The Role of Land Use Pattern and Process in the Diffusion of Valuable Tree Species

Abstract

Evidence is mounting that conventional forestry approaches will not be able to address the extent of deforestation and land degradation underway in the tropics at the magnitude with which these problems and associated consequences presently operate. Subsistence populations for whom woody biomass and food supply is most critical can embrace many difficult and complex problems involved in the non-adoption of tree planting and tree management practices. The occurrence of the unintentional or inadvertent spread of valuable tree species as a side-effect of certain patterns and practices involved in specific land-uses, invites examination of the functional aspects involved, and the transferability of these. This paper explores some of the concepts likely to be involved in the unintentional diffusion of valuable tree species across human-occupied landscapes under the influence of extensive land-uses in the tropics. The role of these concepts in the formulation of approaches designed to encourage this form of tree dissemination as a form of reforestation is also discussed.

Planting coconuts in Indian villages: ethnoecological aspects and evaluation of a "sustainable development" project

“…Unruh, writing about the effect of different patterns of land use on the process of diffusion of valuable plant species, knowledge or ignorance about the attributes of specific tree species at a given point in time, may interact favorably or unfavorable in man's dealing with the plant so that the opportunities for proliferation are gained or lost (Unruh 1994). This can be manifested in different ways.…”

“…Subsistence populations living in high risk conditions can have very immediate needs which preclude even modest additional investments of time and labor into tree planting and maintenance. Furthermore, the deliberate planting and management of trees by local populations in the tropics will, to a large degree, be subject to the availability of time, energy, money, and inclination, as well as to the limited and changing priorities of development efforts in highly variable ecological, economic, social and political environments (Unruh 1994).…”

“…However, such hazards are limited to plant species characterized by a strong capacity for rapid growth and dispersal (Mills et al 1993, Case 1996, Myers et al 2000. Unintentional or inadvertent spread of valuable tree species as a side-effect of certain patterns and practices and the fortuitous spread of valuable trees can and does occur over large areas as a result of the interaction between land use and ecological process (Unruh 1994). Nevertheless, due to characteristics of coconut biology, the establishment of coconuts in the villages cannot be a by-product of the functioning of the land-use ecology itself.…”

Interpreting Resource Gradients and Patches for the Conservation of Woody Plant Diversity at Mt. Kasigau, Kenya

“…Earlier research at Makwasinyi and Jora, documented a high diversity of native plant resources across their homes and farms and accordingly a high number of plants with many uses (see Medley & Kalibo 2005. The ecological setting of their current settlements shows potential for the production of valued resources that might enrich landscape conditions to serve their needs (Unruh 1994). The management of these currently 'disturbed' land areas also needs to be integrated into the assessment of "social assets" on the landscape and the evaluation of innovative practices that can best ensure sustainable access to extractive resources (del Campo & Wali 2007).…”

Value chain development for mango (Mangifera indica) around Outamba Kilimi National Park in Sierra Leone: constraints and opportunities for smallholders

“…Therefore, actions need to be taken to encourage Sierra Leoneans farmers to grow more mango trees so that the country fully benefit from this important fruit crop. A first step towards these actions is the identification and investigation of constraints within prevailing fruit tree value chains as suggested by Unruh [11]. Not only is the identification of the constraints important, but the identification of copping alternatives developed by rural people as well as opportunities and links between actors involved in the fruit tree exploitation is also relevant to improve the performance of the whole fruit tree chains [12].…”