PSYC 2000 Lecture : Lecture Slides 08 21 12 Intro To Class
Document Summary
In addition to climate, texture and composition of soil are major factors determining the distribution of plants. Leaching- removal of nutrients from soil by water that percolates through it: most pronounced in sandy soils (large grained soils). Clays (very small grained soils) are the best at holding onto nutrients. Concept 37. 2- plants require essential elements to complete their life cycle: plants derive most of their organic mass from the co2 in the air, also need soil nutrients like water and minerals. Macronutrients- required by plants in relatively large amounts. Micronutrients- elements that are needed in only small amounts (function mainly as cofactors in chemical reactions: table 37. 1. Limiting nutrient: relative availability in environment is less than plants need for it. Concept 37. 3- plant nutrition often involves relationships with other organisms. Soil bacteria and nitrogen availability: nitrogen fixation- bacteria convert n2 to nh3, ammonification- bacteria convert n-containing compound to nh4, nitrification- bacteria convert nh4 no3, denitrification- bacteria convert no3- to n2.
