Diversity Of Soil Mites Research Articles

Effects of site preparation techniques on communities of soil mites (Acari: Oribatida, Acari: Gamasida) under short-rotation forestry plantings in New York, USA

To address the question of how production of woody biomass crops on retired agricultural land will affect soil biodiversity, we investigated the effects of site preparation techniques associated with production of willow ( Salix sp.) on the abundance, species diversity and community structure of two groups of mites (Oribatida and Gamasida). The effects of tillage, herbicide application, cover crop and mode of planting were evaluated in a 4 year-long replicated field experiment. Twenty-eight species of Oribatida and 35 species of Gamasida were represented in willow plantings. The predaceous Gamasida had more pronounced changes in abundance and diversity in response to the site preparation treatments than saprophagous and mycophagous Oribatida. Results indicated that (1) soil cultivation had negative effects on the abundance and diversity of soil mites during the first year of the experiment, later superceded by other factors; (2) the use or lack of tillage contributed to differences in mite community structure; and (3) following the initial disturbances, the abundance and diversity of soil mites increased in all treatments up to the end of the experiment. The success or failure of the willow crop and the changes in soil environments created by the different plant communities could explain the differences in soil mite populations among treatments best, especially 2 and 3 years after the beginning of the experiment.

Changes in abundance and diversity of microarthropods associated with Fescue Prairie grazing regimes

Summary Livestock grazing influences plant community structure, soil quality and health, and is likely to also affect the populations and diversity of soil biota. In our study, we determined the abundance and family level diversity of soil mites under very heavy and light grazing regimes, and a very heavy grazing exclosure, and asked whether there were differences in abundance of mite taxa that reflected the severity of disturbance. The field experiment we sampled was established in 1949 on a Rough Fescue Prairie with Orthic Black Chernozemic (Udic Haploboroll) soils near Stavely Alberta Canada. Soil cores were taken from the light (L)(1.2 AUM (animal unit month) ha –1 ) and very heavy (VH) (4.8 AUM ha –1 ) grazing regimes and the grazing recovery exclosure (Ex) in the very heavy grazing site in June and October 1999. The results showed that the soil temperature, moisture and bulk density varied between the grazing regimes, soil depth and the sampling times. Collembola were not abundant at any of the sites compared with Acari. Among Acari, prostigmatid mites were significantly more abundant in VH site and all the grazing treatments at both depths and sampling times. Oribatida, and to a lesser extent Mesostigmata, were more closely associated with reduced and undisturbed habitats than the Prostigmata, and there was a positive relationship between increased grassland productivity and the abundance and diversity of soil microarthropods. Our results suggest that Acari are sensitive to soil disturbance.

Abundance and diversity of soil mites of fragmented habitats in a biosphere reserve in Southern Nigeria

Soil samples were collected from the top 7.5 cm of soil in a Strict Natural Reserve (SNR), a surrounding buffer zone, a cassava farm and matured plantations of Gmelina, teak, and pine, so as to determine if plantation establishment and intensive cultivation affect the density and diversity of soil mites. Altogether, 41 taxonomic groups of mites were identified. The diversity and densities of mites in within the SNR, the buffer zone and the Gmelina were more than the diversity and densities in the cassava farm, teak and pine plantations. Each plantation had its own unique community structure which was different from the community structure in the SNR plot. The SNR plot and Gmelina were dominated by detritivorous cryptostigmatid mites unlike teak and pine which were dominated by predatory mesostigmatid and prostigmatid mites respectively. Low cryptostigmatid mite densities in the plantations and cassava farm were seen as a consequence of low fertility status of the soil, the evidence of which was revealed by soil pH and organic matter data.

Multispecies toxicity assessment of compost produced in bioremediation of an explosives‐contaminated sediment

AbstractA multispecies terrestrial test system was used to assess the environmental effectiveness of composting for bioremediation of explosives‐contaminated soils. The assessment involved comparing biological responses, from the individual to the community level, in remediated and reference composts. A 6‐month greenhouse study incorporated two soil invertebrate species, three plant species and an associated symbiont, and the naturally occurring complement of soil microorganisms. Measured parameters included growth and reproduction of earthworms and isopods; soil mite diversity; soil lipid class composition as an indicator of soil microbial community structure; plant growth, photosynthesis, and reproduction; and root nodulation and symbiotic N2 fixation. Additional short‐term toxicity tests of seed germination and earthworm survival were performed to supplement the mesocosm data. Compost prepared from the explosives‐contaminated soil inhibited several aspects of plant growth and physiology, but few adverse effects on soil invertebrates were detected. An initial lag in earthworm and isopod reproduction occurred in the reference compost, reflecting some inherent compost differences not associated with contamination, and highlighting the importance and the difficulty of finding appropriate reference soils for assessing hazardous waste sites or remediation technologies. Nonetheless, the results from this study suggested some nonlethal effects from the contaminated‐soil compost, primarily to plants. The mesocosm methodology used in this study can bridge the gap between traditional short‐term toxicity testing and longer term field assessments, and provide information on ecological effects by explicitly including measurements of multiple species across several levels of ecological organization.