‘No’ to forestry in fynbos areas, says invasive species specialists
May 17, 2012 
9 Comments
Dr Brian van Wilgen
It may no longer make economic or environmental sense to pursue forestry endeavours using conifers in the Western Cape. If local plantations are to be maintained, invasive pine trees will continue to spread, the Cape’s water supply will continue to dwindle and the unique natural diversity of the fynbos region will be changed forever.
This is the opinion of two of South Africa’s leading researchers on invasive plant species, Dr Brian van Wilgen, Chief Ecologist at the Council for Scientific and Industrial Research (CSIR) and Prof Dave Richardson, Director of the DST-NRF Centre of Excellence for Invasion Biology (CIB) at Stellenbosch University (SU). They co-authored a paper in Journal of Environmental Management which looked at the benefits and impacts 300 years after the first alien conifer species (mainly pine trees) were introduced in South Africa.
“We realise that the phasing out of plantation forestry in the fynbos region would be politically difficult given the prevailing socioeconomic needs for employment,” says Dr van Wilgen, who is also a core team member of the CIB. “However, it is the right thing to do, as it is the only way to control invasive conifers in a sustainable way and to conserve our water resources and unique biodiversity to the benefit of the people of the region.”
Forestry in South Africa
The planting of non-native conifer species in South Africa commenced with European colonisation in the mid-seventeenth century, and was pursued amongst others to ensure a steady supply of timber. Initially, plantation-based forestry was a government undertaking which gained specific momentum in the 1930s, while privately-owned plantations expanded in the middle to late twentieth century.
The area in South Africa under formal afforestation with conifers (almost exclusively pines) reached a peak of 798 000 ha in 1997, but had declined to 660 000 ha by 2009. The industry supports 211 processing plants, ranging from small sawmills to large pump mills. Annual forestry exports worth R9.5 billion include solid wood, pulp and paper.
Prof Dave Richardson
Most pine plantations lie in the native grasslands of the summer rainfall areas of Mpumalanga, Limpopo and KwaZulu-Natal. In contrast, only 5,8% of plantations in South Africa are found in the fynbos biome, often in areas of exceptional biological diversity that are vital for water production and conservation.
“It is only the plantations in the northern parts of the country that show a reasonable return on investment,” believes Dr van Wilgen. “Here plantation-based forestry is an attractive and viable land-use option because of the demand for building timber and its contribution to job creation and the economy in general.”
“Forestry endeavours in the Western Cape contributed relatively little (R146 million) to the national roundwood sales in 2009,” Dr van Wilgen says. “Plantations in the region were often established on poor sites and do not yield economic returns to justify on-going management costs.”
The non-profitability of forestry endeavours of the southwestern fynbos region was already acknowledged during the privatisation of the South African Forestry Company Limited (SAFCOL) in the 1990s. These plantations were deemed to be “economically unattractive” and failed to attract any bidders from the private sector. Many unprofitable plantations have been abandoned under the policies of privatisation and have since been handed over to cash-strapped conservation agencies which do not have the resources needed to rehabilitate these areas.
Impact of invasive pine trees
At the heart of the matter is the invasive nature of pine trees that have been planted in forestry plantations outside of their native ranges. The trees have subsequently spread beyond the neat confines of plantations into surrounding vegetation.
“In South Africa, as in many other parts of the world, invasive pine trees are a widespread environmental problem,” says Prof Richardson.
At least five of the 57 conifer species planted in South Africa are already considered as widespread invaders, with several more having the potential to become invasive.
Research has shown that water use by vegetation increases, and that runoff decreases considerably in areas where grasslands or shrublands have been replaced by either plantations or self-sown stands of invasive trees.
In one experiment, for instance, a 55% reduction in streamflow was noted in a fynbos catchment area 23 years after it was planted with pine trees. Streams in some grassland catchment areas have completely dried up within 12 years of pines and eucalyptus trees being planted.
The rate of invasions in South Africa, which is considered to be a water poor country, is increasing despite substantial efforts to keep them in check.
“Because there is still much suitable habitat available were these trees can establish, invasions will continue to spread if current conditions prevail,” believes Prof Richardson. “This is despite laudable initiatives to clear them through eradication projects such as the Working for Water programme, or bold legislative steps by our government to impose environmental taxes or to introduce different categories of weeds.”
Invasive trees causes loss of R2 billion worth of water
“The rugged and inaccessible terrain of the fynbos region prevents effective control operations, while the prevailing fire regime promotes the spread and densification of pines,” Dr van Wilgen explains. “This will have a growing impact on how much water is available to the people of the region and on other ecosystem services in years to come.”
“If the current rate of pine invasion continues over the next 100 years, Cape Town will lose 30% of its water supply through a loss of runoff to its storage dams,” Dr van Wilgen predicts.
Research in 2010 quantified the benefits and impacts of invasive species in monetary terms. In the fynbos biome alone, the loss of ecosystem services such as water was estimated at R2 billion annually. “There is no way that this loss can be offset by on-going forestry endeavours under a scenario of ‘business as usual’,” says Dr van Wilgen.
He says recent clearing efforts to control the spread of invasive trees have proceeded under a “strategy of hope”, where available (but inadequate) resources are directed at pockets of the problem in an uncoordinated manner, without objective prioritisation, leading to ineffective control.
“Legal instruments that require landowners and growers to take effective steps against invasions have either remained unenforced, or have been ignored with impunity,” adds Dr van Wilgen. “Public resistance to clearing operations in more accessible areas, where clearing is practically feasible, further impedes progress towards an environment free of invasive trees.”
“We need a drastic rethink of plantation forestry in the light of the new bioeconomy,” he says. “Although we need to ensure the availability of products such as timber and pulp on the one hand, we also need new innovative approaches which take global economic and environmental issues into account.”
“We need substantially higher levels of funding for control operations through schemes that use payments for ecosystem services. We also need to raise awareness of why we need to remove certain tree species and we need to resume national effort to find suitable biological control agents to effectively help manage the spread of invasive species, including pines” adds Prof Richardson.
* This article is based on a review article “Three centuries of managing introduced conifers in South Africa: Benefits, impacts, changing perceptions and conflict resolution” by Brian W van Wilgen and David M Richardson in Journal of Environmental Management 106(2012) 56-68.
Released by:
Engela Duvenage, Media: Faculty of Science, Stellenbosch University
+27 21 808 2684 science@sun.ac.za
A SAASVELD PERSPECTIVE
The Van Wilgen et al paper and the subsequent debate on this blog site and in newsletters was the topic for discussion in our post-graduate Journal Club at the NMMU George Campus at Saasveld. The group of Master’s students in Forestry, and Nature Conservation, respectively, concluded that the issue was a classical example of a “wicked problem” with no single and clear-cut solution and no logical end point. There is thus a need for dialogue and co-innovation through adaptive management. Depending on the context and technological innovations, conservation and forestry could be compatible land uses as long as the trees can be kept inside the plantations. We identified a number of research and engagement priorities and believe that academics could act as objective ‘bridging agents’ between sectors such as conservation and forestry which actually have much in common. A more complete account of the Saasveld debate was posted by Kate Southey at http://connect.nmmu.ac.za/Blogs/Sustainable-Research-Unit/April-2013/A-call-for-dialogue,-sensibility-and-innovation-in
As an alumnus at Stellenbosch University as well as a forest scientist I would like to add my opinion on the article “Tyd ryp om bosboubedrywighede in fynbosstreek te staak, glo kundiges oor indringerspesies” published on the university blog site on 17 May 2012. This article is totally lob sided and misrepresents the “bigger picture” of agricultural related activities in the Western Cape. The National Water Resource Strategy which was compiled by the Department of Water Affiars and Forestry(DWAF) in 2004 reported that forestry requires 428 million cubic meters of water per year (3% of the annual water usage of South Africa). This does sound like a lot of water, but compared to the staggering 7 920 million cubic meters of water required annually for irrigation (62% of the annual water usage), forestry does not impact on water as much as other methods of agriculture. One of the agricultural activities which the Western Cape is most famous for is the production of wine which I would like to use as an example.
In 2008, WaterWatch (www.waterwatch.nl) , issued a report entitled “Water use efficiency of table and wine grapes in Western Cape, South Africa.” The results that were obtained showed that table grape production consumed an average of 809mm of water per year while wine production consumed an average of 662mm of water per year. Bear in mind that the active growth stages of vineyards are during summer, which in the case of the Western Cape, is the dry season! At the beginning of the growing season, soil moisture is enough to sustain plant growth but this water store is quickly depleted and the vineyards have to be irrigated. The average rainfall in the Western Cape ranges from 650 – 1300mm per year. Water consumption by vineyards can therefore use a substantial amount of the annual rainfall. In forestry on the other hand plantations are not irrigated. The trees will use the water they require and once they are under water stress, their growth will slow down, resulting in decreased water use. Another difference between forestry and vineyards is that various chemicals are used to protect the vineyards against pests and diseases. Dawbrowski et al. (2002) reported increased levels of the pesticides endosulfan, deltamethrin, azinphos-methyl, chlorpyrifos, and procymidone due to rainfall-induced runoff in the Lourens river. The transient pesticide levels exceeded the target water quality limit set by (DWAF). Not only do vineyards use a lot of water but they also contribute to decreased water quality and effectively decrease the amount of water available for human consumption. During forestry operations very little chemicals are used and protection against pests and diseases mainly focus on biological, physical and cultural control.
The claim made by the authors that 30% of the water supply of Cape Town will be lost due to invasive pine species is absurd. As example I’ve only mentioned how much water vineyards use, but add to that the production process of wine which uses. In the article “Turning water into Wine” published on the website of The Wine Economist (accessed 28 May 2012) it is stated that to make 3.8 litres of wine, 22.7liters of water is used! According to a PriceWaterhouseCooper report on the South African wine industry, 8,654,879 litres of wine was produced from the 2010 harvest. Do the math and see how much water was used for that particular season! Compared to wine production, water use by the timber industry is not even a drop in the consumption bucket.
As to the claims that forestry destroys biodiversity, yes, forestry does have an impact. However, a recent MSc study completed at Stellenbosch University found that there was more biodiversity in the open areas and corridors in between plantation compartments than in a national reserve adjacent to the plantation (Joubert 2011). Kehinde (2011) reported that due to vineyard management, both taxonomic diversity and diversity of species interaction networks are experiencing declines as a result of agricultural intensification at habitat and landscape scales. The expansion of urban and agricultural areas into natural fynbos is aspects the authors of the blog article did not comment on. The potential for forestry expansion opportunities in the Western Cape is not a lot, due to planting permit restrictions, but urban and agricultural encroachment is a greater danger to destroying biodiversity than forestry and this deserves some attention.
To be able to report scientifically correct facts, one needs to look at all the sides of the Rubix cube, not just the colour that pleases you. I am disappointed that such a one sided article was published in the public domain and I also would like to add my support to Dr Ben du Toit’s plea for the authors to continue this debate in a scientifically balanced manner.
References
Dabrowski, J.M, Peall, S. K. C., Reinecke, A.J., Liess, M., Schulz, R. 2002. Runoff-Related Pesticide Input into the Lourens River, South Africa: Basic Data for Exposure Assessment and Risk Mitigation at the Catchment Scale. Water, Air and Soil Pollution, 135: 265 – 283.
Joubert, L., 2011. Biodiversity value of grassland ecological networks in afforested areas, KwaZulu-Natal, South Africa. MSc Thesis. University of Stellenbosch (http://scholar.sun.ac.za/handle/10019.1/6465 ).
Kehinde, T.O., 2011. Effects of vineyard management and landscape context on taxonomic diversity and interaction networks of flower-visiting insects in the Cape Floristic Region biodiversity hotspot. MSc Thesis. University of Stellenbosch (http://scholar.sun.ac.za/handle/10019.1/17980)
Websites
The Wine Econimist. (http://wineeconomist.com/2008/11/27/turning-water-into-wine/ , accessed 28 May 2012)
Please read the MSc. Forestry thesis of Ms. Carien de Beer about the “Economic impact of the phasing out of plantations in the Western and Southern Cape regions of South Africa : a case study of three plantations” at http://scholar.sun.ac.za/handle/10019.1/20328
Is daar iemand wat weet hoeveel werksgeleenthede die denneplantasies rondom Stellenbosch in stand hou?
Water use and runoff reduction shows that if you look hard enough and you will find literature that supports these lopsided claims. Can fynbos bulid houses or generate enough work? All that happens with land left in the hands of ‘nature conservation’ is it is left unmanaged and becomes a fire risk. The hands-off approach to this resouces management has cost millions in wild fires yearly. Manage fynbos properly before you point fingers at forestry, that considering, does a far better job than cape nature in managing the fire risk and biodiversity in fynbos area under their control.
Bosbou plantasies in die Wes Kaap skep werk en onderhou ‘n aansienlike sekondere bedryf. Om te se dat net plantasies in die noordelike deel van die land geld maak is eenvouding nie waar nie. Dr. Van Wilgen jy is welkom om die regte feite by die Departement Bos en Houtkunde te kom kry.
it will be my pleasure if i visit africa forests as research. i love to read research stories