NRES 201 Lecture 30 Outline of Last Lecture I. Fundamentals of limingII. Neutralizing value of a liming materialIII. Liming CalculationsIV. Common liming materialsV. Soil acidificationVI. Salt - affected soilsOutline of Current Lecture I. The diversity of soil organismsII. The food webIII. Organism abundance and metabolic activityCurrent LectureThe diversity of soil organismsTypes of organisms - - Animals v plantso Fauna = animalso Flora = plants + non-animal microbes- Domainso Eukarya = plants, animals, and fungio Bacteria and Archaea = microbes- Food Source- Carbon and other sourceso Heterotrophs use organic compoundso Autotrophs use CO2 for carbon - energy from photosynthesis or chemicaloxidationDiversity and Isolation - - Species diversity vastly greater for soils than for aquatic environments owing to a nearlylimitless food variety and a much wider range of habitat conditions.- Soil aggregates isolate meso- and microorganismsImportance of Diversity - - The presence of more species increases:o Functional diversity - A wider variety of substrates can be used to carry out awider array of processes.These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o Functional redundancy - A given process occurs under a wider range ofenvironmental conditions. - Benefits of biological diversityo For soil quality, ecosystem stability, and resilience o Soil processes remain active and recover from disturbance Implications for global biodiversity - - Soil is a major storehouse of genetic information because so many species liveunderground - Mankind has learned to utilize some of this information in making antibiotics, yogurt andbeer- The soil DNA bank is as valuable resource for genetic engineeringo Microbial genes utilized for plant or animal improvementEcosystem Engineers - Some organisms create new habitats for others by altering theirenvironment Organism abundance and metabolic activity- Populations and biomasso Controlled by food supply, physical factors, biotic factors, and chemical factors. - Generalizations: o Greater fauna diversity in forest soilso Greater faunal mass and activity in prairie soilso Soil tillage reduces faunal numbers, mass, and activityComparison of different organisms- Basis of comparison (per unit volume or area)o Number of individualso Their collective weight (biomass)o Their metabolic activity (CO2 production) - Microflora are dominant o Bacteria most numerous o Fungi produce the most biomass o Account for about 80% of total soil
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