Adapting Conservation Strategies to Accommodate Impacts of Climate Change in Southern Africa

Adapting Conservation Strategies to Accommodate Impacts of Climate Change in
Southern Africa
G.P. Von Maltitz, R.J. Scholes, B. Erasmus and A. Letsoalo
CSIR, South Africa
AIACC Working Paper No. 35
August 2006

An electronic publication of the AIACC project available at www.aiaccproject.org.
AIACCWorking Papers
Distributed by:
The AIACC Project Office
International START Secretariat
2000 Florida Avenue, NW
Washington, DC 20009 USA
www.aiaccproject.org

AIACC Working Papers, published on-line by Assessments of Impacts and Adaptations to Climate Change (AIACC), is a series of papers and paper abstracts written by researchers participating in the AIACC project. Papers published in AIACC Working Papers have been peer reviewed and accepted for publication in the on-line series as being (i) fundamentally sound in their methods and implementation, (ii) informative about the methods and/or findings of new research, and (iii) clearly written for a broad, multi-disciplinary audience. The purpose of the series is to circulate results and descriptions of methodologies from the AIACC project and elicit feedback to the authors.

The AIACC project is funded by the Global Environment Facility, the Canadian International Development Agency, the U.S. Agency for International Development, and the U.S. Environmental Protection Agency.
The project is co-executed on behalf of the United Nations Environment Programme by the global change SysTem for Analysis Research and Training (START) and The Academy of Sciences for the Developing World (TWAS).
Assessments of Impacts and Adaptations to Climate Change (AIACC) seeks to enhance capabilities in developing countries for responding to climate change by building scientific and technical capacity, advancing scientific knowledge, and linking scientific and policy communities. These activities are supporting the work of the United Nations Framework Convention on Climate
Change (UNFCCC) by adding to the knowledge and expertise that are needed for national communications of parties to the convention and for developing adaptation plans. AIACC supports 24 regional assessments in Africa, Asia, Latin America and small island states in the Caribbean, Indian and Pacific Oceans with funding, mentoring, training and technical assistance.
More than 340 scientists, experts and students from 150 institutions in 50 developing countries and 12 developed countries participate in the project. For more information about the AIACC project, and to obtain copies of other papers published in AIACC Working Papers, please visit our website at
www.aiaccproject.org.
1
Adapting Conservation Strategies to Accommodate Impacts of Climate Change in Southern Africa1
G. P. Von Maltitz, R. J. Scholes, B. Erasmus, and A. Letsoalo
1. Introduction

Current predictions are that global climate change will have substantial impacts on southern Africa’s biodiversity, including wide-scale extinctions over the next 50 years (Rutherford et al., 1999; Hannah et al., 2000a,b; Gitay et al., 2001, 2002 et al.; Midgley et al., 2002a,b; MA, 2005). At a global scale, Thomas et al. (2004) predicted that 15–37% of species in their sample (that covered 20% of the earth surface) may be at risk of premature extinction due to anthropogenically caused global change by 2050. The Millennium Ecosystem Assessment, using different models and assumptions based largely on habitat loss, reached similar conclusions (MA, 2005). Within South Africa, one of the few areas in sub-Sahara Africa where detailed analysis has been conducted, the predictions are that most of the current biomes will reduce in size and will be shifted to the east of the country. Up to half of the country will have a climatic regime that is not currently found in the country (Rutherford et al., 1999).

The succulent karoo biome, (a succulent-dominated semi-desert located on the southwestern coast of southern Africa) is projected to be the most severely impacted, with the grassland and fynbos (a Mediterranean-climate sclerophyllous thicket that approximates to the Cape Floristic 1 The research reported in this paper was supported by grant number AF04 from region) biomes also likely to suffer from high climate change impacts (Rutherford et al., 1999; Midgley et al., 2002a,b). Fynbos and succulent karoo are biodiversity hotspots of international importance (Myers et al., 2000), with the latter being one of only two globally important arid-climate biodiversity hotspots. Two main aspects of the climate have widespread influence on animal and plant species distributions: temperature and water balance (a combination of precipitation and evaporation, which, in turn, is directly influenced by temperature) (Cubasch, 2001). The dynamics of plant and animal populations change at the edge of individual species’ distribution, as net mortality becomes larger than net fecundity, with a spatial gradient of declining population numbers as a result. In a scenario of climate change, this will lead to the progressive extinction of nonvagile species in their natural range, beginning with population dieback in the so-called "trailing edge" of the historical distribution range (Davis and Shaw, 2001). This change in local population dynamics is affected directly by temperature and water balance, but it is also indirectly through aspects such as interspecies competition, fire frequency, pollinator distribution, herbivory and predation,
food availability, soil type, topography etc. (e.g., Gaston, 2003).

Few species occupy their "fundamental niche,", i.e., the range determined by the physiological tolerance limits.
Their actual range, the "realised niche," is a subset of this resulting from the outcome of interactions with other species. The degree to which species distribution can be predicted
based on their climatically defined habitat niche differs between species (e.g., Thuiller et al., 2006).

http://www.aiaccproject.org/working_papers/Working%20Papers/AIACC_WP35_vonMaltitz.pdf