APES - Core Content Recall for Unit #1 - The Living World: Ecosystems (1.1-1.7)

Individual

One individual organism (ex. 1 elk)

Population

Group of same-species organisms (ex. herd of elk)

Community

All living organisms in an area--all biotic factors in an ecosystem.

Ecosystem

All abiotic and biotic factors

Biome

Large area with similar climate conditions (temperature and precipitation) that determine the plant and animal species present.

Competition

Organisms fighting over a resource, such as food/shelter, reduce population size since few resources available, meaning fewer organisms may survive. Both lose!

Resource Partitioning

Different species use same resource in different ways to REDUCE competition, favored by evolution. Reduces dirrect competition, allowing different species to thrive and grow population sizes as they are not directly competing.

NOTE: Different species DO NOT MEET to discuss how they use the resources; evolution favors traits that allow different species to use the same resource in slightly different ways.

Temporal Resource Partitioning

Different species use the same resources at DIFFERENT TIMES.

Ex. Wolf and Coyotes hunting at different times (night vs. day).

THINK: "Different Species → Different Times"

Spatial Resource Partioning

Different species use different areas of a shared resource.

Ex. Different species of the Warbler bird occupy different areas of the tree.

THINK: "Different species → Different Area of Shared Resource"

Morphological Resource Partioning

Different species that hunt for the same resource (ex. prey) will evolve slightly different body/morphological features to utilize different portions of the same resource.

Ex. Ferret and Irvine have different jaw and tooth sizes → hunting different-sized prey; not competing directly for the exact same resource.

Predation

(+/-) One organism uses another organism as an energy source. "One wins, the other loses!"

Ex. Hunters, Predators, Herbivores.

Herbivores

Plant eaters (Ex. Giraffe eating tree)

Technically, they practice predation since an animal is eating another living thing (plant).

Carnivores

Meat eaters; true predators--killing and eating prey for energy (Ex. Leopard & Cheetah).

Parasites

Uses a host organism for energy, often without killing the host and often living inside the host. The parasite organism benefits at the cost of the host's suffering.

Ex. Mosquitoes, Tapeworms, Sea lamprey

Ex. of Parasitic Relationship: Ticks & Mammals -- Ticks attach themselves to the host's skin and feed on its blood, deriving nutrients at the host's expense. The host may experience irritation, blood loss, or even diseases like Lyme disease transmitted through the tick's bite.

Parasitoids

Specific type of parasite; lays egg inside host organisms; once eggs hatch, the larvae will eat their way out of the host organism (killing the host organism, most of the time) for energy.

Symbiosis

Any long-term, permanent interaction between two organisms of DIFFERENT species. Mutualism (+/+), Commensalism (+/0), and parasitism (+/-) are all symbiotic relationships.

Mutualism

(+/+) Both species benefit from relationship (ex. coral reef + photosynthetic algae) "win-win for both!"

Commensalism

(+/0) One species benefits; other species isn't affected (ex. birds and trees).

Parasitsm

(+/-) One species benefit (the parasite) at the cost of the host suffering. Parasites use a host organism for energy, often without killing the host and often living inside the host. The parasite organism benefits at the cost of the host's suffering. (ex. ticks and mammals)

Defining Characterstics of a Biome

Temperature and Precipitation

Climate

Combo of average temperature and precipitation trends over a year

Nutrient Availability

Availability of nutrients in a biome. Nutrient Availability ultimately determines what plants and animals (organisms) can survive in the biome.

Shifting Biomes

Biomes shift in location on Earth as the Climate Changes.

Ex. Warming Climate (Global Warming) will shift Boreal Forests further north (increasing northern latitude) as Tundra permafrost soil melts and lower latitudes become too warm for Aspen and Spruce Trees

Tundra

Very cold, very little precipitation

Upper Canada, Upper Russia, Arctic Circle

Flora: Small woody shrubs, mosses, heaths, lichen

Fauna: Muskoxen, Arctic Foxes, Polar Bears

Taiga / Boreal Forest

Cold climate, low precipitation, nutrient-poor soil

Between ~50-60°N in Europe, Russia, and North America

Flora: Coniferous Trees (Pine, Spruce, Fir), Deciduous Trees (Birch, Maple, Aspen)

Fauna: Beavers, Brown Bears, Wolverines

Temperate Rainforest

Temperate Climate (annual temperatures between 5°C and 20°C, or 41°F-68°F), high precipitation. Relatively mild summers and winters—winters: rainy; summers: foggy.

Nutrient-poor soil

Mid-latitudes—West Coast of North America, Southern Chile, East Coast of Australia, Tasmania, West Coast of New Zealand

Flora: Coniferous Species (Fir, Spruce, Cedar, Hemlock), Coastal redwoods, ferns, mosses

Fauna: Black-tailed deer, Pacific giant salamander, Pacific treefrog

Temperate Seasonal Forest / Temperature Deciduous Forests

Warm summers, and Cold winters, over 1M (39 in.) of annual precipitation

Nutrient-rich soil.

Eastern US, Japan, China, Europe, Chile, and Eastern Australia

Flora: Broadleaf Deciduous Trees (Beech, Maple, Oak, Hickory), some Coniferous Trees

Fauna: White-tailed Deer, Red Foxes, Gray squirrels

Shrubland / Woodland / Chaparral

Shrubland / Woodland / Chaparral

Summer: Hot & Dry—high temperatures, low precipitation Winter: Mild, Rainy—low temperatures, high precipitation

Nutrient-poor soil; plant growth constrained insufficient precipitation in summer and cold temperatures in winter

Southern California, Southern South America, Southwestern Australia, Southern Africa, Mediterranean

Flora: Plants resistant to fire & drought due to significant occurrence of wildfires & drought—yucca, scrub oak, and sagebrush

Fauna (in North America): California Quail, Black-tailed jack-rabbits, Southern pacific rattlesnakes

Temperate Grassland / Cold Desert

Summer: Hot & Dry Winter: Cold, harsh Plant growth constrained insufficient precipitation in summer and cold temperatures in winter—amount of rainfall determines what plants survive in this region

Nutrient-rich soil

Great Plains of North America (prairies), South America (pampas), Central Asia & Eastern Europe (steppes)

Flora: Grasses, nonwoody flowering plants

Fauna: Bison, Greater prairie Chickens, prairie kingsnake

Tropical Rainforest

Temperatures greater than 20°C (68°F)

Warm and Wet Biome between 20°N & S of Equator, frequent precipitation—seasonal patterns in precipitation Warm temperatures & abundant rainfall,

Nutrient-poor Soil; MOST BIODIVERSE: HIGHEST PRIMARY PRODUCTIVITY & NPP

Central and South America, Africa, Southeast Asia, Northeastern Australia, Large tropical islands

Flora: Tropical trees, epiphytes (plants that hold small pools of water supporting small aquatic ecosystems above the forest floor), woody vines (aka lianas)

Fauna: jaguars, orangutans, red-eyed treefrogs

Savanna / Tropical Seasonal Forest / Tropical Deciduous Forests

Warm temperatures, distinct wet and dry seasons Summer: Most precipitation

Central America, Atlantic coast of South America, Southern Asia, Northwestern Australia, sub-Saharan Africa

Large grazing animals, several species of gazelles & zebras, large predators (African lions and cheetahs)

Hot Desert / Subtropical Desert

Located at 30°N and 30°S Hot temperatures, extremely dry conditions, sparse vegetation

Mojave Desert in Southwestern US, Sahara in Africa, Arabian Desert of the Middle East, Great Victoria Desert of Australia

Flora: Cacti, euphorbia plants, succulent plants

Fauna: Multiple species of tortoises, Camels, roadrunners

Characteristics of Aquatic Biomes

Salinity, Depth, Flow, Temperature

Salnity

Amoujnt of salt present in body of water; determines which species can survive & usability for drinking water

Depth

Influences how much sunlight can penetrate and reach plants below surface for photosynthesis

Flow

Movement of water; determines what plants and organisms can survive and how much dissolved oxygen is in the water.

Temperature

Very important--the warmer the water gets, the less dissolved oxygen is present, which results in fewer aquatic organisms.

There is an inverse correlation between temperature and the amount of aquatic organisms, as there is a direct correlation between the amount of dissolved oxygen and the amount of aquatic organisms.

↓Amount of Dissolved Oxygen = ↓Amount of Aquatic Organisms

↑Temperature = ↓Amount of Dissolved Oxygen

↑Temperature = ↓Amount of Aquatic Organisms

Freshwater Rivers and Lakes

Rivers have high dissolved oxygen due to flow mixing water and air, which carries nutrient-rich sediments. Thus, deltas and floodplains contain very fertile soil. This freshwater biome is characterized by fast-flowing water that can originate from underground springs or runoff, which carries sediment and organic material.

Lakes serve as standing bodies of fresh water, being a key drinking water source.

Different zones of Body of Water

littoral, limnetic, profundal, benthic

Littoral Zone

Shallow water with emergent plants (ex. Reeds, Cattails). Roots embedded in bottom of body of water but most of the plant extends out of the water.

Limnetic Zone

Where light can reach plants, photosynthesis occurs here, no rooted plants--only phytoplankton

Profundal Zone

No photosynthesis, too deep for sunlight

Benthic Zone

Murky botom where bugs reside, nutrient-RICH sediments due to containment of organic materials

Wetland

This biome contains a nutrient-rich environment created by falling leaves and trapped organic materials from the large trees, and it provides the ecosystem service of filtering pollutants from water. Area with soil submerged/saturated in water for at least part of the year, but shallow enough for emergent plants.

Emergent plants

Plants with roots in the soil are saturated with water, but the majority of plants extend outside of the water. These plants must be adapted to living with roots standing in the water as most would die due to lack of oxygen, being submerged in water.

Benefits of Wetlands

Stores excess water during storms, reduces damage of flooding.

Rechrges groundwater by absorbing rainfall into soil

Roots of wetland plants filter pollutants from water draining through.

High plant growth due to lots of water and nutrients (dead organic matter) in sediment.

3 types of Wetlands

Swampes (Cypress trees), Marshes (Reeds and Cattails), and Bog (Extemely Acidic Soil, Spruce Trees and Sphagnum Moss)

Estuaries

Areas where rivers empty into the ocean. Mix of freshwater and saltwater → species must adapt to this.

High productivity due to nutrients in sediments deposited in estuaries by river.

2 types of estuaries: Salt Marsh & Mangrove Swamps

Estuaries: Salt Marsh

Estuary habitat along coast in temperate climates. Serves as breeding ground for many fish and shellfish species.

Estuaries: Mangrove Swamp

Estuary habitat along the coast of tropical climates. Mangrove trees with long, stilted roots stabilize the shoreline, providing the habitat for many species of fish and shellfish.

Coal Reef

Warm shallow waters beyond the shoreline; MOST DIVERSE (HIGHEST BIODIVERSITY) MARINE BIOME ON EARTH.

Mutualistic relationship between coral and algae, as both species rely on reach other since coral cannot survive without energy from algae and the algae need home of reef and carbon dioxide.

Intertidal Zones

A Narrow band of coastline between high and low tide.

Organisms must be ADAPTED to survive crashing waves and direct sunlight/heat during low tide

Ex. Barnacles, Sea stars, and Crabs that can attach themselves to rocks in the intertidal zones, so they don't go out with the waves

Open Ocean

Low productivity area as only algae and phytoplankton can survive in most of the ocean. The ocean is too deep for most plants to survive. Large biome where algae and phytoplankton produce a significant amount of Earth's O2 needed for human survival and absorbs a significant amount of atmosphere CO2.

Zones in Open Ocean

Photic Zone - Photosynthesis can happen here

Aphotic Zone (Abyssal) - NO photosynthesis as the area is too deep for photosynthesis. Organisms that reside in the Abyssal zone require adaptations such as bioluminescence (allows them to glow to provide a source of light for navigation purposes) and the ability to withstand high pressures due to the amount of water in the abyssal zone.

Importance of Carbon

20% of organism's total body weight, found in every biological macromolecule, few molecules in bodies of organisms lack Carbon (ex. water).

Processess of the Carbon Cycle

Photosynthesis, Respiration, Exchange, Sedimentation, Burial, Extraction, Combustion

Fast-moving aspect of Carbn Cycle

Processes involved with living organisms that hold Carbon for a short period of time - Respiration & Photosynthesis, Exchange of Carbon Dioxide between Air & Water, Combustion of Organic Carbon → Carbon Dioxide Released into Atmosphere

Slow-moving aspect of Carbon Cycle

Carbon is held in rocks, soils, and petroleum hydrocarbons (material used for fossil fuels).

May be stored in these forms for millions of years.

Carbon Cycle Reservoirs

Largest: Ocean

Long-term Storage: Fossil Carbon Pools, Carbonate Rocks

Smaller, More Active Pools: Atmosphere and Biota

Photosynthesis

Performed by plants and algae--Solar energy is used to convert Carbon Dioxide and Water → Glucose & Oxygen

Portion of energy consumed by herbivores (primary consumers) and predators of those herbivores (secondary consumers/carnivores).

Respiration

Organisms return a portion of their Carbon in the form of Carbon Dioxide when Aerobic Respiration is used.

More Carbon is returned when organisms die as the Carbon part of the alive biomass reservoir → dead biomass reservoir, broken down by decomposers → return of Carbon Dioxide to water or air via respiration, continuing the cycle.

Exchange

Carbon is exchanged between the atmosphere and the ocean.

Amount of Carbon released from Ocean into Atmosphere = Amount of Atmospheric Carbon Dioxide diffused into ocean water.

Some Carbon Dioxide dissolved in ocean enters food web via photosynthetic algae.

Sedimentation

Carbon dioxide dissolved in the ocean combines with the calcium ions in the water to form Calcium Carbonate (CaCO₃). This compound precipitates out of the water, forming limestone and dolomite rock via sedimentation.

Sedimentation is a very slow process as small amounts of Calcium Carbonate sediment have been accumulated over millions of years, forming largest Carbon reservoir in slow aspect of Carbon cycle.

Burial

Small amount of Organic Carbon in dead biomass reservoir has been buried and incorporated into ocean sediments prior to decomposition to its constituent elements.

Organic matter gets fossilized and over millions of years may form fossil fuels.

The amount of Carbon removed from the Food Web = Amount of Carbon returned to the atmosphere via weathering of Carbon-containing rocks (ex. Limestone) or via Volcanic Eruptions.

Extraction

1 of 2 final processes of the Carbon Cycle.

Extraction of Fossil Fuels by humans is a relatively recent phenomenon in the context of history, starting when humans began relying on coal, oil, and natural gas as energy sources. Extraction does not alter the Carbon Cycle, but rather the Combustion that happens afterwards affects the cycle

Combustion

Final process of Carbon Cyce.

Caused by humans or natural combustion of Carbon via fires or volcanoes, causes the release of Carbon into the atmosphere as CO2 or into the soil (as ash). Burning of Carbon.

Human Impacts on Carbon Cycle

1) Formation of Greenhouse Gases due to increased usage of fossil fuels, disrupting the natural equilibrium of the Carbon Cycle. Since the Industrial Revolution, the burning of fossil fuels (combustion) has caused more Carbon to enter the atmosphere at a greater rate than carbon leaving the atmosphere through sedimentation and burial processes → carbon concentrations increased, upsetting balance/equilibrium between Earth's carbon reservoirs and atmospheric reservoir.

2) Tree-Harvesting: Trees store large amount of Carbon in wood, above and below ground. Deforestation of forests by cutting and burning increases amount of CO2 in atmosphere.

Importance of Nitrogen

Found in proteins and nucleic acids - biological macromolecules.

Acts as a limiting nutrient for plants and algae.

Limiting Nutrient

A nutrient required for the growth of an organism, but available in a smaller quantity than other nutrients. The presence of limiting nutrient constricts growth of plans and algae.

Largest Reservoir of Nitrogen - Nitrogen Cycle & Nitrogen Gas

The Atmosphere is the largest reservoir of Nitrogem, as the atmosphere is 78% Nitrogen by volume. However, this nitrogen is primarily stored in the form of Nitrogen Gas (N₂), making it unusable for plants and algae.

Nitrogen Fixation

Process converting atmospheric Nitrogen Gas (N₂) into usable forms of Nitrogen. Can be done via abiotic or biotic processes.

Biotic processes convert N₂ to ammonia (NH₃).

Abiotic processes convert N₂ to Nitrate (NO₃⁻).

Biotic process of Nitrogen Fixation

Few species of bacteria convert Nitrogen Gas (N₂) into Ammonia (NH₃) and then rapidly convert into Ammonium (NH₄⁺)--a form readily usable by plants.

Nitrogen-fixing bacteria include cyanobacteria, and certain bacteria residing within the roots of legumes (peas, beans, few species of trees).

Nitrogen-fixing organisms use fixed nitrogen to synthesize their own tissues, then excreting any excess fixed nitrogen. Cyanobacteria excrete excess fixed nitrogen into water, which is taken up by aquatic plants and algae.

Nitrogen-fixing bacteria living within plant roots excrete excess ammonium ions into plant root system--plant supplies nitrogen-fixing bacteria with sugars produced from photosynthesis.

Abiotic processes of Nitrogen Fixation

1) Lightning and Combustion Processes: Nitrogen Gas can be fixed in the atmosphere via lightning or combustion processes, converting Nitrogen into Nitrate (NO₃⁻), which is carried to the Earth's surface.

2) Synthetic Nitrogen Fixation: Techniques developed by humans for nitrogen fixation into Ammonia (NH₃) or Nitrate (NO₃⁻) to be used in plant fertilizers.

Requires a significant amount of energy. Humans now fix more nitrogen artificially than the amount of nitrogen fixed naturally. Development of Synthetic Nitrogen Fertilizers results increased crop yields (notably: corn).

Nitrification

Nitrifying bacteria convert Ammonium (NH₄⁺) into Nitrite (NO₂⁻) and then into Nitrate (NO₃⁻).

Assimiliation

Plants and algae take up either ammonium (NH₄⁺) or Nitrate (NO₃⁻). Herbivores assimilate nitrogen by eating plants and algae.

Ammonification/Mineralization

Decomposes in soil and water break down biological nitrogen compounds into Ammonium (NH₄⁺).

Denitrification

In a series of steps, denitrifying bacteria in oxygen-poor soil and stagnant water convert nitrate (NO₃⁻) into Nitrous Oxide (N₂O) and eventually Nitrogen Gas (N₂).

N₂

Nitrogen Gas

NH₃

Ammonia

N₂O

Nitrous Oxide

NH₄⁺

Ammonium

Human Impacts on the Nitrogen Cycle

Nitrogen serves as a Limiting Nutrient so excess amounts of Nitrogen can have drastic impacts on an ecosystem.

Adding nitrogen to soils in fertilizers increases atmospheric concentrations of nitrogen in the area fertilizer is applied.

Nitrogen may be transported through atmosphere, being deposited by rainfall in natural ecosystems where they have adapted over time to a specific level of nitrogen availability.

Can alter distribution/abundance of species in those ecosystems.

Reservoir

Components of biogeochemical cycle that contain the matter—air, water, and organisms

Source Reservoir

LEAVE - Where atoms and molecules LEAVE a reservoir.

Sink Reservoir

ENTER - Where atoms and molecules ENTER/GET STORED in the reservoir--absorbing more than it releases

Importance of Phosphorus

Used in many biological processes, acts as a limiting nutrient in plants, aquatic ecosystems, and terresterial/freshwater ecosystems

Main reservoir of Phosphorus Cycle

Rocks and Sediments comprised of minerals containing phosphorus

Impact of Phosphorus Lacking a Gas Phase/Direct Atmospheric Component

Due to having no gas phases, there is limited movement of Phosphorus from the ocean back to to Terrestrial and Freshwater environments, which causes Phosphorus to act as a limiting nutrient in terrestrial and freshwater environments.

Does phosphorus change form often?

Nope.

The Phosphorus Cycle

Movement of phosphorus around biosphere among reservoir sources and sinks.

Assimilation and Mineralization in the Phosphorus Cycle

Steps 1-2 of the Phosphorus cycle.

Inorganic phosphorus is taken up by plants and animals, assimilating phosphorus into their tissues as organic phosphorus.

INITIAL: Inorganic Phosphorus

LOCATION: Tissue system of Plants and Animals

OUTPUT: Organic Phosphorus

Waste products and eventual dead bodies of these organisms decomposed by fungi and bacteria, causing mineralization of organic phosphorus into inorganic phosphorus. Organic Phosphorus → Inorganic Phosphorus.

Sedimentaton in the Phosphorous Cycle

Step 3 of Phosphorus Cycle. Abiotic processes of the Phosphorous Cycle, resulting in movements between water and land. Phosphorus is not very soluble in water, which causes phosphorus to precipitate out of the solution in the form of phosphate-laden sediments in the ocean.

Geologic Uplift

Step 4 of the Phosphorus Cycle. Phosphate-laden sediments lifted by geologic forces, forming mountains.

Weathering in the Phosphorus Cycle

Phosphate rocks in the mountains are slowly weathered by natural forces (ex. Rainfall). Causes phosphorus to be brought to terrestrial and aquatic habitats.

Why is phosphorus a limiting nutrient in Aquatic Systems?

Soils tightly hold phosphorus → phosphorus not easily leeched into water bodies from soil + significant amounts of phosphorus precipitate out of solution → ittle dissolved phosphorus natural present in streams, rivers, and lakes

Human Impacts on the Phosphorus Cycle

Mining to produce fertilizer, Eutrophication, Altering Plant Communities

Brief Summary of Eutrophication

Increased phosphorus and nitrogen → algal bloom, increasing algae levels → as algae die, a lot of oxygen is used → formation of hypoxic environments → dead zones → lack of life in area

Main Reservoirs of Water Cycle

Oceans, polar ice caps and glaciers, soil

The Hydrologic Cycle

Movement of water across biosphere among reservoir sources and sinks

What is the driving force behind the Hydrologic Cycle?

Heat from the Sun