South African Journal of Botany 2004, 70(2): 331–369 Copyright © NISC Pty Ltd Printed in South Africa — All rights reserved SOUTH AFRICAN JOURNAL OF BOTANY ISSN 0254–6299 South African Association of Botanists Abstracts of papers and posters presented at the 30th Annual Congress of the South African Association of Botanists held at the University of KwaZulu-Natal Durban, 19–22 January 2004 The presenter of multi-authored papers is underlined $ Awards made to students Plenary Lecture Leaf elongation rate was greater in plants under elevated CO2, with leaves under elevated CO2 emerging a day ahead of plants grown Ethics, land use, and the responsibilities of Botanists under ambient CO2 conditions. Plastochron age differed in plants grown under control and elevated CO2, with leaves of the same B Page plastochron age not being of the same length. Lateral branching School of Life and Environmental Sciences, University of KwaZulu-Natal, was prominent in plants under elevated CO2 and mineral N supply. Durban 4041, South Africa The evidence from the experiments conducted thus far, shows that It is common cause amongst biologists that a large proportion of the growth of nodulating plants was enhanced under elevated CO2 the world’s biota will be extinct within the next several decades. The when mineral N is supplied. However, the growth of non-nodulating primary forces driving the extinction process are extirpation, habitat plants was significantly enhanced over that of nodulating plants in destruction and accelerated climate change that arise as a conse- the presence of mineral N supply. quence of the economies established by rapidly increasing human populations. In particular, refugia that could harbour remnants of I believe: a short history of technology in the classroom species with contracting ranges under a particular climate shift, and dispersal corridors for species with expanding ranges under the A Amory same shift, have been removed from landscapes. The result of Centre for IT in Higher Education, University of KwaZulu-Natal, Durban 4041, these biogeographic changes will be extinction cascades of varying South Africa magnitude. To a large extent awareness of the threat of the 6th Educational practices range from instruction to construction. extinction event still resides with professional biologists. Instructivists believe that the teacher is the source of all knowledge Development of land in southern Africa is occurring at unprecedent- and through instruction knowledge is passed from teacher to pupil. ed, very high rates. Professional biologists and environmental sci- Also, information is often taught through abstract examples that are entists are to a large extent failing to prevent impacts from develop- habitually memorised, is supported by external motivation that often ment. Several recent examples from the urban setting in Durban, attempts to modify behaviour, allows for no learner control or co- the toll road through Pondoland, and development in the Greater St operation and attempts to realise specific learning goals. Social con- Lucia Wetland Park, are used as examples. Some suggestions structivists believe that everyone knows something, that learning about how Botanists might improve the situation are made. occurs when new information is incorporated into an existing world view and that inconsistencies between new information and existing knowledge are resolved through social interaction. Constructivist Papers approaches support the use of concrete examples where the goals are not clearly defined. Also, the use of constructivism is closely allied with cognitive development and collaborative tasks that allow Analysis of the interactive effects of elevated CO2, nodu- lation and mineral N supply on growth and leaf devel- for individual differences and can be open ended. Many education- opment of Pisum sativum L. using the plastochron ists believe that the marriage between technology and learning will only succeed in constructivist learning environments. This paper index explores how advances in technologies influenced my teaching practices and thereby my worldview over the past 10 years. OE Ade-Ademilua and CEJ Botha Hyperlink technology (late 1980s), the corner stone of the Internet Botany Department, Rhodes University, PO Box 94, Grahamstown 6140, (1991), was initially conceived to represent the way our brains map South Africa knowledge. PlantSex (1994), a hypermedia document of plant –1 The effect of elevated CO2 (1 000µmol mol ) on the growth and reproduction, provided learners with a resource to support their col- leaf development of nodulating and non-nodulating Pisum sativum laborative problem-solving exercises. While this hyperlinked L. var. Greenfeast was studied under both nitrogen (6mM) and nitro- resource helped learners complete their tasks, many students only gen-free nutrient solution supply. Seeds were sown and kept under used it as the source of information. The development of Internet ambient and elevated CO2 throughout their subsequent growth peri- database technologies (1993–1995) allowed for the storage and od. Growth studies were based on the use of the plastochron index retrieval of content and student assignments. Such database tech- as a growth parameter. Short-term exposure to elevated CO2 nology was used to develop a tool where individual learners wrote induced plant growth under all treatments. Long-term elevated CO2 assignments on the Web that were reviewed by peers, experts and treatment did not affect leaf appearance rate (LR) in nodulated the course co-ordinator (1998). The tool allowed learners to devel- plants irrespective of mineral N supply, but enhanced LR in non- op critical review skills and simultaneously reflect on their own nodulating plants supplied with mineral N. Mineral N supply induced insights and change the way in which assignments are written and leaflet elongation rate significantly under both ambient and elevated reviewed. Web-based databases were also used to investigate the CO2 in nodulated as well as in non-nodulated plants. However, value of the Internet as a content distribution tool (2000). A course leaflet elongation rate was not significantly affected by nodulation. on carbohydrate metabolism provided diverse views of a single 332 Conference Abstracts knowledge domain and included the ability to search for information include Cyperaceae within a greatly-enlarged Order Poales. Bremer represented in different ways (multifaceted representation of infor- (2002) using rbcL and atpB sequences combined, shows that mation). The lipid metabolism course was designed as a ‘notes-on- Cyperaceae, Juncaceae and Thurniaceae constitute a well-support- the-Web’ module (single linear representation). Both were taught ed Cyperoid clade, while Poaceae, Restionaceae, etc. constitute a using problems solved by small groups of learners. Student pass well-supported Graminoid clade, with Xyridaceae–Eriocaulaceae rate was superior in the carbohydrate course which suggests that falling between. Clearly Cyperales sensu Dahlgren et al. is para- interactive components that foster constructivist-based learning phyletic and not permitted according to strict cladistic theory, but skills are more effective in on-line learning environments than pres- subsuming Cyperales into Poales sensu lato will cause a certain entation of information. Despite such findings and others that learn- loss of predictive information. Much discussion has taken place in ing has little to do with content management and distribution, ven- recent years on the inapplicability of cladistic methodology with dors persist in the publishing of expensive student- and content respect to Angiosperm phylogeny. Using Cyperaceae as an illustra- management Web-based systems. The emergence of the Open tion, and considering our present state of knowledge I ask: How Source movement (from 1998) has made available Web-based appropriate is it to impose the changes suggested by cladification scripting (e.g. PHP V. 3.0, 1998) and database tools that provide practices onto our existing Linnaean taxonomy? building blocks to develop software that makes use of construc- tivism both in software and course design. The Open Learning System (OLS) was developed to meet these aims and provides an A new look at Malpighiales? easy mechanism to expand the software to provide tools that sup- port cognitive development and co-operation between all members RH Archer of a learning community (2002). OLS was used to deliver four mod- National Herbarium, National Botanical Institute, Private Bag X101, Pretoria ules to Honours and MA students (2003) that clearly showed that 0001, South Africa students perform best when they are given tools that support coop- The Malpighiales is presently one of the largest orders recog- erative learning. The past eight years has also seen rapid techno- nised by the Angiosperm Phylogeny Group (1998, 2003). At least 18 logical advances in 3D-graphics on the desktop which supported the (or 20) of the 29 (or 37) families are represented in southern Africa. explosive development of computer games (e.g. DirectX V. 3.0, Numbers differ because provision is made by them for optional, 2000). The Game Object Model (GOM) was created to explore the acceptable monophyletic alternatives. Our improved understanding relationship between educational theories, game design and game of relationships within the order in a relatively short time is consid- development, that attempts to provide a practical framework for the erable. Who would have