Factors Affecting Soil Microbial Processes

Soil is one of the most abundant environments on the Earth, where microbial processes take place, thus understanding the soil microbial processes in the context of factors influencing their environment is crucial. Soil microbial processes control soil nutrient cycling, foremost carbon cycling; therefore they affect global climate change. Organic and inorganic forms of carbon of natural or anthropogenic origin are sequestered via microbial activity into so-called soil organic matter that can be preserved in the soil for many decades. Soil microbial processes, such as carbon cycling, can be described by models emphasizing either the importance of physicochemical factors or the involvement of microbes. Balancing the carbon intake (e.g., photosynthesis) and output (e.g., decomposition) is one of the most important microbial tasks in the soil. Soil microbial processes are mediated by enzymes and thus are affected by environmental factors affecting enzymatic activities, such as temperature, water content, pH, and seasonality, but also by factors affecting diversity and abundance of microorganisms, such as nutrient availability, amount of soil organic matter, or presence of the symbiotic tree. Some microbial processes, such as N mineralization, are influenced more by abiotic factors (temperature and moisture) than the diversity of the microbial community since many groups of microbes are involved in this redundant process.