Asymmetric response of forest and grassy biomes to climate variability across the African Humid Period: influenced by anthropogenic disturbance?

Details

Serval ID
serval:BIB_3BDA67A0A3DC
Type
Article: article from journal or magazin.
Collection
Publications
Title
Asymmetric response of forest and grassy biomes to climate variability across the African Humid Period: influenced by anthropogenic disturbance?
Journal
Ecography
Author(s)
Phelps L.N., Chevalier M., Shanahan T.M., Aleman J.C., Courtney-Mustaphi C., Kiahtipes C.A., Broennimann O., Marchant R., Shekeine J., Quick L.J., Davis B.A.S., Guisan A., Manning K.
Publication state
In Press
Peer-reviewed
Oui
Language
english
Abstract
A comprehensive understanding of the relationship between land cover, climate change, and disturbance dynamics is needed to inform scenarios of vegetation change on the African continent. Although significant advances have been made, large uncertainties exist in projections of future biodiversity and ecosystem change for the World’s largest tropical landmass. To better illustrate the effects of climate-disturbance-ecosystem interactions on continental-scale vegetation change, we apply a novel statistical multivariate envelope approach to subfossil pollen data and climate model outputs (TraCE-21ka). We target paleoenvironmental records across continental Africa, from the African Humid Period (AHP: c. 14,700-5,500 years BP) -- an interval of spatially and temporally variable hydroclimatic conditions -- until recent times, to improve our understanding of overarching vegetation trends and to compare changes between forest and grassy biomes (savanna and grassland). Our results suggest that although climate variability was the dominant driver of change, forest and grassy biomes responded asymmetrically: (1) the climatic envelope of grassy biomes expanded, or persisted in increasingly diverse climatic conditions, during the second half of the AHP whilst that of forest did not; (2) forest retreat occurred much more slowly during the mid to late Holocene compared to the early AHP forest expansion; and (3) as forest and grassy biomes diverged during the second half of the AHP, their ecological relationship (envelope overlap) fundamentally changed. Based on these asymmetries and associated changes in human land use, we propose and discuss three hypotheses about the influence of anthropogenic disturbance on continental-scale vegetation change.
Keywords
vegetation change, African Humid Period, disturbance dynamics, climate-disturbance-ecosystem interactions, land use and land cover change, paleoecological reconstruction
Create date
27/03/2020 15:04
Last modification date
28/03/2020 7:26
Usage data