Assessing conservation practices in Amalacaxco Gorge (Izta-Popo National Park, Central Mexico) using fallout 137Cs and Optically Stimulated Luminescence (OSL)

作     者：MUNOZ-SALINAS E CASTILLO M 

作者机构：Departamento de Geología Regional Universidad Nacional Autónoma de México Ciudad UniversitariaCiudad de MexicoMexico Laboratorio Nacional de Geoquimicay Mineralogia Ciudad Universitaria Ciudad de Mexico Mexico 

出 版 物：《Journal of Mountain Science》 (山地科学学报（英文）)

年 卷 期：2018年第15卷第3期

页      面：447-460页

核心收录：

学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 0907[农学-林学] 090705[农学-野生动植物保护与利用] 07[理学] 08[工学] 09[农学] 0903[农学-农业资源与环境] 0834[工学-风景园林学（可授工学、农学学位）] 0713[理学-生态学] 

基　　金：funded by grant CONACYT CB-2015-01 (255098) 

主　　题：Sediment transfer Soil erosion Natural protected areas Alpine grassland Caesium-137 Optically stimulated luminescence 

摘      要：This study aims to assess conservation practices in Izta-Popo National Park(Central Mexico) by evaluating the mechanisms of sediment transfer. We applied a methodology based on fallout ^(137)Cs and optically stimulated luminescence(OSL) analysis. This was tested in the upper catchment of Amalacaxco Gorge, selected for being one of the sectors of the park in which man-made actions have been implemented in last decades to favor forest growth in the alpine grassland and to reduce the effect of water runoff. We quantified the ^(137)Cs activity using gamma and beta spectrometry of fine sediment grains extracted from the surface of parcels of 0.4 m2 in areas of natural forest, natural alpine grassland, alpine grassland with conservation practices, ravines and trails. In general, ^(137)Cs values increases as local slope decreases as it was expected. The natural forest is the most stable area in terms of soil erosion and sediment accumulation and, mean ^(137)Cs activity was taken as reference to assess cumulative zones, with higher ^(137)Cs values and erosive, with lower. We found that trails are accumulative surfaces but in other areas, erosion predominates. Man-made ditches, trenches and afforestation in the alpine grassland have higher ^(137)Cs values than thenatural grassland, which indicates that conservation practices are limiting the sediment transfer from hillslopes to channels, however, soil retention is less than in the natural grassland. Additionally, we evaluated the luminescence(OSL) values obtained from samples extracted from the sediment transported in ravines that are cutting into different sectors of the study area to assess the grade of resetting of fluvial materials. These luminescence results indicated that the sediment transported in ravines that are cutting into the natural forest and alpine grassland is bleached more efficiently than the sediment transported in the alpine grassland with conservation practices. Results of fallout ^(137)Cs and luminesce