Philip Ayres, F Siebert & SJ Siebert School of Environmental - PowerPoint PPT Presentation

Philip Ayres, F Siebert & SJ Siebert School of Environmental Sciences and Development North-West University

Browsing and Climate Channel type animal movement Riparian Geomorphology Anthropogenic Vegetation structure Hydrology Landscape Patch history (Floods, fire, Geology anthropogenic)

Changes in vegetation structure may affect: Habitat & heterogeneity Aesthetic Transpiration value Nutrient Water table cycle Riparian vegetation Large Water Woody temperature Debris Bank Flow stability velocity Sedimentation

Linkage between geomorphology and Riparian vegetation o Changes in vegetation composition is caused by a change in the combination of geomorphological factors o Two distinct morphological units o MCB (Macro Channel Bank) – stable infrequently flooded (only large floods-LID; 2000), less vegetation impact o MCF (Macro Channel Floor) – less stable, frequently flooded, geomorphic and hydrological dynamic, higher vegetation impact (high energy zone) o 4 Channel types (van Coller, 1997): Bedrock Anastomosing (BA) o Pool Rapid (PR) o Mixed Anastomosing (MA ) o Braided (Br) o Mixed Anastomosing. Adapted from McLoughlin C.A. et al., 2007

Research History Wits (1990) Wits (2004) NWU (2010) Woody species Woody species Woody species Environmental data Environmental data Environmental data 11 Transects, 20 m wide 24 Transects, 30 m wide 4 Transects, 30 m wide (Masters Project) Transects selected in 6 Transects in each of the 1 Transect in each of the stratified-random fashion four channel types four channel types (based on geology and channel type) Belt-transect across entire Belt-transect across entire Same as CWE & Wits MC, perpendicular to river MC, perpendicular to river (2004) o The purpose of this study (SANPark’s registered project): o Continue with long-term monitoring of riparian vegetation o Investigate patterns of floristic and structural change (since 2000 flood). o The objectives of this project: o correspond with the Post-flood Program of monitoring riparian vegetation change along o the Sabie River

Study design: CWE and Wits (2004) o Results and conclusions by previous studies CWE & Wits (1990 and 2004) were considered during the analysis of the results and study design o Parsons, M., Mcloughlin, C.A., Rountree, M.W. and Rogers, K.H. 2006. The Biotic and Abiotic Legacy of a Large Infrequent Flood Disturbance in the Sabie River, South Africa. River Research and Applications 22: 187 – 201. o Van Coller, A.L., Rogers, M.W. and Heritage, G.L. 1997. Linking riparian vegetation types and fluvial geomorphology along the Sabie River within the Kruger National Park, South Africa. African Journal of Ecology 35: 194 – 212.

Study design… Study area: •Pre-selected (SANParks and CWE) •Represents the four main river channel types: • Bedrock Anastomosing (BA) •Pool Rapid (PR) •Mixed Anastomosing (MA ) Belt-transect no Latitude Longitude •Braided (Br) 2 (BA) 24°59'21.398" 31°17'13.814" 3 (PR) 24°58'54.565" 31°18'03.106" 4 (MA) 25°01'30.035" 31°47'24.932" 5 (Br) 24°58'22.848" 31°32'31.006"

Study design… Study area: MCF Belt-transect 2 (BA) •13 (30m x 5m) plots •MCB = 5 plots •MCF = 8 plots MCB •24° 59'21.398" S 31° 17'13.814" O MCF Belt-transect 3 (PR) •26 (30m x 5m) plots •MCB = 4 plots •MCF = 22 plots •24° 58'54.565" S 31° 18'03.106" O MCB

Study design… MCF Study area: Belt-transect 4 (MA) •12 (30m x 5m) plots •MCB = 4 plots MCB •MCF = 8 plots •25° 01'30.035" S 31° 47'24.932" O MCF Belt-transect 5 (Br) •12 (30m x 5m) plots •MCB = 7 plots •MCF = 5 plots MCB •24° 58'22.848" S 31° 32'31.006" O

Field surveying… Data sampling (SOP): S

Statistical Analyses o SPSS (PASW Statistics 18, Release Version 18.0.0. ) o 3-way Anova (height) o Cross tabulation (number of stems) o Significant change

1200 Results: Total number of individual 1000 Descriptive trees/shrubs 800 Shrubs 2004 600 Increase Shrubs 2010 957 Trees 2004 400 729 Trees 2010 200 356 346 0 Shrubs & Trees Total number of tree and shrub counts from 2004 to 2010 250 120 234 200 208 100 Total number of individual shrubs 105 Total number of individual trees 100 175 80 150 151 72 77 60 74 144 100 118 114 60 70 107 40 51 87 77 42 72 50 75 60 35 20 22 34 28 27 19 26 3 27 3 0 0 1 2 3 4 1 2 3 4 2 (BA) 3 (PR) 4 (MA) 5 (Br) 2 (BA) 3 (PR) 4 (MA) 5 (Br) Belt-transect Belt-transect MCF (2004) MCF (2010) MCB (2004 MCB (2010) MCF (2004) MCF (2010) MCB (2004) MCB (2010) Total number of shrubs counts on the Total number of trees counts on the MCF & MCB: 2004 - 2010 MCF & MCB: 2004 - 2010

Results Shrubs avg. height Trees avg. height 3.500 2.500 3.224 2.118 2.110 2.059 2.014 3.000 1.978 2.000 2.481 2.341 Avg. height (m) Avg. height (m) 2.500 1.627 Stable 2.177 2.170 2.058 1.397 1.952 1.500 1.306 2.000 1.460 1.500 MCB 2004 1.000 2004 MCB MCB 2010 1.000 2010 MCB .500 .500 .000 .000 2 (BA) 3 (PR) 4 (MA) 5 (Br) 1 2 3 4 1 2 3 4 2 (BA) 3 (PR) 4 (MA) 5 (Br) Belt-transect Belt-transect Average shrub height (m) for Belt-transects on Average tree height (m) for belt-transects on the the MCB: 2004 - 2010 MCB: 2004 - 2010 4.000 3.000 2.714 3.570 3.500 2.500 2.191 3.000 1.883 2.709 2.470 2.000 2.441 Avg. height (m) Avg. height (m) 2.500 1.378 1.484 1.827 1.500 2.000 1.760 1.190 1.157 1.135 MCF 2004 2004 MCF 1.500 1.287 1.000 1.241 MCF 2010 2010 MCF 1.000 .500 .500 .000 .000 1 2 3 4 2 (BA) 3 (PR) 4 (MA) 5 (Br) 1 2 3 4 2 (BA) 3 (PR) 4 (MA) 5 (Br) Belt-transect Belt-transect Average shrub height (m) for belt-transects on the Average tree height (m) for belt-transect on the MCF: 2004 - 2010 MCF: 2004 - 2010

Results 2004 2010 Shrubs: distribution of stem classes 2% 2% 18 : 82 35 : 65 1 1 1 8% 14% 7% 2 – 3 2 – 3 2 – 3 30% 33% 4 – 6 4 – 6 4 – 6 20% 7 – 10 7 – 10 7 – 10 11 – 55 11 – 55 11 – 55 52% 32% Distribution of shrub stem classes on the MCF Distribution of shrub stem classes on the MCF for 2010 for 2004 3% 3% 17 : 83 44 : 56 16% 1 1 11% 29% 6% 2 – 3 2 – 3 45% 4 – 6 4 – 6 22% 7 – 10 7 – 10 38% 27% 11 – 55 11 – 55 Distribution of shrub stem classes on the MCB Distribution of shrub stem classes on the MCB for 2010 for 2004

Results Trees: distribution of stem classes 2004 2010 2% 2% 9 : 91 9% 13 : 87 9% 1 1 2 – 3 2 – 3 22% 4 – 6 4 – 6 34% 57% 7 – 10 7 – 10 65% 11 – 55 11 – 55 Distribution of tree stem classes on the MCF for Distribution of tree stem classes on the MCF for 2004 2010 2% 2% 1% 6% 8 : 92 13 : 87 1 1 10% 2 – 3 2 – 3 4 – 6 4 – 6 33% 21% 7 – 10 7 – 10 59% 66% 11 – 55 11 – 55 Distribution of tree stem classes on the MCB for Distribution of tree stem classes on the MCB for 2004 2010

Conclusion Shrubs Trees Height Number of stems ��������������������������������������������������� ������������������������������ ��������������������������������������

The way forward o Structural change o Basal area o Investigating compositional change o Alien invasive o Functional types o Most abundant and successful functional type o Regeneration, recruitment and nursing effect o Reed associated o Large Woody Debris o Termite mounds

Acknowledgements o CWE (Wits) for providing GIS-based data and other relevant information regarding re-sampling in 2010 o Karen Kotschy (CWE) and Craig McCloughlin (SANParks) for valuable discussions on the project o SANParks scientific services for logistic support o Hugo Bezuidenhout for valuable inputs into the project and for acting as SANParks coordinator for die registered research project o North West University for financial support o Suria Ellis for providing valuable guidance concerning the statistical analysis of the data o Pieter Kloppers and Madeleen Struwig for assisting in the fieldwork o Thomas (SANParks field guide) for keeping us safe in the veld and sharing is knowledge of the environment