Environment and Ecology: Basics and Organization

Basics of Environment and Ecology

• The environment encompasses all living and non-living components, influences, and events surrounding an organism.
• Ecology examines the interactions between living organisms and their biotic and abiotic environment.
• Ecology studies the relationship between plants and animals and their physical and biological environment.

Levels of Organization in Ecology

• An organism is an individual living being capable of independent action or function; plants, animals, bacteria, and fungi can all be organisms.
• A population is a group of organisms, typically of the same species, that occupy a defined area within a specific time frame.
• A biological community includes all populations of different species living and interacting within a particular area or habitat.
• Such populations may include plants, animals, fungi, and microorganisms and are interdependent, affecting each other's survival and well-being.
• An ecosystem consists of a community of living organisms interacting with the environment, exchanging materials between them and the physical world.
• British ecologist Arthur Tansley first coined the term "ecosystem" in 1935.

Components of an Ecosystem

• An ecosystem comprises both abiotic and biotic components.
• Abiotic components consist of climatic factors, edaphic factors, and topography.
• Biotic components consist of producers, consumers and decomposers.

Functional Units of an Ecosystem

• Productivity refers to the rate of biomass production.
• Energy flow describes the sequential process through which energy moves from one trophic level to the next.
• Energy from the sun is captured by producers, transferred to consumers, and eventually to decomposers, before returning to the environment.
• Decomposition involves the breakdown of dead organic material, an activity that primarily takes place in the topsoil.
• Nutrient cycling involves the consumption and recycling of nutrients within an ecosystem, making them available in various forms for different organisms.

Biome Basics

• A biome is a large geographic area defined by specific climate conditions, plants, and animal life.
• Each biome possesses unique characteristics that dictate the types of plants and animals able to thrive in its environment.
• Forests, grasslands, tundra, deserts, and aquatic environments like oceans, rivers, and lakes are all considered biomes.

Biosphere Defined

• The biosphere is where life can exist on Earth.
• Atmosphere (air), Hydrosphere (water) and Lithosphere (land) integrate to create a highly interactive zone known as the biosphere.
• The Biosphere has a thickness of approximately 20 km.
• Most of the life on Earth exists between 500 meters below the ocean surface and 6 km above sea level.

Habitats

• A habitat is the place where an organism or community lives, including all living and nonliving factors.
• Microhabitat defines specific conditions and organisms in the immediate area surrounding a plant or animal.

Niche Defined

• A niche is a species' unique role or position within an ecosystem, including the physical and biological conditions for survival and reproduction.
• Temperature, humidity, light, soil type, and food availability describe a niche.
• Producers, consumers, and decomposers define an organism's niche and interactions within the ecological structure of the ecosystem.

Habitat vs Niche

• Habitat is the physical space occupied by an organism.
• A niche is the functional space occupied by an organism where it gets the resources needed to survive.

Types of Niches

• Niches come in three types: habitat niches, trophic niches, and multidimensional niches.
• A habitat niche is defined as the physical area of a habitat where a species resides.
• A trophic niche is a trophic level occupied by a species within a food or ecological chain.
• A multidimensional niche is a concept encompassing the fundamental niche and the limiting factors that affect it.
• The Fundamental niche is where an organism can exist without any ecological interactions.
• The Realized niche is where its population exists in the presence of interactions and competition.

Niche Overlap

• When 2 organisms share the same niche, it increases competition and lowers survival chances.
• The Gauss Law explains that if two species occupy the same niche, the competition will exclude one of them.
• The Galapagos Islands are a study on niche overlap and competition.

Competitive Exclusion and Resource Partitioning in Niche Overlap

• Niche overlap describes when species share portions of their ecological niche.
• Overlapping niches can cause competitive exclusion, where two species competing for the same resource cannot coexist with stable population sizes.
• Resource partitioning can reduce niche overlap, moving resources around to adjust niche size appropriately.

Ecotones

• An ecotone represents a transition zone joining two+ diverse ecosystems.
• Ecotones are biodiverse because edge effects exist.
• Examples of ecotones include marshlands, mangrove forests, grasslands, and estuaries.

Ecotone Characteristics

• An ecotone is a zone of tension.
• Ecotones are linear and show increasing species from one incoming community that decreases from the other outgoing adjoining community.
• Well-developed ecotones have organisms entirely different from those in adjacent communities.

Edge Effect

• The edge effect refers to changes in population or community structures at the boundary of two habitats.
• The number of species and the population density of some species is greater in the ecotone compared to either community, which is called the Edge Effect.
• Ecotypes are species that have adapted and can survive in areas with Edge Effects.

Ecotypes

• Ecotypes are a species which are genetically different from other populations of the same one, due to local conditions which have allowed the selection of unique physiological characteristics.
• Ecotypes are adapted to survive in an ecotone.
• A Royal Bengal Tiger, adapted to mangroves and being able to drink salt water, is an example of an ecotype.
• The Indian Rhino and Kharai Camel (Gujarat) are examples of Ecotypes.

Trophic Levels

• A trophic level represents energy flow in an ecosystem.
• A trophic level is the position an organism holds in a food chain and how it connects with other ecosystem members based on nutritional needs.
• A trophic level interaction involves Food Chain, Food Web and Ecological Pyramids

Energy Dynamics

• Just under 1% of sunlight is absorbed by plants.
• Photosynthetic organisms create 170 billion metric tons of food each year.
• Photosynthesis and respiration are the two main energy and food making processes that take place in life.

Producers

• Autotrophs make their own food
• Primary producers are green plants, certain bacteria, and algae.
• They produce carbs from carbon dioxide and water through photosynthesis, and sustain non-producers.
• On land, herbaceous and woody plants are producers but aquatic system producers are microscopic algae species.
• Phototrophs and chemotrophs are Producers.
• Primary producers are organisms performing photosynthesis include chlorophyll, combining carbon dioxide, water, and sunlight into sugar and oxygen.
• Chemotrophs use chemical reactions to make their food.
• Sulphur bacteria like thiobascillus does this.
• Carbon dioxide, water, hydrogen sulfide, and oxygen combine to form carbohydrates and sulfuric acid.

Consumers

• Heterotrophs are incapable of generating food through photosynthesis.
• Heterotrphs rely upon plants and or other animals.
• Macro and Micro are two groups of this type of species.

Macroconsumers

• Macroconsumers eat plants and/or animals depending on the food source.

Macroconsumer types

• Herbivores are primary consumers that mainly eat plants, such as rabbits and cows.
• Secondary consumers feed on primary consumers, such as wolves.
• Carnivores are secondary-consumer eaters and are tertiary consumers, such as wolves and lions.
• Omnivores eat animals and plants like monkeys and men.
• Scavengers consume the organisms that are decaying and or/ dead.

Detritivores (Microconsumers)

• Detritivores are bacteria and fungi, that get nutrients and energy through decomposition of decaying plant and and animal material.
• Detritivores consume minute particles of organic material that converts to inorganic nutrients.
• Nutrients from decomposition goes back to the ecosystem for producers to utilise them through recyling,
• Worms and soil organisms such as arthropods/nematodes decompose material and are detritus feeders

Aquatic Ecosystem Example

• Diatoms, phytoplankton and blue green algae are producers of the aquatic ecosystem.
• Small fish, zooplankton and crustaceans are primary consumers.
• Bigger fish, herrings and sharks are secondary consumers.

Defining Food Chains

• Food chains are an order of organisms where each one feeds on the last.
• Food chains involve transferring food energy via green plants (producers) to other organisms in a repetitious pattern of consumption.
• Arrows denote the unidirectional energy flow inside a food chain.

Food Webs

• A food web shows the interdependence of organisms in an ecosystem and tracks energy and nutrient flow from one organism to another.
• Food webs have nonlinear and multidimensional energy flow.
• More biodiversity and interactions make the food web more complex and stable.

Consequences of Food Web Collapse

• Food webs are interconnected in an ecosystem and collapse when interactions breakdown in an ecosystem or cannot function sustainably.
• Food web degradation is due to climate change, overuse by humans, los of key species, and pollution.
• Food web collapse leads to: loss of biodiversity, reduced activity and or collapse in an ecosystem.

Ecological Pyramids Defined

• Ecological pyramids are graphical depictions of trophic levels in an ecosystem.
• Each trophic level shows relative biomass and abundance, and how energy and nutrients pass thru a food chain/ecosystem.

The 10% Law

• Only biomass transfers from one trophic level to the next.
• Organisms convert energy to biomass, but not all energy is used.
• 10% of each trophic level's energy is available to the next level because only 10% goes to biomass.
• The amount of energy decreases quickly, so is due to the 10% rule.
• Heat creation and moving around consumes the majority of the lost energy.
• The 10 per cent Law was given by Raymond Lindeman

Pyramid of Energy

• The flow of energy in an ecosystem is graphically shown by the pyramid of energy.
• It is always upright.
• Available energy shrinks as the pyramid ascends from the 10% Rule.
• Energy is decreased by thermodynamics laws.
• A Food Pyramid shows energy flow in an ecosystem, and helps understand the importance of energy limits.
• Interaction is a simple way to show complex interactions and energy.

Biomass Pyramid

• A biomass pyramid is a graph displaying the amount of matter vs level in an ecosystem.
• Each level's representational has the most biomass at the base, with decreasing biomass at upper ones.
• It isn't a perfect shape, and is affect by size, and turnover rate of the creatures in the level and trophic level that it occupies.
• Aquatic has an inverted pyramid.
• Upright grass is a grassland ecosystem.

Inverted Biomass in bodies of water

• At one particular moment, low trophic biomass is lower than biomass at a higher thropic level, therefore there is an inverted level.
• Aquatic: phytoplankton in days are 2-3, Zooplankton in 7-8, fish at 15-20 and that of the shark at 10 years.

Pyramid of Numbers

• There is a depiction of the number of organisms in it and is the count of their trophic level.
• The number of people at each level is shown where it is shaped like a true pyramid.
• True pyramids feature huge base counts but exceptions may occur.

Bioaccumulation

• Bioaccumulation happens when substances such as pesticides, accumulate inside on organism in a gradual manner.
• This also happes if an organism absorbs at a rate quicker than it can be eliminated.

Food Chain Accumulation

• Mosquitos contaminate food chains after consuming micro plastics.
• Study proven beads in all states of mosquito development but decreased number as species developed.
• Platic travels if a flying insect spends time in water, and biomagnifies at high thrphic levels.

Biomagnification

• A build of DDT was seen this in fishes.
• If said fishes are consumed by another being, then it will increase at a successive trophic level and is called biomagnification.

Biomagnification Explained

• Bioamplification or biomagnification happens when a harmful thing amplifies into tissues at high levels in a chain.
• Can result from subsistence, chain energetic, or very little rates of degradation.
• Is water-insoluble.

How Biomagnification Occurs

• Long-lived, Mobile, and soluble in fat are properties in substances that increase bio magnification.
• Chlorinated hydrocarbons, inorganic compounds like mercury and pollutants have such properties.

Types of substances that demonstrate Bioaccumulation

• R. Carson wrote the silent Spring and her book mentions that DDT is harmful to eagles since it crushed their eggs - due to use of DDT against mosquitos.
• Minamata is due Mercury in shellfish, consumed to mercury poisoning for local populations.
• Borneo cats is explained in class.
• Indian Vulture Crisis occurred due to diclofenac.

Biotic Interactions

• Biotic events have interactions of one or another organism in different living entities of the ecosystem. Such organisms include both positive and negative in nature.
• Biotic interactions may affect composition, distribution or abundance of species when communities have ecosystems.

Mutualism

• Mutualism occurs if species and/ or interactions enhance and are beneficial.
• Mutualist highlights ecosystem interdependence