Domestic Tree Research Articles

Tree domestication in tropical agroforestry

We execute tree ‘domestication’ as a farmer-driven and market-led process, which matches the intraspecific diversity of locally important trees to the needs of subsistence farmers, product markets, and agricultural environments. We propose that the products of such domesticated trees are called Agroforestry Tree Products (AFTPs) to distinguish them from the extractive tree resources commonly referred to as non-timber forest products (NTFPs). The steps of such a domestication process are: selection of priority species based on their expected products or services; definition of an appropriate domestication strategy considering the farmer-, market-, and landscape needs; sourcing, documentation and deployment of germplasm (seed, seedlings or clonal material); and tree improvement research (tree breeding or cultivar selection pathways). The research phase may involve research institutions on their own or in participatory mode with the stakeholders such as farmers or communities. Working directly with the end-users is advantageous towards economic, social and environmental goals, especially in developing countries. Two case studies (Prunus africana and Dacryodes edulis) are presented to highlight the approaches used for medicinal and fruit-producing species. Issues for future development include the expansion of the program to a wider range of species and their products and the strengthening of the links between product commercialization and domestication. It is important to involve the food industry in this process, while protecting the intellectual property rights of farmers to their germplasm.

Feasibility of cultivation of sugarcane in agroforestry systems

Brazil is the world's main sugarcane producer and the production system has changed abiding to legal and technical recommendation. In Piracicaba many smallholders grow sugarcane in steep areas. Under such situation, mechanization at harvest makes cultivation impossible. This work assess the viability of agroforestry systems on joining crop production and conservation of natural resources. Soils at 12-20% slope class were identified, tree species which could be cultivated along with sugarcane were selected, and the design of the systems to be adopted was evaluated. Identified area occupies 11,556 ha and the most representative soil types are Typic Kandiuldult and Lithic Hapludoll. The exotic species coconut, eucalyptus, pejibaye and rubber, and eight native species have potential to be grown in contourhedgerows with sugarcane. Initial planting of exotic, domesticated trees is recommended, and gradual introduction of native, non-domesticated species, can be set according to their ecological requirements.

Biosims — a method for the calculation of woody biomass for fuel in Sweden

A planning model and a computer programme, ‘Biosims’, have been developed. A test of the model was conducted in Dalarna (Kopparberg), Sweden, in 1994. Modified ecological restrictions were tested using the current ecological restrictions as a reference. Recycling of wood ash was assumed to be a standard method. The results show that 24–56% of the total forest land area is affected by the ecological restrictions in the county of Dalarna. Translation of these results to woody biomass quantities shows that the total ecological potential of woody biomass for fuel is 20.5 PJ per year. The total use of woody biomass for fuel is 3.3 PJ per year. The remaining potential of woody biomass for fuel in the county of Dalarna is 17.2 PJ per year. The method uses stand data or sample plot data from the National Forest Survey (NFS). A method for application of ecological restrictions has been used. These restrictions are based on variables, e.g. soil and vegetation classes, included in the NFS-data. Two methods for woody biomass calculations are used: (1) the biomass functions for the main domestic tree species ( Pinus silvestris, Picea abies, Betula pubescens, Betula verrucosa); and (2) the ratio method based on forest inventory data and conversion factors or functions between stand variables. The woody biomass is measured as oven dry weight per unit area. The results can be transformed, e.g. into energy equivalents and biomass nitrogen content. Different assumptions, such as heat value and moisture content, can be programmed and various technical and ecological restrictions can be imposed. The results can be presented in the GIS.

Timur(Zanthoxylum armatum)Production in Nepal

The use of nontimber forest products (NTFPs) in tropical forest management is currently receiving greater attention. Use of NTFPs starts with extraction from natural forests but may gradually be intensified to cultivation of domesticated trees. In order to enhance understanding of the evolutionary processes in NTFP production, this article analyzes the different management systems of timur (Zanthoxylum armatum) production in Nepalese forests. Products of this medicinal plant are regularly traded with India. Four different management regimes on open-access state lands, two different types of community-controlled lands, and private lands are described, each being characterized by a specific set of access regimes, organizational rules for collecting and managing timur, and management practices. A gradual increase in management intensity takes place from public lands to private lands as a result of various socio economic and politico-legislative factors. In contrast to earlier Nepalese studies, increased market price rather than increased scarcity was found to be the most important factor inducing intensification. It is concluded that the effects of supply and demand factors on management intensity of NTFPs cannot be generalized; these effects depend on both the management and marketing characteristics of specific NTFPs.

La domesticación de Leucaena (Fabaceae, Mimosoideae) en Mexico

Se analiza el proceso de domesticación de algunas especies de Leucaena (Fabaceae, Mimosoideae) en México integrando evidencia taxonómica, fitogeográfica, arqueobotánica, etnohistórica, etnobotánica y genética (isoenzimas). Se propone un modelo del proceso de domesticación para estos árboles y arbustos. El modelo intenta explicar cómo avanzó este proceso mediante la propagación por semillas, tomando en cuenta la longitud del ciclo de vida y la polinización abierta. Estas características coinciden en la mayoría de los árboles frutales domesticados en Mesoamérica pero contrasta con la propagación vegetativa de los primeros árboles domesticados en el Medio Oriente. Los resultados de esta investigación sugieren que, si bien el favorecimiento in situ y el cultivo conducen a mantener a cierto nivel la calidad de los productos deseados en las condiciones locales (aunque a un paso lento), sólo mediante la difusión es posible mejorar dicha calidad. Esta difusión sería responsable de la fundación de cultivos, y debe continuarse o se corre el riesgo de perder la calidad, la productividad, o ambas. Los cultígenos se obtienen mediante un extenso muestreo selectivo de poblaciones naturales y manejadas. A escala local, la difusión y el manejo generan variantes.

From natural forest to tree crops, co-domestication of forests and tree species, an overview

The process of domestication of tree crops has only been given limited attention. This process starts with the protection of natural forests and ends with the cultivation of domesticated tree crops. In this evolutionary process three types of human-influenced forest environments may be distinguished: (1) conserved forests, (2) modified forests, and (3) transformed forests. During the process of domestication an increasing input of human energy per unit of exploited forest takes place. Accordingly three phases in the domestication of forests may be distinguished: (1) an acculturalization phase in which social measures aimed at controlling the utilization of valuable tree species or patches of forests are implemented, (2) a phase of manipulation of wild tree species in which the socially-oriented management practices are enhanced with measures aimed at enhancing the (re)productive potential of valued species, and (3) a phase of cultivation of genetically modified tree crops. As a result of the co-domestication of forests and trees various types of forests and/or tree cultivation systems can be distinguished. So far more attention has been given to understanding the characteristics of the early and end phases than to the various intermediate phases represented by indigenous forest management and agroforestry systems. These are characterized by a modification of the highly diverse natural forest ecosystems to a state in which the biodiversity has been somewhat reduced, but in which a larger proportion of useful resources are present. Such systems provide interesting examples of the wide range of options for managing forest resources with varying degrees of biodiversity and productive values.

Methodology and techniques for the appraisal of wood fuel balances in Sweden

The consumption of woody biomass for fuel has increased by 100% in 15 years. The current level is about 40 TWh per year and the total annual supply, excluding black liquor, is about 130 TWh per year. The rising demand for woody biomass for fuel purposes has made the need of a model for the calculation of the raw material base apparent. A model and a computer programme, “Biosims”, have been developed. Two different methods for woody biomass calculations are used in the model: 1) the regression estimate method, and 2) the ratio method. Both methods can be used at the stand level and at the regional level. The dry substance of woody biomass is calculated by using the biomass functions for the main domestic tree species ( Pinus Silvestris, Picea Abies, Betula Pubescens, Betula Verrucosa). Volume of marketable timber is calculated by using the volume functions. Different assumptions, such as heat value and moisture content, can be programmed and various technical and ecological restrictions can be imposed. In the stand level method, diameter and height distributions are used for calculations. It is also possible to use the list of diameters for all trees in the stand or for utilized trees. The regional method works directly on a site represented by sample data and information from the National Forest Survey (NFS). These methods and the programme have been tested in several studies in Sweden. From the results of these studies it can be concluded that both methods provide satisfactory accuracy. The model can be used for energy planning at stand and at regional levels, and it can also be used by wood fuel producers as a tool for decision making.

Ethnobotany of the genusCyphomandra (Solanaceae)

Plants of the genusCyphomandra (Solanaceae) have long been utilized for their edible fruits in their native Latin America. The best-known species is the domesticated tree tomato or tamarillo,Cyphomandra betacea. This species, popular as a raw or cooked fruit, is widely cultivated in Andean South America and is now dispersed worldwide in subtropical areas. Its origin and wild relatives are still unknown, but there are tentative reports of wild populations ofC. betacea in southern Bolivia and northwestern Argentina. Wild species ofCyphomandra such asC. hartwegii, C. sibundoyensis, andC. cajanumensis also produce edible fruits. Other species ofCyphomandra are used in medicinal preparations and as dyes. This group of plants is of increasing economic importance and may have considerable potential for future exploitation.

The future of Finnish forest resources and forest landscapes

Because of an increasing world demand for paper and other forest products, the Finnish wood-using industries are expanding rapidly. This has raised serious concern about the future of forest resources. Clearing of land for agriculture has slightly decreased the forest area during recent decades. Today, however, the forest area is increasing, owing to peatland drainage and afforestation of surplus agricultural land. The growing stock of the forests has remained approximately unchanged during all the fifty years covered by repeated national forest inventories. Due to the present expansion of industry, however, intensive silvicultural measures are required to balance the increasing drain from the forests. Calculations show that, with feasible methods, by the year 2000 the annual increment of the forests could be raised by over 50 per cent, and measures have been taken to finance such a programme. Intensive silviculture (artificial reforestation, drainage, fertilization, etc.) will also change the forest scenery. In general, however, the changes will be small, as domestic tree species are favoured and rough terrain, rocky ground, and the Finnish type of forest ownership, prevent the establishment of large uniform monocultures. The biggest change in the scenery will be caused by the large-scale drainage of peat-bogs for forestry.

João Da Ascensão, O. F. M. and the Cultivation of Cinnamon and Pepper in Brazil

In the days Portugal held sway over vast territories in Africa and in both the East and the West Indies, she made valuable contributions towards the development of these lands, not the least being the introduction of certain domestic animals, plants, both nutritional, and medicinal, and trees. Any number of plants or special strains were transported from East to West and vice-versa. Some of them have thrived so well in alien soil that today they are considered indigenous.