Part2 ecosystem

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Transcript of Part2 ecosystem

  • 1. General Ecology PART II: ECOLOGICAL PRINCIPLES & CONCEPTS I. CHARACTERISTICS Living organisms and their nonliving environment are inseparably interrelated and interact upon each other. Any unit that includes all of the organisms (biotic) in a given area interacting with the physical environment (abiotic) which leads to clearly defined trophic structure, biodiversity, and material cycles in a system is known as Ecological System or Ecosystem. Biosphere is the global ecosystem or the sum of all the planets ecosystems. Biodiversity is the degree of variation of life forms within a given species, ecosystem, biome, or planet. It includes genetic diversity, species diversity, and ecosystem diversity. Types of Ecosystem 1. Aquatic Ecosystem Marine Freshwater 2. Terrestrial Ecosystem Forest Grassland Dessert Urban II. STRUCTURAL COMPONENTS OF AN ECOSYSTEM Minerals EcosystemEcosystem Abiotic Climatic Rain Light pH TemperatureSoil pH Edaphic Topography Producers Consumers Biotic Decomposers

2. CvSU Vision The premier University in historic Cavite recognized for excellence in the development of globally competitive and morally upright individuals. CvSU Mission Cavite State University shall provide excellent, equitable and relevant educational opportunities in the arts, sciences and technology through quality instruction and responsive research and developmental activities. It shall produce professional, skilled and morally upright individuals for global competitiveness. CAVITE STATE UNIVERSITY (CvSU) Imus Campus Abiotic Components Abiotic components (also called abiotic factors) are non-living chemical and physical factors in the environment which affect ecosystems. Example: There is a significant difference in access to water as well as humidity between temperate rainforests and deserts. This difference in water access causes diversity in the types of plants and animals that grow in these areas. Energy Source Lack of sunlight is seldom the most important factor limiting plant growth for terrestrial ecosystems. Although shading by trees does create intense competition for light among plants growing on forest floor. In many aquatic environments, light cannot penetrate beyond certain depths and as a result, most photosynthesis in a body of water occurs near the surface. Hydrothermal vents are strange ecosystems that lie deep under the ocean. They are adjoining edges of giant plates of Earths crust where molten rocks and hot gases surge upward from Earths interior. This ecosystem is powered by chemoautotrophic bacteria that drive energy from oxidation of inorganic chemicals such as hydrogen sulfide (pictures available on the site). Temperature Temperature is an important abiotic factor because of its effect on metabolism. Metabolism refers to the total of all chemical reaction of an organism. Few organisms can maintain a sufficiently active metabolism at temperatures close to 0o C, and temperatures above 45o C destroy the enzymes of most organisms. Thermopiles are organisms that thrive at relatively high temperatures, between 45 and 122 C. Thermophilic bacteria are suggested to have been among the earliest bacteria and are found in various geothermally heated regions of the Earth such as hot springs and see deep hydrothermal vents (pictures available on the site). Water For terrestrial organisms, the primary threat is drought. Many land species have watertight coverings that reduce water loss. A waxy coating (cuticle) on the leaves and other aerial parts of most plants helps prevent dehydration (pictures available on the site). Aquatic organisms are surrounded by water, but they face problems of water balance if their own solute concentration does not match that of their surroundings (application of the principle of osmosis). Nutrients Plants obtain inorganic nutrients such as compounds of nitrogen and phosphorus from the soil. Soil structure, pH and nutrients play major roles in determining the distribution of plants. In aquatic ecosystems, low levels of nitrogen and phosphorus limit the growth of producers like algae and photosynthetic bacteria. Oligotrophic environment refers to ecosystems which have very little nutrients to sustain life. 2 3. CvSU Vision The premier University in historic Cavite recognized for excellence in the development of globally competitive and morally upright individuals. CvSU Mission Cavite State University shall provide excellent, equitable and relevant educational opportunities in the arts, sciences and technology through quality instruction and responsive research and developmental activities. It shall produce professional, skilled and morally upright individuals for global competitiveness. CAVITE STATE UNIVERSITY (CvSU) Imus Campus Eutrophic environment refers to ecosystems which are rich in nutrients to sustain life. Other Aquatic Factors Dissolved oxygen in water Salinity Currents Tides Other Terrestrial Factors Wind Natural / Phenomenal Disturbances Biotic Components Trophic (trophe which means feeding or nourishment) level of organisms is the position it occupies in a food chain. 1. Producers They are autotrophic organisms. Autotrophs are organism that produces complex organic compounds from simple substances present in its surroundings, generally using energy from light (photosynthesis) or inorganic chemical reactions (chemosynthesis). Photoautotrophs / Phototrophs are autotrophic organisms that use the energy from light to carry out various cellular metabolic processes. In terrestrial environments, plants are the predominant phototrophic variants while aquatic environments include a range of phototrophic organisms such as algae (kelp or seaweeds), other protists (euglena), phytoplankton, and bacteria (cyanobacteria or blue-green algae). Chemoautotrophs use inorganic energy sources, such as hydrogen sulfide, elemental sulfur, ferrous iron, molecular hydrogen, and ammonia. These are the chemoautotrophic bacteria in Hydrothermal vents and thermophilic bacteria. 2. Consumers They are also called macroconsumers or phagotrophs (phago means to eat) which ingest other organisms or particulate organic matter. They are either directly or indirectly dependent on Autotrophs. Classification of Consumers (Food Chain Perspective) 2.1. Primary Consumers are Herbivores or animals which are directly dependent and feed on autotrophs. 2.2. Secondary Consumers are carnivores or animals which feed on primary consumers. Carnivores derive its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue. Omnivore which feeds on both plants and animals, can also be considered a secondary consumer. 2.3. Tertiary Consumers also known as an Apex Predator are usually on top of food chains capable of feeding on secondary consumers and primary 3 4. CvSU Vision The premier University in historic Cavite recognized for excellence in the development of globally competitive and morally upright individuals. CvSU Mission Cavite State University shall provide excellent, equitable and relevant educational opportunities in the arts, sciences and technology through quality instruction and responsive research and developmental activities. It shall produce professional, skilled and morally upright individuals for global competitiveness. CAVITE STATE UNIVERSITY (CvSU) Imus Campus consumers. Tertiary consumers can be either fully carnivorous or omnivorous. Humans are example of a tertiary consumer. Consumers are also heterotrophic organisms. Heterotrophs are organisms that cannot fix carbon and uses organic carbon for growth. Classification of Heterotrophs (Depending on Energy Source) 2.1. Photoheterotrophs are heterotrophic organisms that use organic compounds from the environment to satisfy their carbon requirements. 2.2. Chemoheterotrophs utilize organic compounds both as a carbon source and an energy source. They break down complex organic compounds like carbohydrates, fats, and proteins produced by autotrophs into simpler compounds like glucose, fatty acids and glycerol, and amino acids. Examples of these are animals. Saprotrophic nutrition is a chemoheterotrophic digestion which involves breaking down dead or decaying organisms (known as detritus) 3. Decomposers They are also called Saprotrophs that carry out the natural process of decomposition. Decomposers use dead organisms and non-living organic compounds as their food source. Detritivore utilizes decomposing material. Examples of these are bacteria and fungi. Bacteria are vital in the recycling of nutrients such as nitrogen by Nitrogen-fixing bacteria. Scavenger eats decaying flesh. Examples of these are vultures, scavenging birds. Worms can also act as scavengers. III. PRODUCTION AND DECOMPOSITION IN NATURE Biomass is the mass of living biological organisms in a given area or ecosystem at a given time. Production or Productivity refers to the rate of generation of biomass in an ecosystem. Primary production is the synthesis of new organic material from inorganic molecules such as H2O and CO2. It is dominated by the process of photosynthesis which uses sunlight to synthesis organic molecules such as sugars, although chemosynthesis represents a small fraction of primary production. Organisms responsible for primary production include land plants, marine algae and some bacteria (cyanobacteria) Secondary production is driven by the transfer of organic material between trophic levels and represents the quantity of new tissue created through the use of assimilated food. Organisms responsible for secondary production include animals, protists, fungi and many bacteria. Decomposition is the natural process of dead animal or plant tissue being rotted or broken down. The result of decomposition is that the building blocks required for life can be recycled. During the process of decomposition, the decomposers provide food for themselves by extracting chemicals from the dea