Abstract
The soil is a complex three-dimensional habitat and any changes in its structure and porosity are likely to affect the type and abundance of soil biota. Oribatid mites play an important role in the decomposition and mineralization of soil organic matter and their abundance depends on diverse soil parameters, including soil texture, organic matter content, pH, moisture, and the pore system. The aim of the present work is to analyze some of the edaphic variables that condition the habitat of oribatid mites in Luvic Phaeozems under <em>Pinus radiata </em>(site P) and <em>Eucalyptus globulus </em>(site E) plantations, in the Southeast of Buenos Aires, Argentina. Bulk density, penetration resistance, pH, moisture, pore system parameters, and oribatid abundance and species composition were analyzed. Site E had a greater total porosity than site P. The high tortuosity of the pores in both sites generates a complex habitat architecture for the development of oribatid mites. In both sites, oribatids of 70-400 μm in size predominated and were more abundant in site E. A positive correlation between the abundance of oribatids and the pore size in both sites was observed. In site E this correlation was lower for 70-600 µm (R = 0.13) or negative for 70-400 µm (R = -0.78). Therefore, the oribatid abundance could be explained by a greater complexity of the structure of the organic horizon, lower bulk density and lower penetration resistance. These conditions favor the mineralization of organic matter, and therefore food availability. On the other hand, in site P, oribatid abundance is mainly influenced by the porous system, which conditions the access to food, competition between organisms and refuge from predators. Two new species were registered for Argentina:&nbsp;<em>Mesotritia elegantula </em>and<em> Acrogalumna longipluma.
Highlights
Soil structure is defined as the arrangement of particles and pores of the soil (Oades 1993)
We propose the following hypothesis: “the abundance of oribatid mites in these soils is mainly influenced by the porosity characteristics”
The structure and porosity parameters in the thin section images did not show any significant difference between the studied sites. Both soils presented a granular microstructure with rough, interconnected compound packing pores
Summary
Soil structure is defined as the arrangement of particles and pores of the soil (Oades 1993). The shape, size and spatial distribution of pores control the behavior of water and air, and provide information on transfer processes and life in the soil (Porta et al 1999). Soil management has negative effects on total porosity, quantity, distribution, and continuity of pores. This, in turn, causes changes in the flow of air, gases and water inside the pores, affecting the development of soil organisms (Kay and VandenBygaart 2002; Iglesias et al 2007; Alvarez et al 2008). Soil is a complex system and provides space for the development of organisms of different sizes (Estrade et al 2010). The concept ofhabitable pore space' suggests that there is a [ EDAPHIC VARIABLES CONDITIONING THE HABITAT OF ORIBATID MITES IN LUVIC PHAEOZEMS UNDER FOREST PLANTATIONS (BUENOS AIRES, ARGENTINA) ]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have