The numbers and biomasses of soil invertebrates were investigated in a reserved field in central Finland. Samples were taken monthly from June to September. Five methods were employed to extract the animals from the soil samples. The animals were counted, measured and their dry biomasses were estimated by body length/weight regressions and dry weight/wet weight ratios derived from the literature. In July the total biomass of the soil invertebrate community (excluding Protozoa, Tardigrada and Rotatoria) was about 9.6 g dry weight m-2. The most dominant groups were Lumricidae (73.1 %), Enchytraeidae (5,7 %), Oribatei (5.0 %), and Nematoda (4.4 %). In September the biomass of Diptera larvae was high (1.0 g dw m-2). In numbers nematodes were superior (maximum 12 million m-2) to other groups. Oribatei, Mesostigmata and Collembola were more concentrated to the soil surface than other Acari, Enchytraeidae and Nematoda. The mean individual size decreased with depth in all of the studied groups.

Lamto savannas (Ivory Coast) are characterized by the heterogeneity of their structure and by their dynamic evolution towards forest. Life—forms and phenological cycles of herbs, shrubs, and trees reflect the constraining factors of the environment. Biomass and productivity are largely dependent on soil and climate. The specific cycles of above— and belowground biomass allow an estimate of the primary productivity. Production of shrubs and trees, obtained from size—biomass correlations and growth measures, is compared with herb production to give an insight into the ecological balance of the savanna communities.

v | ok | kirjasto Aj-K | Keskivuomalaisen pakettipellon maaperäeläinten runsasus ja biomassa

The behavior of CO2 production, urease, phosphatase, and protease activities, amino acids, amino sugars, bacteria, and fungi was investigated during the microbial growth after the addition of a glucose-sodium nitrate solution to a red earth soil. The peak of the CO2 evolution rate preceded all other tested biochemical and microbiological criteria. Urease and phosphatase activities were significantly correlated with bacterial but not with fungal biomass. All other biochemical criteria tested did not show a correlation, on normal regression analysis, with biomass. Fungal growth occurred both in the glucose-amended soil and in the control. The temporal sequence observed among the tested enzymes was due to their different roles in the soil metabolism of glucose, as well as to their different cellular locations. The newly synthesized, acid-soluble, amino acids nitrogen and protease activity were short lived. Yet, some sort of stabilization for urease and phosphatase activities occurred. The changes in total amino acids nitrogen were due to behaviors of neutral and acidic amino acids. Of the amino acids tested, lysine, histidine, arginine, valine, isoleucine, leucine, and phenylalanine showed negligible differences among values of corresponding soil samples moistened with glucosenitrate solution and with distilled water.The results show that no one measurement of activity is sufficient to interpret microbial growth in the soil system. Each of the indices measured must be used in conjunction with other tests to have a complete picture of the system.