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Abstract:
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"Researchers, planners and other concerned institutions are contending with varied arguments and explanations on burning issues of deforestation and forests/soil degradation in the Himalayan region for long; and a common consensus regarding the causes of these processes has not been reached yet. Since land-use, land-use changes especially agricultural land expansion and degradation of forests and soil in developing country are related to socio-economic characteristics, population and livestock growth, technological change, consumption patterns, etc., their dynamics need to be analyzed by incorporating both the socio-economic behavior and ecological processes simultaneously. This paper, representing an effort to offer some deep insights in this debatable topic, discusses and develops a dynamic bio- economic model for analyzing land use changes and forest/soil degradation processes under systems approach. The modeling technique is basically drawn from simultaneous global optimization with mathematical programming algorithm which incorporates both the production and consumption problems at the watershed level in Nepal. Five different relevant policy scenarios, namely business as usual with two per cent population growth rate and five percent of discount rate (and other parameters and scalars), reducing population growth rate to 1.5 per cent per annum, increasing prices of major crops (maize, paddy, wheat and millets) by 10 per cent, reducing emigration of active labor force from current rate of 20 to 10 and 15 per cent from the watershed have been tested. Planning horizon of the model extends for 25 years and the objective function consists of discounted net income flow from agriculture, livestock and forestry production subject to constraints on land, labor and capital availability along with the fulfillment of minimum cash and consumption requirements for the entire watershed in each period. The outcomes of this modeling exercise indicate that while reduced labor emigration rates and increase in major agricultural crops' prices lead to expansion of agricultural land at the cost of forest and other non- agricultural lands and shift of clearing activity from degraded forest to nearby forest land and more soil loss; reduced population growth rate shows the opposite effect. The land clearing is severer in the case of reducing emigration rate to 10 per cent than 15 per cent. Thus the model disentangles the systems behaviors of both socio-economic and ecological interactions at the watershed level with policy implications on reduction of population growth and maintaining current rate of off-farm employment for slowing down the agricultural expansion and processes of forest/soil degradation."
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