| Popis: |
Paramos are endemic and climatically sensitive ecosystems in the northern part of the Andes, where changes in climate and land use have a powerful impact on landscapes and flora and fauna diversity. On the other hand, soils provide ecosystem services such as carbon sequestration and water regulation; which have a high risk of degradation associated with land use dynamics. Six soil profiles under different soil uses and geomorphological positions in the Guerrero paramo, Eastern Andes, were morphologically, physicochemically, mineralogically, and micromorphologically described. A low level of nitrogen fertilization, low technologic level, and high trampling characterized the mountain grasslands systems. Current changes in land uses with the transition from natural forest to pasture make the soil vulnerable to degradation by compaction, erosion, and carbon dioxide emissions in relation to anthropogenic activities. The results showed kaolinite and quartz as dominant in clay size fraction in all soils, followed by illite, vermiculite, and interstratification chlorite-vermiculite, and traces of imogolite, halloysite, muscovite, and interstratification illite-smectite. Soils are mainly acidic, with a high Al saturation and a low base saturation. Organic matter illuviation and iron and manganese nodules, coatings, and hypocoatings associate with hydromorphism. The studied profiles show soils with high amorphous organic matter content with tissues, macroinvertebrates, mite and earthworm features; not in allophanic Andisols, where organic and ecological conditions are a key factor. Soils are moderately evolved under the present scenario of forest clearance and expansion of pastureland in combination with paleoenvironmental conditions associated with volcanic ash deposition and stone line presence leaving its mark in soil profiles. |
