - Siebert, Stefan John

Abstract

Pollen morphology of Prototulbaghia Vosa: A comparative palynological study of the Southern African Alliaceae. The Southern African Alliaceae Borkh. is represented by four genera (Allium L., Nothoscordum Kunth, Tulbaghia L. and Prototulbaghia Vosa) and 28 species. The pollen morphology of the endangered monotypic genus Prototulbaghia has not been described before. A comparative study of the pollen morphology of Prototulbaghia siebertii Vosa, Nothoscordum borbonicum Kunth, Tulbaghia simmleri P.Beauv. and T. violaceae Harv. is presented in this article. Scanning electron microscopy, as well as light microscopy, were used to examine the pollen. The pollen morphology of the species can be described as perprolate and monosulcate, and the surface sculpture as reticulate and heterobrochate. However, the pollen of Prototulbaghia siebertii displays a unique characteristic as the grains are folded in their breadth with the tips touching, hence causing the grain to display a triangular and disulcate appearance. It might be possible to ascribe this fold to the process of harmomegathy or a still unknown event that occurs during the development of the pollen grain. This phenomenon should be further investigated to determine the cause of folding and whether it is a unique taxonomic characteristic of this genus, and if it could be of evolutionary significance for the Alliaceae. http://www.satnt.ac.za/index.php/satnt http://www.satnt.ac.za/index.php/satnt/article/view/389 doi: 10.4102/satnt.v32i1.389

Published
2013

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