BIOL 1202 Study Guide - Humus, Mycorrhiza, Nitrification
Document Summary
Concept 37. 1: soil is a living, finite, resource. In addition to climate, texture and composition of soil are major factors determining the distribution of plants. Soil horizons: soil horizons are visible in vertical profile. A horizon is a mix of humus and minerals: humus consist of decomposing organic material, prevents packing of smaller mineral particles and allows retention of water. Leaching: removal of nutrients from soil by water that percolates through it, most pronounced in sandy soils, clays are best at holding onto nutrients. Concept 37. 2: plants require essential elements to complete their life cycle: plants derive most of their organic mass (biomass) from the co2 in the air, also need soil nutrients like water and minerals. Limiting nutrient: relative availability in environment is less than plants need for it. Concept 37. 3: plant nutrition often involves relationships with other organisms. Clicker question: biological nitrogen fixation is performed by _______.
