Wild vegetables (WV) are an important source of food in the maize based subsistence farming sector of rural South Africa. Their main role is as relish as they are used as an accompaniment for staple cereal based diets. They are generally reported to be rich in micronutrients. Although they may be consumed in small quantities, they influence the intake of cereal staples, manage hunger and play a central role in household food security for the poorer rural groups. Mixing several WV species in one meal contributes to dietary diversity in terms of more vegetable types as well as in terms of choice of relish. For some very poor families WV are substitutes for some food crops. The seasonal occurrence of these vegetables leaves many families without a food source during the off-season. Wild vegetables increase agro-biodiversity at the household level. This agrobiodiversity helps in buffering against the accumulation and multiplication of pests and diseases and provides important cover for the soil. Further research on agronomic, social and economic dimensions is required to understand the roles of WV in subsistence farming systems in South Africa.

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11Wetlands are conservation priorities worldwide, due to their high biodiversity and productivity, but are 12 under threat from agricultural and climate change stresses. To improve the water management practices 13 and resource allocation in these complex systems, a modelling approach has been developed to estimate 14 potential recharge for data poor catchments using rainfall data and basic assumptions regarding soil and 15 aquifer properties. The Verlorenvlei estuarine lake (RAMSAR #525) on the west coast of South Africa 16 is a data poor catchment where rainfall records have been supplemented with farmer's rainfall records. 17The catchment has multiple competing users. To determine the ecological reserve for the wetlands, the 18 spatial and temporal distribution of recharge had to be well constrained using the J2000 rainfall/runoff 19 model. The majority of rainfall occurs in the mountains (±650 mm/yr) and considerably less in the 20 valley (±280 mm/yr). Percolation was modelled as ~3.6% of rainfall in the driest parts of the catchment, 21 ~10% of rainfall in the moderately wet parts of the catchment and ~8.4% but up to 28.9% of rainfall in 22 the wettest parts of the catchment. The model results are representative of rainfall and water level 23 measurements in the catchment, and compare well with water table fluctuation technique, although 24 30 31 4 groundwater level. This approach can also be called actual recharge, as it determines the amount of 59 water that reaches the groundwater table (Rushton, 1997), but in doing so it neglects any processes that 60 occur in the unsaturated zone, thereby reducing its spatial and temporal extent. However, for numerical 61 modelling of recharge, it is not possible to neglect what is happening in the unsaturated zone, as most 62 models require information on the physical and chemical pathways of recharge. Therefore, this type of 63 approach is rather defined as potential recharge, which is constrained by the amount of water that has 64 percolated through the unsaturated zone, contributing to the saturated zone (Rushton, 1997), and hence 65 requires knowledge of the percolation rate. 66Within numerical modelling, the percolation rate (Scanlon et al., 2002) can be modelled either by 67 looking at variably saturated flow or rainfall/runoff partitioning. Both these methods use a water-68 balance to determine the percolation volume using input data, such as climate (rainfall, temperature), 69 vegetation (interception) and biosphere (soil texture) to partition water into runoff, infiltration, 70 evaporation and recharge. These two methods differ in their ability to simulate soil moisture. Variably 71 saturated flow models can simulate vertical distributions of soil moisture and estimate recharge by 72 routing water through the soil column using soil hydraulic conductivities. Many rainfall/runoff models 73 partition infiltrated water into storages based on soil type parameters (J2000: Krause, 2001; and ACRU: 74 Schulze, 1995) . This makes variably saturated flow more favoura...

Abstract.A major task of the newly established "Southern African Science Service Centre for Climate Change and Adaptive Land Management" (SASSCAL; www.sasscal.org) and its partners is to provide science-based environmental information and knowledge which includes the provision of consistent and reliable climate data for Southern Africa. Hence, SASSCAL, in close cooperation with the national weather authorities of Angola, Botswana, Germany and Zambia as well as partner institutions in Namibia and South Africa, supports the extension of the regional meteorological observation network and the improvement of the climate archives at national level. With the ongoing rehabilitation of existing weather stations and the new installation of fully automated weather stations (AWS), altogether 105 AWS currently provide a set of climate variables at 15, 30 and 60 min intervals respectively. These records are made available through the SASSCAL WeatherNet, an online platform providing near-real time data as well as various statistics and graphics, all in open access. This effort is complemented by the harmonization and improvement of climate data management concepts at the national weather authorities, capacity building activities and an extension of the data bases with historical climate data which are still available from different sources. These activities are performed through cooperation between regional and German institutions and will provide important information for climate service related activities.

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