de Oliveira Junior Jairo Calderari, Beirigo Raphael Moreira, Chiapini Mariane, do Nascimento Alexandre Ferreira, Couto Eduardo Guimarães, Vidal-Torrado Pablo
Department of Agronomy, Federal University of Technology-Parana, Dois Vizinhos, Parana, Brazil.
Agricultural Science Center, Federal University of Paraíba, Areia, Paraíba, Brazil.
PLoS One. 2017 Jul 12;12(7):e0179197. doi: 10.1371/journal.pone.0179197. eCollection 2017.
Vegetated mounds are an important geomorphological feature of the Pantanal, where the influence of floods dictates not only hydropedological processes, but also the distribution and ecology of the flora and fauna. This work aimed to identify factors and processes that influence the formation and spatial distribution of the mounds, which are commonly associated with termite activity. In order to characterize pedological processes, macro and micro morphological descriptions, satellite image interpretation, dating of the sandy sedimentary material using OSL and carbon dating using 14C AMS were carried out. This dating of the materials indicates that the sediments in which the soils were formed were deposited during the Pleistocene, while the carbonates are from the Holocene. The basin-like format of the laminar structures suggests that part of the more clayey material was deposited in lacustrine environments. The more humid climate in the Holocene intensified argilluviation, which at an advanced stage, led to a more pronounced textural gradient, reducing drainage and leading to ferrolysis and thickening of the E horizon. Besides pedogenic processes, more erosive flooding during the Holocene began reducing and rounding the landscape's more elevated structures (paleolevees). In the final stage, these structures were occupied by termites to shelter from flooding. Thereafter, the bio-cementation action of the termite nests has increased the resistance of the vegetated mounds to processes of erosion.
植被土丘是潘塔纳尔湿地重要的地貌特征，在那里洪水的影响不仅决定了水文土壤学过程，还决定了动植物的分布和生态。这项工作旨在确定影响土丘形成和空间分布的因素和过程，这些土丘通常与白蚁活动有关。为了描述土壤学过程，进行了宏观和微观形态描述、卫星图像解释、利用光释光对砂质沉积物质进行测年以及利用14C AMS进行碳测年。这些物质的测年表明，形成土壤的沉积物是在更新世沉积的，而碳酸盐则来自全新世。层状结构的盆状形态表明，部分粘性较大的物质沉积在湖泊环境中。全新世较为湿润的气候加剧了粘化作用，在后期导致了更明显的质地梯度，减少了排水，导致铁铝化作用和E层加厚。除了成土过程，全新世期间更具侵蚀性的洪水开始减少并使地貌中较高的结构（古堤）变得圆润。在最后阶段，这些结构被白蚁占据以躲避洪水。此后，白蚁巢穴的生物胶结作用增加了植被土丘对侵蚀过程的抵抗力。
