Ecosystems

Working together since the Earth was formed.EcosystemsLifeAll forms of life:Are made of cells, with highly organized internal structures.Have characteristic types of DNA molecules in each cell.Carry out metabolism (utilize matter and energy to supply their needs for survival)Maintain homeostasis (a constant internal environment despite external conditions)Reproduce, either sexually or asexually.Adapt to environmental changes by modifying their genes through the inheritance of beneficial mutations.The SpheresThe Lithosphere (lithos = rocky)The lithosphere is the rocky component of Earth.The top layer of the crust is broken into 8 major and many minor tectonic plates. These rocky plates float, and move about, on a layer of molten rock beneath called the mantle.In this class, we will only discuss the crust and upper mantle.

The Spheres Plate TectonicsAs the tectonic plates move, their boundaries interact and revolutionary change is possible.As these plates move, they are able to remodel the surface of the Earth.Earthquakes, volcanic activity, mountain-building, and oceanic trench formation are all caused by plate tectonics.The type of boundary dictates the type of interaction and forces involved.

The Spheres - continuedThe Hydrosphere consists of water in all three phases:Liquid both surface and groundSolid ice caps and glaciersGas water vapor in the atmosphere.All water has been part of the Water Cycle and has occurred as each phase many, many times.Water is quickly becoming the most precious commodity on Earth and will likely be the impetus for more wars than any other reason.The Spheres - continuedThe Atmosphere is the gaseous layer that surrounds Earth.The atmosphere is so thin, it can be represented by the skin of an apple.There are 5 layers to the atmosphere, but in this class we will only be concerned with two of them.Each layer is separated from another by a pause.The Troposphere is the lowest region and is where all life can be found.The Troposphere extends from Earths surface to an altitude of between 30,000 feet at the poles and 56,000 at the Equator.The Stratosphere is found above the Troposphere and is where the Ozone layer is found.The Stratosphere extends from the Tropopause to an altitude of approximately 170,000 feet.This layer protects us from deadly ionizing radiation.The Atmosphere

How is Life sustained on Earth?Life depends on the ability of organisms to utilize matter and energy in a sustainable fashion.Three factors are vital to the sustenance of life:The one-way flow of high-quality energy.This energy comes from the Sun and drives virtually all life processes.The cycling of matter or nutrients.Virtually all matter on Earth has always been here and will always remain.Gravity.Gravity keeps the atmosphere present surrounding Earth and causes the downward movement of chemicals in matter cycles.Solar Radiation and Earths cycles

Photosynthesis = 0.023%DiversityBiological Diversity Genetic Diversity variability in the genetic makeup in a single species)Species Diversity variety of species in different habitats.Ecological Diversity variety of biological communities that interact with each other and the non-living environment.Cultural Diversity a recent development in historic terms.variety of human societies, norms, mores, and cultures, and their interactions.

Trophic LevelsProducers Primarily plants and algaeAutotrophsPhotosynthesisChemosynthesis1o Consumers Herbivores2o Consumers Omnivores3o Consumers CarnivoresScavengers Detritivores Decomposers 10% RuleEnergy Flow in EcosystemsTo graphically illustrate the flow of energy in an ecosystem, we use a pyramid of energy flow.

Why are there no 4o consumers?

Food Chain or Food Web?

Matter Cycling in EcosystemsThere are 5 major Cycles of Matter:CarbonNitrogenPhosphorusSulfurWaterCarbon Cycle

Carbon Cycle (continued)Carbon has been cycling naturally and sustainable through the biosphere since the Earth was formed.The largest reservoir for the Carbon Cycle is sedimentary rock in the form of limestone (CaCO3), followed by the water of the oceans.

Which two human activities have drastically altered the balance of the Carbon Cycle?

Nitrogen Cycle

Nitrogen Cycle (continued)The reservoir for the Nitrogen Cycle is the atmosphere.Approximately 78% of the air we breathe is Nitrogen.Nitrogen is a necessary element for amino acids and, therefore, proteins.However, we lack the ability to assimilate this element.Nitrogen fixing bacteria capture atmospheric nitrogen and make it available to plants.Animals are able to capture this element by consuming plant material.There are 21 amino acids on which we depend. Very few plant products contain all 21. Therefore, eating only plant material requires one to be cognizant of their amino acid intake.How have humans disrupted the Nitrogen Cycle?Phosphorus Cycle

Phosphorous Cycle (continued)The Phosphorous Cycle is the only cycle of nutrients which has no atmospheric component.Phosphorous is an essential element in DNA.We are unable to assimilate this element from nature. Weathering and erosion of rocks makes phosphorous available to plants. We get the phosphorous when we consume the plant material.Humans are disrupting the Phosphorous Cycle in 3 ways:Overuse of commercial phosphorous-based fertilizersReducing phosphorous in forest ecosystems through deforestation.Excess phosphorous is entering waterways though the use of animal manure as a fertilizer.Sulfur Cycle

Sulfur Cycle (continued)Sulfur is an essential element in many proteins.The metabolism of sulfur by cellular respiration results in minor amounts entering the atmosphere.Under typical conditions, sulfur cycles very slowly from rocks, through organisms, to the atmosphere, and back.Humans are disrupting this cycle through the combustion of fossil fuels.Hydrologic Cycle

Hydrologic Cycle (continued)Water vapor enters the atmosphere from the surface of the Earth by evaporation, sublimation, and transpiration.Water vapor then cools and form clouds through condensation.Water molecules coalesce around a dust particle and form droplets.When the droplets get large enough, the water droplet falls as precipitation.Water can runoff into streams, rivers, ponds, lakes, and the ocean. This is surface water.Water can also enter the soil by infiltration and move deep in the soil (carrying with it nutrients and chemicals) through percolation. This is called groundwater.T.A.C.T.Some would define tact as the ability to tells someone to go to h*ll and have them look forward to the trip.For us, in Biology, T.A.C.T. stands for transpiration, adhesion, cohesion, and tension.Plants utilize T.A.C.T. to move water from their roots to their leaves for photosynthesis.

How much water does a mature redwood transpire per day?A mature redwood tree can reach 100 meters in height.Mature redwood trees transpire approximately 350 gallons per day.Water weighs approximately 8 pounds/gallon (a pints a pound, the world around).Therefore, a mature redwood tree moves approximately 2,800 pounds of water more than 300 feet against gravity every day.Imagine carrying 2 buckets of water (each containing 2 gallons) to the top of the World Trade Center in downtown Baltimore over 700 times. Each day.