/ 9 December 2016

Ensuring that South Africa’s trees thrive

Moving up: Keeping trees healthy involves research and expertise from a surprisingly wide array of fields
Moving up: Keeping trees healthy involves research and expertise from a surprisingly wide array of fields

Picture a world without trees. For most of us, images of a post-apocalyptic wasteland with no shade or shelter immediately spring to mind. And if these images make us feel suffocated and uncomfortable, it’s because the breathable air in such a world would be limited — in fact, a world without trees would likely not be habitable for humans.

The most obvious benefits of trees are in the products we harvest from them for our everyday use: timber for construction, fibre for paper, fruit and nuts for consumption and fuel for cooking and heating. Trees also provide us with unseen yet essential goods and services that are crucial for the proper functioning of biological systems. For example, trees improve air quality because they remove the harmful greenhouse gas carbon dioxide from the atmosphere by fixing it in biomass (the organic material that trees are made of) and releasing life-giving oxygen.

In addition to their commercial and environmental benefits, trees also contribute to our general health and wellbeing. Science is increasingly showing that people living in tree-rich environments have improved mental health and fewer stress-related diseases. Some research shows that living in such environments can even strengthen our immune systems. Trees therefore represent one of the most important renewable resources on our planet.

The efficiency with which trees provide goods and services depends on their overall health and the health of the ecosystems they occupy. Like humans and animals, trees can also succumb to diseases, pests and adverse environmental factors. Such threats to tree health consequently pose significant risks to the industries built around tree-based products, such as the forestry, tourism and textile industries. They also threaten the benefits trees provide such as clean air and water, healthy and biodiverse ecosystems and aesthetically desirable recreational areas.

The socioeconomic and environmental importance of trees implies that their health is often the focus of national and regional governments, nongovernmental organisations, commercial entities and research institutes. In South Africa, the largest research programme focused on tree health is the department of science and technology’s (DST) National Research Foundation Centre of Excellence in Tree Health Biotechnology (CTHB), hosted by the University of Pretoria in the Forestry and Agricultural Biotechnology Institute. The CTHB is funded by the DST and the forestry industry and includes 35 doctoral-level researchers and 105 postgraduate students from five local universities, with numerous international collaborators from across the world.

The vision of the CTHB is to promote the long-term health and sustainability of trees in natural woody ecosystems and planted environments. These include trees relevant to the plantation forestry and fruit tree industries, as well as those of ecological and recreational importance in gardens, parks and other protected areas. The CTHB team undertakes research across a broad suite of disciplines including genetics, microbiology, entomology, genomics, plant pathology, ecology, biostatistics, biochemistry and chemistry. The research in this centre also spans a range of topics underlying tree health, especially those relating to the control or containment of microbial diseases and insect pests by employing biotechnological approaches and biological control. To inform management and policy decisions, the CTHB also investigates the effects of climate change, fire, drought and human activity on our woody resources and ecosystems.

Apart from generating knowledge and technologies aimed at ensuring the health of trees, the CTHB has the important task of human capacity development. As members of university staff, CTHB researchers participate actively in educating and training students at all levels (BSc, BSc Honours, MSc and PhD). The centre further supports various outreach initiatives to attract high school learners to university and encourage them to pursue science as a career. Significant knowledge transfer also occurs during the CTHB team’s interaction with its stakeholders and professionals from industry and government. In so doing, the CTHB facilitates and advances education and training in the multidisciplinary fields relevant to tree health, while at the same time contributing to the national goals of strengthening our human resource base.

Rather than imagining a world without trees, picture one where they are valued for their products, services and the livelihoods built around them. In such a world trees are also cherished because they are beautiful and make us happy. Kahlil Gibran wrote: “Trees are poems the earth writes upon the sky.” Because their existence is so tightly linked to ours good science, a skilled workforce, knowledgeable civilians and informed managers and legislators support tree health and sustainability. By following the CTHB’s motto “keeping trees healthy”, this important natural resource can and should be safeguarded, not only for our needs, but for the needs of future generations too.

Professor Emma Steenkamp is the deputy director and programme manager of the DST-NRF Centre for Excellence in Tree Health Biotechnology, Forestry and Agricultural Biotechnology Institute, University of Pretoria. Professor Mike Wingfield is the director of the same institute