Soil biotic and abiotic traits as driven factors for site quality of Araucaria angustifolia plantations

Abstract

Purpose: The role of soil biotic and abiotic factors in crucial ecosystem services such as primary production, organic matter dynamics, nutrient cycling, and soil biota community structure in the Araucaria ecosystem remains poorly quanti ed. We aimed to understand how the site quality affects the development of organic horizons, root growth, soil chemical properties, and the entire soil biota community in even aged and monospeci c Araucaria angustifolia plantations.Methods: We collected soil monoliths to describe layers of organic matter and the complex soil food web into these layers. We determined soil pH, soil moisture, total nitrogen, available P, and total organic carbon into each layer (litter, F-layer, H-layer, and A horizon), the biomass of ne roots, the community structure of soil biota, arbuscular mycorrhizal fungi, and nematodes, as well as the microbial biomass carbon.Results: In the high-quality site, there was signi cantly higher organic matter formation, nutrient cycling (N and P), root growth, soil moisture, soil biota diversity, arbuscular mycorrhizal fungi, nematodes, and microbial activity evaluated by the microbial biomass carbon compared to the low-quality site.Conclusions: High-quality sites promote the development of organic horizons, root growth on super cial layers that provide plant nutrient release, the A horizon nutrient contents, and the entire soil biota community in monospeci c Araucaria angustifolia plantations located on humid subtropical Cambisols. This creates a positive plant-soil feedback that maintains soil quality and increases primary production, nutrient cycling, and habitat and food for the soil food web.

Forest–Fruticulture Conversion Alters Soil Traits and Soil Organic Matter Compartments

“…The soil fertility in such conditions was influenced by management practices that created different pathways into the soil ecosystem, as we had found in our PCA analysis. It agrees with the investigations performed by Six et al [ 20 ] and Souza et al [ 15 ] that reported a positive correlation between soil organic matter compartments and soil P content in natural ecosystems, and positive influences on soil fertility as affected by soil management, as we observed in this study for the Amazon Rainforest, and all fruticulture systems, respectively [ 26 ].…”

“…In soil from Brazil’s Legal Amazon, the soil organic matter compartments are modulated by plant community composition. According to Souza et al [ 1 , 15 ] plant community with the following characteristics: (i) high diversity; (ii) with nitrogen fixers; (iii) high soil reaction in the rhizosphere by the extrusion of H + ; and (iv) high biomass production may enhance resource availability and improve both soil traits and soil organic matter compartments. However, in the fruticulture systems as land use, we lost all of these four characteristics.…”

“…We tested all variables for normality using the “Shapiro.test()” function. The “Moran.I function” from the “ape” package was used to find spatial autocorrelation among soil samples [ 15 ]. None of the studied variables were found to have any site effect (e.g., no spatial relationship) with the sampling point.…”

“…We also hypothesized that soil traits will be associated with certain plant patterns (e.g., plant community composition, nutrient export by shoots and fruits, root density, etc.) and, therefore, the variability among plots on soil traits will be a function of the cumulative effects of fruticulture as land use [ 15 ]. In tropical conditions, land use with high plant diversity is crucial to promoting soil traits, and soil organic matter compartments.…”

Site quality for Araucaria angustifolia plantations with subtropical Cambisol is driven by soil organism assemblage and the litter and soil compartments

“…The role of soil quality remains far from being understood, primarily because of a wide range of soil functions, and the different interactions among soil compartments. We also must take in consideration the lack of scienti c studies gathering dataset from long-term eld experiments considering the interaction of organisms, litter, and soil as in uenced by soil quality degrees (Souza et al 2022a). Soil compartments, such as: (i) litter that may be characterized by litter deposition (kg m − 2 ) and k-factor (years − 1 ) assess the input of organic matter, and the nutrient cycling process; (ii) soil -solid phase may be characterized by the chemical properties that determines the soil fertility and the soil capacity to sustain high biomass production; and (iii) soil organisms' community composition that may be characterized by the abundance of insects, arachnids, myriapods, etc.…”