ENVS200 Lecture Notes - Lecture 2: Biogenic Substance, Calcium Sulfate, Hydrosphere
15 Jun 2015
School
Department
Course
Professor
Document Summary
Plants are able to use only a small sublet of the wavelengths, and the majority of the sun"s energy is absorbed by non chlorophyll material and are converted into heat. Increased intensity of light can result in greater phtosynthetic rates, until a threshold is reached. Resources - water use of radiation in photosynthesis costs water. Plants favour leaves that erform well, shed weak ones. Siunlight and c02 concentrations ont usually limit plant productivity. Plants may either avoid stress, or tolerate it. Avoiders concentrate growth and reproduction during periods of sufficient water, inactive other times. Desert annuals lie dormant for years until there is a rain event. Toleraters have leaves that adapt to minimize water loss, enabling them to survive, at the cost of slow growth. Mineral nutrition is complex, a large number of elements are required by living things and there is variation in their distribution in the environment. The general chemical composition of living protoplasm is the redfield ratio,
