Environmental change is a direct driver that influences the ability of both natural and manmade
ecosystems to supply ecosystem services that are essential for the sustenance of human
livelihoods (Shackleton et al., 2008). The literature is extensive on environmental and climate
change impacts such as increasing incidence of droughts, desertification and aridity from
changes in rainfall and intensified land use, as well as food security risks from declines in
agricultural production in combination with water shortage for plants and animals (Burton et
al., 2006; Schneider et al., 2007; Dessler and Parson, 2006; Umoh et al., 2004). Daily et al.
(1997) defines ecosystem services as ‘conditions and processes through which natural
ecosystems and the species that make them up, sustain and fulfill human life’. Put in simple
terms, ecosystem services are benefits people obtain directly or indirectly from ecosystems
(Millennium Ecosystem Assessment, 2005; Costanza et al., 1997; De Groot et al., 2002;
Yang, 2008).
The Millennium Ecosystem Assessment (2005) classifies ecosystem services along functional
lines into four general categories of provisional services, regulating services, cultural services
and supporting services. Provisioning or production services are predominantly tangible
products from ecosystems (e.g. food and fibre), raw materials (e.g. wood for construction,
genetic and medicinal resources), ornamental resources (e.g. handicrafts) and fresh water (De
Groot et al., 2002). Regulatory services are benefits that contribute to human welfare in many
diverse indirect ways such as the regulation of atmospheric carbon dioxide by plants, control
of floods by vegetation and waste treatment by aquatic ecosystems (De Groot et al., 2002;
UNDP and IISD, 2004). Cultural services are mostly the intangible benefits derived by people
from natural ecosystems and include spiritual and religious values, aesthetic appreciation (i.e.
beauty in various aspects of ecosystems), recreational facilities and tourism (recreation and
nature based tourism) and educational value (nature provides many opportunities for
education and research (Millennium Ecosystem Assessment, 2005). Supporting services drive
the production of other ecosystem services and impact indirectly on human wellbeing
(Millennium Ecosystem Assessment, 2005). They include biodiversity that forms the basis of
provisioning, cultural and regulatory services. One of the important supporting services is that
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of habitat provision, where ecosystems play two important roles of offering a refugium
service for flora and fauna and providing nursery services or suitable breeding sites for most
aquatic fauna such as fish (De Groot et al., 2002).
In the Okavango Delta, situated in northern Botswana, river flow provides crucial ecosystem
services that support various livelihood activities. However, at variable locations within the
Boteti and Okavango wetlands, river channels have tended to dry up for a number of years or
permanently, resulting in potentially adverse impacts on water-dependent livelihood activities
such as fishing and flood recession agriculture. Desiccation of river channels is caused by
changes in rainfall patterns as well as by shifts in flow distribution that are vegetation and
sediment related (Wolski, 2009a) or caused by tectonic activity. Models of climate change
reveal that increased desiccation of river channels is likely to be one of the impacts of climate
change in the future (Wolski, 2009b). Research in other developing countries reveals that poor
and marginalised groups are more vulnerable to such environmental change because they lack
the means and resources to cope with or to adapt to them (Shackleton et al., 2008). While
some climate change predictions thus forecast increased dessication in the Okavango Delta,
only a few studies (e.g. Kgathi et al., 2007) have documented the impact of flood flow
changes (channel dessication, in this case) on rural livelihoods or resources. There is also a
dearth of information on how households adapat to actual and anticipated changes, on social
and economic factors constraining or enhancing human adaptive capacity or vulnerability and
on the cost associated with measures taken to adapt. Furthermore, differences in the level of
reponsiveness or adaptive capacity by different households to climate change is not well
understood.
Enhanced documentation of the effects of environmental change of ecosystems supporting
human livehoods and the household adaptive strategies to such changes will contribute to
wider knowledge on the effects of environmental change on household economies. The
results from this study are expected to assist the Government of Botswana in guiding policy
decisions on identifying measures that will mitigate the impacts of environmental change on
human wellbeing in rural areas of Botswana.