近百年台湾省林地时空格局重建研究——1910-2010年

摘要

Reconstructing long-term changes of forest cover(FC)can provide reliable underlying data for carbon source/sink accounting and simulation of the effects of land use on the climate and environment.Historical maps contain a wealth of forest related information and can provide first-hand data for studying the changes in FC over a long time period.Taking the reconstruction of FC in Taiwan Province from 1910-2010 as the research object,we used map extraction and mining methods to extract forest distribution information from historical forest thematic survey maps,topographic and land cover maps,and reconstructed the spatiotemporal patterns of FC in Taiwan from 1910-2010.The results show that:first,the relative bias of the FC area extracted from the historical maps of Taiwan was below 8%,meaning the FC information contained in maps is highly accurate.Second,the FC of Taiwan has generally declined in the past 100 years.From 1910-2010,the forest area declined from 2.62×10^(6) ha to 2.47×10^(6) ha,with relatively obvious forest reduction having occurred.In stages,the forest area of Taiwan decreased by 26.39×10^(4) ha from 1910 to 1950;and increased by 10.53×10^(4) ha during the period 1950-2010.Forest reduction was obvious during the Japanese occupation period,while forest increase was remarkable during the Kuomintang period.Third,during the study period,the total area of patches maintained as forests was 2.17×10^(6) ha with little change in the overall pattern,and forests were mainly distributed in the mountain regions.The loss of forest mainly occurred in the plains,with expanding forest areas mainly in the mountain regions at high elevations and on steep slopes.Fourth,land clearing for agriculture during the Japanese occupation period has been the important driver of forest reduction in Taiwan over the past century.After retreated to Taiwan,the Kuomintang government introduced effective and remarkable reforms that led to effective restoration of forest vegetation in many areas where forests had previously disappeared.