Agricultural Biodiversity, Tree Crop Diversity, TRD-Based Concepts
Total Page：16
File Type：pdf, Size：1020Kb
International Journal of Agriculture and Forestry 2016, 6(1): 1-7 DOI: 10.5923/j.ijaf.20160601.01 A Concept of Wild Flora and Biodiversity Based on Tree Resource Domestication in Agriculture Benjamin E. Uchola Faculty of Agriculture, Federal University, Dutsin-ma, Nigeria Abstract Tree Resource Domestication (TRD) is an influential process in the development of a tree crop and its large scale cultivation. But TRD have a minimal impact on the meaning of concepts such as wild flora and biodiversity as they are popular with conservation interests and Natural Resource Management. Tree Resource Domestication (TRD) as a development process of tree crops involves the relocation of valued parts of a tree or whole seedlings from forest to artificial environments, the adaptation of successive generations of relocated trees to human-controlled environments and the selection of desired production traits in plantation-grown populations of trees. A close association exist between TRD and tree species of wild origin, established populations of cultivated trees as well as their cultivars/clones. These relationships were explored so that the unique experiences of TRD in agriculture would be reflected in concepts that are closely associated with the domestication process. The derivatives are more specific concepts of wild flora, tree crop diversity and biodiversity. Keywords Agricultural biodiversity, Tree crop diversity, TRD-Based concepts 1. Introduction of controlled breeding programmes. These two main phases in TRD are demonstrated in a number of valued trees Tree is a distinct category of plants. The presence of trees, including the macadamia [12-14], the oil palm [15-19], the their composition and number per hectare are important rubber [20-22] and in the ongoing domestication of the features of major ecological zones. A landscape of trees and African bush mango [23-29]. Indeed, the progressions of other associated woody plants, the size of land area with tree wild trees from natural resource that were exploited to crops crown or the average height of trees at maturity are among that are cultivated in plantations characterize the the criteria that have been employed in defining what development of all known tree crops [30, 31]. As a result, constitutes a forest [1, 2]. The composition of tree species Tree Resource Domestication (TRD) becomes the that constitute a forest are most diverse in the rainforest transformation-based process that extends across successive which extends from South America through Africa to parts generations of a tree and results in its domestic form whose of Asia [3, 4]. Some native trees in natural forest have be production traits are better expressed. discovered by indigenous peoples to be of value leading to Tree Resource Domestication (TRD) as a process of their continuous exploitation but also to their protection and transforming wild trees into their cultured equivalent may be conservation [5-7]. employed in understanding the concept of wild flora and An important sphere in the rational use of forest resources biodiversity. Although these terms have also been applied in is the domestication of wild trees. Generally, the crop improvement programmes [32-34], their meanings is domestication of food resource is believed to be a human yet to be clearly differentiated from similar concepts in response to the threat of unsustainable supply from the wild Natural Resource Conservation as evident in the documents due to changes in climatic conditions [8-11]. Nevertheless, of the International Union for the Conservation of Nature Tree Resource Domestication (TRD) comprises an initial (IUCN), Flora and Fauna International (FFI) and other phase that involves the relocation of valued parts of a tree or Conservation-based Organisations [5, 35]. The use of both whole seedlings to human-controlled environments as well terms may be enhanced when the fundamental process of as a final phase which comprise selection of faster growth Tree Resource Domestication (TRD) is emphasized. An rate, larger fruit size and other desired traits through series enhanced concept of wild flora and biodiversity based on TRD would distinguish them from those used in Natural * Corresponding author: [email protected] (Benjamin E. Uchola) Resource Conservation. For this reason, the study focuses on Published online at http://journal.sapub.org/ijaf developing these terms so that they could reflect and express Copyright © 2016 Scientific & Academic Publishing. All Rights Reserved the unique experience of TRD in agriculture. 2 Benjamin E. Uchola: A Concept of Wild Flora and Biodiversity Based on Tree Resource Domestication in Agriculture 2. Tree: A Natural Resource 21]. Even more, the extraction of tree products as a form of production is central to the development of the palm oil The importance of trees as a distinct category of plants industry in West Africa and the rubber industry in South includes those related to the environment and its value to America prior to the use of plantation-grown trees. humans. An extensive landscape of trees and other The continuous exploitation of tree resource threatens the associated woody plants or interspersed trees with grassland survival of natural populations and their capacity to meet is an important part of the environment and constitutes an human demands. As a result, there are on-going attempts ecological zone [1-3]. Furthermore, trees as an integral part aimed at preserving tree populations in their natural habitats of the environment are important source of food, latex and so as to prevent their loss especially those of rare species other valuable items to indigenous peoples in particular and [5-7]. These concerns find concrete expression in the human society in general [15, 20]. preservation of valuable trees on forest farmlands and the The role of trees as an integral part of an ecosystem can be establishment of Protected Areas/Forest Reserves [15, 18, 19, perceived from the differences in flora composition across 44, 45]. Some fruit-diverse forests in Asia and the wild broad ecological zones like the rainforest and savannah. coffee-rich forest in Ethiopia are among the Protected Areas Forest as vast area of tree-cover is an habitat for several acknowledged by the International Treaty on Plant Genetic groups of plants and animals but more importantly a centre Resource for Food and Agriculture (ITRGRFA). Conserved of diversity for many tree species. The oil palm (Elaeis spp), population of trees in natural habitats or on farmlands, as in cocoa (Theobroma spp) and gmelina (Gmelina spp) are few the case of oil palm and bush mango, are most often the of the several hundreds of tree species that are native to the founding stock for domestication purposes [15, 23, 44, 45]. rain forest zone which extends from the Amazon in South America through parts of Africa to parts of Asia while the locust bean (Parkia biglobosa), baobab (Adansonia digitata) 3. Tree Resource Domestication and marula (Sclerocarya birrea) are among the relatively few tree species that are endemic to the savannah region of Domestication of tree resource is a complex biological Africa [15, 36-39]. Many of these wild trees scarcely express process that entails the interaction between humans and trees. their full productive potentials due to the influence of wide This often involves the relocation of valued trees from their range of environmental factors and often manifest this natural habitat to artificial environment and selection of restriction in the form of prolong growth period, irregular desired production traits. But most importantly, it leads to fruiting patterns and low productivity [40-42]. A species of the development of trees that are well adapted to macadamia tree that is native to the Australian forest grows human-controlled environments and highly productive for up to two decades before the commencement of [30, 31]. flowering and fruiting activities which are often Introduction of valued trees into artificial environments is characterized by irregular patterns and low productivity [12, a major first step in the long process of domesticating wild 13]. Similarly, the oil palm of the humid lowland rainforest trees. The ecological aspects is pronounced in the of west and central Africa matures after growing for over domestication of a number of valuable wild trees such as the three years while the bush mango in the same region requires macadamia [12-14], the oil palm [15-18] and the rubber a growth period of not less than a decade to attain maturity [20, 21]. Relocation of native trees from their natural habitat [15, 17, 25]. Long juvenile period, late maturation and to artificial environment is a distinct phase in the process of inconsistent fruiting pattern as a result of environmental domestication but there may have been a transition phase in factors are generally associated with the primitive state of the form of preservation on forest farmlands. The avocado plants and trees [30, 31]. and cocoa of south America, figs and olives of the Wild trees are often subjected to evaluation in the course Mediterranean region, mango and apples of the Asian of human-tree interactions. Some species of trees such as continent were most likely preserved and monitored in their Elaeis guineensis, Mangifera indica and Theobroma cocoa, natural habitats prior to their relocation to human-controlled were identified as sources of valuable food items while environments [33, 43, 46]. Similarly, the oil-bearing African others like Hevea brasiliensis and Gmelina arborea proved palm were preserved on forest farmland before its to be good sources of latex and timber respectively [15, 20, introduction into artificial environments in Southeast Asia 21, 36, 37, 43]. Nevertheless, the yields from wild trees are just as rubber trees were tapped in the Amazonian forest by often low due to limited expression of their production native Indians prior to its introduction to a botanical garden potentials [40-42]. This fact is illustrated vividly in wild in England and Southeast Asia afterwards [15, 18, 20, 21].