8/30/2011 CHAPTER 4 Ecology & Geology Linkage Ecology • Study of relationships between living things and their ECOLOGY AND GEOLOGY environments; the study of control factors over the distribution, abundance, and health conditions of living things Environmental Geology • Study of geological processes and their effects on environment The linkage • complex linkages, varies at different scales Ecosystem Fundamental Ecology Terms • An ecological community and its surrounding • Species: a group of individuals capable of environment in interbreeding; can be indigenous or exotic which the flows •Poppgpulation: a group of individuals of the same of energy and species living in the same area cyclfles of chemicals • Community: a group of the populations of support the different species living in the same area living community • Biota: all organisms living in an area or a region • Biosphere: the part of Earth where organisms exist and function Figure 4.2 Natural Service Functions of Types of Ecosystems Ecosystems • Natural indigenous: ecosystem as the result of • Natural Service Functions are those processes completely natural evolutional processes, rarely responsible for producing clean water, air, and living matter exist • Direct funct ions • Human modified: the one modified by human ¾ Cycle of chemical elements, e.g., CO2, O2 use and interest, almost all the major ecosystems ¾ Flow of energy & nutrients • Human constructed: man-made ecosystem for ¾ Removal of pollutants many different purposes at many sites, such as • Buffering functions: providing protections from natural ponds, canals, wastewater treatment pools hazards, e.g., wetlands against coastal flooding and erosion 1 8/30/2011 Biodiversity Geology & Biodiversity The number or abundance of species in an ecosystem or • Geology affects the overall environmental ecological community conditions of an ecosystem • Species richness: the number of species – Changes in topography, e.g., mountain building • Species evenness: the relative proportion of species & slope movement • Species dominance: one of multiple species more – Plate tectonics and ecosystem barrier, e.g., common than others North America & Europe tree diversity vs. mountain range distribution • Keystone species: exerting a stronger community – Changes in climate: ice age, glaciation, and effect disproportionate to their abundance global warming – Soils development Keystone Species (2) Keystone Species (1) Figure • Keystone species: species exert strong 4.5 community effects disproportionate to their abundance • Case studyy,,: wolf, elk, and mountain stream system in Yellowstone National Park ¾ 1960s to mid-1990s: elk overbrowsed the riparian vegetation and affected the stream ecosystem ¾ late 1990s: reintroduced wolves that hunted elk and promoted the growth of riparian vegetation, water quality, and stream ecosystem Before After Keystone Species (3) Sea otters, urchins, and kelp • Kelp forests: three parts – rootlike holdfast, stem (stipe), and blades (leaves) • Holdfast attached to boulders or the rocky bottom, part of the active geological environment • Urchins fed on the holdfast of kelp • Sea otters were restored and fed on urchins, kelp forests were restored 2 8/30/2011 Factors to Increase Biodiversity • Favored geological environment ¾ Moderate amount of disturbance – hazards creating or renewing habitats ¾ Harsh environments for certain uniqqpue specialized species, increasing biodiversity at regional scale • Relatively constant environmental conditions, such as T, P, precipitation, and elevation • Highly modified biologically productive environment Factors to Reduce Biodiversity Human Domination • Extreme geological environment • Human activities exerting dominant community ¾ Extreme disturbances damage habitats effects ¾ Limit the number of habitats and ecological niches at ¾ Massive land use transformation – urban, agriculture, a local scale recreation, and industry development ¾ Pollution and other stresses restricting the flow of ¾ Global climate changes energy and nutrients ¾ Changes in biogeochemical cycles – O2, CO2, energy, • Fragmentation of ecosystems by land use transformation and nutrients • Intrusion of invasive exotic species ¾ Most rapid extinction of many species during the last • Habitat simplification (engineering structure) or migration 2000 years barriers Case Study: Seawalls and Biodiversity • Seawall construction ¾ Beach space narrowed ¾ Biodiversity on the beach reduced ¾ Waves are deflected ¾ Gradient increases of offshore slope 3 8/30/2011 Time Dimension: Reduce the Human Footprint Human Time vs. Earth Time • Human population reduction • Geological processes on Earth time scale • More efficient use of resources • Human activities and expectations on human time • Better management of our waste scale • Better understanding of ecosystems • Need to operate with an appropriate environmental ethic to prevent degradation • The importance of human-dominated ecosystems and other types of ecosystems • The Point: Earth will be here long after us Ecological Restoration Ecological Restoration Kissimmee River Everglades • The process of altering a site or area to reestablish • Since 1900, urban development, much of the indigenous historical ecosystems Everglades drained ¾ Prior to 1940, wide floodplain with diverse wetland • One of the most valuable wetland ecosystems pp,lants, wading birds, waterfowl, ,, fish, and other wildlife ¾ 11, 000 species of plants ¾ 1942–1971: 2/3 of the floodplain drained, degraded ¾ Hundreds of species of birds, fish, marine mammals ecosystem functions and reduction of bird and fish ¾ 70 threatened or endangered species populations • Multilevel partnership restoration project ¾ 1992: restoration project authorized by Congress ¾ 12-km straight channel restored to a meander • Reduction of pollution and removal of invasive exotic species Important Restoration Aspects Restoration Process & Procedure • Hydrologic process: surface water & groundwater • Soil and rock: Geological conditions (rock and soil type, slope, landscape) • Vegetation: the cover materials on land and wetland • Socioeconomic shareholders: interests and start point • Science: restoration goals and endpoints 4 8/30/2011 Biological Engineering in Ecological Restoration • Using vegetation in engineering projects to achieve specific ecological goals • Designing and constructing certain ecosystems • Mo dify ing func tions of ecosyst ems 5.