EMERGY SYNTHESIS 3: Theory and Applications of the Emergy Methodology

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1 EMERGY SYNTHESIS 3: Theory and Applications of the Emergy Methodology Proceedings from the Third Biennial Emergy Conference, Gainesville, Florida Edited by Mark T. Brown University of Florida Gainesville, Florida Managing Editor Eliana Bardi University of Florida, Gainesville, Florida Associate Editors Daniel E. Campbell US EPA Narragansett, Rhode Island Vito Comar State University of Mato Grosso do Sul Dourados, Brazil Shu-Li Haung National Taipei University Taipei, Taiwan Torbjorn Rydberg Centre for Sustainable Agriculture Uppsala, Sweden David Tilley University of Maryland College Park, Maryland Sergio Ulgiati University of Siena Siena, Italy November 2005 The Center for Environmental Policy Department of Environmental Engineering Sciences University of Florida Gainesville, FL ii

2 38 Emergy Analysis of Three Forest Activities in Taiwan Chung-Hsin Juan and Yu-Fung Chang ABSTRACT Three forest management activities: silviculture, tree nurseries, and forest recreation (forest cafe), were analyzed from an emergy perspective. Results showed that silviculture and tree nurseries utilized more renewable resources, and forest recreation utilized more non-renewable resources. The empower densities of silviculture, tree nurseries, and forest recreation were 1.12, 1.17, and 8.15 (10 12 sej/m 2 /yr), respectively. Compared with the empower densities of Taiwan in 1960, 1970, 1980, 1987, and 1990, when the economy was gradually shifting from agriculture to industry, the empower densities of silviculture and tree nurseries were lower than that of the national economy in 1960, but the empower density of forest recreation was higher than the empower density of Taiwan in This indicated that forest activities have shifted in a manner similar to the main economy in Taiwan. The case study of forest recreation was located in the Taipei suburban area, near the national park. The emergy density of the case study site was between that of the park and the newly developed suburban zone. It displayed that, in the spatial distribution of emergy, the forest recreation zone was a transitional area from the natural lands to the lower newly developed lands. INTRODUCTION As the economy shifted in Taiwan, the utilization of forests also changed. When the Taiwanese economy was still dominated by agricultural activities, the forest economy consisted mainly of lumbering virgin forests. Lumber trees were later planted on the previously logged lands. As industry and urban areas developed in Taiwan, lumbering became less profitable and the natural landscape became more degraded (Jen, 1992a). Fast-growing trees were intentionally planted to restore the green landscape in developed areas for purely aesthetic reasons. The wood of the fastgrowing trees was low-rated and could not be utilized for construction or ornamental wood (Jen, 1992b). Recently, a new forest management pattern has emerged in Taiwan, the establishment of cafes in reforested areas. A small part of the reforested fields are remodeled as a café. People come to enjoy meals in nice gardens, relax under the trees, or buy trees. This system is considered a type of forest restoration. Therefore, it is becoming more popular in Taiwan. The authors have called this forest activity forest café in this study. If a landowner in Taiwan decides to use his land for forest economic activities, he may use it for silviculture, fast-growing tree nurseries, or construction of a forest café. The purpose of this research was to use emergy to evaluate these three forest activities to understand the economic benefits and environment impacts of these activities. METHODS An emergy evaluation on the three forest activities was conducted. The emergy evaluation for silviculture and the fast-growing tree nursery were developed from the published forest economics reports in Taiwan (Jen, 1984 and Jen, 1992a). The silviculture field was China fir (Cunninghamia lanceolata). The fast-growing tree nursery was Paliamara alstonia (Alstonia scholaris). The emergy -489-

3 evaluation for the forest café was a case study on a forest café in the Taipei suburbs based on field visits. Description of Case Studies Case Study I: Emergy Evaluation of the Silviculture Farm China fir is one of main lumber tree species in Taiwan. Planted China fir occupies 73% of the total forested land in Taiwan (Jen, 1984). It usually takes 15 years for a seedling to be ready for lumbering. It requires human inputs of land preparation, planting, and fertilizing at the initial stages (in the first four years), after which it can be left for natural growth. Figure 1 illustrates this system. In this case, the complete planting and growing process was considered, but lumbering and shipping was not considered in this evaluation. Case Study II: Emergy Evaluation of Tree Nursery Paliamara alstonia was introduced to Taiwan from other Southeast Asia countries in After seedlings are planted, they usually take only four years to grow to a height of about three meters in the nursery and can be transplanted for the purpose of landscaping in urbanized areas. After Paliamara alstonia is transplanted it grows to a height of about ten meters or higher and it has aesthetic appeal and provides good shade. Since it is only grown in the nursery for four years, the tree density can be greater to allow for higher profits. However, it requires more care than silviculture in order to maintain ideal growing conditions for trees. The human inputs are fertilizer, pest-control, plasticcovering, and labor. Figure 2 illustrates the systems diagram for this option. Only the planting and growing processes were considered in the study. The harvesting and replanting processes were not included in this case study. Case III: Forest Café A forest café system of one hectare located at the foothills of the Yang-Ming Mountains in the Taipei suburbs was selected for this case study. In this case study, the café occupies 0.1 hectares and the tree nursery occupies about 0.4 hectares. The remainder of the forest café is maintained in a Figure 1. Systems diagram for the China fir tree farm in Taiwan

4 Figure 2. Systems diagram for the Paliamara alstonia tree nursery in Taiwan. natural state. The trees in the café area were transplanted from the tree nursery. The owner built gazebos, pavilions, and a small pond, planted flowers, and decorated the café area. The whole café area looks like a beautiful garden with nice shade trees. The café is similar to other cafés providing coffee, tea, and light meals. People also come to buy trees. Occasionally, since some café customers like the garden design of the café area, they ask the owner to build gardens for them. Therefore, three different kinds of businesses are run in this forest café: the café, the tree nursery, and the garden design and construction business. The systems diagram of the forest café is displayed in Figure 3. Comparison of Emergy Indices Emergy indices were computed to explore and compare the three forest activities. The emergy indices were taken from Odum (1996) and Brown et al. (2000) and are defined as follows: 1. Emergy Yield Ratio (EYR): the ratio of the emergy yield to the sum of the input purchased emergy and services. 2. Environmental Loading Ratio (ELR): the ratio of the input emergy, other than the renewable resources, to the emergy of renewable resources. 3. Emergy Sustainability Index (ESI): the ratio between the emergy yield ratio and the environmental loading ratio. 4. Investment Ratios: several ratios relate the economic contributions to environmental contributions: i) Nonrenewable/Renewable: the ratio of nonrenewable resources to renewable resources. ii) /Free resources: the ratio between service and renewable (free) resources. iii) /Resources: the ratio between service and resources (renewable and nonrenewable resources, without including service). RESULTS AND DISCUSSION The emergy evaluation of the three case studies is shown in Table A.1, A.2, and A.3 in the appendix. The calculated results of the emergy indices are shown in Table 1. The total emergy used for the China fir system is sej per hectare for a 15-year growing period and the average -491-

5 Seedling Fertilizer & Pesticide Goods & Materials Labor & Wind Rain Tree Nursery Garden Design & Building Money Market Sun Garden Cafe Figure 3. Systems diagram for the forest café in Taiwan. empower density per year is sej/m 2 /yr. The total emergy used for the Paliamara alstonia tree nursery is sej per hectare for a 4-year growing period and the average empower density per year is sej/m 2 /yr. The total emergy used per hectare for the forest café is sej in 2002, and the average empower density is sej/m 2 /yr. The empower density of the lumber tree farm and tree nursery are very close, but that of the forest café is around seven times higher. The emergy indices of the three case studies are listed in Table 1. The ELR of the forest café is the highest while the one of the silviculture system is lowest. On the other hand, the EYR of the silviculture system is the highest and the EYR of the forest café is the lowest. The ESI of the silviculture is the highest and that of the forest café is the lowest. The ratios between nonrenewable and renewable resources showed that the forest café used more nonrenewable resources than renewable resources and the silviculture field and nursery used far fewer nonrenewable resources than the forest café. The ratios between service and renewable and non-renewable resources suggested that the forest café had more human service inputs than the other systems. Huang et al. (2001) classified the Taipei area into six different energy zones: mixed-use urban core, high urban residential, service and manufacturing urban district, agricultural district, newly developed suburban district, and natural area. The empower densities of the three case studies were between that of the newly developed suburban district ( sej/m 2 /yr) and the natural area ( sej/ m 2 /yr). Huang et al. (2001) also listed the empower density of forest area as sej/ m 2 /yr. The empower densities of the silviculture field and tree nursery differed little from the empower density of the natural forest in the Taipei area. These two forest activities can be considered a rural type of agriculture that mostly uses natural resources. The empower density of the forest café ( sej/ m 2 /yr) was between the empower density of the natural land zone ( sej/ m 2 /yr) and the newly developed suburban district zone ( sej/ m 2 /yr). This could be explained by the fact that the forest café is located near a natural park with very little development

6 Table 1. Emergy indices of the three case studies of forest economical activities in Taiwan. Silviculture Tree Nursery Forest cafe Empower Density (10 12 sej/m 2 /yr) Environmental Loading Ratio Emergy Yield Ratio Sustainability Index Nonrenewable / Renewable / Free Resources / Resources The emergy utilization should, therefore, resemble more the natural land zone than the newly developed suburban zone. Jen (1992b) stated that Taiwanese forest policies have shifted from lumbering in the 1950 s; to balancing lumbering and conservation in 1960 s; to multiple goals of long-term management of conservation, lumbering efficiency, and forest recreation in 1970 s; and finally to forest conservation and forest restoration since the 1980 s. The empower density of Taiwan also shifted as its main economy grew. The empower density of Taiwan in 1960, 1970, 1980, 1987, and 1990 was , , , , and (sej/ m 2 /yr), respectively (Huang & Odum, 1991; Shih, 1991). The empower densities of silviculture and the tree nursery were lower than the average empower density of Tawain in the 1960 s, but the empower density of the forest café was higher than the empower density of Taiwan in Forest activities have gradually shifted in a manner that matches the trend of the entire economy. Emergy utilization in forest activities has increased along with the historical increase in emergy utilization of the economy. CONCLUSIONS The three forest activities in Taiwan, the silviculture field, the tree nursery, and the forest café, require different levels of human inputs and nonrenewable resources from outside the systems. It is obvious that the forest café requires far more human service and nonrenewable resources than the others. Therefore, the forest café has the lowest sustainability index, the lowest emergy yield ratio, and the highest environmental loading ratio. Comparing the empower densities of different energy zones in the Taipei area and those of Taiwan in different years showed that the forest activities have shifted in a manner similar to shifts in the Taiwanese economy. Comparing the emergy density and the locations of the forest cafe with those of the different zones in the great Taipei area, forest cafe ranked between the natural lands and newly developed suburban area both in terms of spatial location and empower density values. REFERENCES Brown, M. T., S. Brandi-Williams, D. Tilley, and S. Ulgiati, Emergy Synthesis: An Introduction in Brown, M. T. ed. Emergy Synthesis: Theory and Applications of the Emergy Methodology. University of Florida, Gainesville, Florida, p Huang, S. L. and H. T. Odum Ecology and Economy: Emergy Synthesis and Public Policy in Taiwan. J. of Environmental Management 32: Huang, S. L., H. Y. Lai, and C. L. Lee Energy Hierarchy and Urban Landscape System. Landscape and Urban Planning 53:

7 Jen, I. A An Economic Analysis on Planting China Fir (Cunninghamia Lanceolata (Lamb.) Hook) in Taiwan. Forest Bulletin No.433, Taiwan Forestry Research Institute, Taipei, Taiwan. (In Chinese). Jen, I. A. 1992a. Economic Analysis of Planting Paliamara Alstonia (Alstonia scholaris) in Agricultural Land of Taiwan A Case Study. Bulletin Taiwan Forestry Research Institute New Series 7(3): (In Chinese) Jen, I. A. 1992b. The Changes of Taiwan Forestry Policies. Taiwan Forestry 18(8):2-4. (In Chinese) Odum, H.T Environmental Accounting Emergy and Environmental Decision Making. John Willey & Sons, Inc., New York, US. Shih, T. H The Ecological Economics System Status and Changing in Taiwan. Master Thesis. National Chung-Hsing University, Taiwan. APPENDIX: TABLES OF THE EMERGY ANALYSIS Table A.1. Emergy evaluation on a per hectare basis of the China fir tree farm in Taiwan for fifteen years of operation ( ). Note Item Data Units Emergy/ Unit (sej/unit) Solar Emergy (10 13 sej) Renewable 1 Sun (1984~1998) J Wind (1984~1998) J , Rain, chemical (1984~1998) J 15,444 2, Sub-total 16, Nonrenewable from outside 4 Fertilizer N g P g K g Seeds (1984) NT$ Sub-total Labor (1984) NT$ Labor (1985) NT$ Labor (1986) NT$ Labor (1987) NT$ Labor (1988) NT$ Sub-total Total 16,

8 Table A.2. Emergy evaluation on a per hectare basis of the Paliamara alstonia (Alstonia scholaris) tree nursery in Taiwan for four years of operation ( ). Note Item Data Units Emergy/ Unit (sej/unit) Solar Emergy (10 13 sej) Renewable 1 Sun (1992~1995) J Wind (1992~1995) J 623 3, Rain (chemical) (1992~1995) J 15, Sub-total 4, Nonrenewable from outside 4 Fertilizer N g P g K g Seeds (1992) NT$ Herbicide (1992~1994) NT$ Plastic cloth (1992) NT$ Sub-total Labor (1992) NT$ Labor (1993) NT$ Labor (1994) NT$ Labor (1995) NT$ Sub-total Total 4,

9 Table A.3. Emergy evaluation of one-hectare forest café in Taiwan for one year of operation (2002). Note Item Data Units Emergy/Unit Solar Emergy (sej/unit) (10 13 sej) Renewable 1 Sun J Wind J Rain (chemical) J Sub-total 1, Nonrenewable from outside 4 Soil g Seedlings NT$ Fertilizer N g P g K g Pesticide 1.06X Food Vegetable J Rice J Coffee beans J Sugar J Utilities Natural gas J Electricity J , Other Goods , Sub-total 3, Labor (Self-hired) NT$ , Labor NT$ Sub-total 3, Total 8,