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Forest Resources
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Modeling Landscape changes using Logit Models
Table 1. Results of the multinomial logit model for conifer plantations
The logit models can be used to spatially predict the landscape changes. Taking coniferous plantation as an example, the observed and model predicted landscape changes were compared in Fig. 2. The figures showed that, though not perfect, the model predicted landscape changes match the observed landscape changes fairly well.
Fig. 2. Comparisons between the observed and model predicted landscape changes.
4. Conclusions
Several conclusions can be drawn from the results of this study:
- In analyzing factors contributing to landscape changes, topographic effects and edge effects appeared to be more influential than patch attributes. Whether a man-made plantation would turn into natural forests or not is largely determined by its distance to natural forests as well as its elevation. Whether a forested area would become bare lands or not depends on its slope. Factors that had the most significant effects included elevations, slopes, distances to natural forests, and distances to roads. On the other hand, bare lands with gentle slope and farther away from roads were more likely to recover into natural forests.
- Although logit models can be used to predict "what" land cover change would occur on a given place, but if the observed land cover changes only consist of a small portion of the landscape, the predicted probabilities of change will be under estimated. Therefore, it is not practical to use logit models for prediction in such cases. However, logit models are useful in comparing the relative likelihood of landscape change at different locations.
- In this study, factors affecting landscape change coincide with the a-priori expectation in general. One major advantage of logit models is that the extents of influences can be quantified and compared. Such comparisons can provide very useful information to decision maker in management planning.
References
- Baker, W. L., 1989. A review of models of landscape change. Landscape Ecology, 2(2), pp. 111-133.
- Burnham, B. O., 1973. Markov intertemporal land use simulation model. Southern Journal of Agricultural Economics, 5, pp. 253-8.
- Dale, V. H., O'Nell, R. V., Pedlowski, M., Southworth, F., 1993. Causes and effects of land-use change in central Rondônia, Brazil. Photogrametry Engineering & Remote Sensing, 59(6), pp. 997-1005.
- Forman, R. T. T. , Godron, M., 1986. Landscape ecology. (NY): John Wiley and Sons. 619 p.
- Hsu, L. T., 1996. Modeling land use change in human dominated landscapes: a case study of urbanization in an Indiana watershed [dissertation]. West Lafayette (IN): Purdue Univ. 255 p.
- Hsu, L. T. , Cheng, C. C., 1999. Assessing landscape change in Liukuei ecosystem area using Markov model. Taiwan Journal of Forest Science, 15(1), pp. 41-49.
- Li, H., 1990. Spatio-temporal pattern analysis of managed forest landscape: a simulation approach [dissertation]. Corvallis (OR): Oregon State Univ. 166 p.
- Lin, J. S., 1996. Study on the change detection of ecological environment by using the remotely sensed data on vegetation ecosystem: an illustration of Tainan district [dissertation]. National Taiwan University. 252 p. [in Chinese with English summary]
- Lindsay, B. E., Dunn, D. L., 1979. Land use projections under alternative policies: a transition matrix approach. J Northeastern Agricultural Economic Council 8(2), pp. 87-99.
- McMillen, D. P., 1989. An empirical model of urban fringe land use. Land Economy, 65(2), pp. 138-45.
- Muller, M. R., Middleton, J., 1994. A Markov model of land-use change dynamics in the Niagara Region, Ontario, Canada. Landscape Ecology, 9(2), pp.151-7.
- O'Neill, R. V., Krummel, J. R., Gardner, R. H., Sugihara, G., Jackson, B., DeAngelis, D.L., Milne, B.T., Turner, M.G., Zygmunt, B., Christenser, S. W., Dale, V. H., Graham, R. L., 1988. Indices of landscape pattern. Landscape Ecology, 1, pp.153-162.
- Turner, M. G., 1987. Spatial simulation landscape changes in Georgia: A comparison of 3 transition models. Landscape Ecology, 1(1), pp.29-36.
- Turner, M. G., 1990. Spatial and temporal analysis of landscape patterns. Landscape Ecology, 4, pp.21-30.
- Turner, M. G., Gardner, R. H., 1991. Quantitative methods in landscape ecology. Ecological Studies. Vol. 82. (NY): Springer-Verlag. 536 p.
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