TY  - JOUR
A1  - Tabares, Ximena
A1  - Mapani, Benjamin
A1  - Blaum, Niels
A1  - Herzschuh, Ulrike
T1  - Composition and diversity of vegetation and pollen spectra along gradients of grazing intensity and precipitation in southern Africa
T2  - Review of palaeobotany and palynology : an international journal
N2  - Understanding vegetation-modern pollen relationships is essential to provide confidence in fossil pollen reconstructions of long-term vegetation changes in savanna ecosystems. In this paper we compare the taxonomical composition and the diversity (Hill NO, N1, N2) of vegetation and modern pollen along precipitation and local grazing-intensity gradients in Namibian savannas. Modern pollen was extracted from surface soil samples collected from 5 x 5 m plots distributed along four 500 m gradients. Vegetation was surveyed in each plot. The results show a high correspondence between vegetation and pollen data in terms of composition. Precipitation and grazing explain a significant although low proportion of compositional change in the vegetation and pollen spectra. We identified pollen taxa as indicators of grazing pressure such as Limeum, Alternanthera, and particularly Tribulus. Correspondence between vegetation and pollen data in terms of taxa richness (NO) is limited, probably because of the influence of landscape heterogeneity and openness, as well as low pollen concentrations. In contrast, the effective numbers of common and dominant taxa (N1, N2) are consistent among the different datasets. We conclude that in spite of limitations, modern pollen assemblages can reflect changes in vegetation composition, richness and diversity patterns along precipitation and grazing gradients in savanna environments. (C) 2018 Elsevier B.V. All rights reserved.
KW  - Modern pollen-vegetation relationships
KW  - Hill numbers
KW  - Indicator species
KW  - Savanna ecology
KW  - Namibia
Y1  - 2018
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/52849
SN  - 0034-6667
SN  - 1879-0615
VL  - 253
SP  - 88
EP  - 100
PB  - Elsevier
CY  - Amsterdam
ER  -