General definition of ecosystem

What is an ecosystem? a community and its physical environment treated together as a functional system www.uwn.edu All the populations in an ecosystem All the organisms in an ecosystem that belong to the same species How are ecosystems named? Ecosystems can be named in two ways: biotic or abiotic Based on the abiotic environment Based on the primary/dominant biotic organisms/ species in the community The dimensions of ecosystems? Ecotones? Ecosystems are not isolated from one another One ecosystem blends into the next through a transitional region—an ecotone—that contains any species common to both systems THE RULES OF ECOLOGY Everything is connected to everything else Everything must go somewhere There is no such thing as a free lunch The Law of Thermodynamics FIRST LAW : • Energy is neither created or destroyed • It may change form , pass from one place to another, or act upon matter in various ways The Law of Thermodynamics SECOND LAW: • Transformations of energy always result in some loss or dissipation of energy • Or, In energy exchanges in a closed system, the potential energy of the final state will be less than that of the initial state • Or, Systems will tend to go from ordered states to disordered states (to maintain order, energy must be added to the system, to compensate for the loss of energy) Ecosystem is an open system Energy and nutriel received from the other ecosystem The Earth receives energy only from the Sun Natural ecosystems always exchanges energy and matter with the surrounding environment Ecosystems are self-correcting system Limit of tolerance When the environment changes, the relationships within rearranged to fit When impacts over the limit, the system can not be adjusted Structural components of the ecosystem Physical Environment (abiotic) ECOSYSTEM Community (biotic) Agricultural Ecosystem Nguồn: Mai Đình Yên cộng Urban Ecosystems Special structure Nguồn: Mai Đình Yên cộng What is the Difference Between a Natural & Artificial Ecosystem? Ecosystem Services and Sustainability Solar Capital Lessons From Nature! Water resources and purification Air resources and purification Soil formation and renewal Waste removal and detoxification Climate control Natural Capital Natural pest and disease control Biodiversity and gene pool Recycling vital chemicals Renewable energy resources Nonrenewable energy resources Nonrenewable mineral Potentially resources renewable matter resources Use Renewable Solar Energy As Energy Source Recycle the chemical nutrients needed for life How Do Humans Affect Ecological Succession? • Clearing the land for the garden and preparing the soil for planting represents a major external event that radically restructures and disrupts a previously stabilized ecosystem The disturbed ecosystem will immediately begin a process of ecological succession • Plant species that adapt to the sunny conditions and the broken soil will rapidly invade the site and will become quickly and densely established These invading plants are what we call "weeds“ in which we consider a nuisance or invaders How Do Humans Affect Ecological Succession? • A gardener's only course of action is to spend a great deal of time and energy weeding the garden or using chemicals to infringe upon the weeds and the ecosystem around it • The farmers and gardeners who are growing our foods incur an immense cost in terms of time, fuel, herbicides and pesticides that humans pay every growing season because of the force of ecological succession Sustainable Ecosystems A sustainable ecosystem is a system that survives, functions, and is renewed over time Sustainable Ecosystems Processes For an ecosystem to be sustainable, it must use energy efficiently Several essential processes occur within an ecosystem to ensure the flow of energy and resources Photosynthesis uses energy from the sun to make food and energy for plants When animals feed on the plants, the energy is shared As plants and animals die, the decomposition of organic material makes nutrients such as carbon dioxide and nitrogen again available to the ecosystem's organisms In this way, an ongoing flow of energy sustains the ecosystem Sustainable Ecosystems Resistance A sustainable ecosystem will exhibit some resistance to change or environmental pressures For example, many plants can cope with short-term water shortages by closing their stomata the pores on their leaves during the warm daylight hours The stomata are sites of gas exchange By closing them, plants avoid losing moisture Also, plant growth may slow during arid conditions to conserve the plant's resources Rather than dying off, the plant resists environmental stress, maintaining its sustainability Sustainable Ecosystems Resilience An ecosystem's resilience affects its sustainability Resilience describes how quickly an ecosystem recovers after a disturbance, whether natural (fire) or man-made (clearing of a forest) To cope, an ecosystem must maintain energy reserves from which it can draw For example, fire is a common occurrence in prairie ecosystems While fire might destroy the above-ground plant growth, the root systems contain the necessary stored materials to recover and replace the lost plant material Sustainable Ecosystems Predator-Prey Relationships It is important to the ecosystem's sustainability that its resources are not depleted too quickly Sustainability means being able to keep up with the replacement of resources in balance with the demand Predator-prey relationships illustrate this concept Prey species such as deer will continue to forage as long as food is available Left unchecked, populations increase to the point where some members starve Predators will take the weakest members of the herd as an efficient means to get food with the least amount of effort The prey population recovers and is stronger as the ecosystem's sustainability returns Sustainable Ecosystems Threats Human disturbance can threaten the sustainability of an ecosystem by causing change to occur too rapidly for it to cope Examples of these threats include deforestation and pollution If large tracts of forest are harvested, a forest might take a long time to recover Likewise, pollution can cause long-term soil pollution In these cases, the sustainability is compromised What is the Difference Between a Natural & Artificial Ecosystem? Definition An ecosystem is a community of living and non-living things that work together These can occur naturally, or they can be created through artificial means Artificial Ecosystems Artificial ecosystems, as the name suggests, are those made by man to mimic a naturally-occurring ecosystem Chance A natural ecosystem is created through biological laws and chance Predators eat prey, trees will try to crowd out other plant life, etc In an artificial ecosystem, this may not be the case, since it will have thought and planning put into it Control There is a great deal more control in artificial ecosystems The placement of plant life, which animals are allowed in, the content of the soil, and in some cases, like terrariums, even the light and temperature can be controlled Imitation While an artificial ecosystem may imitate a natural ecosystem, so long as there is a control factor, the ecosystem cannot be considered natural Biodiversity Natural Ecosystems are much more diversity than Artificial Ecosystem ... examples of adaptation? Types of Ecosystems • There are many types of ecosystems on earth • Major classes of relatively contained ecosystems are called Biomes • There are Major classes of ecosystems... River and Stream Ecosystem Nguồn: Mai Đình Yên cộng Lakes Ecosystem Terrestrial Ecosystems • Many & diverse types of ecosystems • Location usually dependent on: • the latitude of the area, and... amount of precipitation Forest Ecosystem Nguồn: Mai Đình Yên cộng Ocean Ecosystems • Very large amount of Earth is covered by ocean (~75%) • 40% of all photosynthesis occurs in oceans • types of