Lecture 4: Life in Water - Properties, Nutrients, and Gases in Aquatic Systems - Prof. Eve, Study notes of Ecology and Environment

Download Lecture 4: Life in Water - Properties, Nutrients, and Gases in Aquatic Systems - Prof. Eve and more Study notes Ecology and Environment in PDF only on Docsity! Lecture 4 Life in Water Goals: Be familiar with points from lectures 1-3 before proceeding Be able to list the main physical factors important to most animals and plants Be able to explain the main properties of water that make it a good medium for life Be able to explain how ionic composition of water effects organisms Be able to explain how light availability changes with depth in water, the parameters that effect changes in light availability and how this controls productivity and distribution of organisms in the water Be able to explain how the thermal structure of lakes is established and how it changes seasonally Know the major nutrients important to life and how productivity can be limited by them Be able to explain availability of gases in water and how photosynthesis and respiration effect them Outline: Review: Ecology = organisms interacting with physical environment and other organisms Focus of unit 1 = physical environment Focus of last 2 lectures = how physical environment (climate) varies on large scale to create predictable global distribution patterns (biomes) Small-scale physical variation Important variables influencing individual organisms on small scales Water, Light, Temperature, Gases, Ions, Nutrients Distributions are influenced through niche preference Different variables effect aquatic and terrestrial systems differently Life in Water Properties of water that make it a good medium for life Hydrologic cycle Ions – coping with fluctuating salinity and pH Light Amount and types reaching water Amount and types penetrating water Light extinction, calculating rates Why light matters Productivity Visibility – food & mate finding, predator avoidance Temperature Thermal structure in lakes Influence of cycling on lake productivity