South African Forestry Research Articles

The role of landscape and parent material on regolith under timber plantations at Highflats, KwaZulu-Natal, South Africa

Regolith is an important component of the Earth's critical zone. Little investigative work has been done in southern Africa on regolith characteristics as a component of the critical zone, and in particular the importance to forestry plantation productivity in the eastern hinterland of South Africa. Regolith cores were extracted from five positions across two slopes underlain by sandstone and tillite to characterize these regolith profiles and ascertain the effect of slope position and parent material on regolith development. Regolith profiles were characterized and analysed on hill crest and lower midslope positions at both sites. The profile descriptions noted the degree of weathering, rooting activity, and mineral composition. The deepest in situ weathering of regolith was found on the hill crest positions; sandstone crest (24.0 m) and tillite crest (8.2 m) respectively. The accumulation of colluviated sediment on lower slopes also resulted in a thicker regolith at the tillite site, despite the less intensely weathered bedrock. These findings were consistent with earlier geophysical and pedohydrological studies of the area and the regolith profiles are consistent with those described for a range of other sedimentary lithologies in similar regions in sub-tropical and tropical landscapes The results show that tree roots utilize the saprolite and saprock below soil horizons and the nature of these layers indicate the full regolith profile should be considered in the water and nutrient supply available to forest plantations. Current concepts of ‘effective rooting depth’, as widely used by South African forestry, are inadequate for understanding ecosystem processes in forest plantations.

The forestry sector of South Africa supporting the achievement of SDG 15

Orientation: The National Framework for Sustainable Growth South Africa was introduced to re-orientate South Africa’s development path in a more sustainable direction. The South African Forestry Industry is discussed detailing commitment to ensure plantation forest establishment and management within the most socio-economically and environmentally beneficial way possible. Research purpose: The South African Forestry Industry is discussed detailing commitment to ensure plantation forest establishment and management within the most socio-economically and environmentally beneficial way possible. Motivation for the study: By identifying the way natural resources are managed, the sustainability of the forestry industry, and innovatively assisting people who directly depend upon this industry to work in safety and live under conditions of acceptable quality can be assured. Research design, approach and method: The conceptual study focusses on the Sustainable Development goals as formulated by the United Nations and specifically SDG 15. The National Framework for Sustainable Growth South Africa was introduced to re-orientate South Africa’s development path in a more sustainable direction. Main findings Although many different methods and approaches monitoring and verifying the sustainability of wood are acknowledged, verification from the Forest Stewardship Council is the preferred certification for the World Forestry Organization. The community’s increased control over forests will ensure that the UN Voluntary Positive impacts of sustainable forest management (SDG 15) will be followed. Practical/managerial implications: Industry is discussed detailing commitment to ensure plantation forest establishment and management within the most socio-economically and environmentally beneficial way possible. By identifying the way natural resources are managed, the sustainability of the forestry industry, and innovatively assisting people who directly depend upon this industry to work in safety and live under conditions of acceptable quality can be assured Contribution/value-add: Although many different methods and approaches monitoring and verifying the sustainability of wood are acknowledged, verification from the Forest Stewardship Council is the preferred certification for the World Forestry Organization. The community’s increased control over forests will ensure that the UN Voluntary Positive impacts of sustainable forest management (SDG 15) will be followed.

BASE MODELS FOR SIMULATING THE SOUTH AFRICAN FORESTRY SUPPLY CHAIN

The South African forestry supply chain is a complex system that involves both the production of trees (site preparation, re-establishment, tending, and maintenance operations) and the production and distribution of wood products from plantation stands to the pulp- and sawmills. This paper reports on a study that investigated the suitability of discrete-event simulation for modelling forestry supply chains. As part of a larger research project, two discrete-event simulation models with bi-objective optimisation of the South African pulpwood and saw-timber supply chains respectively were developed. The simulation models were developed for each supply chain by first mapping out the supply chain processes through subject-matter expert and stakeholder consultation. Thereafter simulation concept models were developed, and the required input data were identified, acquired, and verified. The simulation models were verified and validated to be realistic representations of the supply chains that they imitate. The study concluded that the simulation models demonstrated the ability to perform scenario analysis and bi-objective optimisation. It was also demonstrated that the two disciplines of industrial engineering and forestry science can successfully collaborate. Keywords supply chain; simulation; forestry; bi-objective optimisation

Screening of ectomycorrhizal and other associated fungi in South African forest nurseries

The South African forestry industry covers approximately 1.3 million hectares and is dependent on exotic pine and eucalypt species. Nursery seedlings are not inoculated with ectomycorrhizal (ECM) fungi. This investigation assessed levels of naturally occurring ECM colonisation of Pinus patula seedlings from 10 different South African forestry nurseries using a grid line intersect method. Fungi from colonised roots were identified using morphological characteristics and Illumina sequencing. Colonisation of seedlings in production nurseries was low (2–21%). Morphologically, the ECM fungi Thelophora terrestris, Suillus sibiricus, and the genera Russula and Pseudotomentella were identified. Molecularly, the ECM fungi T. terrestris, Inocybe jacobi and the genus Sphaerosporella, as well as several other ECM-containing families were identified, along with many saprotrophic/ endophytic fungi belonging to genera such as Penicillium, Ramasonia and Talaromyces. As can be seen, a combination of both molecular and morphological identification techniques are needed as neither is able to give a full picture of the species present in isolation. This study reveals an initial insight into the root microbiome community associated with Pinus patula seedlings, which should be taken into account when inoculation with beneficial microbes is considered. It determined that natural ECM fungal root colonisation levels are very low throughout the South African nurseries investigated, indicating the need for ECM fungal inoculation, which can increase seedling growth, viability and resistance to pathogens.

TREND-RUN model application of surface temperature and its implications for South African forestry and reforestation using local weather services data

Temperature can directly and indirectly impact the livelihood of inhabitants of a country and the natural environment as a whole. The surface temperature trend approximations for South Africa (SA) were calculated using a linear-regression fitting model. The model was adapted at The University of Reunion Island and was referred to as the Trend-Run model. The geophysical signal of the model was split into a sum of oscillations, which was used to clarify most of its variability. The trend values were calculated from the residual terms as a linear function. The model used atmospheric oscillations, which included Annual (AO), Semi-Annual (SAO), Quasi-Biennial Oscillations (QBO), El Niño-Southern Oscillation (ENSO), the 11-years solar cycle-Sun Spot Number (SSN) and Indian Ocean Dipole (IOD). The South African Weather Service (SAWS) data were used for the study. Data sets over a 31-year period, from March 1980 to December 2011, were used to measure the validity of the Trend-Run model, to determine the contribution and effect of this particular oscillation, and the validity of the model. The Trend-Run model showed very high applicability to the surface temperatures in all provinces across the SA region under investigation. High coefficient of determination values between (0.70-0.91) were recorded for surface temperatures across all provinces in the country with minor variations. The AO, ENSO and SAO were the highest contributing forcings in the model, thereby showing their high relevance to the success of this model in the study area. The temperature increases are expected to negatively impact on the biomes of SA, including the forest biome. Selected tree species of Acacia, Eucalyptus and Pinus could be impacted negatively with rising temperatures, which would negatively impact on the forestry industry in SA. As expected, the model did obtain a high success rate that ranged from 70% to 91% in the areas under study, however, there was still room for improvement by the possible inclusion of additional atmospheric forcings to the model that maybe be applicable to the weather and forestry distribution in SA.

Frost tolerance of various Pinus pure species and hybrids

Pinus species are widely planted by the South African forestry industry and are utilised for pulp, paper and saw timber products. Historically, Pinus patula Schiede ex Schltdl. et Cham. was the most widely planted commercial species in the summer rainfall area, but has come under severe threat due to the fungus Fusarium circinatum. Fusarium circinatum causes mortality in nurseries and in-field after establishment. Other Pinus species, such as P. tecunumanii F.Schwerdtf. ex Eguiluz et J.P.Perry and P. oocarpa Schiede ex Schltdl., have been crossed with P. patula to increase tolerance to F. circinatum and these hybrids have largely overcome the post-planting mortality problem. However, these hybrid-partner species are more prone to frost damage. This study reviewed laboratory screening techniques to assess the frost tolerance level of a range of Pinus pure species and hybrids. In vitro screening was done with the electrolyte leakage and whole-plant freezing techniques. Seedlings and rooted cuttings from a range of genotypes, supplied by Sappi, were tested in vitro at different target temperatures (−3, −6, −9 and −12 °C) to determine their relative frost tolerance. These genotypes included a range of Pinus pure species, four interspecific hybrids (P. patula × P. tecunumanii low elevation [LE], P. patula × P. tecunumanii high elevation [HE], P. elliottii Engelm. × P. caribaea Morelet), and a three-way cross (P. patula × (P. patula × P. oocarpa)). Results from this study indicated that the electrolyte leakage technique was a reliable method to determine frost tolerance under laboratory conditions, with similar pure species rankings as experienced under field conditions. The interspecific hybrids of P. patula × P. tecunumanii LE and HE ranked intermediate between the parental species and the P. patula × P. tecunumanii HE hybrid was more frost tolerant than the P. patula × P. tecunumanii LE hybrid.

Communities’ perceptions of benefit-sharing mechanisms for forest-based land reform models in South Africa

One of the dominant challenges facing the South African forestry sector is the issue of land restitution. The aim of this study was, therefore, to assess the perception of beneficiaries of benefit-sharing modalities for forest-based land reform initiatives in their locality. A random sampling technique selected 140 and 175 households in Amabomvini and Cata communities in KwaZulu-Natal and Eastern Cape provinces, respectively. The household beneficiaries showed a lack of knowledge of the criteria used for the disbursement of the benefits. In addition, over 70.0% of household beneficiaries in Amabomvini, compared with far less than 70.0% in Cata, preferred using rental income for infrastructure development in their respective communities. The results further showed that the relationship between the responses of the respondents from both Amabomvini and Cata communities regarding their perception on the existence of the criteria established to share the benefits, was statistically significant (χ2 = 34.452, df = 4, p < 0.005). However, a lack of transparency, trust and greed were among the factors that household beneficiaries identified as the root causes to the poor benefit-sharing mechanisms. Therefore, it is recommended that there should be political will and commitment from government in order to ensure the development and strengthening of existing benefit- sharing policies for the improvement of livelihoods of the land beneficiaries.

Desiccant herbicides tested for the preparation of fire-break tracer lines, South Africa

Over the past 32 years, 75 599 ha of plantations within South Africa have been lost through fire. Fire prevention, in the form of firebreaks on landholding boundaries, are required (by law) by landowners from whose land a fire might start or spread. On forestry land, paraquat dichloride (1,1′-dimethyl-4.4′-bipyridinium ion) has been used for the desiccation and subsequent burning of two parallel tracer lines in late summer, prior to the burning of the vegetation bordered by these tracer lines and when conditions allow (early to late autumn). Paraquat is listed as a highly hazardous pesticide within South African forestry, by the Forest Stewardship Council, and will be discontinued for use from 2018. Therefore, alternative contact/defoliation herbicides were tested at various rates for the preparation of tracer lines outside George, Western Cape. The vegetation cover was assessed prior to herbicide application to determine initial herbicide efficacy (16 d after application) and again at vegetation recovery (83 d). Of the products tested, pelargonic acid applied at 7%, 10% and 13% produced results most similar to that of paraquat (82% desiccation at 16 d; 95% vegetation recovery at 83 d). Further testing is required on different sites, and with different vegetation, to improve the timing, rates and methods of application.

Concerns of the south african forestry industry

Concerns of the south african forestry industry

Cost-productivity analysis of South African pine sawtimber mechanised cut-to-length harvesting

The South African forestry industry is experiencing an increase in the number of fully mechanised timber-harvesting systems. Understanding the productivity of these systems, for which data is currently limited for South Africa, is an important step to maximise the utilisation of machines being used. A time study of a mechanised cut-to-length system was conducted in Pinus elliottii sawtimber plantations in the Southern Cape forestry region of South Africa. A harvester and a forwarder were studied with the intention of analysing the division of work time amongst work elements, modelling each machine’s productivity and cost, and estimate fuel consumption. For the harvester’s productivity, a multiple regression model was developed using diameter at breast height (DBH), average distance moved per work cycle and slope class as predictors (adjusted R2 = 0.80). The harvester had a mean productivity of 33.6 m3 per productive machine hour (PMH0) under the current conditions with most of the productive time being used in the moving element. It consumed 25.5 L PMH0 −1 of diesel on average. The forwarder’s fuel consumption was calculated as 16.8 L PMH0 −1, while productivity was 46.8 m3 PMH0 −1. The forwarder spent the longest portion of the work cycle in the loading and unloading phases. A productivity regression model was created that included load size and distance moved during the driving in the loaded phase (adjusted R 2 = 0.78).

A case study assessment of socio-economic sustainability and alternative management regimes for state forest plantations in Limpopo Province, South Africa

South African Forestry Company Limited (SAFCOL) through the University of Pretoria and the University of Venda.

Forestry in Reconstruction South Africa: Imperial Visions, Colonial Realities

This articles analyses the establishment of state forestry programs in the Orange Free State and Transvaal following the end of the South African War/Second Anglo-Boer War (1899–1902). British imperial administrators, led by Alfred Milner, sought to reconstruct the economy of the Transvaal and Orange Free State by using personnel who had worked previously in India and Egypt rather than by drawing on local experts in the Cape Colony or Natal Colony. Colonial foresters from the Cape Colony used the opportunities provided by reconstruction to export Cape-centric ideas about forest management to the Transvaal and Orange Free State. Ultimately, Milner's desire to bring in a top-rate forester from India failed, although his program of reconstruction instead brought in foresters from the Cape Colony who helped to harmonise South African forestry practices before Union in 1910. The interpretation put forward in this article helps to explain how Cape foresters exported ideas about climatic comparison and afforestation from the Cape into the rest of South Africa.

Risk assessment for Puccinia psidii becoming established in South Africa

Puccinia psidii, the causal agent of myrtle rust, was first recorded from Latin America more than 100 years ago. It occurs on many native species of Myrtaceae in Latin America and also infects non‐native plantation‐grown Eucalyptus species in the region. The pathogen has gradually spread to new areas including Australia and most recently South Africa. The aim of this study was to consider the susceptibility of selected Eucalyptus genotypes, particularly those of interest to South African forestry, to infection by P. psidii. In addition, risk maps were compiled based on suitable climatic conditions and the occurrence of potential susceptible tree species. This made it possible to identify the season when P. psidii would be most likely to infect and to define the geographic areas where the rust disease would be most likely to establish in South Africa. As expected, variation in susceptibility was observed between eucalypt genotypes tested. Importantly, species commonly planted in South Africa show good potential for yielding disease‐tolerant material for future planting. Myrtle rust is predicted to be more common in spring and summer. Coastal areas, as well as areas in South Africa with subtropical climates, are more conducive to outbreaks of the pathogen.

Softwood sawlog secondary transport travel speed prediction for the South African forestry industry

The objective of this study was to develop a predictive model for travel speed of softwood sawlog timber transport (STT) vehicles over a range of forest and provincial roads of varying condition for the South African forestry industry. Data was accumulated from both the Eastern Cape/KwaZulu-Natal and Mpumalanga forest regions of South Africa. Vehicle location and payload data were collected remotely using a combination of GPS tracking and remotely sensed data. Road condition, including road width, was assessed for each identified road segment in-field according to a visual condition indicator (VCI) index. Two STT contractors were selected from each forest region transporting pine sawlogs directly from compartment roadside landings to either a processing plant or log storage area. Five STT vehicle types, representative of transport operations in the two forest regions, were assessed. Principal component analysis was conducted to determine the degree of communality between the respective predictor variables combining road width and VCI as one factor, and truck maximum power and the percentage of (legal) maximum payload as a second factor. Comparisons of the correlations between average speed and the respective predictor variables showed that road width and percentage of maximum (legal) payload had the highest correlations. Multiple linear regression of these two factor variables were used in the model showing both variables as significant (p < 0.05) with an adjusted r2 value of 0.52.

The Role of Alien Trees in South African Forestry and Conservation: Early 20th-Century Research and Debate on Climate Change, Soil Erosion and Hydrology

In the late 19th and early 20th century, many of the positions adopted in South Africa to argue for the conservation of indigenous forests were taken up by the state and various other commercial and industrial tree-growing bodies to legitimise the planting of alien trees in large artificial ‘forests’. These included the perceptions of the positive impact that forests may have on climate and ultimately rainfall, the contribution of forestry in combating soil erosion and halting the process of desertification, and the influence of forests on groundwater supplies and streamflow quality. The deeply rooted and lengthy association of scientific forestry with a conservationist ethos has, despite growing contradictions, continued to dominate the contemporary forestry and industrial tree-growing discourse. Today's forestry officials and private tree-growers still maintain that conservation and industrial tree-growing go hand in hand, reiterating the legend that the Department of Forestry is the oldest conservationist body in South Africa. Supporters of the tree-growing sector cite the preservation of indigenous forests, the protection of river catchment areas, the prevention of soil erosion and the combating of coastal driftsands as examples of forestry's conservation successes. Even if the remnants of indigenous forest, which still dot the South African countryside, bear testimony to forestry officials' success in maintaining and conserving a portion of the floral diversity of South Africa, the role of forester as conservationist has not been without its inconsistencies and contradictions. It is also a position that became increasingly contested in the 20th century, as a variety of political, economic and ecological interests became more entrenched in the new order which emerged in the Union period.I am as certain as I stand here that Nature intended wide tracts of South Africa to be forest country.Lord Milner (1905)Conserve with forestry – these are no idle words, nor is it a ‘green front’ put forward to burnish the image of the forestry amidst the current stream of increasing global awareness. It is, in fact, a reality that dates back to the start of man's history in this country.Department of Water Affairs and Forestry (1992)

Wood chip exports and the challenges faced by private pulpwood farmers in Southern KwaZulu-Natal

The South African forestry industry contributes to the economic growth of the country by the planting of trees and the processing of these trees for the export market. The purpose of this study is to examine the trends in wood chip exports from the Port of Durban and to examine the stability and growth of private pulpwood production in Southern KwaZulu-Natal. The methodology used in this study includes questionnaires distributed to timber farmers and semi-structured interviews with respondents in forestry. The findings show that wood chip exports from Durban have increased between 2006 and 2011. Dominant challenges faced by the farmers were land reform, transportation costs and municipal rates. Land claims, road infrastructure, cash flow and variation in the demand for timber were the most challenging factors affecting private timber production.

Sanitation of a South African Forestry Nursery Contaminated with Fusarium circinatum Using Hydrogen Peroxide at Specific Oxidation Reduction Potentials.

Pitch canker, caused by Fusarium circinatum, was first reported in a forestry nursery in the Mpumalanga Province of South Africa in 1990, and it has since spread to almost all forestry nurseries in the country, where it causes significant economic losses. The aim of the current study was to (i) identify sources of F. circinatum contamination in the Karatara forestry nursery in the Western Cape Province and (ii) manage the disease by implementing an oxidation reduction potential (ORP)-based sanitation method using hydrogen peroxide. The irrigation water, planting tray inserts and seeds were screened for fungal contamination. Fusarium circinatum colonies were identified morphologically and confirmed by polymerase chain reaction using species-specific primers. Both the irrigation water and planting tray inserts served as sources of inoculum that introduced the pathogen into the nursery. The irrigation water was amended with hydrogen peroxide at an ORP level of 400 mV for an exposure time of 6 h because it was observed that such a treatment effectively killed all F. circinatum spores and was not phytotoxic to pine seedlings under laboratory conditions. In addition, the contaminated planting tray inserts were cleaned in water amended with hydrogen peroxide at an ORP value of 360 mV for 6 h, which was shown to efficiently eliminate all inoculum from planting tray inserts. Since the introduction of the ORP-based sanitation method at Karatara nursery, losses of pine seedlings were reduced to insignificant levels, and field losses were minimized.

First fungal genome sequence from Africa: A preliminary analysis

Some of the most significant breakthroughs in the biological sciences this century will emerge from the development of next generation sequencing technologies. The ease of availability of DNA sequence made possible through these new technologies has given researchers opportunities to study organisms in a manner that was not possible with Sanger sequencing. Scientists will, therefore, need to embrace genomics, as well as develop and nurture the human capacity to sequence genomes and utilise the 'tsunami' of data that emerge from genome sequencing. In response to these challenges, we sequenced the genome of Fusarium circinatum, a fungal pathogen of pine that causes pitch canker, a disease of great concern to the South African forestry industry. The sequencing work was conducted in South Africa, making F. circinatum the first eukaryotic organism for which the complete genome has been sequenced locally. Here we report on the process that was followed to sequence, assemble and perform a preliminary characterisation of the genome. Furthermore, details of the computer annotation and manual curation of this genome are presented. The F. circinatum genome was found to be nearly 44 million bases in size, which is similar to that of four other Fusarium genomes that have been sequenced elsewhere. The genome contains just over 15 000 open reading frames, which is less than that of the related species, Fusarium oxysporum, but more than that for Fusarium verticillioides. Amongst the various putative gene clusters identified in F. circinatum, those encoding the secondary metabolites fumosin and fusarin appeared to harbour evidence of gene translocation. It is anticipated that similar comparisons of other loci will provide insights into the genetic basis for pathogenicity of the pitch canker pathogen. Perhaps more importantly, this project has engaged a relatively large group of scientists including students in a significant genome project that is certain to provide a platform for growth in this important area of research in the future.

Recovering the Lost History of Fire in South Africa's Fynbos

From the 1930s, state foresters in South Africa were responsible for managing extensive ecologically sensitive mountain catchment areas. Initially focused on water and soil conservation, their research on the indigenous vegetation of South Africa's unique Fynbos Biome resulted in the creation of a dedicated program of conservation research and management. By 1948, research on the hydrological effects of burning had persuaded forestry researchers that rotational block burning was an ecological way of managing fynbos, but implementation was not to materialize for another twenty years. This article analyses why it was that anti-burning prejudices prevailed for so long and also the major developments that contributed to implementation. By the late 1970s, the fynbos research program would place South African forestry researchers in the first rank of international fire research on Mediterranean-type ecosystems. Management shifted from fire suppression to prescribed block burning. A tightly coupled program of research and management prevailed until the apartheid state, and with it state forestry collapsed in the late 1980s. This article recovers the history of conservation forestry research and management of fire in fynbos, and it explores the environmental consequences of the Department of Forestry's management interventions and also its demise.

Hydration Status of South African Forestry Workers Harvesting Trees in Autumn and Winter

To determine both the prevalence and severity of dehydration of forestry workers harvesting trees in autumn and winter. Two cross-sectional observational studies were conducted on convenience samples of 103 and 79 workers in autumn and winter, respectively. The prevalence of dehydration pre- and post-shift was determined using urine specific gravity (U(SG)), and the severity of dehydration by the percent loss of body weight across the shift. Pre-shift, 43% in autumn and 47% in winter were dehydrated (U(SG) > 1.020 g ml(-1)) on arrival at work. There was a significant increase (P ≤ 0.001) in the prevalence of dehydration post-shift as 64% (P ≤ 0.001) in autumn and 63% (P = 0.043) in winter were dehydrated. In each area, ±22% had dehydrated by ≥2% loss of body weight. Pre-shift, 23% in autumn and 13% in winter were overhydrated (U(SG) < 1.013 g ml⁻¹). Post-shift, 4% in autumn and 2% in winter were overhydrated. An excessive consumption of hypotonic fluid (water) in combination with a reduced salt intake to prevent hypertension exposed an important minority to the risk of potentially fatal dilutional hyponatremia. Neither dehydration nor hyperhydration was related to season, gender, or job category. During average shifts, the South African forestry workers, regardless of season, gender, or job category, experienced dehydration of a magnitude that compromised both their safety and productivity.