@article{JeltschWeberParueloetal.2000,
  author    = {Jeltsch, Florian and Weber, Gisela and Paruelo, J. and Dean, W. R. J. and Milton, Sue J. and VanRooyen, N.},
  title     = {Beweidung als Degradationsfaktor in ariden und semiariden Weidesystemen},
  year      = {2000},
  language  = {de}
}
@article{SchurrDeanMiltonetal.2004,
  author    = {Schurr, Frank Martin and Dean, W. R. J. and Milton, Sue J. and Jeltsch, Florian},
  title     = {A conceptual model linking demography of the shrub species Grewia flava to the dynamics of Kalahari savannas},
  year      = {2004},
  abstract  = {Environmental heterogeneity is a major determinant of plant population dynamics. In semi-arid Kalahari savannas, heterogeneity is created by savanna structure, i.e. by the spatial arrangement and temporal dynamics of woody plant and open grassland microsites. We formulate a conceptual model describing the effects of savanna dynamics on the population dynamics of the animal-dispersed shrub Grewia flava. From empirical results we derive model rules describing effects of savanna structure on several processes in Grewia's life cycle. By formulating the model, we summarise existing information on Grewia demography and identify gaps in this knowledge. Despite a number of such gaps, the model can be used to make certain quantitative predictions. As an example, we apply the model to investigate the role of seed dispersal in Grewia encroachment on rangelands. Model results show that cattle promote encroachment by depositing substantial numbers of seeds in open areas, where Grewia is otherwise dispersal-limited. Finally, we draw some general conclusions about Grewia's life history and population dynamics. Under natural conditions, concentrated seed deposition under woody plants appears to be a key process causing the observed association between Grewia and other woody plants. Furthermore, low rates of recruitment and high adult survival result in slow-motion dynamics of Grewia populations. As a consequence, Grewia populations interact with savanna dynamics on long temporal and short to intermediate spatial scales.},
  language  = {en}
}
@article{JeltschWeberDeanetal.2000,
  author    = {Jeltsch, Florian and Weber, Gisela and Dean, W. R. J. and Milton, Sue J. and VanRooyen, N. and O'Connor, Terry and Moloney, Kirk A.},
  title     = {Entstehung und Bedeutung r{\"a}umlicher Vegetationsstrukturen in Trockensavannen : Baum-Graskoexistenz und Artenvielfalt},
  year      = {2000},
  language  = {de}
}
@article{TewsEstherMiltonetal.2006,
  author    = {Tews, J{\"o}rg and Esther, Alexandra and Milton, Sue J. and Jeltsch, Florian},
  title     = {Linking a population model with an ecosystem model : assessing the impact of land use and climate change on savanna shrub cover dynamics},
  doi       = {10.1016/j.ecolmodel.2005.11.025},
  year      = {2006},
  abstract  = {In semiarid savannas of Southern Africa current land use practices and climate change may lead to substantial changes of vegetation structure in the near future, however uncertainty remains about the potential consequences and the magnitude of change. In this paper we study the impact of climate change, cattle grazing, and wood cutting on shrub cover dynamics in savannas of the southern Kalahari. We use an established savanna ecosystem model to simulate landscape dynamics in terms of rainfall, fire and distribution of the dominant tree Acacia erioloba. We then incorporate these data into a spatial population model of the common, fleshy-fruited shrub Grewia flava and investigate shrub cover dynamics for a period of 100 years. Depending on the intensity of commercial wood cutting practices tree removal of A. erioloba led to a strong decline of the G. flava population, as shrub recruitment is concentrated in tree sub-canopies due to bird-mediated seed dispersal. Under climate change shrub cover slightly decreased with decreasing precipitation and was unchanged with increase in precipitation variability. Contrarily, grazing by cattle strongly increased shrub cover and facilitated shrub encroachment because of cattle-induced distribution of G. flava seeds into the matrix vegetation. Knowledge of the latter process is particularly important because shrub invasion is a major concern for conservation and savanna rangeland management as a result of its adverse effects on livestock carrying capacity and biodiversity},
  language  = {en}
}