Litter Microarthropod Research Articles

Seasonal fluctuation of different edaphic microarthropod population densities in relation to soil moisture and temperature in a pine,Pinus kesiya Royle plantation ecosystem

Seasonal fluctuations of soil and litter microarthropod populations in a pine,Pinus kesiya Royle plantation of North Eastern India were investigated between November 1976 and November 1977. Three major groups were recognized: (a) Collembola, (b) Acarina and (c) miscellaneous. Collembola was the most abundant group and was dominated byIsotoma trispinata (MacGillivray). The total microarthropod density ranged from 26,800 per m2 to 145,200 per m2. Collembola densities ranged from 10,000 to 121,200 per m2, Acarina densities ranged from 8,800 to 41,600 per m2, and the miscellaneous group ranged from 1,200 to 6,400 per m2. Soil moisture was positively correlated with total arthropod, Collembola and Acarina densities. Soil temperature was positively correlated only with Acarina. Densities of Collembola and Acarina were negatively correlated.

Diurnal migration and responses to simulated rainfall in desert soil microarthropods and nematodes

Diurnal patterns of microarthropod abundance in surface leaf litter were related to its moisture content. Leaf litter moisture was nearly 7% by weight at 0800h but fell to less than 1% by mid-day. Oribatid and tydeid mites moved into litter in the early morning and back into the soil before mid-day. There were no significant differences in numbers of nematodes in litter or soil and 78–98% of the nematodes were anhydrobiotic (coiled) in soil and litter at all times sampled. Following simulated rainfall there were fewer microarthropods in litter at mid-day in the absence of marked decreases in soil and litter moisture content. During drying, there were gradual reductions in numbers and species diversity of litter microarthropods. Nematode numbers did not change as litter dried. Anhydrobiotic nematodes in the soil increased from 14% on day 1 to 85% on day 4. Between 24 and 36 h after simulated rainfall, the proportion of anhydrobiotic litter nematodes increased from 35 to 80%,. Within 1 h after simulated rainfall, there were marked increases in numbers and diversity of microarthropods in surface litter. No collembolans were extracted from dry litter controls but the wet litter was dominated by isotomid, sminthurid and onychiurid collembolans. There were increases in numbers and diversity of oribatid, tydeid and gamasid mites in the wet surface litter within l h after wetting compared to controls.

Herbicide Effects on Leaf Litter Decomposition Processes in An Oak‐Hickory Forest

Herbicide treatments (2, 4, 5—Trichlorophenoxyacetic acid) of 0.225 g/m2 and 2.250 g/m2 were applied in a Latin square design to the forest floor of an oak—hickory forest in Georgia. White oak (Quercus alba) leaf litter decomposition and litter and soil microarthropod populations were studied in control and treated areas. Weight loss of natural white oak leaf litter averaged 35% for the 1st yr and reached 67% after 2 yr. Litter decomposition rates were similar in control and treated areas. However, white oak leaves defoliated through stem injections lost 59% of their biomass in 1 yr. Decomposition was increased because of initially higher N levels and a lower C:N ratio in defoliated leaf tissue. Herbicide spray treatment increased microarthropod densities for up to 8 mo after application. The herbicide spray apparently influenced springtail and mite reproductive activity in treated areas. The increases in soil and litter microarthropod densities were not sufficient to affect leaf litter weight losses. Repeated defoliation of plant communities and the resulting increased decomposition rates could cause imbalances in litter dynamics and cycling processes. Changes in the timing of annual litterfall and the rates of nutrient release may thus lead to soil desiccation and the depletion of available nutrient pools.