10/26/2010 1 Geog 1001: Climate and Vegetation Lecture 17: Ecosystem Essentials Professor Holly Barnard October 26, 2010 Ecosystem Components and Cycles Biotic Ecosystem Operations Ecosystems, Evolution, and Succession Ecosystem Essentials The Web of Life Figure 19.1 Basic terms I Eco-logy: the study of our house Focus: The relationship or interaction between organisms (biotic) and their surrounding environment (abiotic) Bio-geography: the geography of living beings Focus: The distribution of plants & animals, including the biotic & abiotic processes, and in the past & present (spatial & temporal)10/26/2010 2 Ecosystem Components I Communities Def.: Animal populations interactions Plant populations Characteristics Physical appearance Richness (species present) Abundance of each species Complex patterns of interdependence Trophic (feeding) structure Ecosystem Components: Communities Habitat Environment where an organism resides (or biologically adapted to live) Requirements with limits & specific regimes of sustaining nutrients Ecosystem Components: Communities Niche (to nest) Def.: function or role of a life form within a given community [when occupying a space] Way an organism obtain and sustain the physical, chemical, & biological factors it needs to survive Biotic Interactions and Competition Species interactions simple interactions (two species, pairwise interaction, 5 scenarios, three dominant). 1. Competition 2. Predation, Parasitism, Herbivory 3. Mutualism 4. Commensalism 5. Amensalism10/26/2010 3 Mimicry Adaptation and Acclimation Biotic and Abiotic factors can create selection pressure on a population of organisms. Adaptation and acclimation are responses of biological organisms to adjust to changes in critical biotic and abiotic factors. Generalists and specialists Ecosystem Components II Plants: The Essential Biotic component …Why? Energy flow in Ecosystems: Photosynthesis Net Primary Productivity (NPP) Abiotic & Biotic Ecosystem Components Abiotic Climate, water, minerals, insolation, heat E released Limiting Factors Life zones10/26/2010 4 Vascular Plant Anatomy http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookPS.html Photosynthesis CO2 O2 H2O unites CO2 and H photo = light synthesis = manufacturing Photosynthesis Photo-synthesis10/26/2010 5 Photosynthesis and Respiration Figure 19.5 NET PHOTOSYNTHESIS The Local Plant Carbon Cycle Autotrophic Respiration of CO2 Heterotrophic Respiration of CO2 Root mortality & exudation Litterfall Photosynthesis Energy Budget of the Biosphere Figure 19.710/26/2010 6 Photosynthesis – Respiration=NPP (Biomass) Figure 19.8 Global Carbon and Oxygen Cycles Figure 19.10 Abiotic Ecosystem Components Climate, weather, water, minerals, insolation, heat E released (i.e. Physical or Chemical components all but biotic!) Determine to some extent where an organism could regenerate, reproduce, and eventually persists Limiting Factors Life zones Limiting Factors10/26/2010 7 Limiting Factors Def.: One physical or chemical abiotic component that most inhibit biotic operation, through either its lack or excess Examples Temps (low at high elevations) H2O (lack in deserts & excess in bogs) Nutrients Changes in topography Changes in climate Temperature and Precipitation Figure 19.8 The Nitrogen Cycle Figure 19.11 http://msucares.com/crops/fertilizer/index.html10/26/2010 8 Atmospheric Nitrogen Deposition N Saturation and Algal Blooms The Gulf Coast Dead Zone Figure 19.2.1 Communities Plants: The Essential Biotic Component Photosynthesis and Respiration Abiotic Ecosystem Components Ecosystem Components and
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