Alien invasive species a massive threat to biodiversity

*Lantana camara … one of the top ten alien invasive plants that has invaded 69 regions around the world – including South Africa.*

The severe global threat posed by invasive alien species is underappreciated, underestimated, and often unacknowledged. According to a major new report by the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES), more than 37,000 alien species have been introduced by many human activities to regions and biomes around the world. This conservative estimate is now rising at unprecedented rates. More than 3,500 of these are harmful invasive alien species – seriously threatening nature, nature's contributions to people and good quality of life. Too often ignored until it is too late, invasive alien species are a significant challenge to people in all regions and in every country.

Approved on Saturday in Bonn, Germany, by representatives of the 143 member States of IPBES, the Assessment Report on Invasive Alien Species and their Control finds that alongside dramatic changes to biodiversity and ecosystems, the global economic cost of invasive alien species exceeded $423 billion annually in 2019, with costs having at least quadrupled every decade since 1970.

In 2019, the IPBES Global Assessment Report found that invasive alien species are one of the five most important direct drivers of biodiversity loss – alongside changes in land and sea use, direct exploitation of species, climate change and pollution. On the basis of this finding, Governments tasked IPBES to provide the best available evidence and policy options to deal with the challenges of biological invasions. The resulting report was produced by 86 experts from 49 countries, working for more than four and a half years. It draws on more than 13,000 references, including very significant contributions from indigenous peoples and local communities, making it the most comprehensive assessment ever carried out of invasive alien species around the world.

"Invasive alien species are a major threat to biodiversity and can cause irreversible damage to nature, including local and global species extinctions, and also threaten human wellbeing," said Professor Helen Roy (United Kingdom), co-chair of the Assessment with Prof. Anibal Pauchard (Chile) and Prof. Peter Stoett (Canada).

The authors of the report emphasize that not all alien species become invasive – invasive alien species are the subset of alien species that are known to have become established and spread, which cause negative impacts on nature and often also on people. About 6% of alien plants; 22% of alien invertebrates; 14% of alien vertebrates; and 11% of alien microbes are known to be invasive, posing major risks to nature and to people. People with the greatest direct dependence on nature, such as indigenous peoples and local communities, are found to be at even greater risk. More than 2,300 invasive alien species are found on lands under the stewardship of indigenous peoples – threatening their quality of life and even cultural identities.

While many alien species were historically introduced on purpose for their perceived benefits to people, the IPBES report finds that the negative impacts of those that do become invasive are enormous for nature and people. "Invasive alien species have been a major factor in 60% and the only driver in 16% of global animal and plant extinctions that we have recorded, and at least 218 invasive alien species have been responsible for more than 1,200 local extinctions. In fact, 85% of the impacts of biological invasions on native species are negative," said Prof. Pauchard. Examples of such impacts include the ways that North American beavers (Castor canadensis) and Pacific Oysters (Magallana gigas) change ecosystems by transforming habitats – often with severe consequences for native species.

Nearly 80% of the documented impacts of invasive alien species on nature's contributions to people are also negative – especially through damage to food supplies – such as the impact of the European shore crab (Carcinus maenas) on commercial shellfish beds in New England and the damage caused by the Caribbean false mussel (Mytilopsis sallei) to locally important fishery resources in India.

Similarly, 85% of documented impacts negatively affect people's quality of life – for instance through health impacts, including diseases such as malaria, Zika and West Nile Fever, spread by invasive alien mosquito species like Aedes albopictus and Aedes aegyptii. Invasive alien species also damage livelihoods, for example in Lake Victoria where fisheries have declined due to the depletion of tilapia, as a result of the spread of water hyacinth (Pontederia crassipes), which is the world's most widespread terrestrial invasive alien species. Lantana (Lantana camara), a flowering shrub, and the black rat (Rattus rattus) are the second and third most widespread globally, with far-reaching impacts on people and nature.

"It would be an extremely costly mistake to regard biological invasions only as someone else's problem," said Pauchard. "Although the specific species that inflict damages vary from place to place, these are risks and challenges with global roots but very local impacts, facing people in every country, from all backgrounds and in every community – even Antarctica is being affected."

The report shows that 34% of the impacts of biological invasions were reported from the Americas, 31% from Europe and Central Asia, 25% from Asia and the Pacific and about 7% from Africa. Most negative impacts are reported on land (about 75%) – especially in forests, woodlands and cultivated areas – with considerably fewer reported in freshwater (14%) and marine (10%) habitats. Invasive alien species are most damaging on islands, with numbers of alien plants now exceeding the number of native plants on more than 25% of all islands.

"The future threat from invasive alien species is a major concern," said Prof. Roy. "37% of the 37,000 alien species known today have been reported since 1970 – largely caused by rising levels of global trade and human travel. Under 'business-as-usual' conditions, we project that total numbers of alien species will continue to increase in this way."

*Chromolaena odorata … another of the global top ten alien plant invaders … it is here in South Africa as well.*

"But business-as-usual is actually unlikely," continues Roy. "With so many major drivers of change predicted to worsen, it is expected that the increase of invasive alien species and their negative impacts, are likely to be significantly greater. The accelerating global economy, intensified and expanded land- and sea-use change, as well as demographic changes are likely to lead to increases in invasive alien species worldwide. Even without the introduction of new alien species, already established alien species will continue to expand their ranges and spread to new countries and regions. Climate change will make the situation even worse." The report underscores that interactions between invasive alien species and other drivers of change will be likely to amplify their impacts – for example invasive alien plants can interact with climate change, often resulting in more intense and frequent fires, such as some of the devastating wildfires experienced recently around the world, releasing even more carbon dioxide into the atmosphere.

The IPBES experts point to the generally insufficient measures in place to tackle these challenges. While 80% of countries have targets related to managing invasive alien species in their national biodiversity plans, only 17% have national laws or regulations specifically addressing these issues. This also increases the risk of invasive alien species for neighbouring States. The report finds that 45% of all countries do not invest in the management of biological invasions.

On a more positive note, the report highlights that future biological invasions, invasive alien species, and their impacts, can be prevented through effective management and more integrated approaches. "The good news is that, for almost every context and situation, there are management tools, governance options and targeted actions that really work," said Prof. Pauchard. "Prevention is absolutely the best, most cost-effective option – but eradication, containment and control are also effective in specific contexts. Ecosystem restoration can also improve the results of management actions and increase the resistance of ecosystems to future invasive alien species. Indeed, managing invasive alien species can help to mitigate the negative effects of other drivers of change."

Prevention measures – such as border biosecurity and strictly enforced import controls – are identified by the report as having worked in many instances, such as the successes achieved in Australasia in reducing the spread of the brown marmorated stink bug (Halyomorpha halys). Preparedness, early detection and rapid response are shown to be effective at reducing rates of alien species establishment, and to be especially critical for marine and connected water systems. The PlantwisePlus programme, assisting smallholder farmers in Africa, Asia and Latin America is spotlighted by the report as a good example of the importance of general surveillance strategies to detect new alien species.

Eradication has been successful and cost-effective for some invasive alien species, especially when their populations are small and slow-spreading, in isolated ecosystems such as islands. Some examples of this are in French Polynesia where the black rat (Rattus rattus) and rabbit (Oryctolagus cuniculus) have been successfully eradicated. The report indicates that eradication of alien plants is more challenging due to the length of time that seeds may lie dormant in soil. The authors add that successful eradication programmes depend on, amongst other elements, the support and engagement of stakeholders and Indigenous Peoples and local communities.

When eradication is not possible for different reasons, invasive alien species can often be contained and controlled – especially in land-based and closed water systems, as well as in aquaculture – an example being the containment of the invasive alien Asian tunicate (Styela clava) in aqua-cultured blue mussels in Canada. Successful containment can be physical, chemical or biological – although the appropriateness and effectiveness of each option is dependent on local context. The use of biological control for invasive alien plants and invertebrates, such as introducing a rust fungus (Puccinia spegazzinii) to control bitter vine (Mikania micrantha) in the Asia-Pacific region, has been effective – with success in more than 60% of known cases.

"One of the most important messages from the report is that ambitious progress in tackling invasive alien species is achievable," said Prof. Stoett. "What is needed is a context-specific integrated approach, across and within countries and the various sectors involved in providing biosecurity, including trade and transportation; human and plant health; economic development and more. This will have far-reaching benefits for nature and people." Options explored in the report include considering coherent policies and codes of conduct across sectors and scales; commitment and resourcing; public awareness and engagement, such as citizen science campaigns like those promoting 'check, clean and dry'; open and interoperable information systems; filling knowledge gaps (the authors identify more than 40 areas where research is needed); as well as inclusive and fair governance.

"The immediate urgency of invasive alien species, with extensive and growing harm to nature and people, makes this report so valuable and timely," said Dr. Anne Larigauderie, the Executive Secretary of IPBES. "The Governments of the world agreed, in December last year, as part of the new Kunming-Montreal Global Biodiversity Framework, to reduce the introduction and establishment of priority invasive alien species by at least 50% by 2030. This is a vital, but also very ambitious commitment. The IPBES Invasive Alien Species Report provides the evidence, tools and options to help make this commitment more achievable."

Top 10 Most Widespread Invasive Alien Species Worldwide

Organism group	Taxon	Number of regions
Vascular plant	Pontederia crassipes (water hyacinth)	74
Vascular plant	Lantana camara (lantana)	69
Mammal	Rattus rattus (black rat)	60
Vascular plant	Leucaena leucocephala (leucaena)	55
Mammal	Mus musculus (house mouse)	49
Mammal	Rattus norvegicus (brown rat)	48
Vascular plant	Ricinus communis (castor bean)	47
Vascular plant	Ailanthus altissima (tree-of-heaven)	46
Vascular plant	Robinia pseudoacacia (black locust)	45
Vascular plant	Chromolaena odorata (Siam weed)	43

The number of regions where a species has been recorded and classified as invasive based on GRIIS (Pagad et al., 2022). Note this table only refers to the distribution of invasive alien species and not their impacts.

Using drone & satellite to track pest damage

Dr MIchelle Schröder (FABI) and PhD candidate Phumlani Nzuza prepare to launch the drone that will capture detailed images of canopy damage caused by the Gonipterus snout beetle. (Photo courtesy of FABI)

FABI and ICFR researchers are collaborating in an innovative project to develop a system to monitor the impact of the Eucalyptus snout beetle on the health of eucalypts using a combination of drones and satellite remote sensing.

Gonipterus sp. n. 2, is an invasive insect native to Australia and a significant defoliator of Eucalyptus. Management of this pest, commonly known as the Eucalyptus snout beetle, relies mainly on classical biological control by a tiny wasp Anaphes nitens, which was first introduced into South Africa in 1924. The biological control has been effective in keeping Gonipterus infestations under control for decades, but in the past few years Gonipterus infestations have increased and the damage to eucalypt plantations in South Africa is on the rise.

The project is a collaboration between the Forestry and Agricultural Biotechnology Institute (FABI) based at the University of Pretoria, the ICFR’s Dr Ilaria Germishuizen and Dr Benice Sivparsad and international researchers Prof Wouter Maes of the University of Ghent in Belgium and Dr Rene Heim of the Institut für Zuckerrübenforschung.

*Gonipterus* is a small beetle with a distinctive X mark on its back. It eats mainly along the leaf margins, leaving a characteristic scalloped leaf edge. It prefers new growth on *E. dunnii, E.smithii* and hybrids.

The use of a drone to measure Gonipterus damage is key as it provides very high resolution images of the tree canopy that cannot be seen from ground level once trees reach more than 2 m height. The satellite imagery is useful in that it can detect canopy damage but is not fine enough to provide the detailed information that the researchers require.

The project has two main objectives:-
• To use satellite and drone imagery to assess and monitor the extent of canopy damage from Gonipterus.
• To understand the relationship between the canopy damage and the productivity of the compartment, which will provide forest managers with the info necessary for them to decide when and where to incur the costs of applying a chemical spray to reduce Gonipterus infestations. The info gathered from the study will also enable the researchers to assess the impact of a chemical spray application on the population of the biological control agent A. nitens.

The drone provides detailed images of the tree canopy from above, allowing researchers to gauge Gonipterus damage. (Photo courtesy of FABI)

The model that will be developed through this study will be applicable to monitor the impacts of other pests and diseases that defoliate eucalypts.

Earlier this year PhD candidate Phumlani Nzuza, Dr Michelle Schroder and Ofentse Mathibela from FABI went to the KwaZulu-Natal midlands to map Gonipterus sp. n. 2 defoliation levels using their newly acquired drone. For field ground truthing they are using ICFR’s Gonipterus impact trials at Hodgsons (Greytown) and Sutton (Ixopo)

The ICFR’s work is supported by FSA, Sappi, NCT and TWK.

Are multi-storey timber buildings viable in South Africa?

Multi-storey timber frame buildings are financially feasible in SA, but suitable construction grade timber would need to be imported as local timber resources are limited.

Research by a structural engineer finds that construction of multi-story timber buildings would be financially feasible in South Africa, but that suitable timber would need to be imported as local resources are ‘over-subscribed’ …

The economic viability of multi-storey mass timber buildings in South Africa has come under the spotlight in a research study carried out by Stephanus van der Westhuyzen, a Structural Engineer at leading consulting engineering and infrastructure advisory firm Zutari.

Sawmilling South Africa (SSA) and the Institute for Timber Construction South Africa (ITC-SA) have both proposed that timber be designated a construction material of choice. This will assist in alleviating the housing crisis in densely populated informal settlements that have been hardest-hit by the Covid-19 pandemic, where quality accommodation needs to be built as quickly and as cost-effectively as possible.
Timber as a building material can substantially reduce greenhouse gas (GHG) emissions in the building sector, in addition to reducing the waste, pollution and costs associated with construction, and thereby contribute to a more physically, psychologically and aesthetically healthy built environment.

Van der Westhuyzen’s research focuses on whether or not South African plantations can provide sustainable volumes of high-grade (S7, S10) timber to sustain a multi-storey mass timber building market. This was followed by the design of two eight-storey commercial buildings consisting of a mass timber frame and a reinforced concrete frame respectively.

A focus-group workshop conducted with industry professionals assisted with developing the construction schedules, while a financial model was used to determine the overall development cost and financial feasibility of the two approaches. Finally, a sensitivity analysis was conducted to investigate the effect of certain variables on the overall profitability of the mass timber frame option in particular.

The research revealed that mass timber products would need to be imported to satisfy the rapid growth in the multi-storey mass timber building market in South Africa, as current timber supplies (S5, S7, S10) are oversubscribed. Studies suggest that future log resources could be added to the market through the development of new plantations, although the reality is that the opportunities for establishing additional plantations in South Africa are extremely limited. In any event it would take a minimum of 24 to 30 years before any new plantations could produce suitable construction grade timber.

The focus group workshop found that construction of the reinforced concrete frame building would take 42 weeks, while the mass timber frame building would take 21 weeks to build. Furthermore, the total capital investment required for the mass timber frame building would be 10% more than that of the reinforced concrete frame option. The five-year internal rate of return (IRR) of the timber building would be 20.9% vs 25.7% for the reinforced concrete frame option.

Notably, the five-year IRR of both options is above the 15% minimum acceptable rate of return (MARR), indicating that they are both financially feasible. A significant finding of the sensitivity analysis was that the mass timber frame building proved to generate a higher five-year IRR than that of the reinforced concrete frame once the mass timber building achieved a rental premium of 7.8% or more. The sensitivity analyses further revealed that importing mass timber elements is an expensive option at a 16.4% five-year IRR.

The research study highlighted a number of aspects in the manufacturing sector that can be addressed to develop a sustainable multi-storey mass timber building market. This includes improving the sourcing of high-grade structural timber (S7, S10) and investing in equipment to enable the large-scale production of large beams and columns typically required in multi-storey mass timber structures.

Due to the sturdy and resilient qualities of timber and the relative ease of construction, timber-frame construction is one of the oldest known building methods, especially in the Northern Hemisphere. While timber construction in South Africa can be traced back to the 1800s, it only became a bona fide building method over the last 30 years.

This resulted in the formation of the Timber Frame Builders’ Association in the early 1980s, with SABS 082 amended in 1988 to include standards for timber construction in particular. The Institute of Timber Frame Builders (ITFB) and the ITC were aligned in August 2014, with the ITC-SA established to promote and sustain timber engineered products in South Africa.

To read the full thesis by Stephanus van der Westhuyzen, click HERE.

Andrew Morris - big contribution to forestry research

Andrew Morris during an ICFR field day, KZN midlands.

Dr Andrew Morris, who retired from his post as CEO of the Institute for Commercial Forestry Research (ICFR) at the end of March, has had a big impact on the forestry industry in southern Africa in the course of a long and distinguished career.

He has been at the centre of ground-breaking research in Swaziland and South Africa that has played a key role in improving soil quality, plantation productivity and forest health. Imbued with an infectious sense of humour and an irrepressible intellect, Andrew can always be counted on to raise challenging questions and engage in robust debate and exchange of ideas among colleagues and forestry professionals.

After graduating with an Honours degree in Soil Science from Reading University in the UK in 1976, Andrew was employed as a Soil Physicist at the Agriculture Research Centre of the University of Swaziland.

In 1979 he joined the Usutu Pulp Company of Swaziland where he was involved in ground breaking research to explain and correct a yield decline in pine pulpwood plantations. This led to the introduction of fertilizer applications to improve the fertility of the soil, which reversed the productivity decline. This research was the basis for his PhD which he obtained through Reading University in 1987.

Andrew Morris engaged in a trial inspection in a mature Pinus patula stand at Usutu Forests, Swaziland, in the 1980s.

On his return to Swaziland, he formed a multidisciplinary research team that developed silviculture research in re-establishment practice, weed control, site-species matching, tree breeding and forest protection, that together with a new site classification realised significant benefits through the introduction of site-specific silvicultural practices.

In 1997 he was appointed General Manager for Research and Nurseries with Sappi Forests based at Tweedie in the KZN midlands. He transferred the concepts of integrated multidisciplinary research used in Swaziland, founded on site classification, across Sappi’s South African plantations. This led to the application of site-specific silviculture practices, and the continued development of tree improvement programmes that delivered improved eucalypt and pine planting stock to the plantations. Propagation research resulted in the modernisation of nursery production to produce the genetically improved rooted cuttings of various hybrids.

The application of this work has had a big impact on the forestry industry with eucalypt wood production per unit area of land significantly increased. Sappi’s eucalypt MAI effectively doubled between 1981 and 2000. Site classification, site-species matching, genetically improved planting stock, application of fertilizer at planting and improved weed control have all played a key role in this productivity improvement.

In a country where the area suitable for commercial wood production is limited with no opportunity for significant expansion, these productivity improvements are crucial in meeting growing demand for wood and wood fibre in South Africa.

Seeking a new challenge to help develop research initiatives beneficial to the whole forestry sector, Andrew joined the ICFR as Research Manager in 2013. His career up to this point had taken him from active research to research management, and the move to the ICFR was intended to reverse this trend. But once again he was required to perform a management role when, from 2017, as Director he led the institute through a major restructure securing new funding for a suite of research projects.

The ICFR Business Manager Karin Nagel took over from Andrew as Acting CEO from 1st April. She has a strong management support team in Julian Chan (Group Leader Tree Breeding), Ilaria Germishuizen (Group Leader Sustainable Production) and Greg Fuller (Technical Support).

“The ICFR continues to provide high quality applied research relevant to policy and practice in the forestry sector which requires continued collaboration with other organisations to deliver the needed multidisciplinary understanding,” concluded Andrew.

Andrew Morris (2nd from right, front row) with the tree improvement team in 1995 at the first Pinus patula seed orchard at Usutu Pulp Company, Swaziland. Front row (L to R): Tree Breeder, Arnulf Kanzler, Senior Research Foreman, Milton Nkambule, Research Manager, Andrew Morris, Research Foreman, Simon Maseko. Back row (L to R): Boy Dlamini, Willian Msibi, Richard Nkambule, Benson Maseko, Sipho Dlamini, Bethwell Maseko.

Andrew has been an Honorary Professor, Department of Plant and Soil Sciences, University of Pretoria, and Honorary Research Fellow of the University of KwaZulu-Natal. He is author and co-author of more than 35 peer reviewed scientific papers and has presented at numerous scientific conferences, symposia and workshops. He has been involved in several forestry feasibility studies in Africa, South America, China and South East Asia. Industry roles have included Chairman of the Advisory Board for the Camcore International Tree Improvement Cooperative at North Carolina State University (2003-2011), leader of the South African Pitch Canker Control Programme and Editor-in-Chief of Southern Forests: A Journal of Forest Science.

A scientist at heart, Andrew says he is looking forward to continuing his involvement in the forestry industry as a research associate for the ICFR.

“Throughout my career I have been privileged to work with a host of knowledgeable, innovative and motivated researchers, technicians and foresters, and it would be nice to help the next generation in some small way,” he said.

He believes further opportunities exist for investment in forestry research that can bring important improvements to the various forestry value chains important in South Africa, and benefit to the tree farmers who supply the wood.

SA researchers push the innovation envelope

Three South African researchers have made it to the global shortlist of the Blue Sky Young Researchers and Innovation Awards.

The awards, launched in 2016 by the International Council of Forest and Paper Associations (ICFPA), aim to recognise, celebrate and promote innovations in the global forestry sector.

Justin Phillips and Hester Oosthuizen, both from the University of Pretoria, and Eddie Barnard from Stellenbosch University, go up against another 18 of their peers from around the world. The top three finalists will win cash prizes and get an opportunity to present their work at the ICFPA’s Global CEO Roundtable virtual discussion on 29 April.

Particle board from paper sludge
Eddie Barnard is exploring the commercial viability of using technical lignin (a by-product from the wood pulping phase in pulp or paper making) and pulp and paper sludge (rejected, degraded, and spilled fibres and water from the pulping and paper making processes) to make composite materials.

Eddie Barnard from Stellenbosch University is exploring the potential of combining lignin with paper sludge to make construction materials, such as a replacement for particle board.

Lignin has binding properties, which when combined with sludge, could be used to make construction materials such as a replacement for particle board. The use of lignin together with pulp and paper sludge could replace components that would otherwise be produced from fossil-based resources, and reduce associated waste, greenhouse gas emissions and disposal costs.

Cattle dip for killing ticks
Justin Phillips has looked at how starch and nano-cellulose can be used as a carrier material for pesticide application in the agricultural sector. The insoluble solid active ingredient in the pesticide attaches to the carrier, which is water-soluble and allows for safer and more efficient and safe controlled release of the pesticide, especially in aqueous environments such as animal dipping for tick prevention.

Justin Phillips from the University of Pretoria is looking at how starch and nano-cellulose can be used as a carrier material for pesticide application in the agricultural sector.

A substitute for petroleum-based plastics
Cellulose is uniquely positioned to substitute many petroleum-based plastics, however it cannot be melt-processed and dissolved using common organic solvents. This is why Hester Oosthuizen examined the efficacy of using choline chloride and ionic liquids, considered greener and less volatile, to make cellulose fluid enough to produce cellulose-based materials using existing polymer processing techniques.

Hester Oosthuizen from Pretoria University is exploring the potential for using cellulose to substitute for petroleum-based plastics.

“We are immensely proud of our finalists for making it this far, and demonstrating that South Africa can hold its own against the best in the world,” says Jane Molony, executive director of the Paper Manufacturers Association of South Africa (PAMSA). “As a sector we constantly look for ways to support young people with an interest in science and technology and are proud of the career opportunities our member companies can offer them.”

Wood – a renewable alternative to conventional materials
As a sustainably farmed resource that stores carbon, wood is increasingly being used not only in the built environment for houses and high-rises, but also for its cellulose, lignin and sugars. These elements all have a role in helping the world find renewable and low-carbon alternatives to the likes of plastic, chemicals, steel and concrete.

“Two key advantages that commercially farmed trees bring are their renewability and their carbon storage,” explains Molony. “The fact that trees are sustainably planted, harvested and replenished on the same land makes both wood and paper products renewable and efficient resources. For a low carbon future, it’s tremendously exciting – especially when we look at the kind of research our young scientists are producing.”

An international panel with connections to industry, academia and public policy has been assembled to judge the awards, including:
• Lyndall Bull, Forestry Officer at the Food and Agriculture Organisation of the United Nations (UN)
• Barbara Tavora Jainchill, Programme Management Officer, Forest Affairs, with the UN Forum on Forests Secretariat
• Fernando L. Garcia Bertolucci, Executive Director of Technology and Innovation at Suzano S.A. and Member of IUFRO
• Professor Gil Garnier, Director of BioPRIA within the Department of Chemical Engineering at Monash University
• John Innes, Dean of the Faculty of Forestry at University of British Columbia.
The local round was adjudicated by Valeske Cloete (Mpact), Sanet Minnaar (Sappi) and Mike Nash, former head of PAMSA’s Process Research Unit and experienced chemical engineer.