5th Natural Forests and Woodlands Symposium
Below are highlights of the Fifth Natural Forests and Woodlands Symposium which was held in Richards Bay from 10-14 April, and was hosted by the Department of Agriculture, Forestry and Fisheries. There were 120 participants.
Compiled by Coert Geldenhuys, forest ecologist
Professor Rudi van Aarde of the Department of Zoology and Entemology at the University of Pretoria was on hand to provide conference delegates with insights into the recovery of indigenous ecological processes after land disturbance, in this case mining. Professor van Aarde and his team have been studying the regenerating coastal forests in this 'outdoor laboratory' for the past 20 years.
|Dr Coert Geldenhuys sharing his views on the state of the rehabilitating coastal sand forest with Professor Paxie Chirwa of the University of Pretoria.
|Conference delegates in an eight to ten-year-old stand of rehabilitating coastal forest. After opencast mining by Richards Bay Minerals, the dune was rebuilt and then planted with sunflowers and grass to stabilise the sand. Thereafter, the Acacia karroo emerged naturally, closing the canopy.
Professor Rudi van Aarde of the Department of Zoology and Entemology at the University of Pretoria was on hand to provide conference delegates with insights into the recovery of indigenous ecological processes after land disturbance, in this case mining. Professor van Aarde and his team have been studying the regenerating coastal forests in this 'outdoor laboratory' for the past 20 years. (Symposium presentations are available on www.daff.gov.za)
The Deputy Director-General: Forestry, Dr M Rampedi, opened the symposium and indicated that we need three languages for progressive development in forestry, i.e. science (ecology), economics and politics (policy), to build bridges, share experiences and expertise, and develop innovative solutions through cross-sectoral collaboration "towards sustainable natural resource management in a changing environment" (theme of symposium). Some of this was achieved with 38 papers and eight posters in five session themes with lively discussions. Several papers were presented by people from outside South Africa (Malawi, Zambia, Mozambique, Gabon, Cameroon and West Africa) to provide for an essential African connection and perspective to the sustainable management of our forest and woodland resources.
Several papers dealt with successional dynamics in forest recovery. In tropical moist forest in Gabon, five pioneer tree species developing on abandoned slash-and-burn sites contributed to recovery of tree species diversity. In Cameroon, forest farmers use their traditional knowledge of tree/shrub/herb species, the site and forest condition at the agriculture-forest interface to manage different land uses in the cropping-fallow-forest conversion cycles in an orderly manner to maintain forest recovery and diversity. The large-scale human clearing of Miombo woodlands that may induce changes in their species composition, structure and ecological function is a concern and the need was expressed to understand woodland dynamics at both individual species and stand levels.
Photo monitoring of a burned forest in the Southern Cape over 10 years showed two distinct succession pathways, i.e. a Keurboom pathway and a mixed undergrowth recovery pathway. The declining yield from harvesting Rumohra fern leaves from the Southern Cape forests was primarily a natural phenomenon of understorey change in stand development. Tree senility patterns in mature Southern Cape forests follow a steady decline in response to tree ageing and stand crowding with some accidental deaths, affecting the timber harvesting system. The current management philosophy for Australian blackwood in the Southern Cape forests was presented in relation to potential ecological threats to natural forest dynamics.
The field day visit to the open-air laboratory showing the natural succession process of Richards Bay coastal dune forests' rehabilitation after mining of heavy minerals, provided participants with a first-hand experience. It begins with placing topsoil from ahead of the mining path onto the reshaped sand dunes behind the mining process. Dense stands of Sweet thorn (Acacia karroo) develop over extensive areas from the banks of long-living seed in the topsoil. Over time, the acacia stands thin out naturally to enable other forest species to establish towards eventual development into diverse regrowth forest.
Three symposium papers provided more information on the ecological process. Colonisation patterns differ when the abundance of rodents, birds, millipedes, dung beetles, herbs and trees was compared to regenerating and intact dune forests. Landscape structure is important in setting restoration targets, and canopy characteristics in the early stage of dune forest succession influenced species composition of the regeneration.
Indigenous tree species
The health of indigenous tree species of South Africa is the specific focus of the Centre of Excellence in Tree Health Biotechnology (CTHB) at FABI in Pretoria. Some organisms from native tree species affect introduced plantation trees, and vice versa, which need to be understood to effectively manage the health of natural resources in our changing environment. Specific studies include wood-borer insects of Acacia, the effect of Ceratocystis wound-infecting pathogens of plantation and fruit trees through their association with bark and other beetles, and factors associated with the mass die-back of Euphorbia ingens in Limpopo Province.
Integrated and multiple use of land and resources based on ecological knowledge of the targeted species have been presented as sustainable, pro-active resource management options. The volumes and efficiency of water used by selected indigenous and introduced tree species was of particular interest for the consideration of alternative forms of forestry with indigenous tree species. The design and management of ecological networks at landscape level among plantation stands, grasslands and natural forests were shown to be important to stem biodiversity loss and maintain ecosystem processes on the forestry estate.
The successes and challenges of invasive alien plant species management through the Working on Fire programme in the changing Durban urban environment was presented in relation to maintaining ecosystem services and poverty alleviation.
Incorporation of rural communities to achieve utilisation and conservation goals were addressed in relation to eco-agriculture management in the Lubombo Transfrontier Conservation Area; sustainable use of Baobab fruit as an important food source and cosmetic oil to support thousands of rural people, mainly women, in northern Limpopo; improved harvesting techniques for Sneezewood and Umzimbeet through a coppice management system along the Eastern Cape Wild Coast to supply construction and other material important in rural livelihoods; and rotational fuelwood harvesting in the central Lowveld of Mpumalanga, which reduced deforestation and increased stem densities.
Dry forest products
The use of dry forest products was shown to be important in reducing the vulnerability of poor rural and urban women in Burkina Faso, Ethiopia and Zambia. Community-based Natural Resource Management (CBNRM) is another way to deal with resource use at rural level if the problems associated with it can be dealt with. The threats and opportunities associated with planting biofuel sources in terms of deforestation and threatened livelihoods in Miombo woodlands need careful management.
Sustainable management of resource use was the focus of several studies. Tree response to bark harvesting in the Eastern Cape showed that different tree species respond differently and need to be assessed separately to develop appropriate harvesting guidelines. Seeding, seedling plantings and mainly coppice management were useful approaches to ensure regeneration of harvested Miombo woodland timber species in Mozambique.
Partial analysis of forest growth in 16 long-term plots in the South African natural forests showed that a higher volume of indigenous timbers could be harvested annually, but this needs to be considered with great care. Tree growth and mortality response to timber harvesting is monitored and the effect of competition between trees on individual tree growth is modelled for the Southern Cape forests. A study provided stem diameter growth rates for Marula trees in protected areas in the Lowveld (Mpumalanga).
The responsibility for the long-term monitoring of the South African natural forests has been discussed in terms of a correct and reliable basis for assessment. Two studies dealt with the methodology in terms of narrow band remote sensing and GIS techniques to accurately assess the changes in Dukuduku forest cover through human disturbances. Another technique is the potential use of ground-based and airborne LiDAR measurements of tree characteristics. The discussions around the DAFF regulations to protect trees and forests threatened by development and the concerns expressed over the state of the Wild Coast forests in terms of unsustainable resource use, deforestation and alien plant invasions, emphasised the need to develop objective criteria for assessment and evaluation in relevant context.
The symposium provided participants, including many young people from diverse institutions, with much to think about. Much lively discussion, both inside and outside the presentations, added to the learning and sharing of experiences between colleagues.
The expectation is that there will be an improved focus on sustainable resource management within our natural forests and woodlands going forward. We look forward to the next forest and woodland symposium that will take place within the next two years so that we can maintain the momentum created by this event.
Published in April 2011