ENVS 1126 Lecture : Lecture 13 Soil Resource
Document Summary
Biodiversity: species diversity, genetic diversity in species, ecosystem diversity. Extinction: endemic species; the pt (permian-triassic extinction) Policies: lacey act (1900); endangered species act (esa); the iucn red list (1964); cites (1975): ban the international trade in ivory in 1989; 90% of all food comes from land-based agriculture. Protecting and nurturing soil is the cornerstone of food production and sustainability. Soil erosion from plowing and lack of trees was a greater influence by humans. Humans still make this mistake today (dust storm in phoenix, arizona, 2011) Soil profile: a description of the different, naturally formed layers within a soil. Horizons: horizontal layers of soil from soil formation (can be quite distinct) Productive topsoil involves dynamic interactions among organisms, detritus, and mineral particles of the soil. Sand particles settle first, then silt, then clay. Soil comes in an almost infinite variety of structures.
