+ Site Statistics
References:
54,258,434
Abstracts:
29,560,870
PMIDs:
28,072,757
+ Search Articles
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ PDF Full Text
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Translate
+ Recently Requested

Drought, climate change and vegetation response in the succulent karoo, South Africa



Drought, climate change and vegetation response in the succulent karoo, South Africa



South African Journal of Science 105(1-2): 54-60



For the winter-rainfall region of South Africa, the frequency of drought is predicted to increase over the next 100 years, with dire consequences for the vegetation of this biodiversity hotspot. We analysed historical 20th century rainfall records for six rainfall stations within the succulent karoo biome to determine if the signal of increasing drought frequency is already apparent, and whether mean annual rainfall is decreasing. We found no evidence for a decrease either in mean annual rainfall or in the incidence of drought, as measured by the Standardised Precipitation Index (SPI) over the 20th century. Evidence points to a drying trend from 1900-1950 while no significant trend in rainfall and drought was found at most stations from 1951-2000. In a second analysis we synthesised the information concerning the response of adult succulent karoo biome plants and seedlings to extended drought conditions. General findings are that responses to drought differ between species, and that longevity is an important life history trait related to drought survival. Growth form is a poor predictor of drought response across the biome. There was a range of responses to drought among adult plants of various growth forms, and among non-succulent seedlings. Leaf-succulent seedlings, however, exhibited phenomenal drought resistance, the majority surviving drought long after all the experimentally comparative non-succulent seedlings had died. Our synthesis showed that previous studies on the impact of drought on succulent karoo biome plants differ greatly in terms of their location, sampling design, measured values and plant responses. A suite of coordinated long-term field observations, experiments and models are therefore needed to assess the response of succulent karoo biome species to key drought events as they occur over time and to integrate this information into conservation planning.

(PDF emailed within 1 workday: $29.90)

Accession: 066218967

Download citation: RISBibTeXText


Related references

Long-term vegetation change in the Succulent Karoo, South Africa following 67 years of rest from grazing. Journal of Arid Environments 72(5): 808-819, 2008

A simulation model of long-term climate, livestock and vegetation interactions on communal rangelands in the semi-arid Succulent Karoo, Namaqualand, South Africa. Ecological Modelling 183(2/3): 211-230, 2005

Vegetation of the Hantam-Tanqua-Roggeveld subregion, South Africa Part 2 Succulent Karoo Biome related vegetation. Koedoe: 1, 160-183, 2008

Effects of heuweltjies and utilization on vegetation patterns in the Succulent Karoo, South Africa. Journal of Arid Environments 87: 198-205, 2012

Effect of grazing on vegetation and soil of the heuweltjieveld in the Succulent Karoo, South Africa. Acta Oecologica 77: 27-36, 2016

Vegetation dynamics after experimental fire disturbance in the arid Succulent Karoo, South Africa. African Journal of Range and Forage Science 33(2): 131-135, 2016

Long-term vegetation dynamics (40 yr) in the Succulent Karoo, South Africa: effects of rainfall and grazing. Applied Vegetation Science 18(2): 311-322, 2015

Similarity between the soil seed bank and the standing vegetation in the Strandveld Succulent Karoo, South Africa. Land Degradation & Development 14(6): 527-540, November-December, 2003

Effects of multispecies clumping on survival of three succulent plant species translocated onto mine spoil in the Succulent Karoo Desert, South Africa. Restoration Ecology 13(1): 15-19, 2005

Small-scale soil patterns drive sharp boundaries between succulent dwarf biomes (or habitats) in the arid Succulent Karoo, South Africa. South African Journal of Botany 101: 129-138, 2015

The Plant Ecology of Namaqualand, South Africa || Reserve Selection in the Succulent Karoo, South Africa: Coping with High Compositional Turnover. Plant Ecology 142(1-2): 35-55, 1999

The Plant Ecology of Namaqualand, South Africa || Community Structure on Unusual Habitat Islands: Quartz-Fields in the Succulent Karoo, South Africa. Plant Ecology 142(1-2): 57-69, 1999

Vegetation change in a semi-arid succulent dwarf shrubland in the eastern Cape, South Africa. South African Journal of Science 86(7-10): 392-395, 1990

Evaluation of restoration techniques for the Succulent Karoo, South Africa. Restoration Ecology 11(3): 308-316, 2003

Seasonal gas exchange responses under three different temperature treatments in a leaf-succulent and a drought-deciduous shrub from the Succulent Karoo. South African Journal of Botany 66(2): 118-123, 2000