Lec 02 BOI 102 Ecology 2023 PDF

2 ECOSYSTEM CONCEPTS What is Environment Definition The total surrounding of an organism. Environment is an interacting system of physical, chemical, biological social, and cultural elements. Attributes 1. Environmental systems usually do not have well-defined boundaries. 2. Environment...

2 ECOSYSTEM CONCEPTS What is Environment Definition The total surrounding of an organism. Environment is an interacting system of physical, chemical, biological social, and cultural elements. Attributes 1. Environmental systems usually do not have well-defined boundaries. 2. Environmental characteristics change over a gradient. 3. Environmental system is an open system because it receives inputs from and gives outputs to other systems. 4. Environment ultimately determines the quality and survival of life  ENVIRONMENT PHYSICAL ENVIRONMENT BIOTIC ENVIRONMENT LITHOSPHERE HYDROSPHERE ATMOSPHERE BIOSPHERE (Solid Earth) (Water) (Air) (Living Organisms) FLORA FAUNA MICROBES  The Earth environment is the home (habitat) of all forms of life including humans. All life forms depend on the proper functioning of our environment! The biosphere is a global ecosystem composed of living organisms (biota) and the abiotic (nonliving) factors from which they derive energy and nutrients. Earth's environmental spheres. Earth's environment includes the atmosphere, the hydrosphere, the lithosphere, and the biosphere. What is an Ecosystem? Ecosystem is the interaction and interrelationship between the living community (plants, animals, and organisms) in relation to each other and the non-living community (soil, air, and water). Thus, an ecosystem is a structural and functional unit of the biosphere. It is made up of living and non-living beings and their physical environment. In other words, a natural ecosystem is defined as a network of interactions among organisms and between organisms and their environment. Nutrient cycles and energy flows keep these living and non-living components connected in an ecosystem. What is an Ecosystem? Definition: An ecosystem is a biological community of interacting organisms and their physical environment. Components: Biotic factors (living things: plants, animals, microorganisms) Abiotic factors (non-living things: air, water, soil, temperature) Examples: Forests, lakes, deserts, coral reefs Ecosystem Ecosystem is a part of natural environment consisting of a community of living beings and the physical environment, where both constantly interchanging materials and energy between them. It is the sum of the environment or a part of nature. Ecosystem The study of ecosystem or environmental studies has been seen to be multidisciplinary in nature, hence, it is considered to be a subject with great scope. It is no more confined only to the issues of sanitation and health; rather, it is now concerned with pollution control, biodiversity conservation, waste management and conservation of natural resources.  ECOSYSTEM CONCEPT In biology, an ecosystem is a community of organisms and their physical environment. The notion of an ecosystem recognizes the many ways that an organism interacts with and depends on various parts of its environment. The term ecosystem was coined in 1935 by the Oxford ecologist Arthur Tansley to encompass the interactions among biotic and abiotic components of the environment at a given site. The living and non-living components of an ecosystem are known as biotic and abiotic components, respectively.  ECOSYSTEM CONCEPTS History of the Ecosystem Concept The term "ecosystem" was first coined by Roy Clapham in 1930, but it was ecologist Arthur Tansley who fully defined the ecosystem concept. Tansley defined ecosystems as: "The whole system,… including not only Arthur Tansley the organism-complex, but also the whole complex of physical factors forming what we call the environment"  ECOSYSTEM CONCEPTS Modern Ecosystem Concepts Eugene Odum, a major figure in advancing the science of ecology, deployed the ecosystem concept in a central role in his seminal textbook on ecology, defining ecosystems as: Eugene Odum (1913-2002) "Any unit that includes all of the organisms (ie: the "community") in a given area interacting with the physical environment so that a flow of energy leads to clearly defined trophic structure, biotic diversity, and material cycles (ie: exchange of materials between living and nonliving parts) within the system is an ecosystem."  ECOSYSTEM CONCEPT Ecosystem that defined by Eugene Odum encompassed: The ecosystem idea generalizes the "food chain" and "food web" concepts, allowing for more relationships than just consumption. For example, plants provide not just food for animals but also shelter, shade, moisture, etc.  ECOSYSTEM CONCEPTS Definition: Ecosystem is the basic structural and functional unit of ecology. “Ecosystems are the basic units of nature on the face of the earth” – Tansley (1935) “An ecosystem is an ecological unit, or a subdivision of the landscape, or a geographic area that is relatively homogeneous and reasonably distinct from adjacent areas” – Marr (1961)  ECOSYSTEM CONCEPTS Another View of Ecosystems Ecosystem is a spatial functional structure The space may be geographically large or small Largest ecosystem. e.g., Planet earth Smallest ecosystem e.g. a handful of soil and moss in a sealed jar.  ECOSYSTEM CONCEPTS The concept of ecosystem was first put Interaction forth by Tansley (1935). Ecosystem is the major ecological unit. Structure Function It has both structure and functions. Interaction Interaction The structure is related to species diversity. The more complex is the structure the greater is the diversity of the species in the ecosystem. Biodiversity Energy The functions of ecosystem are related to the flow of energy and cycling of materials through structural components of the Ecosystem ecosystem. Ecosystem is the basic structural and functional unit of ecology.  ECOSYSTEM CONCEPT While organisms in an ecosystem may be engaged in competition or predation, the concept focuses on interdependence — one organism's reliance on another or on the ecosystem as a whole. The idea of an ecosystem has been adopted for social and economic systems. An "ecosystem" is the environment that a company is part of, including suppliers, partners, consumers, and the underlying structure and behavior of the technology, markets and social context. Framing economic interactions as being an ecosystem promotes establishing alliances with companies that might have been seen as competitors. There are many possible economic relationships, just as there are many possible relationships between organisms in a biological ecosystem.  ECOSYSTEM CONCEPT One can contrast the use of the term "ecosystem" with that of "system," which focuses on the collective behaviors. "Ecosystem" is typically used in discussing the internal dependencies of the larger system especially as they pertain to a particular part. For example, one might say "A is part of B's ecosystem" to recognize B's dependence on A in the larger context. Thus, "ecosystem" is almost a substitute for the term "environment," but it emphasizes the existence of various parts of the environment, rather than the environment as a single entity.  ECOSYSTEM CONCEPT Still, in ecology, the term also alludes to whole-system collective behaviors, such as the forest lifecycle that might include destruction by fire and stages of regrowth. The idea of an ecosystem means viewing an organism, corporation, or other entity as part of a larger system whose parts are interacting and interdependent.  ECOSYSTEM an ECOSYSTEM consists of all the organisms and the abiotic pools with which they interact an ECOSYSTEM is the sum of all of the biological and nonbiological parts of an area that interact to cause plants to grow and decay, soil or sediments to form, and the chemistry of water to change ECOSYSTEM – basic unit and probably the most important concept in ecology Types of Ecosystem: 1.Open system – the presence of inputs and outputs (matter and energy) 2.Closed system – no exchange of matter and energy (usually artificially made, e.g. terrarium) EXAMPLE OF ECOSYSTEMS (CLOSED AND OPEN)  Type of Ecosystem Terrestrial Ecosystems: Forests, grasslands, deserts, tundra Aquatic Ecosystems: Freshwater (lakes, rivers) and marine (oceans, coral reefs) Artificial Ecosystems: Urban areas, agricultural lands Common characteristics of the ecosystems The ecosystem is a major structural and functional unit of ecology. The structure of an ecosystem is related to its species diversity in the sense that complex ecosystem have high species diversity. The function of ecosystem is related to energy flow and material cycles within and outside the system. The relative amount of energy needed to maintain an ecosystem depends on its structure. Complex ecosystems needed less energy to maintain themselves. Young ecosystems develop and change from less complex to more complex ecosystems, through the process called succession. Common characteristics of the ecosystems The ecosystem is a major structural (biotic & a biotic components) and functional unit of ecology. The structure of an ecosystem is related to its species diversity; the more complex ecosystems have high species diversity. Adaptation to local environmental conditions is the important feature of the biotic components of an ecosystem, failing which they might perish. The function of the ecosystem is related to energy flow and material cycling through and within the system. The relative amount of energy needed to maintain an ecosystem depends on its structure. The more complex the structure, the lesser the energy it needs to maintain itself. Common characteristics of the ecosystems Each ecosystem has its own energy budget, which cannot be exceeded. Both the environment and the energy fixation in any given ecosystem are limited and cannot be exceeded without causing serious undesirable effects. Ecosystems mature by passing from less complex to more complex states. Early stages of such succession have an excess of potential energy and a relatively high energy flow per unit biomass. Later (mature) stages have less energy accumulation and its flow through more diverse components. The function of every ecosystem involves a series of cycles, e.g., water cycle, nitrogen cycle, oxygen cycle, etc. these cycles are driven by energy. A continuation or existence of ecosystem demands exchange of materials/nutrients to and from the different components. Alterations in the environments represent selective pressures upon the population to which it must adjust Organisms which are unable to adjust to the changed environment must needs vanish. Common characteristics of the ecosystems The ecosystem is an integrated unit or zone of variable size, comprising vegetation, fauna, microbes and the environment. Most ecosystems characteristically possess a well-defined soil, climate, flora and fauna (or communities) and have their own potential for adaptation, change and tolerance. The functioning of any ecosystem involves a series of cycles, e.g., the water cycle and the cycles of various nutrients. These cycles are driven by energy flow, the energy being the solar energy Continuation of life demands a constant exchange and return of nutrients to and from (amongst) the different components of the ecosystem. Other words: Characteristics of Ecosystem 1. Ecosystem has no particular size 2. Ecosystem maybe natural or man made 3. It can change with time 4. Different organisms interact with each other & they have their role in the ecosystems 5. Biotic & abiotic works/interacts together 6. The foundation on which ecosystem resets is the production of organic materials by photosynthesis  Ecosystems consist of: Components Biotic – Living Organisms Abiotic – Non Living Organisms Processes Energy Transfer – Trophic Level, Food Chain & Food Web; Interactions - between Biotic & between Abiotic components Biogeochemical Cycles – Water, Carbon, Nitrogen & Phosphorus cycles  ECOSYSTEM COMPONENTS PROCESSES interaction (Energy Flow; Trophic Level; Food Chain & Food BIOTIC ABIOTIC Web; Biogeochemical interaction Cycles)