Human landscapes have complex trajectories: reconstructing Peruvian Amazon landscape history from 1948 to 2005

摘要

Long-term landscape history studies can probe the complexity of landscape dynamics that appear linear or determined by a single driver on shorter time scales, and may span variations of both human-initiated and naturally occurring drivers. With a variety of historical sources this study traces the history of landscape change in Amazonian communities that have existed since the early 1900’s, in a region comprising both upland and riverine ecosystems. Aerial photography from 1948, 1965 and 1977 and satellite images from 1993 to 2005 are analyzed to reconstruct spatial transformations of the study region. The reconstructed landscape history is analyzed as a result of shifts in economy, policy, local markets and river dynamics. In 1948, the upland region was used for agriculture and farms appeared to be encroaching into primary forest. However by 1965, 49% of the upland farm area had become secondary forest, as farmers left upland farms fallow and moved into the floodplain to farm crops promoted through agricultural credit programs. Between 1965 and 1977 river channel migration affected the riverine landscape, dramatic floods occurred throughout the Amazon River and many farmers migrated to the city. During the 1980’s the credit given to small farmers greatly increased, resulting in the highest density of farms in the landscape by 1993. The disappearance of these credits is reflected in reduced farming activity and increased charcoal production. The results show that agricultural activity and deforestation do not always have a simple trajectory of increment.