BI102

General Biology

Spring 2008

Dr. Brian K. Penney

Goulet 2320

603 641-7149

bpenney@anselm.edu

Brian K. Penney 's web page

---

1. Ecology is the study of the interactions between organisms and their environment and other organisms.

   • There are four main branches of ecology: physiological (organismal), population, community, and ecosystem ecology.

   • Ecosystems are comprised of both biotic and abiotic components.

   ---

2. The biosphere is the total of all Earth's ecosystems, ranging from the upper atmosphere to deep rock and ocean.

   • The biosphere's self-contained nature sets limits on the total resources available, and means human inputs are cycled through different parts.

   • It can be subdivided into smaller patches or habitats.

   ---

3. Abiotic factors and climate generally limit the large-scale distribution of organisms.

   • Energy is required to drive ecosystems and comes primarily from light, but sometimes from chemicals.

   • Water and temperature are important limiting factors for most organisms.

   • Fluid flow (wind, currents) can affect rates of exchange, or present an important disturbance regime.

   • Distribution of these factors across the globe help determine climate, and are largely explainable by planetary dynamics,

     • the most important influence is variation in solar radiation intensity with latitude, followed by tilt of planet axis relative to plane of orbit
     • produces polar, temperate and tropical zones.

   • Organisms are adapted to abiotic/biotic factors of particular zones, which limits their distribution. Subdivisions of the planet based on typical climate and lifeforms are biomes.

   ---

4. Water biomes are first divided into marine and freshwater zones.

   • Marine habitats are the most extensive according to area and volume, but the least explored by humans. Primary divisions are: benthic vs. pelagic, and photic vs. disphotic vs. aphotic.

   • Aquatic (freshwater) habitats include lakes, ponds, rivers and streams, and show more seasonal variation than marine habitats. Running water biomes change with distance downstream from sources.

   • Three important zones with both water and terrestrial components are: intertidal, wetland, and estuary.

Copyright 2007-2008, Brian K. Penney

How to succeed in this course