Structure and above ground biomass along an elevation small-scale gradient: case study in an Evergreen Andean Amazon forest, Ecuador

A soil quality index for seven productive landscapes in the Andean-Amazonian foothills of Ecuador

“…In the case of the chemical indicators selected, they reflect the nature of the soils in the area (Espinosa et al, 2018). In this study, the results for TOC confirm the history of management and potential use of the Amazon Region (forest) and the use of analogous forestry systems such as agroforestry cocoa, silvopastoral systems Torres et al, 2019). The components of soil acidity and pH associated with quality reflect the acidic and low fertility nature of these soils, which is confirmed by the values of the primary forest as a reference use.…”

“…All this means that as the BD increases, the porosity distribution values decrease, especially total porosity and macroporosity. Due to the low density of the soil, these maintain an adequate volume of pores in the soil, improving aeration and drainage in the soil (Torres et al, 2019;Viana et al, 2014). In this study, regardless of land use, the values obtained for physical properties (BD, Ksat, TP and RP), especially the forest and some types of chakras, confirm the strong influence of the content and variation of organic matter in the soil.…”

“…The predominant bioclimatic conditions vary between pluvial humid and hyper humid (MAE, 2013), with an average annual rainfall of 3481.7 mm, evapotranspiration of 150 mm, average temperatures of between 23.4 and 25.4degC and a relative humidity of 87%. The lowest precipitation occurs from January to April, whilst the highest occurs from May to July and the temperature varies all year around (Torres et al, 2019). The soils belong to the Andisols order (Soil Survey Staff, 2006), meaning they have a clay loam texture and a granular and blocky structure.…”

“…However, in Amazonian conditions, it is important to consider the effect of soilforming factors and processes and the historical background of land use (Nieto & Caicedo, 2012;Quesada et al, 2011;Viana et al, 2014). In this sense, the pedogenesis of Amazonian soils shows a very particular character, marked by different factors, including a climate characterised by high and intense rainfall with annual averages of around 4000mm, high temperatures that can range from 24 to 30°C, and habitats ranging from tropical rainforest to very humid rainforest (Nieto & Caicedo, 2012;Torres et al, 2019). In addition to this, traditional forest use generates a stratified profile, with a surface layer of average thickness between 10 and 12cm, with a higher organic matter content than the other horizons .…”

“…The Ecuadorian Amazon Region is particularly susceptible to severe soil degradation due to its special geological conditions and fragile ecosystems (Bravo, Marín, et al, 2017;Custode & Sourdat, 1986;Espinosa et al, 2018;Nieto & Caicedo, 2012). In this region, large areas have been subjected to deforestation process and a change in land use towards agricultural and livestock systems that have greatly deteriorated its resources (soil, water, vegetation and biodiversity), affecting its productive potential and capacity (Bravo et al, 2015;Torres et al, 2019).This situation is magnified by the area's characteristics with unfavourable soil chemical parameters coupled with harsh climatic conditions (abundant, high-intensity rainfall), an irregularly topographical agricultural landscape and high slopes (Espinosa et al, 2018).…”