Blue skies and burnt trees

The Cape is a special place to do just about anything; surfing, whale watching, brewing, foresting and field tripping. On the 19th of August, I set off on a 3800 km journey to and around the Southern and Eastern Cape with one of FABI’s extension officers, Sandisiwe Jali, and two graduate students, Bianca Jardim and Sydney Sithole. The purpose of this field trip was to collect insect specimens and investigate various pest and disease issues in commercial forestry plantations. It isn’t often that the Tree Protection Co-operative Programme (TPCP) finds itself in the Cape, when compared to the much closer Limpopo, Mpumalanga and KwaZulu-Natal provinces, which made this trip quite distinctive.

Field trips around South Africa are always memorable; you get to see more of this beautiful country, you get to interact more closely with other students, meet the people in the forestry industry, and put your finger on the pulse of plant health in SA. Our first stop was to Stellenbosch, wine country, to meet Deon Malherbe, a researcher at Stellenbosch University. Deon is monitoring a Eucalyptus (gum) trial, which was setup by Camcore–an international tree breeding organization–to look at the performance of various hybrids across different sites. This valuable trial is under attack by a number of Eucalyptus pests, which we helped Deon identify. Together, we worked out a scoring system for better assessing the damage caused by these insects.

From there, we set off east to Riversdale, about 50 km north of Still Bay, to collect a few pine logs containing the larvae of a woodwasp, Sirex noctilio. The larvae and adults of this wasp will be examined at FABI for the presence of a tiny worm, Deladenus siricidicola—a bio-control agent developed at FABI that has saved the South African forestry industry more than 400 million rand. Here we paused to take in some of the sights while we thought about what R400 million could buy you.

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The next day, we continued east–towards Knysna–to meet Awelani Netshituka, a forester working for PG Bison at the Ruigtevlei office. Many parts of the Cape have been, and still are, at the mercy of a severe drought—the worst in 100 years. We were often reminded about using water sparingly by the little notes stuck on the walls near the taps and toilets of our accommodation. While the drought meant one couldn’t take long showers anymore, it also meant that much of the vegetation hadn’t had a good shower either. The dry conditions, high winds speeds and building fuel load led to the fires that swept through Knysna and the surrounding areas, claiming seven lives.

Awelani showed us some of the areas that had been devastated by the fires and the recovery operations under way to try and salvage some of the burnt timber. In the valley below the Ruigtevlei office, in front of thousands of dead trees, there are long lines of what looked like neatly stacked mounds of charcoal. When we asked what those lines were, we were told that they were the burnt logs they had harvested after the fire. They have harvested so much, the market is flooded. Now they have to try and store it! The arrangement of theses logs under sprinklers are called wet decks, which helps keep the wood moist until they can be used.

While many trees were harvested, the lesser-affected younger stands were left to recover. Awelani took us to some of these compartments. The prolonged drought has had a significant impact on these trees. They are trying to recover but without good rains they are being attacked by a number of different secondary or opportunistic pests and fungi, killing those too weak to put up a fight. And this wasn’t isolated to a single company or region. We saw more examples of this at a number of sites we visited.

For any industry growing plants and selling their products, climate is going to be a more important part of planning; for South Africa, a water scarce country, even more so. We are going to have to be smart with how we collect, store and recycle our water. For our plants, we are going to have to develop more efficient breeding strategies, develop and implement possible GMOs, and we are going to need more scientists to understand the effects of climate on pests and diseases because we are going to have many more blue sky days (no rain) and more burnt trees (any crop plant, really) if we don’t.

 

“Read this and call me in the morning”

-Darryl Herron, Tree Doctor

The forest floor may not always seem as impressive as the giant trees that congregate around it but it is probably one of the more interesting places you’re likely to come across. During certain times of the year, if you’re lucky, have patience, and timed your visit after some rain, you will see a once plain forest floor come to life with wonderful colours and weird shapes, like the glowing pale green cap of Mycena chlorophos; the bird’s nest fungus, Cyathus novaezelandiae (yes, resembles a bird’s nest with eggs); and the characteristic creamy star-shaped earthstar, Geastrum triplex. My friends call me a tree doctor, and that’s what I am, sort of…

 

Side note: Before mycology was a recognized field, fungi were thought of as plants and were even grouped with them. The first scientists studying fungi were really botanists; so if we were living in 17th century, my friends would have been right.

I’m actually many things. I am a microbiologist by training; that is my broad field of study. The core focus of my PhD is on a fungus, which also makes me a mycologist (I study fungi). The fungus I work on kills pine trees and is a huge problem for the forestry industry, globally. Because I study a tree disease and work, part-time, in a plant clinic which diagnoses tree health issues, it also makes me a forest pathologist. I could call myself any one of these (and more) but I have adopted the title tree doctor. Like human doctors need to know about human physiology, the diseases which affect them and the medicines to remedy them, I need to understand that about plants.

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A tree doctor in action

Tree doctors are as awesome as — no, wait — are more awesome than medical doctors because a tree doctor has (or will have, in my case) the title “Dr” without having to worry about medical malpractice. We face a tougher challenge, however: tree doctors, like veterinarians, work with “patients” that cannot tell you what is wrong and the medical research for plants is far behind anything we have for humans and other animals. I essentially treat plants in the medical Stone Age! Yes, there are high mortality rates.

The knowledge gap is wide and that makes my job both interesting and disappointing. A few weeks ago I was called out to give some advice on a beautiful 100-year oak tree that was dying. The owner— having grown up with this tree, like her father before her—was willing to do anything to save this tree. Unfortunately, this oak was suffering with a root rot that was quite advanced and would eventually kill it. Had I the chemotherapy equivalent, the technology to safely cut out the diseased tissue or the knowledge of synthetic root growth, we could have done something to save this tree. But yeah, we’ve focused on animal health for millennia, and we still almost nothing about green living things.

Some individual trees have great sentimental value to people, but generally we seem to take them for granted. We should not. Trees quite literally provide the air that we breathe, and many animals (birds, squirrels, various pollinators) rely on them for safe spaces or food. We need healthy trees. As a farmer or forester, you realize the value of plants because you sell the plant or its products for a living. While these commercially important species are well protected and somewhat studied by many plant doctors, there are far too many plant species that do not receive the same attention—unless there are small pockets of them left, like many of our cycads or the redwoods in the US. Because our knowledge and the technology for plant health is so far behind, should these precious plants ever become diseased, it’s going to take a miracle to save them.

When you walk out of your house tomorrow morning, take a moment to look at what’s around you. Look at the plants in your garden, the trees on the street and those lining the horizon. Now, imagine if the only plants you’d ever see were grown in commercial plantations or massive, monotonous farms.

Herron_Eucalyptus

Research shows that green spaces in cities boost our own mental health, that getting out into nature (not just well-tended gardens or farms) restores balance in our own rushed lives. It’s not just the green spaces, but the pale green, bird-nest lookalike, star-shaped spaces too—trust me, I’m a doctor.

Plants may not always seem as impressive as the humans that congregate around them but they are the lungs of our planet, and keep us mentally rooted (pardon the pun). We need a few more tree doctors to make sure that they don’t simply disappear and turn to dust under our feet.