Eduardo Barbosa

1. GEST - Dry Savanna Site Eduardo Barbosa Wageningen University- Resource Ecology Group, Droevendaalsesteeg 3a, 6708 PB Wageningen, The Netherlands Email: Eduardo.Barbosa@wur.nl

2. Outline Field Site Kruger National Park SAWC Pilot Field Experiment Methods Preliminary Results Experiment Set up Logistics Costs Problems

3. FIELD SITE Southern African Wildlife College ~ 1 square Km fenced area Timbavati Private Reserve Greater Kruger National Park Lowveld region Summer rainfall: 200-600 mm per annum

4. Kruger National Park Geology Granites + Gabbro Ecca Shales Rhyolite Ecozones 15 Ecozones Vegetation Structure

5. Kruger National Park 35 landscapes extremely heterogenic region rich in flora and fauna

6. FIELD SITE SAWC (Field Sites) + Mixed Bushwillow Woodlands Thorn Veld (Gabbro) (Granites) Climate The average rainfall 450 and 550 mm per year Climate mild and sporadic frost Vegetation bottomlands uplands open tree savanna dense bush savanna vegetation dense grass cover spruits and rivers Acacia nigrescens Combretums dense riverine vegetation Terminalia sericea Combretums Sclerocarya caffra Albizias Diospyros mespiliformis Combretum imberbe Acacia robusta

7. Pilot experiment • Five block replications of the treatments (factorial block design) - ~ 100x100 meters • Water, Light - whole plot treatments • Grass sub-plot treatments • Species – sub-sub plot (6 specimens of each species) Acacia sieberiana, Dichrostachys cinerea , Terminalia sericea, Colophospermum mopane

8. Pilot experiment – Preliminary Results Anova results for number of live leaves interaction

9. Pilot experiment – Preliminary Results Interaction: Grass/water treatment Seedlings have lower nº of live leaves in the even treatment ( ~100 mm) compared to natural rainfall Interaction between grass and rain: grasses reduce nr of live leaves, regardless rainfall treatment G0 – no grass G1 – grass W0 – natural rainfall Interaction: Grass/shade treatment W1 – even water treatment L0 – 100% sun L1 – 80% shade Seedlings have similar nº of live leaves in 80% shade, whereas they have lower nº of live leaves with grasses in 100% sun Interaction between grass and shade: in 100% sun, grasses reduce nº of live leaves

10. Pilot experiment – Preliminary Results Anova results for apical height interaction

11. Pilot experiment – Preliminary Results Interaction: Grass/water treatment G0 – no grass Interaction: Grass/shade treatment G1 – grass W0 – natural rainfall W1 – even water treatment L0 – 100% sun L1 – 80% shade Seedlings are smaller in 100% sun compared to 80% shading. Interaction between grass and rain: grasses reduce apical height in 100% sun, but have no effect in 80% shade

12. Experimental set up – Logistics 2 months (4 workers) Open and clean the field site • Removal of all vegetation • Plow the soil 100x100 meters Set up the shelters and Shade net • Construct the structure 2 month (15 in total : 5x5 m) • Cover with plastic sheets and shade cloths

13. Experimental set up – Logistics Planting the grasses seeds • Marking the Plots 30 days (40 sub-plots) • Sowing the seeds • (3 times) (3 months after the plantation) • Construct the structure Set up the Nursery 15 days • Cover with shade cloths • Fill the plant bags

14. Experimental set up – Logistics Planting the tree seeds • pre-treatment 30 days (~5000 seeds) • Sowing the seeds Transplant the seedlings to the field • make the holes on the plots 15 days • Clipping the grasses • Plant the seedlings (2 months after the grasses plantation)

15. Experimental set up - Costs

16. Experimental set up - Problems Seed Germination Nice seedlings !!!! • Germination rate • Seedling predation (insects, birds) • Seedling mortality (?) Seedling transplant to the main experiment Other problems • “Baboon” effect • Insect herbivory (Ants, Termites, Grasshoppers) • Weeds “encroachment”

17. Thank you