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Redefining the Griqualand West Centre of plant endemism
178
Abstracts
c Laboratory for Imaging Algorithms and Systems, Rochester Institute of Technology, USA d Council for Scientific and Industrial Research (CSIR), University of Pretoria, Department of Geography, PO Box 395, Pretoria 0083, South Africa
The co-existence of woody plants and grasses characterises savannas, with the horizontal and vertical spatial arrangement of trees creating a heterogeneous biotic environment. To understand the influence of biogeophysical drivers on the spatial patterns of 3D structure of woody vegetation, these patterns need to be explained over large areas to capture the context. The aim of the study was to produce an ecologically meaningful savanna classification using LiDAR (Light Detection and Ranging). We then applied the classification to detect change in a protected area (PA) and a communal rangeland (CR). Canopy height model (CHM) and volumetric pixel (voxel) data from the Carnegie Airborne Observatory-Alpha system were used to create the structural classification. Vegetation was classified as shrub (1–3 m), low tree (3–6 m), high tree (6–10 m) or tall tree (N10 m). A hierarchical a priori approach was used to develop classification criteria. Metrics were based on the cover and spatial arrangement of the height classes: Canopy Cover, Sub-canopy Cover, Canopy Layers, Simpson's Diversity Index and Cohesion. For change detection four of the metrics were used (Canopy Cover, Canopy Layers, Cohesion and Number of height classes present). Gains, losses and persistence (GLP) of cover at each height class and of the four structural metrics were calculated. GLP of clusters of each metric (calculated using Local Indicators of Spatial Association) were used to assess the changes. Trees N3 m in height showed gains up to 2.2 times higher in the CR where they are likely to be protected for cultural reasons, but losses of up to 3.2 times more in the PA, possibly due to treefall caused by elephant and/or fire. A 3D classification approach was successful in detecting fine scale, short term changes between land uses, and can thus be used as a monitoring tool for savanna woody vegetation structure.
doi:10.1016/j.sajb.2015.03.041
Redefining the Griqualand West Centre of plant endemism A.W. Frisbya, S.J. Sieberta, D. Cilliersa, A.E. Van Wykb a Environmental Sciences and Management, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa b Department of Plant Science, University of Pretoria, Pretoria 0186, South Africa The Griqualand West Centre of plant endemism (GWC) is located in north-central South Africa, extending through parts of the Northern Cape and North-West provinces. It is a vast area (roughly 450 × 220 km) and larger than KwaZulu-Natal. The high local floristic diversity of the region is well known — a single survey by John Acocks in 1953 yielded more species per sample point than any other across South Africa. Despite this obvious diverse and endemic-rich edaphic flora, the GWC has remained vaguely defined and floristically poorly explored because of its large size, complex geology, complex mosaic of vegetation types and arid environment. The GWC was, prior to this study, only broadly defined based on its geology. This study aims to quantitatively test the existence, floristic composition and boundaries of the GWC. Data regarding the plant taxa present in the area, their affinities and distribution was sourced from the Plants of Southern Africa (POSA) database, literature surveys, herbarium collections and field work. Plant distributions were mapped with ArcGIS (ESRI 2011) and criteria were developed to classify taxa as endemic, near-endemic or floristic elements. Hitherto twenty-three plant species were identified as endemic and five species as near-endemic to the GWC. The endemic
species' distribution maps were overlaid to produce preliminary new GWC boundaries. These boundaries were further refined by the concept of core area due to the wide ranges of several endemic species. The preliminary results of this study confirm the presence of plant species which are restricted to Griqualand West. However, further studies are in progress in this botanically data-deficient region of South Africa. doi:10.1016/j.sajb.2015.03.042
Conservation of indigenous medicinally important plants through the application of micropropagation using both liquid and solid cultures C. Glyn-Woods, E. Schroeder, N.P. Makunga Department of Botany and Zoology, University Stellenbosch, Private Bag X1, Matieland 7602, South Africa Unveiling of the medicinal properties of indigenous medicinal plants, can render wild populations prone to exploitive and potentially extinctive harvesting, to meet commercial demands for medicinally important phytochemicals. In vitro plant and cell culture technologies have the potential to satisfy the stringent quality and volume requirements of the pharmaceutical production of such compounds, while concomitantly shielding wild populations from these commercial pressures. The focus of this study aimed at the development of such in vitro approaches for medicinally important members of the Aizoaceae family. Initial results indicate that in vitro, adventitiously proliferating, clonal, shoot culture lines retain the capacity to produce the phytochemicals of interest after repeated subculture, as do ex vitro plantlets derived from a truncated, rooting/ hardening off protocol. These techniques make possible the in vitro bulk production of elite chemotypes for pharmaceutical feedstock material or the rapid generation of elite chemotypes for in vivo production facilities. Callus lines, established from clonal material, have been shown to produce the phytochemicals of interest, opening the possibility of the use of high throughput, liquid culture bioreactor technologies. With a view to understanding the possible biological function, and the application of these findings to in vitro production systems, a parallel study is under way to investigate the effect of the seasonal fluctuations and microclimate factors on the phytochemical chemotype signatures in vivo. doi:10.1016/j.sajb.2015.03.043
Host range and symbiotic effectiveness of indigenous rhizobia isolated from TGx and non-TGx soybean C. Gyogluua, S.K. Boahenb, S.K. Jaiswalc, F.D. Dakorac a Department of Crop Sciences, Tshwane University of Technology, Pretoria 0001, South Africa b International Institute of Tropical Agriculture, Nampula, Mozambique c Department of Chemistry, Tshwane University of Technology, Pretoria 0001, South Africa Rhizobia are known to vary widely in their ability to nodulate many species of legume host plants, with some strains showing specificity in their nodulation, only nodulating a limited host whiles others are more promiscuous, nodulating a wide host range of legumes. A major strategy towards addressing the increasing decline of soil fertility in Africa will involve the sustainable use of rhizobia, capable of effective N2 fixation with a host of legumes. Ten authenticated soybean rhizobia isolates were tested for their ability to nodulate five (5) grain legumes. The legumes included two Glycine max varieties (TGx 1835-10E,
Abstracts
c Laboratory for Imaging Algorithms and Systems, Rochester Institute of Technology, USA d Council for Scientific and Industrial Research (CSIR), University of Pretoria, Department of Geography, PO Box 395, Pretoria 0083, South Africa
The co-existence of woody plants and grasses characterises savannas, with the horizontal and vertical spatial arrangement of trees creating a heterogeneous biotic environment. To understand the influence of biogeophysical drivers on the spatial patterns of 3D structure of woody vegetation, these patterns need to be explained over large areas to capture the context. The aim of the study was to produce an ecologically meaningful savanna classification using LiDAR (Light Detection and Ranging). We then applied the classification to detect change in a protected area (PA) and a communal rangeland (CR). Canopy height model (CHM) and volumetric pixel (voxel) data from the Carnegie Airborne Observatory-Alpha system were used to create the structural classification. Vegetation was classified as shrub (1–3 m), low tree (3–6 m), high tree (6–10 m) or tall tree (N10 m). A hierarchical a priori approach was used to develop classification criteria. Metrics were based on the cover and spatial arrangement of the height classes: Canopy Cover, Sub-canopy Cover, Canopy Layers, Simpson's Diversity Index and Cohesion. For change detection four of the metrics were used (Canopy Cover, Canopy Layers, Cohesion and Number of height classes present). Gains, losses and persistence (GLP) of cover at each height class and of the four structural metrics were calculated. GLP of clusters of each metric (calculated using Local Indicators of Spatial Association) were used to assess the changes. Trees N3 m in height showed gains up to 2.2 times higher in the CR where they are likely to be protected for cultural reasons, but losses of up to 3.2 times more in the PA, possibly due to treefall caused by elephant and/or fire. A 3D classification approach was successful in detecting fine scale, short term changes between land uses, and can thus be used as a monitoring tool for savanna woody vegetation structure.
doi:10.1016/j.sajb.2015.03.041
Redefining the Griqualand West Centre of plant endemism A.W. Frisbya, S.J. Sieberta, D. Cilliersa, A.E. Van Wykb a Environmental Sciences and Management, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa b Department of Plant Science, University of Pretoria, Pretoria 0186, South Africa The Griqualand West Centre of plant endemism (GWC) is located in north-central South Africa, extending through parts of the Northern Cape and North-West provinces. It is a vast area (roughly 450 × 220 km) and larger than KwaZulu-Natal. The high local floristic diversity of the region is well known — a single survey by John Acocks in 1953 yielded more species per sample point than any other across South Africa. Despite this obvious diverse and endemic-rich edaphic flora, the GWC has remained vaguely defined and floristically poorly explored because of its large size, complex geology, complex mosaic of vegetation types and arid environment. The GWC was, prior to this study, only broadly defined based on its geology. This study aims to quantitatively test the existence, floristic composition and boundaries of the GWC. Data regarding the plant taxa present in the area, their affinities and distribution was sourced from the Plants of Southern Africa (POSA) database, literature surveys, herbarium collections and field work. Plant distributions were mapped with ArcGIS (ESRI 2011) and criteria were developed to classify taxa as endemic, near-endemic or floristic elements. Hitherto twenty-three plant species were identified as endemic and five species as near-endemic to the GWC. The endemic
species' distribution maps were overlaid to produce preliminary new GWC boundaries. These boundaries were further refined by the concept of core area due to the wide ranges of several endemic species. The preliminary results of this study confirm the presence of plant species which are restricted to Griqualand West. However, further studies are in progress in this botanically data-deficient region of South Africa. doi:10.1016/j.sajb.2015.03.042
Conservation of indigenous medicinally important plants through the application of micropropagation using both liquid and solid cultures C. Glyn-Woods, E. Schroeder, N.P. Makunga Department of Botany and Zoology, University Stellenbosch, Private Bag X1, Matieland 7602, South Africa Unveiling of the medicinal properties of indigenous medicinal plants, can render wild populations prone to exploitive and potentially extinctive harvesting, to meet commercial demands for medicinally important phytochemicals. In vitro plant and cell culture technologies have the potential to satisfy the stringent quality and volume requirements of the pharmaceutical production of such compounds, while concomitantly shielding wild populations from these commercial pressures. The focus of this study aimed at the development of such in vitro approaches for medicinally important members of the Aizoaceae family. Initial results indicate that in vitro, adventitiously proliferating, clonal, shoot culture lines retain the capacity to produce the phytochemicals of interest after repeated subculture, as do ex vitro plantlets derived from a truncated, rooting/ hardening off protocol. These techniques make possible the in vitro bulk production of elite chemotypes for pharmaceutical feedstock material or the rapid generation of elite chemotypes for in vivo production facilities. Callus lines, established from clonal material, have been shown to produce the phytochemicals of interest, opening the possibility of the use of high throughput, liquid culture bioreactor technologies. With a view to understanding the possible biological function, and the application of these findings to in vitro production systems, a parallel study is under way to investigate the effect of the seasonal fluctuations and microclimate factors on the phytochemical chemotype signatures in vivo. doi:10.1016/j.sajb.2015.03.043
Host range and symbiotic effectiveness of indigenous rhizobia isolated from TGx and non-TGx soybean C. Gyogluua, S.K. Boahenb, S.K. Jaiswalc, F.D. Dakorac a Department of Crop Sciences, Tshwane University of Technology, Pretoria 0001, South Africa b International Institute of Tropical Agriculture, Nampula, Mozambique c Department of Chemistry, Tshwane University of Technology, Pretoria 0001, South Africa Rhizobia are known to vary widely in their ability to nodulate many species of legume host plants, with some strains showing specificity in their nodulation, only nodulating a limited host whiles others are more promiscuous, nodulating a wide host range of legumes. A major strategy towards addressing the increasing decline of soil fertility in Africa will involve the sustainable use of rhizobia, capable of effective N2 fixation with a host of legumes. Ten authenticated soybean rhizobia isolates were tested for their ability to nodulate five (5) grain legumes. The legumes included two Glycine max varieties (TGx 1835-10E,