Environmental Geology 
                                     GLG 110 - CHAPTER 4  - ECOLOGY AND GEOLOGY  
                          
                              •    Ecology – Study of relationships between living things and their environments; the study of 
                                   control factors over the distribution, abundance, and health conditions of living things 
                                              
                                        o    Species – a group of individuals capable of interbreeding 
                                        o    Population – a group of individuals of the same species living in the same are 
                                        o    Community – a group of populations of different species living in the same area, 
                                        o    Habitat – where a particular species lives 
                                        o    Niche – how a particular species makes its living 
                                        o    Indigenous  species  –  species  that  are  found  in  the  area  where  they  evolved  (e.g., 
                                             Kangaroos in Australia) 
                                        o    Exotic species – species brought into an area or region by humans, either purposely or by 
                                             accident 
                                        o    Invasive  species  –  exotic  species  which  compete  with  and  may  replace  indigenous 
                                             species in their habitat 
                                        o    Biosphere – part of Earth where life exists 
                                        o    Biota – all organisms living in an area or region 
                              •    Environmental Geology - Study of geological processes and their effects on environment  
                          
                                         
                              •    Ecosystem – an ecological community (organisms) and its nonliving (geologic) environment in 
                                   which energy flows and chemicals (such as nutrients and water) flow (Keller, p. 108) 
                               
                              •    Succession – the systematic change of species as an ecosystem evolves after a large disturbance 
                                   (e.g., fire, flood, volcanic eruption) starts things over from scratch 
                          
                                        o    Primary succession – new land surface (e.g., lava flows adding land to island of Hawaii) 
                                             gets populated 
                                        o    Secondary succession – reestablishment of previously existing ecosystems (e.g., regrowth 
                                             of forest after a major fire) 
                                         
                              •    Balance of nature in a static state is non-existent – disturbance and change are natural 
                                        o    Humans put themselves in harm’s way and become frustrated when attempting to ignore 
                                             this fact or rely on it “taking a break” during their lifetimes 
                                        o    Climate change occurs naturally 
                                                  ♣  “Global warming” as currently discussed should be focusing on what portion of 
                                                      the current trend has been artificially increased by man’s activities, not on trying 
                                                      to halt any/all change in climate 
                               
                              •    Human-constructed ecosystems can be used to aid in cleaning up environmental problems 
                                        o    Marsh plants use and remove nutrients in water that may represent unwanted waste 
                                         
                              •    Plants on steep slopes stabilize soil – naturally/artificially 
                               
                              •    Removal of helpful ecosystems (like slope vegetation or coastal marshes) can increase hazards to 
                                   human life and property, such as coastal flooding, and reduce ability to naturally clean the water 
                          
                              •    Biodiversity – the number/abundance of species in an ecosystem or ecological community 
                          
                                  o   The number or abundance of species in an ecosystem or ecological community 
                                          ♣  Species richness: the number of species 
                                          ♣  Species evenness: the relative proportion of species  
                                          ♣  Species dominance: one of multiple species more common than others 
                                          ♣  Keystone  species:  exerting  a  stronger  community  effect  disproportionate  to 
                                              their abundance. Examples – wolves in Yellowstone, sea otters in kelp forests, 
                                              bison on prairie, corals 
                                       
                                  o   Geology influences biodiversity from small (hillside) to large (mountain range) scales 
                                          ♣  Example: trees in post-glacial Europe vs. N. America 
                                  o   Increased by diverse habitat with many potential niches, moderate disturbances, harsh 
                                      environmental  conditions  in  places  within  a  diverse  region,  relatively  constant 
                                      climate/elevation, heavily life-modified environments 
                                  o   Decreased  by  extreme  or  very  frequent  disturbance  (e.g.,  inside  a  volcanic  crater), 
                                      extreme  environment  locally  decreases  diversity,  human  transformation  of  the  land 
                                      (dams,  urban  sprawl,  etc.),  pollution  and  other  environmental  stresses,  habitat 
                                      simplification  (e.g.,  farming,  flood  control,  etc.),  introduction  of  invasive  species, 
                                      inopportune orientation of mountain ranges (esp. during ice ages) 
                                           
                      
                                  o   Urban and agricultural land transformations produced by humans over the past 2000 
                                      years have greatly decreased biodiversity and we are in the middle of a human-produced 
                                      mass extinction 
                      
                                   
                              •   Factors to Increase Biodiversity	
   
                                  Ø  Favored geological environment 
                                              Moderate amount of disturbance – hazards creating or renewing habitats 
                                      Harsh environments for certain unique specialized species, increasing biodiversity at 
                                      regional scale 
                                  Ø  Relatively constant environmental conditions, such as T, P, precipitation, and elevation 
                                  Ø  Highly modified biologically productive environment 
                      
                              •   Factors to Reduce Biodiversity 
                                  ³   Extreme geological environments 
                                       Ø   Disturbances can easily damage extreme habitats 
                                       Ø  Hot springs, caves, hypersaline lakes, extreme cold/aridity 
                                       Ø   Limited number of habitats and ecological niches at  a local scale 
                                       Ø   Pollution and other stresses restrict the flow of energy and nutrients 
                                  ³   Fragmentation of ecosystems by land use transformation 
                                  ³   Intrusion of invasive exotic species 
                                  ³   Habitat simplification (engineering structure) or migration barriers 
                                       
                              •   Human Domination 
                                  o   Human  activities  exerting  dominant  community  effects  -  Human  footprint  on  the 
                                      environment  –  impact  we  have  on  our  planet  can  be  reduced  by  either  population 
                                      reduction  (gradual  vs.  catastrophic)  or  to  use  resources  and  manage  our  waste  more 
                                      efficiently.  Impacts include: 
                      
                                  Ø   Massive  land  use  transformation  –  urban,  agriculture,  recreation,  and  industry 
                                      development 
                                  Ø   Global climate changes (global warming) 
                                  Ø   Changes in biogeochemical cycles – O2, CO2, energy, and nutrients 
                                  Ø   Very rapid extinction (many species) during the last 2000 years 
                                  Ø  Currently in a mass extinction event, caused by humans 
                          
                                   •    Human Time vs. Earth Time 
                                        ³  Geological processes on Earth time scale 
                                                  •   We matter very little on this time scale… 
                                        ³  Human activities and expectations on human time scale 
                                                  •   We matter very much on this time scale… 
                                        ³  Need to operate with an appropriate environmental ethic 
                                        ³  Need to make a “pact” with Earth to achieve a more compatible relationship 
                                        ³  Disrespect and disregard resulting environmental degradation 
                          
                                   •    Reduce the Human Footprint 
                                        ³  Human population reduction 
                                        ³  More efficient use of resources 
                                        ³  Better management of our waste 
                                        ³  Better understanding of ecosystems 
                                        ³  The importance of human-dominated ecosystems and other types of ecosystems 
                          
                                   •    Ecological restoration – altering an area in order to recover historical indigenous ecosystems 
                                        o    Waste clean-up 
                                        o    Replanting trees and other plants 
                                        o    Dam removal 
                                        o    Reintroduction of native species 
                                        o    Everglades as a LARGE example 
                                        o    “Big 3” – hydrologic/water conditions/soil and rock/vegetation 
                          
                                   •    Important Restoration Aspects 
                                       ³  Hydrologic process: surface water & groundwater 
                                       ³  Soil and rock: Geological conditions (rock and soil type, slope, landscape) 
                                       ³  Vegetation: the cover materials on land and wetland 
                                       ³  Socioeconomic shareholders: interests and startpoint 
                                       ³  Science: restoration goals and endpoints 
                                            
                                   •    Biological Engineering in Ecological Restoration 
                                       ³  Using vegetation in engineering projects to achieve specific ecological goals 
                                       ³  Designing and constructing certain ecosystems 
                                       ³  Modifying functions of ecosystems 
                                                            Ø  E.g.,  Solarizing the ice plant of the sand dunes in Santa Barbara 
                                                            Ø  Planting native dune vegetation species 
                          
                          
                         WSE  8/2012