Rainfall variability and vegetation dynamics of the lower Limpopo Valley, Southern Africa, 500 AD to present

• The long-term responses of vegetation to climate variability are of relevance for predicting present and future vegetation change, and have implications for the management of savanna and riparian ecosystems. This paper explores the links between regional rainfall, hydrology and vegetation dynamics in the savannas and riverine forests of the lower Limpopo Valley, southern Africa, from 800 AD to the present, reviewing palaeoecological data (fossil pollen, spores, diatoms and lithology) from several hydrological systems in Kruger National Park (KNP), South Africa and Limpopo National Park (PNL), Mozambique. The PNL-KNP records show that riverine arboreal taxa expanded during wetter periods, including 800-1400 AD and after 1800 AD. Between 1400 and 1800 AD, grasses, savanna taxa and generalist taxa were favored over riparian taxa, a change that is linked with the onset of dry spells in the region (corresponding to the so-called Little Ice Age). The most extreme drought events around 1700 AD resulted in a marked decline of riparian forest taxa near Lake Mapimbi, KNP. In contrast, many water-scarce sequences away from the riverine environment, such as Radio Pan, Mafayeni Pan, Malahlapanga Pan and Lake Makwadzi show stable grassland vegetation throughout the last 1200 years. The results demonstrate the resilience of the grassland-savanna ecosystems to projected climate change with warmer and overall drier climate. The riverine forests are predicted to be more vulnerable especially as more extreme weather events are projected.

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences (hsv//eng)

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Environmental Sciences (hsv//eng)

Nyckelord

Vegetation dynamics

Climate change

Pollen

Diatoms

Savanna ecology

Southern Africa

Geovetenskap med inriktning mot kvartärgeologi

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)