Instituto Pirenaico de Ecología (CSIC), Campus de Aula Dei. Apdo. 13034, Zaragoza 50080, Spain.
Departamento de Geografía y Ordenación del Territorio, Instituto Universitario de Ciencias Ambientales, Universidad de Zaragoza, Campus de San Francisco, Zaragoza 50009, Spain.
Sci Total Environ. 2017 Dec 1;599-600:1823-1836. doi: 10.1016/j.scitotenv.2017.05.092. Epub 2017 May 20.
Agriculture forms an essential part of the mountains of the Mediterranean. For centuries, large areas were cultivated to feed the local population, with highly marginal slopes being tilled at times of heavy demographic pressure, using the shifting agriculture system. A great deal of agricultural land was abandoned during the 20th century, giving rise to secondary succession processes that tend to eliminate the agricultural footprint. However, revegetation is a highly complex process leading to areas with dense, well-structured plant cover, and other open areas of scrubland. This article studies the role of traditional agriculture in the deterioration of the landscape. By using experimental plots in the Central Pyrenees to reproduce traditional agriculture and abandonment, maps of field types, and current uses and ground cover, it could be confirmed that shifting agriculture has caused very heavy soil loss, which explains the deterioration of the landscape on several slopes. Burning scrub and adding the ash to the soil as a fertilizer did not greatly help to improve soil quality, but caused high rates of erosion and a very slow process of regrowth. The average data obtained from the shifting experimental plots recorded losses of 1356kghayears, 1.6 times more than the plot of fertilized cereal, and 8.2 times more than the dense scrub plot. Following abandonment, losses in the shifting agriculture plot were almost three times higher than the abandoned sloping field plot. Traditional shifting agriculture in the Pyrenees is the main cause of the deterioration of the landscape 50-70years after agriculture ceased.
农业是地中海山区的重要组成部分。几个世纪以来，人们开垦了大面积的土地来养活当地人口，在人口压力较大的时候，利用迁移农业系统，开垦了高边际坡度的土地。在 20 世纪，大量的农业土地被废弃，导致了次生演替过程，这些过程往往消除了农业足迹。然而，植被恢复是一个非常复杂的过程，导致出现了密集、结构良好的植物覆盖区，以及其他开放的灌丛区。本文研究了传统农业在景观恶化中的作用。通过在比利牛斯山脉中部使用实验田来重现传统农业和废弃农业，以及绘制田地类型、当前用途和地表覆盖图，可以证实迁移农业已经造成了非常严重的土壤流失，这解释了几处斜坡景观的恶化。燃烧灌丛并将灰烬作为肥料添加到土壤中并没有极大地帮助改善土壤质量，但却导致了高侵蚀率和非常缓慢的再生过程。从迁移实验田获得的平均数据记录了 1356kghayears 的损失，比施肥的谷物田高出 1.6 倍，比密集的灌丛田高出 8.2 倍。废弃后，迁移农业田的损失几乎是废弃坡地的三倍。传统的迁移农业是 50-70 年后农业停止后景观恶化的主要原因。
