Programa de Pós-Graduação em Ecologia e Conservação de Recursos Naturais, Universidade Federal de Uberlândia, Instituto de Biologia, Rua João Naves de Ávila, 2121, Umuarama, 38405-320 Uberlândia, MG, Brazil.
Universidade Federal de Uberlândia, Laboratório de Botânica e Ecologia no Domínio Cerrado, Rua 20, 1600, Tupã, 38304-402 Ituiutaba, MG, Brazil.
An Acad Bras Cienc. 2021 Apr 30;93(3):e20200372. doi: 10.1590/0001-3765202120200372. eCollection 2021.
Litter decomposition in the soil is an important stage of the nutrient cycling process that interferes with functioning of terrestrial ecosystems. Soil fertility and litter nutritional quality are fundamental factors that affect decomposition efficiency of plant residues. We evaluated decomposition in two areas of 'cerrado sensu stricto', each with a type of Neosol - limestone (eutrophic) and sandstone (dystrophic). In a rural area located in the municipality of Ituiutaba (MG, Brazil), 10 plots were randomly selected to install litter bags with 10 g of mixture of dry leaves that were used to estimate rate and time of leaf-litter decomposition from October/2015 to January/2016. Decomposition rate in the limestone cerrado was significantly higher than in the sandstone cerrado. This difference mustn't be explained by the edaphic texture between areas, since it was similar between them. But may be explained through aluminum absence and higher soil fertility in the limestone cerrado, especially phosphorus that is highly limiting in dystrophic cerrados like the sandstone cerrados, in which decay of decomposing leaf-litter was directly proportional to the levels of phosphorus. Limestone presence reduces aluminum toxicity and circumvent phosphorus limitation in the cerrado, favoring decomposition. Such influence is probably an important feature for limestone cerrados.
土壤中的凋落物分解是养分循环过程中的一个重要阶段，会干扰陆地生态系统的功能。土壤肥力和凋落物的营养质量是影响植物残体分解效率的基本因素。我们评估了“严格意义上的塞拉多”的两个地区的分解情况，每个地区都有一种新成土——石灰岩（肥沃）和砂岩（贫瘠）。在位于米纳斯吉拉斯州伊图伊塔巴市的一个农村地区，随机选择了 10 个地块来安装带有 10 克干树叶混合物的凋落物袋，用于从 2015 年 10 月到 2016 年 1 月估计落叶凋落物的分解速率和时间。石灰岩塞拉多的分解速率明显高于砂岩塞拉多。这种差异不能用两个地区之间的土壤质地来解释，因为它们是相似的。但可能是由于石灰岩塞拉多中缺少铝和更高的土壤肥力造成的，特别是磷，在像砂岩塞拉多这样的贫瘠塞拉多中，磷是高度限制的，分解中的凋落物分解与磷的水平直接相关。石灰岩的存在降低了铝的毒性，并避免了磷在塞拉多中的限制，有利于分解。这种影响可能是石灰岩塞拉多的一个重要特征。
