Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1016/j.ppees.2009.09.003
Titel (primär) Grass mortality in semi-arid savanna: the role of fire, competition and self-shading
Autor Zimmermann, J.; Higgins, S.I.; Grimm, V.; Hoffmann, J.; Linstädter, A.
Quelle Perspectives in Plant Ecology, Evolution and Systematics
Erscheinungsjahr 2010
Department OESA
Band/Volume 12
Heft 1
Seite von 1
Seite bis 8
Sprache englisch
Keywords Demography; Density-dependent mortality; Disturbance; Intra-specific competition; Tuft mortality; Survival
Abstract Perennial grasses are a dominant component of many vegetation formations and provide important ecosystem services including supporting herbivores and preventing soil erosion. Despite their importance, our understanding of the processes that influence their mortality rates is surprisingly limited. This study explores the effects of local and landscape-scale processes on mortality of a perennial grass (Stipagrostis uniplumis) in semi-arid savanna. We focussed on three local-scale factors: self-shading by the standing dead biomass of a tuft, plant size, and neighbour abundance as a measure of intra-specific competition. Three indices of neighbour abundance were calculated: number of neighbours, sum of the neighbours' basal area, and sum of the neighbours' living basal area. At the landscape scale, we explored the influence of fire on tuft mortality. The amount of standing dead biomass increased the mortality rates of tufts. Neighbour abundance, indexed as the sum of the living basal area of neighbours, was also associated with higher mortality rates, whereas the other indices of neighbour abundance had no influence on mortality rates. On a landscape level, fire significantly increased tuft mortality rates, from up to 31% for unburned tufts, to 73% for burned tufts. Fire, on the other hand, indirectly reduces the risk of future mortality by reducing self-shading and competitive pressure. Our results imply that the timing and frequency of fires is crucial for their positive indirect effects on plant fitness. As the onset of local effects on plant mortality is highly dependent on grazing pressure and stochastic rainfall, fire management should flexibly take into account the accumulation of dead plant material on a site.
dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=10698
Zimmermann, J., Higgins, S.I., Grimm, V., Hoffmann, J., Linstädter, A. (2010):
Grass mortality in semi-arid savanna: the role of fire, competition and self-shading
Perspect. Plant Ecol. Evol. Syst. 12 (1), 1 - 8 10.1016/j.ppees.2009.09.003