Balancing timber production and habitat conservation of Okinawa Rails(Gallirallus okinawae): Application of a harvest scheduling optimization model in subtropical forest in Okinawa, Japan

Finding the right balance between timber production and the management of forest-dependent wildlife species,present a difficult challenge for forest resource managers and policy makers in Okinawa,Japan.A possible explanation of this can be found in the unique nature of the forest management area which is populated with various kinds of rare and endangered species.This issue has been brought to light as a result of the nomination of northern Okinawa Island in 2018 as a candidate for World Natural Heritage site.The nomination has raised public awareness to the possibility of conflicting management objectives between timber extraction and the conservation of habitat for forest-dependent wildlife species.Managing exclusively for one objective over the other may fail to meet the demand for both forest products and wildlife habitat,ultimately jeopardizing the stability of human and wildlife communities.It is therefore important to achieve a better balance between the objective of timber production and conservation of wildlife habitat.Despite the significance of this subject area,current ongoing discussions on how to effectively manage for forest resources,often lack scientific basis to make sound judgement or evaluate tradeoffs between conflicting objectives.Quantifying the effect of these forest management activities on wildlife habitat provides useful and important information needed to make forest management and policy decisions.In this study we develop a spatial timber harvest scheduling model that incorporates habitat suitability index(HSI)models for the Okinawa Rail(Gallirallus okinawae),an endangered avian species found on Okinawa,Japan.To illustrate how the proposed coupling model assembles spatial information,which ultimately aids the study of forest management effects on wildlife habitat,we apply these models to a forest area in Okinawa and conduct a simple simulation analysis.

Harvest optimization for sustainable agriculture:The case of tea harvest scheduling

To ensure sustainability in agriculture,many optimization problems need to be solved.An important one of them is harvest scheduling problem.In this study,the harvest scheduling problem for the tea is discussed.The tea harvest problem includes the creating a harvest schedule by considering the farmers'quotas under the purchase location and factory capacity.Tea harvesting is carried out in cooperation with the farmer-factory.Factory man-agement is interested in using its resources.So,the factory capacity,purchase location capacities and number of expeditions should be considered during the harvesting process.When the farmer's side is examined,it is seen that the real professions of farmers are different.On harvest days,farmers often cannot attend to their primary professions.Considering the harvest day preferences of farmers in creating the harvest schedule are of great importance for sustainability in agriculture.Two different mathematical models are proposed to solve this problem.The first model minimizes the number of weekly expeditions of factory vehicles within the factor and purchase location capacity restrictions.The second model minimizes the number of expeditions and aims to comply with the preferences of the farmers as much as possible.A sample application was performed in a region with 12 purchase locations,988 farmers,and 3392 decares of tea fields.The results show that the compli-ance rate of farmers to harvesting preferences could be increased from 52%to 97%,and this situation did not affect the number of expeditions of the factory.This result shows that considering the farmers'preferences on the harvest day will have no negative impact on the factory.On the contrary,it was concluded that this situation increases sustainability and encouragement in agriculture.Furthermore,the results show that models are effective for solving the problem.