caa a22 4500 475751353 CHVBK 20180406123524.0 cr unu---uuuuu 170329e20001001xx s 000 0 eng 10.1023/A:1026590806682 doi (NATIONALLICENCE)springer-10.1023/A:1026590806682 Ecological buffering mechanisms in savannas: A unifying theory of long-term tree-grass coexistence [Elektronische Daten] [Florian Jeltsch, Gerhard Weber, Volker Grimm] Despite the large spatial extent and the obvious importance of the savanna biome, not to mention several decades of savanna research, the origin, age, nature, and dynamics of savannas are not well understood. Basically, the question surrounding the presence or existence of savannas focuses on the long-term coexistence of the dominating life forms - trees and grasses. How do these two very different components coexist, without one of them dominating the other, and what mechanisms determine the proportion of each? Earlier equilibrium concepts have recently been replaced by non-equilibrium concepts, and the current view is that tree-grass interactions in savannas cannot be predicted by a simple model. Instead, many interacting factors operating at various spatial and temporal scales contribute to creating and maintaining savanna physiognomy. In this paper we analyse a number of studies from savannas in different parts of the world and discuss whether a general pattern can be perceived behind the numerous factors influencing the presence of savannas systems. On the basis of this analysis we propose a new unifying concept of savanna existence, i.e., the concept of ecological buffering mechanisms. In contrast to previous approaches to explain tree-grass coexistence in savannas, the concept of buffering mechanisms does not focus on equilibria or non-equilibria, steady states of the system or domains of attraction. Instead, in the concept of ecological buffering mechanisms we suggest that it is much more useful to focus on the boundaries of savanna existence itself and to investigate the mechanisms that allow a savanna to persist in critical situations where this system is driven to its boundaries, e.g., pure grasslands or tropical forests. The concept of ecological buffering mechanisms integrates both earlier concepts of ecological theory and general ideas on savanna dynamics as well as specific studies of savannas in different parts of the world. Kluwer Academic Publishers, 2000 Browsing nationallicence Fire nationallicence Long-term dynamics nationallicence Microsites nationallicence Stability concepts nationallicence System boundaries nationallicence Jeltsch Florian Plant Ecology and Nature Conservation, Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany aut Weber Gerhard Department of Ecological Modelling, UFZ - Centre for Environmental Research, Leipzig, Germany aut Grimm Volker Department of Ecological Modelling, UFZ - Centre for Environmental Research, Leipzig, Germany aut Plant Ecology Kluwer Academic Publishers 150/1-2(2000-10-01), 161-171 1385-0237 150:1-2<161 2000 150 11258 https://doi.org/10.1023/A:1026590806682 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1026590806682 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Jeltsch Florian Plant Ecology and Nature Conservation, Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany aut NATIONALLICENCE 700 1- Weber Gerhard Department of Ecological Modelling, UFZ - Centre for Environmental Research, Leipzig, Germany aut NATIONALLICENCE 700 1- Grimm Volker Department of Ecological Modelling, UFZ - Centre for Environmental Research, Leipzig, Germany aut NATIONALLICENCE 773 0- Plant Ecology Kluwer Academic Publishers 150/1-2(2000-10-01), 161-171 1385-0237 150:1-2<161 2000 150 11258 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer