Productivity and Biogeography of an Ecosystem PDF

# Productivity and Biogeography of the Ecosystem ## Topic Outline 1. Productivity of an ecosystem 2. Positioning ecosystems 3. Major climate drivers * Differential absorption of the sun's energy * Atmospheric circulation * Patterns of ocean circulation 4. Separating the globe into biom...

# Productivity and Biogeography of the Ecosystem ## Topic Outline 1. Productivity of an ecosystem 2. Positioning ecosystems 3. Major climate drivers * Differential absorption of the sun's energy * Atmospheric circulation * Patterns of ocean circulation 4. Separating the globe into biomes ## Learning Objectives After the discussion, students can: 1. Determine how scientists measure the productivity of an ecosystem 2. Distinguish between latitude and altitude 3. Understand the important climate influences 4. Identify terrestrial and aquatic biomes ## What determines the productivity of an ecosystem? ## Ecosystem Productivity The amount of energy available to support the organisms in an ecosystem. To quantify: measure the rate at which energy is stored in organic matter as a result of photosynthesis * Primary productivity * Secondary productivity ### Primary Productivity * **Gross Primary Productivity (GPP)** * Total rate at which energy is captured through photosynthesis * **Net Primary Productivity (NPP)** * Rate at which energy is stored in organic matter after accounting for respiration in plants * NPP = GPP - R ## Secondary Productivity Measures the rate at which energy is transferred from one trophic level to another. * **Biomass** - total mass of all living matter in a specific area * **Standing crop** - amount of biomass present in an ecosystem in a particular time * standing crop amount: productivity: rate ## Biogeography: how Earth's climate shapes global ecosystem patterns ## What is the difference between climate and weather? * **Climate** * Average weather that occurs in a given region over a long period, typically several decades. * **Weather** * Short-term conditions of the atmosphere in a local area (seconds to number of days). * **Climate conditions** * Ranges of temperature and moisture throughout the year. ## Major Climate Drivers 1. Uneven heating of Earth 2. Atmospheric circulation 3. Patterns of ocean circulation ## Differential absorption of the sun's energy 1. Sunlight hits the Earth at different angles in different places. 2. Earth is tilted on its axis. 3. Land, water, and ice absorbs heat differently. ## Earth tilted on its axis * The Earth's tilt and orbit create seasons. ## Albedo * Percentage of incoming sunlight that is reflected from a surface. * **High albedo** = more reflection = less absorption. * The average albedo of the Earth is around 31%, approx. 30% of sun's energy is reflected back into space. ## Uneven heating drives the circulation of air in the atmosphere ## Atmospheric circulation patterns 1. Convection cells 2. Prevailing winds 3. Orographic uplift ## Convection Cells * a.k.a. circular cells * **Convection** - transfers heat from one place to another through motion. * **Hadley cells** - low-latitude overturning circulations that have air rising at the equator and air sinking at roughly 30° latitude. ### Hadley Cells * Causes heavier rainfall near the equator. * Increasing heat near = increases the evaporation of water (water vapor). ## Coriolis Effect * Causes the movement of air to be slightly curved as a result of Earth's rotation. ## Prevailing Winds * Produced by a combination of atmospheric convection currents and rotation of Earth. * **Easterlies** - prevailing winds from the east (regions around the equator) * **Westerlies** - experienced prevailing winds in mid-latitudes (around 45° North and 45° South) * **Trade winds** - winds blowing east to west just north and south of the equator. * **Jet stream** - narrow, variable band of very strong winds in the upper troposphere. ## Orographic Effect * Impact of mountains on weather and climate, and is caused by air being forced to rise over high topography. * **Rain shadow** occurs when humid winds blowing inland from the ocean meet a mountain range. ## The movement of water through the oceans helps determine weather and climate conditions for different regions of the world. ## Patterns of Oceanic Circulation * Gyres * Upwelling * Thermohaline circulation ### Gyres * Large ocean currents that form circular patterns in the ocean basins. * **Coriolis effect and prevailing winds** * Moves surface water (cold) from poles to the equator (warmed) send it back toward the pole. * Play a role in the formation of storms and nutrient cycling. ### Upwelling * Occurs when surface currents along a coastline are replaced by deeper, colder water. * Deep water brings nutrients from the bottom of the ocean. * Commonly occurs on the west coast of continents. * Surface waters move toward the equator, replaced by cold water that moves up to the surface. ### Thermohaline Circulation * Part of the large scale ocean circulation driven by density gradients. * **Combined effect of temperature (thermo) and salt (haline)** ## Variations in climate determine Earth's dominant plant growth forms ## Biomes Region of the Earth with plant and animal communities that have adapted to a specific range of temperature and moisture conditions. * **Terrestrial** * **Aquatic** ## Terrestrial Biomes * Range of precipitation and temperature throughout the year determines the ecosystems on land. ## Aquatic Biomes * Aquatic biomes are strongly influenced by depth, or the distance they have from sunlight. * **Freshwater** - found on the continents, where water isn't salty. * **Marine** - defined by distance from the shore and depth from surface. * **Estuaries** - straddle regions between freshwater and saltwater. ## Freshwater Biomes * **Streams and Rivers** * Flowing; communities change based on how fast water is flowing and amount of dissolved oxygen (DO) Is In the water. * **Lake and Ponds** * Unmoving; ecosystem changes as distance from shore and surface changes. * Littoral zone: edge * Limnetic: middle * Benthic: profundal: decomposers * **Wetlands** * Anywhere land is saturated or submerged underwater for at least part of the year. * Swamps: trees; marshes: reeds and cattails. * **Estuaries** * Include those biomes along coastlines and in shallow seas. * **Salt marshes** * Where rivers enter a body of salt water. * Highly productive; habitat for fish. * Temperate regions. * **Mangrove swamps** * Found along coastlines in tropical regions. * Trees adapted to salt water. * Roots stabilize coastline by holding sediments in place, creating habitat for fish and birds. ## Marine Ecosystem * 'Zone' is used instead of biome when describing marine ecosystems. * **Intertidal Zone** * Along coastline; covered/uncovered by tides each day. * Organisms need to adapt to changes every day. * Conserve water * Attachment to rocks * Burrow into land. * **Pelagic Zone** * Including the entire ocean water column: outside coastal areas and beyond continental shelf. * **Euphotic zone (200m depth)**: Most sunlight penetrates; home to producers (phytoplankton), include mammals (whales, dolphins), fish. * **Bathyal zone (below 200m)**: less sunlight; disphotic zone. * **Benthic zone (seafloor)**: sand, silt, other sediments; dead organism from pelagic zone (nutrients); fungi, seaweeds, fish, and bacteria, worms, sea stars, and invertebrates * **Abyssal zone or aphotic zone**: no sunlight; organisms adapted to absence of sunlight; chemosynthesis (chemicals to energy) * **Coral Reef** * Farther out in the ocean; warm, shallow, tropical zone. * Most diverse. * Reef are made up of shells from tiny coral animals. * Health of the ecosystem depends on temperature, access to sunlight, and pH of the ocean waters. ## Assignment #2: Human's Impact on Biodiversity Choose a research article (2020-2024) that examines human impact on a specific biome. Summarize and analyze the effects on species, ecological, functional, and genetic diversity. * Make a 15-slide presentation (max), to be presented next class. Submit only the presentation to LMS. * Print the rubric and give it to the instructor before the presentation. * Posted on LMS under 'Biodiversity and Evolution' section. ## References * Fukai, D. T., Oaquim, A. B., & Cirano, M. (2021). How might the ocean change in the future? Frontiers for Young Minds, 9. https://doi.org/10.3389/frym.2021.700622 * Friedland, A., & Relyea, R. (2016). Essentials of Environmental Science (2nd ed.). W.H. Freeman and Company. Libretexts. (2021, February 15). 8.12: Earth's atmospheric circulation system. Geosciences LibreTexts. https://geo.libretexts.org/Bookshelves/Oceanography/Oceanography 101 (Miracosta)/08%3A Atmospheric Circulation/8.12%3A _Earth's_Atmospheric_Circulation_System * Miller, G. T., & Spoolman, S. E. (2014). Environmental Science (15th ed.). Cengage Learning. * Spooner, A. (2023). Environmental Science For Dummies (2nd ed.). John Wiley & Sons, Inc. * World Health Organization. (n.d.). El Niño Southern Oscillation (ENSO). World Health Organization. https://www.who.int/news-room/fact-sheets/detail/el-nino-southern-oscillation-%28enso%29#:~:text=El%20Niño%20Southern%20Oscillation%20(ENSO)%20is