Introduction to Ecology

Introduction to Ecology Ecosystems include Abiotic Factors Abiotic Factors: Things that have never been alive. Examples of Abiotic Factors:       Energy Nutrients Wind Temperature Water Fire Biotic Factors: Things that are alive and or part of living things such as wood or shells. Abiotic Environmental Factors: Atmosphere: This is divided into many levels:     Troposphere: It is where we both live and where weather occurs. Temperature decreases as elevation increases. Stratosphere: The ozone layer is in this layer of the atmosphere and helps absorb the UV radiation and heat from the sun. Temperature increases as elevation increases. Mesosphere: Coldest layer of the atmosphere. Anything coming from space burns up in this layer. Thermosphere/Ionosphere: This is the warmest layer of the atmosphere because of the gamma radiation and UV rays. This is also where the aurora borealis or aurora australis (occurs in the southern hemisphere) Weather vs Climate: Weather: The short-term conditions of the atmosphere at a current time and in each place and is influenced by the movement and transfer of heat energy. This can further influence things such as wind patterns, cloud cover, temperature, air pressure, etc. Climate: The total of all weather occurring over a period of year in each place. Many factors go into affecting climate and they can be too numerous to list. Factors that can affect climate:   Air Masses: Large bodies of air that has similar temperature and moisture content and can be defined by: Equatorial, Tropical, Polar, Arctic, Continental, Marine Air pressure: Decreases with altitude (99% within 20 miles of the Earth’s surface) o Low Pressure fronts: Produces cloudy stormy weather. o High pressure fronts: Contains cool, dense air that drops to the surface and becomes warmer and is commonly associated with fair weather.                 Bond Albedo: The fraction of solar radiation reflected into space and is affected by composition of the atmosphere, surface color, clouds. Things like the ice caps have high reflectivity and things like the dark oceans have a lower reflectivity. Altitude: Every 1000 ft rise in elevation there is a 3 oF drop in temperature and for every 300 ft, there is a shift in the climate and biome to be more like something that is 62 miles north of the current location Angle of sunlight: Areas of the earth closest to the sun receive more direct sunlight which leads to a higher temperature vs the more indirect sunlight rays that are there as you move away from the equator and that leads to lower temperatures. Clouds: Collection of water droplets or ice crystals suspended in the atmosphere. Clouds can help reflect sunlight during the day and at night they can keep in heat radiating from the Earth at night. Proximity to the Ocean: Oceans are thermally more stable than land and the further inland the more extreme the temperature ranges. Greenhouse effect: Water, Carbon dioxide, and methane can trap in the heat. Without the effect, the earth would be too cold to live on and with it and too much of the gases can lead to the earth being too hot. Heat transfer: o Convection: Primary way that heat is transferred from the hotter to colder regions of the planet and is the primary determinant of weather patterns on the planet o Conduction: Involves the transfer of heat through a substance that results from different temperatures in different parts of a substance. Land mass distribution: Oceans absorbed more solar heat than the land masses. Earth receives more solar radiation at lower latitudes than at higher latitudes. Latitude: Higher latitudes= less solar radiation= cooler climate vs Lower latitudes= more solar radiation= hotter climate Moisture content (Humidity): o Atmosphere water vapor: Provides moisture for clouds and rain, acts like a greenhouse gas keeping the Earth warm, primary determinant of plant growth, and dew point is the point in which condensation takes place. Mountain Ranges: Forces air masses from a lower elevation to a higher elevation, the air masses expands and cools as it rises, condenses as it rises raising the humidity and releases rain on the windward side of the mountain, and the leeward side gets less rain and creating a different environment or biome. Pollution: Greenhouse gases from human sources -> Increase in global temperatures Precession: The wobble in the earth on its axis o Changes in pression -> changes in the amount of sunlight that the Earth receives -> atmospheric changes. The Earth’s Rotation affects the day/ night cycle. Solar Output: The Sun’s output varies on an 11-year cycle. o More energy released leads to warmer earth and less a cooler planet. Wind Patterns: Caused by an uneven heating of the Earth’s atmosphere. Causes pressure differences that sets up a convection current and create air cells. o   Coriolis effect: Once an air mass is set in motion (by pressure gradients), it undergoes an apparent deflection from its path due to the rotation of the earth. At the equator this is not in effect. This causes the trade winds around the globe that were big in the age of sails. Atmospheric circulation cells o Hadley air circulation cells: Air heated at the equator rises and expands north and south and the moisture that air has is dropped near the equator. o Ferral air circulation cells: Develop between 30 o N/S, allow for milder latitude Climates have severe winters and cool summers, defined seasons. o Polar air circulation cells: Ice dry air from the poles meet the moist tropical air from the mid latitudes, air returns to the poles cooling and sinking causing precipitation but this precipitation is ice or snow not rain. o Hurricanes: aka cyclones, typhoons: most severe weather on the planet and happens when warm ocean air collides with the trade winds and the cyclone flow happens because of the Coriolis effect Monsoons: Strong violent winds that changes directions with the seasons, blow from land to the sea in the winter and the sea to the land in the summer which brings lots of rain to land o Normal state: water circulation easterly trade winds move water and air warmed by the sun to the west. o El Nino: Air pressure in the southern Pacific changes direction and that reverses the trade winds-> pushes the thermocline deeper and decreases upwelling resulting in a shift in the prevailing wind patterns. o La Nina: The trade winds become stronger and that increases upwelling creating dry weather. Oceans   Many factors affect the oceans. o Upwelling: Happens in the oceans where cold, nutrient-filled water rises to the surface when the warm, oxygen-filled water moves away from the shore via winds o This is different from turnover in lakes and ponds in which there is seasonal change and mixing because of the seasons. Areas of the ocean o Epipelagic: Called a photic zone where most photosynthesis in the ocean occurs and is away from the shore o Mesopelagic: twilight zone where some photosynthesis occurs but not tons o Bathypelagic zone: No photosynthesis occurs and relies on the upper zones for some of the nutrients. o Abyssopelagic o Hadal zone: The trenches where there is extreme pressure and no light and so lots of organisms that are autotrophs use chemosynthesis to develop food. o Thermocline: A steep temperature gradient in a body of water marked by a layer above and below which the water is at different temperatures Plate tectonics  Volcanic aerosols o Sulfur ejected into the stratosphere warms the stratosphere and cools the troposphere. o Can destroy ozone. o Carbon dioxide- greenhouse gas o Increased iron-> increased biological activity-> increases the uptake of CO 2 and cools the planet. o Can trigger El Nino Microclimates: Small areas that have different conditions than the overall area. Examples: Different sides of a mountain, under trees and rocks, burrows Biomes Marine and Aquatic Biomes   For marine biomes (biomes in the ocean) the two main factor that affect them are: Depth and distance from shore. Salinity is the main factor for both Marine and Aquatic biomes: biomes where water is a large factor. o Measured in parts per thousand.  Freshwater: 0-.5 PPT  Intermediate/Brackish: .5-30 PPT  Marine/Saline: 30-50 PPT  Brine: 50+ PPT Different Aquatic Biomes: Biomes in water    Lake and Ponds o Standing water and forms at a low point in elevation o Features of a lake or pond  Limnetic zone: Open water  Littoral zone: Edge zone, plants can root there.  Benthic zone: Bottom  Euphotic zone: region light penetrates. o Ponds are more temporary than lakes. Rivers and Streams o Moving water from a source zone to the transition zone, and can end in a flood plain zone, which is flatter land. o Always flow from high elevation to low elevation o Deltas are where either the river flows into the ocean or the river just ending leading to sediment depositing. Wetlands o Anywhere water fills the ground and oxygen is depleted and oxygen-free processes occur instead. o Water is present permanently or seasonally. Intermediate aquatic biomes   Intertidal zone o Areas along the shoreline that experience different conditions due to the tides. Estuaries o River to marine transition zone Deep Marine Biomes         The different zones as mentioned previously. Coral Reefs Kelp Forests Open Ocean Deep Sea Hydrothermal vents o Areas of the ocean where water and minerals are released because of volcanic activity. o Different diverse communities spring up around chemosynthetic bacteria. Ice floes o They bind to the underside of the ice and have algae and bacteria to create the basis of many food chains. Temporary ecosystems o Whale falls o Wood falls Terrestrial Biomes: Biomes on Land Main influencing factor: Temperature and Precipitation and typically named for the main vegetation in the area.       Polar Ice o Permanent Ice, Permafrost- frozen ground, seasonal ice, o Cold desert with very little liquid water o Have 30 days of straight day in the summer and 30 straight nights in winter. Tundra o Above 60o N or S which overlaps with the polar ice. o Dry, cold, windy Temperate Grassland o Between 30o N or S o Seasonal droughts, wide variation in temperature, and dominated by grass. Tropical rain forests o Between the 30o N and S o Lots of heat, rain, and diversity in the life Chaparral o Around 30o N and S o Coastal, hot dry summers, and wet winters Savanna    o Located between 30o N and S o Between forests and deserts vegetation- wise, long dry summers and wet summers Coniferous Forests/ Taiga/ Boreal/ Snow forests o Located around 60o N o With about 130 of frost-free growing in summer, but has long cold, snowy winters Temperate Broadleaf Forests o Between 30o N/S and 600 N/S o Warm rainy climate with heavy rainfall and a distinct dry season Deserts o Around 300 N or S, inland such as inland Australia o Receives less than 10 in of precipitation per year and can be either hot or cold Other Biomes in Places you generally do not think about     Islands o Oceanic islands: created by hotspots or other geological activity, usually smaller ex: Hawaii o Continental island: created by a unsubmerged part of the oceanic shelf, usually a little larger ex: California Channal Islands o Conditions on islands are determined by things such as latitude, atmospheric cell winds, and oceanic currents o Abiotic factors to consider: Water availability, altitude, weather events, sunlight, ocean currents, size, and geological activity. Mountains o Can cut through other habitats o Formed through plate movement which are still growing and eroding o Changes in altitude mimic changes in latitude in terms of influence on the different biomes o Shape is determined by most common rock type which goes on to influence sunlight, air movement, and water Soil o Latitude and rainfall which affects climate also affects soil composition o Bed rock at the bottom is determined by rock type and depth below the surface  Acts as a place of nutrient and mineral storage o Plants change their root systems to the different soils to reach the nutrients  In temperate zones: root systems are generally shallow  In wetter climates: root systems generally are even more shallow and have more horizontal growth  In the desert: many plants depend on fires for nutrients and plants do a variety of things for water such burrowing down to reach water table. Caves o Depend on the rock or mineral type, solidity, and structure of the rock, can have water flooded or depend on surface seepage, and are formed through geological activity    Ecosystems are very simple, stable, and well defined. Most of the ecosystem depends on surface seepage. Chemosynthesis is what adds nutrients to the ecosystem  Microbiomes o Refers to microscopic organisms that inhabits the bodies of larger organisms o Defined by their host organism with climate conditions dependent on where in the body it is and the diet of the host organism Endolithic o Live inside rock and the conditions are dependent on rock type, depth of rock, water around it and temperature.