What Would a Global Forest Convention Mean for Tropical Forests and for Timber Consumers?

A global forest convention has been advocated for about 15 years, but progress is slow and positions of advocates and opponents appear entrenched. We review several case studies and offer new empirical evidence relating to causes of and remedies for deforestation. We find no evidence to suggest that a forest convention will be effective in halting deforestation. Our data indicate that development assistance may be most effective approach to save forests in developing countries. It appears that "money speaks louder than words". We conclude that a global forest convention will be ineffective unless accompanied by substantial and well-directed development assistance

Improving Productivity in Mixed-Species Plantations

Mixed species plantations are often promoted as being environmentally preferable to monocultures, but are rarely considered operationally viable by commercial forest growers. Despite many publications documenting benefits demonstrated in research studies, and despite continuing calls from a wide range of advocates for mixed-species plantations, polyculture remains the exception rather than the rule in industrial plantation forestry. The following observations are drawn from a recent workshop: - innovative experiment designs and analytical techniques are available to examine species interactions; - despite the enthusiasm for polycultures, relatively few robust experiments have been established, and even fewer have been maintained long enough to allow rotation-length consequences to be evaluated; - commercial polyculture plantations are even more scarce than experiments, and rarely offer data to support publication of financial analyses; - small landholders appear to be the main innovators in establishing and demonstrating polyculture plantations. To provide the evidence to encourage industrial uptake of polyculture plantations, there is a need for - a co-ordinated series of long-term trials, well replicated in time and space, using a standardised design with several treatments (species composition) and comparable species; - operational-scale demonstration plantings that gather ecological, financial and social data as well as the conventional production data

Mixed Species Plantations: Prospects and Challenges

About 2% of English-language literature on plantations deals with mixed-species plantations, but only a tiny proportion

Dynamics of tree diversity in undisturbed and logged subtropical rainforest in Australia

In subtropical rainforest in eastern Australia, changes in the diversity of trees were compared under natural conditions and eight silvicultural regimes over 35 years. In the treated plots basal area remaining after logging ranged from 12 to 58 m2 per ha. In three control plots richness differed little over this period. In the eight treated plots richness per plot generally declined after intervention and then gradually increased to greater than original diversity. After logging there was a reduction in richness per plot and an increase in species richness per stem in all but the lightest selective treatments. The change in species diversity was related to the intensity of the logging, however the time taken for species richness to return to pre-logging levels was similar in all silvicultural treatments and was not effected by the intensity of treatment. These results suggest that light selective logging in these forests mainly affects dominant species. The return to high diversity after only a short time under all silvicultural regimes suggests that sustainability and the manipulation of species composition for desired management outcomes is possible

A long and winding road: the regulation of private native forestry in New South Wales, Australia

This special issue of Small-Scale Forestry is concerned with private native forestry (PNF) in New South Wales (NSW), Australia. Private native forests comprise indigenous species in a semi-natural formation on privately owned land. Such forests are usually uneven-aged, and regenerated naturally rather than by sowing or planting. These forests are of major conservation and commercial importance in NSW, covering 8 M ha and comprising one-third of all native forest in the state (Thompson 2007). The management and harvesting of these forests is known as PNF, and has been the focus of public attention for several years, as the desirability and implications of regulating these activities has been debated

Interplanting Inga edulis yields nitrogen benefits to Terminalia amazonia

We established an experiment in 1993 to test the effect of various treatments on growth of a native timber tree, Terminalia amazonia, on eroded pasture in southern Costa Rica. The 1993 treatments included a control in which T. amazonia was planted alone, and an interplanted treatment with the legume tree Inga edulis. Measurements at 4, 8, and 11 years showed that T. amazonia grew significantly better when mixed with Inga. In 2004 (11 years) we tested whether improved nitrogen nutrition was the mechanism for the effect. We analysed standing crops of vegetation and their nitrogen content in controls, the interplanted treatment, and nearby grazed pasture. Foliar N in Inga was more than double that in other foliage, supporting our assumption that the legume could be a source of N. However, by 2004 soil N was only slightly higher in the interplanted treatment than in controls, suggesting that N might be incorporated rapidly by the other vegetation. In fact, when the interplanted treatment was compared to controls, above-ground biomass and foliar N of T. amazonia was higher. The total nitrogen content in crowns of T. amazonia (biomass × % foliar N) was higher in the interplanted treatment than in controls. Finally, basal diameter and height correlated with foliar N in T. amazonia. Our data were consistent with the hypothesis that improved nitrogen nutrition accounts for improved growth of T. amazonia when interplanted with I. edulis. Total volume production of the crop tree T. amazonia was too low for forestry goals. However, interplanting the two tree species in most cases provided promising beginnings of complexly structured secondary forest for wildlife habitat

Species shade tolerance affects tree basal area growth behaviour in two eucalypt species in thinned and unthinned even-aged monoculture

Individual tree and stand basal area growth were studied in a thinning experiment established over two sites in subtropical eastern Australia. The experiment compared the less shade tolerant species Eucalyptus dunnii with the more shade tolerant Corymbia citriodora var. variegata, both grown in plantation monoculture. Growth was compared over a 2½−3 year period that immediately followed thinning at 5½−7½ years of age. Towards the end of the growth period, tree crown depths and leaf mass per unit area were measured at one site. Crown depth and leaf mass per area of C. citriodora were greater than of E. dunnii, characteristics consistent with a more shade tolerant species. Gross stand basal area growth of E. dunnii was faster than that of C. citriodora. Individual-tree basal area growth behaviour was consistent with inter-tree competition involving asymmetric competition for light. Opening the stand by thinning reduced inter-tree competition to near zero. In unthinned control stands, smaller, more shaded trees of C. citriodora were better able to retain their basal area growth rates than those of E. dunniiin the face of competition. In consequence, the more shade tolerant C. citriodoradeveloped a more evenly spread frequency distribution of tree diameters than less shade tolerant E. dunnii. This would have consequences for the assortment of log sizes that would be available ultimately from monocultures of the two species

Information sources and dispersal channels in the extension of pasture weed management technologies in southern eastern Kenyan rangelands

This paper analyses perceived constraints encountered by farmers while sourcing appropriate information through various communication channels relevant to the adoption of weed management technologies. It further examines the values farmers attach to some pasture weeds that have contributed to the variable uptake of weed management technologies. The study was stimulated by the apparently low adoption of pasture weed management technologies in predominantly livestock dependant communities. In many cases, governments and industry employ a variety of communication media when distributing information relating to improved agricultural practice. Single subject interviews were carried out with 165 participants from two ethnic communities within the south-eastern Kenyan rangelands to explore the uptake of knowledge relating to weed management technologies. An assessment was made of the techniques frequently employed and the obstacles presented to the uptake of new technology. In addition, an assessment of the benefits of some pasture weeds in farmers’ perspectives was assessed. Results indicate that extension agents were largely ineffective in the dissemination of weed management technologies in both communities as was the use of mass media. Other traditional information dissemination mechanisms such as using community decision leaders, neighbours and seminars were less effective than anticipated. Regardless of communication channels and sources of information, it was also found that pasture weeds were valued by farmers in both divisions as livestock feeds and woodfuel. Farmers in Mashuru placed importance on some pasture weeds as a source of construction material and medicinal plants. These mixed reasons for non-uptake of new technologies are discussed and recommendations made for future programs, including the need to improve the skills and resourcing of extension services across cultural settings and production system