Environment · X-Factor Notes
Ecology (Chapter 2) revision notes for UPPCS Prelims.
High-Yield Revision| Concept | What to remember | Asked in UPPCS |
|---|---|---|
| Ecology (Term) | Coined by German zoologist Ernst Haeckel (1866). It refers to the comprehensive study of an organism and its relation to its environment, encompassing interactions with both organic and inorganic environments. | UP R.O./A.R.O. Pre 2014 |
| Ecosystem (Term) | Coined by A.G. Tansley. It is the functional unit of nature. | UPUDA/LDA Pre 2002 |
| Ecosystem Nature | An ecosystem is an open system where there are continuous input and output of energy and substances. It is NOT a closed system. | UP PCS Pre (Re. Exam) 2015 |
| Ecosystem Components | Two basic components: Biotic Producers (Autotrophs), Consumers, and Decomposers; Abiotic materials ( Air, rain, temperature etc.) | |
| Types of Ecosystem | Marine/Oceanic ecosystem is the largest and the most stable ecosystem. Cropland, farmlands, gardens, and rice fields are examples of artificial (anthropogenic) ecosystems. | UP Lower Sub. Spl Pre 2003, UP PCS Pre 2013, UP P.C.S. Pre 2018, UP PCS Pre 2016 |
| Water Habitats | Lentic Ecosystem refers to static water habitats (ponds, lakes, swamps). Lotic Ecosystem refers to moving water habitats (rivers). | UPPSC Prelims 2023 |
| Ecological Terminology | Habitat is the actual location where an organism lives. Ecotone is a region of transition between two biological communities. | UP PCS Pre 2019, UP PCS Pre 2012 |
| Ecological Niche | Describes not only the physical space occupied by an organism but also its functional role in the community. The concept was enunciated by Joseph Grinnell (1917). | UP PCS Pre 2005 |
| Concept | What to remember | Asked in UPPCS |
|---|---|---|
| Energy Source | The primary source and driving force of an ecosystem is Solar Energy. | UP PCS Mains 2015, UP R.O./A.R.O. Re-Exam Pre 2016 |
| Energy Flow | The flow of energy is unidirectional. The amount of energy decreases during transfer from one trophic level to another due to loss as heat. | UP PCS Pre 2019, UP PCS Pre (Re. Exam) 2015 |
| Trophic Levels |
| Concept | What to remember | Asked in UPPCS |
|---|---|---|
| Nutrient Cycling | The movement of nutrient elements through various components of an ecosystem is called the Bio-geo-chemical cycle (or Cycling of elements). | UP PCS Pre 2012, UP PCS Pre 2020 |
| Succession (Sere) | The entire sequence of communities that successively change in a particular area is called Sere. | UP PCS Pre 2020 |
| Phases of Succession |
| Concept | What to remember | Asked in UPPCS |
|---|---|---|
| Ecological Imbalance | Caused primarily by Deforestation/Cutting forest. It is associated with overall environmental degradation. | UPUDA/LDA Pre 2013 |
| Environmental Hazard | Eucalyptus is known as "Environmental evil" or hazard because it absorbs too much inland water and decreases the water level. | UP PCS UDA/LDA Mains 2010, UP PCS Mains 2011, UP PCS Pre 2005 |
| Ecosystem Services |
| Trophic Level I includes Green Plants (Producers/Autotrophs). Producers are typically more than primary consumers. |
| UP PCS Pre 2013, UP PCS Pre 2019 |
| Energy Pyramid | The pyramid of energy is always upright; it can never be inverted. |
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| Biomass Pyramid | An inverted pyramid of biomass can be found in the Marine ecosystem (or a Pond ecosystem). | UPPSC GIC 2010 |
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| Food Chain Sequence | A typical sequence is: Grass → Goat → Humans. A marine food chain example: Diatoms → Crustaceans → Herrings. |
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| UP PCS Mains 2016, UPPSC Pre-2024 |
| Water Gradients | Pycnocline shows the density gradient of a water system. Halocline shows the salt gradient. Thermocline shows the change in temperature with respect to depth. | UP PCS Mains 2016, UPPSC Pre-2024 |
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| Nutrient cycling and crop pollination are examples of Supporting Services described by the Millennium Ecosystem Assessment. |
| Ecology Movements | "Ecology is permanent economy" is the slogan of the Chipko Movement. The movement was primarily against plant conservation/deforestation. | UP PCS Mains 2007, UP PCS Pre 2015 |
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| Conservation Strategy | Biosphere Reserves are the most important strategy for conserving biodiversity together with traditional human life. They aim to protect genetic variation. | UP Lower Spl Pre 2004 |
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| In-situ Conservation | Includes National Parks, Wildlife Sanctuaries, and Biosphere Reserves. Genetic diversity is maintained by this method. | UP P.C.S. Pre 2018 |
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| Ex-situ Conservation | Involves conserving organisms outside their natural habitat. Examples include Botanical Gardens, Zoological Parks, and Seed Banks. Liquid Nitrogen is used for storage (Cryo-Bank). | UP PCS Pre 2018, UP PCS Mains 2009 |
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