Ecology Notes PDF

The Biosphere: The biosphere consists of all of these different sections of the earth in one to support life, then using air from the atmosphere, land from the lithosphere, and water from the hydrosphere. Lithosphere(solid): The Lithosphere is earth’s solid outer layer, which is composed of earth's...

The Biosphere: The biosphere consists of all of these different sections of the earth in one to support life, then using air from the atmosphere, land from the lithosphere, and water from the hydrosphere. Lithosphere(solid): The Lithosphere is earth’s solid outer layer, which is composed of earth's crust and majority of the earth's mantle. Hydrosphere(liquids): The hydrosphere consists of all the water on earth. 97% of earth's water is salt water though Only 3% being fresh water, and only a fraction of that being accessible to us. Atmosphere(gases): The atmosphere is 500 km above the earth and is created by earth's gravitational pull on air molecules. It consists of 78% nitrogen N2 , 21% oxygen O2 and O3, and 1% by other noble gases but it is mostly carbon dioxide.​ Biotic factors A biotic factor is anything living and anything created by a living thing. Abiotic factors Abiotic factors are not alive and are the conditions of an ecosystem for example sunlight or wind or weather. What is an ecosystem? -​ An ecosystem is an area or region consisting of biotic and abiotic factors. The study of ecology is the relationship between these two factors -​ The earth, a province, one forest and even a dead log could be considered and ecosystem because they all have biotic and abiotic factors. Gaia hypothesis -​ The gaia hypothesis is that the earth behaves like a cell or organism that is goal is to achieve balance or otherwise homeostasis. Energy Flow: The source of all energy - The Sun -​ The suns emits radiant energy in two different ways​ - Visable rays: light energy - Invisible Rays: UV, Gamma, Infared Energy distribution -​ 70% of the sun's energy is converted into thermal energy (heat) - this warms the land and the oceans -​ 30% of it is reflected into space Types of energy ​ Radiant ​ Thermal ​ Light ​ Chemical ​ Electrical ​ Nuclear ​ Kinetic ​ Gravitational Chemical Energy: -​ All living organisms need energy in the form of a molecule called ATP, or adenosine triphosphate -​ It can be made by cells using sugars, fats and proteins -​ It is the fuel of the cell, needed to drive chemical reactions -​ ATP is the cell’s energy currency 1st law of thermodynamics: -​ Energy cannot be created or destroyed, only transformed from one form to another Converting Energy: -​ Producers: use 0.023% of the suns light energy and convert it into chemical energy (Sugars ---> ATP) -​ Consumers: must consume/eat other organisms for energy (sugars, fats, proteins ---> ATP -​ Ultimately the source of all energy is the sun -​ Note: it is the light energy of the sun that is being converted. Thermal energy provides heat but cannot be converted into chemical energy Terms: -​ Organisms that produce their own food using the sun's light energy are called Producers, or Autotrophs -​ Terrestrial producers = Plants -​ Aquatic Producers = algae and cyanobacteria, cyanobacteria releasing the oxygen into the earth for the the land to be habitable -​ They make their own food through photosynthesis -​ Organisms that cannot make their own food are called Consumers or Heterotrophs Photosynthesis: -​ Process in which the sun's light energy is converted into chemical energy -​ Organisms that can produce their own food don't need to eat -​ They use a specialized molecules called chlorophyll that captures light energy, this molecule also give plants its green pigment Light Energy -​ Carbon Dioxide Gas + Water ----> Sugar + Oxygen Gas -​ 6CO2 + 6H2O ----> C6 H12 O6 + 6O2 Light Energy -​ The producer uses its chlorophyll to absorb the sun's light energy to combine the low energy molecules like Carbon Dioxide and Water and turn them into a high energy compound like Sugar. -​ The sugar can then be converted and used and used for energy, structure, storage or growth -​ Importantly the excess oxygen the plant produces gets turned into Oxygen Gas that is sent into the atmosphere Cellular respiration: -​ Sugar ----> Carbon Dioxide + Water + Energy(ATP) O2 -​ C6H12O6 ----> CO2 + H2O + Energy O2 -​ Oxygen is used to combust a high energy molecule(Sugar) into low energy molecules (Carbon dioxide, Water) releasing energy that can be transformed and turned into ATP, the CO2 and Water is used for other things by the consumers Conclusion: -​ The sun is the ultimate source of energy -​ All producers use the sun's light energy and perform Photosynthesis and Cellular Respiration, because they use the sunlight to transform low energy compounds like water and carbon dioxide into high energy compounds like sugars and then they need to use CR to convert the high energy from the high energy compound like sugars into ATP -​ Consumers only do Cellular Respiration, because we get our sugar fats and proteins (high energy compounds) from eating other things, and we convert the high energy from the high energy compounds and convert it into ATP for our bodies. -​ These processes compliment each other Food Webs vs Food Chains: In a food chain it's just the energy traveled in one path, however in a food web it is all connected. Also think of the arrow as that going into the other stomach. Trophic Level: The trophic pyramid is just the order in which the producers are consumed, the primary consumer consumes the producer and the secondary consumer consumes the primary consumer. What human impact can do to the food chain: For example say humans start hunting the falcons at the top of the pyramid, the snakes would start to overpopulate because they have no predators, and because the snakes would start to overpopulate the, secondary consumers would start to be hunted down even more leading to them being underpopulated, the primary consumers becoming more populated because they have no predator, and the producers being underpopulated because there is too many primary consumers eating them. However with due time the pyramid will rebalance itself, however if a species is hunted to extinction the whole ecosystem will be permanently disrupted. BIOACCUMULATION & BIOMAGNIFICATION  -​ Bioaccumulation is the process by which animals ingest fat soluble chemicals throughout their lifespan. -​ Biomagnification is like accumulation, however for this one we are looking at the whole picture, for example if a grasshopper eats 3 grasses with 1g of pesticide in it, the grasshopper has now eaten 3g, but now when the frog comes and say it eats 3 grasshoppers, it now gains 9g and so on and so on. Harmful Fat Soluble Chemicals: CHEMICAL WHERE IS IT FOUND and HARMFUL EFFECTS -​ PCBs can be found in the soil, water and air and even in wildlife due to PCB contamination -​ PCBs can cause cancer and damage crucial systems in the body -​ PAHs can be found in fossil fuels, smoke from fires, and cigarette smoke PAH -​ PAHs are harmful to the bodies systems -​ Cyanide can be found in industrial processes like mining and plastic CYANIDE production -​ Some harmful effects of cyanide include respiratory failure  -​ Mercury can be found in human activities like coal combustion, and mining MERCURY -​ Mercury is toxic and can damage the reproductive systems of organisms -​ Lead can be found in paint, pipes, plumbing materials and batteries LEAD -​ Lead contaminants the water and makes it toxic for all organisms in large amounts Pyramids: Trophic Pyramids: Trophic level depicts the energy transfer between organisms, that consume one another, plants only absorb about 1% of the sun's energy, and from there on any organism that consumes another only gets about 10% of the energy, as the organism who had the energy to begin with needs to use 90% to stay alive.​ Biomass: Biomass is the total dry mass of an organism multiplied by the number of that organism in an ecosystem, in most land ecosystems producers usually have the most biomass, and the levels above it have a slightly lower and lower biomass going up. However in most aquatic ecosystems, this is usually reversed as the carnivores usually have the most biomass and the producers and herbivores have less, biomass is also measured in g/m2 Numbers: Pyramids just represent the number of the species in an ecosystem, it can also vary based on the ecosystem. Niche: A niche is the role that an organism fulfills in its environment as it interacts with both the biotic and abiotic components as well the conditions that it requires to fulfill those roles, some examples include habitat, or food. Biodiversity and Endangerment Levels: -​ Biodiversity​ The variety of life in a particular ecosystem, also known as biological diversity -​ Species Richness The number of species in an area -​ Extinct When a species no longer exists -​ Extirpated When a species no longer exists in an area -​ Endangered A species facing imminent extirpation or extinction -​ Threatened A species that is likely to become endangered if factors reducing survival rate continue -​ Special Concern A species that may become threatened or endangered because of a combination of factors -​ COSEWIC The committee that reports the status of different animal species in canada -​ RENEW The agency that prepared en action plan to ensure the recovery of a species Land To Mouth: This land to mouth graph depicts land required to make a meal of different types of substances and the trend of the graph is that it takes much less land to produce a meal of things that come directly from the ground rather than growing crops to feed animals to feed from animals. Different Cycles: Water Cycle: The sun evaporates water from the surface the water condensing into clouds and when there is too much of it rains which is called precipitation Nitrogen Cycle: In the nitrogen cycle the nitrogen from the atmosphere gets fixated using lightning, or nitrogen fixing bacteria it turning into NH3 and their nitrifying bacteria turning it into NO3, some of this NO3 assimilating into the roots of plants them absorbing it, some of the NO3 goes into denitrification bacteria though the nitrogen being sent back into the atmosphere. Animal waste can also go into the soil through ammonification and this animal waste gets turned into NO2 and the nitrifying bacteria turns it into NO3. Carbon Cycle: In the carbon cycle there are sources and sinks, some sources that put CO2 back into the atmosphere include combustion, combustion of fossil fuels, plant and and animal respiration, and organic decomposition, some sinks of CO2 include assimilation by plants and animals, assimilation into the soil, and the biggest sink of CO2 the ocean, the phytoplankton in there absorbing it. Invasive Species: Alien species are species brought to an ecosystem they do not belong in by either accident or on purpose, this may be beneficial or harmful, however the alien species that cause harm to an ecosystem are called invasive species, these species often have no predator in the area reproducing quickly, they cause harm by taking over habitats of native species, disrupt nutrient flow, and compete with other species for food. Example 1 Asian Carp: The asian carp is a voracious feeder, being able to grow to 40-50 kg, the consume large amounts of food muscling out native fish populations, when they reach a certain size then not having any predators. They were brought to the USA to control algae, plants and snails. Flooding allowed them to escape into the Mississippi river system, then also spreading to the Illinois river system, and threatening the great lakes right now. Example 2 Zebra mussels: Zebra mussels were first detected in the great lakes in 1988, arriving in the ballast water of a ship, the zebra mussels blocking pipelines, cutting peoples feet, they were also filter feeders containing high amounts of pollutants, passed on to predators Example 3 Purple Loosestrife: Purple Loosestrife was introduced from europe in the 1800s a ornamental plant, them invading the wetlands throughout eastern North America, choking out many native species, they also altered the wetland ecosystem for other species Limiting Factors: A limiting factor is a factor that limits the population of a species, it could be abiotic or biotic. Abiotic factors include: Light Water Nutrients Temperature Acidity Salinity Space Artificial Chemicals Note that many of these factors are resources a restricted amount could affect the population. Biotic Factors Include: Competition: This could be between species or even the same species but there is competition for everything, food, shelter, space, light, water, and even mates: Predation: There is alway going to be a predator in an ecosystem that limits the population of other species Cooperation: Some examples of cooperation include hunting in packs, caring for young and ill, grooming, and sharing childcare responsibilities. Lack of or too much cooperation can be a limiting factor. Mutualism +/+ In a mutualistic relationship between two species both species are gaining, for example pollinators/nectar, the pollinator being able to get the nectar from the flower as food and the flower getting its species pollinated more.​ Parasitism +/- In a parasitic relationship between two species one is gaining and the other is losing, the parasite either leeching off of the host, shortening its lifespan or injuring it. Commensalism In a commensalistic relationship one species is gaining, while the other is neutral, for example when a cow is eating grass a bird called an egret will eat the insects that were discovered in the grass. Carrying Capacity: Carrying capacity is the maximum number of a species that can be in one ecosystem. This image exceeds carrying capacity, due to there being not enough resources, like food, space and water. Some environmental factors that can affect carrying capacity in an aquatic environment include decreasing o2 supply, low food supply, disease, predators, and limited space. The carrying capacity might increase a little or decrease a little but the species will almost always go back to the carrying capacity. Carrying capacity is always written in a number in geographical location, for example “the carrying capacity of large fish in lake ontario is 8430.