Soil macroinvertebrates’ abundance and diversity in home gardens in Tabasco, Mexico, vary with soil texture, organic matter and vegetation cover

We studied the composition of soil invertebrate communities and vegetation in 50 home gardens in the humid tropical lowlands of Tabasco, Mexico, located in five geomorphological regions. Five monoliths were made in each home garden and soil invertebrates were hand sorted, weighed and classified to morhospecies, functional groups and orders. We determined pH, organic matter, available phosphorus and texture in composed soil samples from each home garden. We determined the botanical name of trees, their diameter at breast height, height, and crown diameter, calculated tree density, tree cover, and biomass per hectare. We found 45 soil invertebrate morphospecies, which belonged to 12 Orders or taxonomical groups. Endogeic macroinvertebrates were significantly more abundant in the fluvial plains, hills, and mountains than in the coastal plains (F = 9.64 p < 0.05). Path analysis produced a significant model, wherein soil organic matter influenced earthworm abundance (T = 3.28, p < 0.05), while tree cover significantly influenced abundance of litter fragmenters (T = 3.16, p < 0.05). Morphospecies richness was not related with tree species diversity. Canonical correspondence analysis with 67% of inertia on principal axes, showed how contents of soil organic matter, clay and silt were associated with earthworms abundance, while abundance of hymenoptera was associated with silt content. Interactions between plants and soil macroinvertebrates varied among regions. The coastal region showed a strong correlation between the abundance of palm trees (Coco nucifera), arachnida and isoptera morphospecies. The abundance of Gliricidia sepium in different regions showed a strong correlation with the abundance of earthworms.

► Interactions between plants and soil macroinvertebrates varied among regions.
► Soil organic matter influenced earthworms abundance.
►  Silt promoted hymenoptera.
► Cocos nucifera enhanced arachnida and isoptera morphospecies.