Students

Current students

---

Mr Gerard Lindner (Ph.D. candidate)

Gerard, who is currently based in the Sabie area, and spends part of his time managing a timber farm, is researching the question of error in models.  He is particularly interested in understanding and quantifying error propagation.  He is exploring the components of error in dominant height models and Site Index prediction, as well as errors in field measurements and how these propagate through to errors in final volume estimation.

 

Mr Kevin Kiptoo (Ph.D. candidate)

Mr Erich Seifert (Ph.D. candidate)

Accurate data on forest structure, stocking volume, biomass, and potential product yield forms the base for efficient forest management. Traditional methods are constrained to only a few tree variables such as tree height and diameter. Information on utilisable stem length, stem taper and sweep, which govern the product yield in a sawmill to a large degree are only estimated by models or not available at all. In consequence stand specific variability is not fully accounted for. The last decades brought about new methods for measuring more tree variables. In particular, high-resolution airborne sensors and new terrestrial sensors such as laser scanning are promising technologies that have undergone successful tests for their application in Forest Mensuration.

Airborne photography is based on the combination of overlapping photographs and provides areal data of a wider spatial range. Modern photogrammetric algorithms such as Structure from Motion (“SfM”) are used to calculate three-dimensional point clouds by combining a large amount of photos. Corresponding points, which identify the same features on different photos are used for this registration process. It has been successfully demonstrated that these methods can be used to determine the crown surface and derive tree heights. Additionally, the usage of multi-spectral imaging allows for identifying tree species. However, airborne photography is not able to provide accurate information on below-canopy structures such as stems and branches.  Certainly, a key challenge is that a successful combination of these methods requires an exact spatial alignment (registration) of terrestrial and airborne derived point clouds.

The objective of Erich’s thesis is to develop novel algorithms for extracting tree and tree parts from remotely sensed data, which can be used for improved combination of dense point clouds from terrestrial laser scanning and high-resolution airborne imagery for forestry applications.  Erich is co-supervised by Prof Jan van Aardt (Rochester Institute of Technology (RIT), USA).

Ms Gugu Gama (Ph.D. candidate)

Gugu Gama was born in Newcastle which is a city located in the province KwaZulu Natal. She later moved to Johannesburg and received her bachelor’s degree in Botany and Biochemistry from the University of Johannesburg. With great interest in wood and bark anatomy, she furthered her studies and obtained her M.Sc. degree from the University of Johannesburg majoring in Plant Anatomy and Molecular Systematics and Plant Evolution. She has a background in lianescent species portraying an uncommon formation of cambial variant in the genus Grewia. Gugu is therefore excited to join the EucXylo team and expand her knowledge on wood formation in Eucalyptus species. The first aspect of her Ph.D. research will investigate the dynamics of xylem growth in Eucalyptus cladocalyx focusing on the relationship among growth and climate under varying climate conditions in South Africa. Learn more about Gugu’s work here.

Mr Mpilo Khumalo (Ph.D. candidate)

Mpilo Khumalo grew up in Bergville, a small town in the beautiful valleys of the Drakensberg mountains in KwaZulu Natal. He obtained his B.Sc. in Biological Sciences, B.Sc. (Hons) in Ecology and Environmental Sciences, and M.Sc. in Ecosystems Ecology from the University of the Witwatersrand. His M.Sc. research focused on Wood respiration in southern African savanna ecosystems supervised by the distinguished Professor Bob Scholes and under the mentorship of Professor Sally Archibald. His research expertise ranges from plant physiology to modelling various ecophysiological processes from tissues to ecosystem level. He has joined Stellenbosch University as a Ph.D. candidate under the EucXylo research group at the Department of Forest and Wood Science. His Ph.D. research will relate xylogenesis (wood formation) in several Eucalyptus varieties to various ecophysiological and biogeochemical processes, for example, evapotranspiration, sap flow, carbon fluxes (namely photosynthesis, sequestration and respiration), and plant resource allocation, all which are mainly driven by changes in climate and environmental conditions. Learn more about Mpilo’s work here.

Mr Brian Mandigora (Ph.D. candidate)

Empirical growth models are important forest management and planning tools. However, in light of the more frequent extreme climate events like floods and droughts experienced over the past few decades, it has become more difficult to accurately forecast forest growth and yield. Past rotations no longer accurately explain future rotations in commercial plantations. Furthermore, current models do not explain how wood properties; which are highly commercially significant; respond to daily climatic events like rainfall. Brian, who is co-supervised by Prof Ben Du Toit, is seeking in his Ph.D. to develop cutting-edge models for growth, yield and wood properties at appropriate spatial and temporal scales in the KwaZulu-Natal region of South Africa. He will make use of data from two collaborating forest companies, Mondi and SAPPI from research plots to build and validate the models. Brian is originally from Zimbabwe, where he obtained his bachelor’s degree. He subsequently undertook an M.Sc. degree from Stellenbosch, before beginning his Ph.D. in 2018. His interests lie in the development and application of models to manage challenges, as well as to exploit opportunities, that climate change and climate variation present in agriculture, particularly forestry.

Mr Oluwaseun Gakenou (Ph.D. candidate)

Learn more about Oluwaseun’s work here, and see his LinkedIn profile here.

Oluwaseun was born and raised in Lagos, Nigeria. He received his bachelor’s degree in Forestry and Wildlife Management from the Federal University of Agriculture Abeokuta (FUNAAB). He completed his M.Sc. project with EucXylo (see here) in 2021, using the stand level hybrid model 3-PG (Physiological Principles Predicting Growth) to predict growth in South African E. grandis X urophylla clones. In 2022, he took on a role as EucXylo’s data steward during which time he migrated much essential data into the GEMS platform. Fueled by his interest in data science and a relentless drive for skill enhancement, he embarked on a journey as a Ph.D. candidate with the EucXylo team in 2023. His project is centered around leveraging LiDAR technology to monitor and characterize crown architecture in young eucalypts. The scope of his work entails acquiring TLS scans at an exceptionally fine temporal scale and developing robust pipelines for the efficient management and analysis of the extensive dataset.

---

Mr Kuno Venter (M.Sc. candidate)

Ms. Erin Ramsay (M.Sc. candidate)

Erin grew up in East London in the Eastern Cape. She has both and undergraduate and honours degree in biodiversity and ecology from Stellenbosch University. She has always been interested in climate and global change, which was fostered through working with the School for Climate Studies here at Stellenbosch University. She has a worked studying Protea physiology through varying climatic conditions and is now broadening her knowledge through her M.Sc., working with various Eucalyptus species. This is a collaborative project between the Global Change Biology Group and EucXylo labs under the supervision of Prof Guy Midgley and Dr David Drew.

Ms. Yasmin DeRaay (M.Eng. candidate)

Yasmin was born in Knysna and grew up in the Transkei. In her free time, she enjoys painting, fishing, hiking, and anything related to nature and the outdoors. Her love for nature and appreciation for the outdoors started during family holidays in Nature’s Valley, where her dad would take them on hikes and pause to share insights about every tree they walked past. She recently obtained her degree in Industrial Engineering, where she developed a machine learning model to identify grapevine cultivars based on their leaves. The prospect of her Master’s journey in 2024 excites her as it will allow her to combine her love for nature with the skills and knowledge gained during her degree. In this upcoming endeavor, she will capture images of Eucalyptus roots and apply machine learning to gain deeper insights into their growth dynamics.

Mr. Christopher Erasmus (M.Eng. candidate)

Learn more about Christopher’s work here.

Christopher Erasmus was born in Johannesburg and moved to Cape Town when he was 5 years old. From a young age, he showed interest in fixing all sorts of things and frustrated his parents by taking things apart to look at their internals. With a strong aptitude in mathematics and science, he wanted to become an astronaut, however as he became older, he became more realistic. He will obtain his B.Eng. in Mechatronics in December 2023 and from the start of 2024 he will enroll in a masters program in electronic engineering, focusing on electronic design and IoT (Internet of Things). The topic of his M.Eng. is the research and development of a wireless dendrometer, under supervision of Prof. Thinus Booysen and  Prof. Dave Drew.

Ms Yenziwe Mbuyisa (M.Sc. candidate)

Yenziwe N Mbuyisa grew up in the small town of Ladysmith KZN. She has a Rhodes University undergraduate degree in environmental science and geology, and an Honours degree in environmental science from the same university. Her interest in trees and climate change was stimulated during an internship program with the Rhodes Restoration Research Group (RRRG) in 2019, where she worked under the guidance of Dr Kathleen Smart and Mr Mike Powell. During this time Yenziwe refined her knowledge on basic plant physiology and picked up skills at the Waainek experimental green house facility, where she ran germination trials on seventeen thicket species and also worked with different electron microscopes to assess the anatomy of these species. Yenziwe’s M.Sc. will be looking at the water use efficiency of different Eucalyptus clones using stable isotopes. This project will be a collaborative effort between EucXylo and the Global Change Biology Group (GCBG) under the supervision of Prof Guy Midgley and Dr David Drew.

Mr Matthew van Eyssen (M.Sc. candidate)

Matthew van Eyssen was born in Cape Town and moved to Paarl when he was 6. He obtained his B.Sc. in Forest and Wood Science at Stellenbosch University, where his focus was on Wood Product Science. Matthew is excited to join the EucXylo team to expand his knowledge in Forestry, specifically focussing on Eucalyptus. Prof. Dave Drew will act as his main supervisor, but the project will also involve a collaboration with Wood Product Science and there Prof. Brand Wessels will be his co-supervisor. The project will involve an in-depth analysis on wood structure, as well as silvicultural regimes to see if there are any strong indictors that could assist with cell wall collapse. In his free time, Matthew enjoys fixing things or inventing objects to ease or improve life. Wood has always fascinated him and throughout his study, his love for it has grown. For Matthew it is a great honour to be able to do his M.Sc. in Forestry and Wood Sciences for the next two years with the Hans Merensky Chair in Advanced Modelling of Eucalypt Wood Formation.

 

---

Mr. Nathan Doyle (Hons. candidate)

Nathan was born in Somerset West and spent a good deal of his childhood in Grabouw amongst the small green pocket of Pines and Apple Orchards. Nathan has always had a fascination with the natural world for as long as he can remember, with a craving to understand how these natural processes function at a deeper level. During the University of Stellenbosch Open Day, Nathan stumbled upon a small booth which exposed him to the concept of pursuing a career in the Forestry and Wood Science sector. Through conversing with highly enthusiastic and good-natured people, he fell in love with the field.

 

---

Graduates

Dr Justin Erasmus (Ph.D.)

Dr. Alta Saunders (Ph.D.)

Dr Rafael Keret (Ph.D.)

Mr Oluwaseun Gakenou (M.Sc.)

Ms Gabigabi Sibiya (M.Sc.)

Ms Gloria Burengengwa (M.Sc.)

Mr Ben van Heerden (M.Sc.)

Mr Johan Stefan (M.Sc.)

Mr Philip van Niekerk (M.Sc.)

Mr Philip Muyambo (M.Sc.)

Ms Lucy Nevhungwili (M.Sc.)

Mr Chris Tonkin (M.Sc.)