EXAMINING THE EFFECTS OF DROUGHT ON SOIL MICROBES: A THOROUGH ANALYSIS HOW IT AFFECTS ENZYME ACTIVITY

Abstract

Drought is a common tragedy in terrestrial ecosystems throughout Earth's history; in human societies, it can lead to a lack of food, one of the Four Horsemen of the Mythic Four. Ecosystems will be impacted and possibly transformed by deeper droughts and rewetting as the global hydrological cycle is enhanced due to global warming. However, soil communities appear to be more resilient to water stress than vegetation or animals are; in fact, the main effects on soil processes appear to be decreased diffusion and restricted nutrient availability for soil organisms. As a result, when a drought ends, the rains not only relieve stress on soil microbes but also produce a resource pulse that stimulates soil microbial activity. Whether rewetting or drying causes the adverse effects of drought on soil processes is still unknown. It's also undetermined which physical/chemical mechanisms that mobilize organic matter and microbial growth or rewetting activities are responsible for the wash out activity. I begin by looking at responses at the organismal level and then consider about how these affect the dynamics of organic matter across the entire soil. The incorporation of these impacts into Earth System models that are capable of accurately representing dry-et cycling is the final area of focus. Drought led to sustained root growth but limited shoot growth across all species. Plants cultivated in mixtures had lower root biomass and root-to-shoot ratios, indicating a stronger competition for light over water and nutrients than monocultures. MBC levels increased under drought in plant mixtures but varied in monocultures. Drought and plant species composition accounted for about 90% of the variation in enzyme activity. Drought reduced the majority of enzyme activity in unplanted soil.