CLIMATE AND TERRESTRIAL AND AQUATIC BIODIVERSITY

CLIMATE AND TERRESTRIAL AND AQUATIC BIODIVERSITY
CHAPTER 6 CLIMATE AND TERRESTRIAL AND AQUATIC BIODIVERSITY Dust storm from North Africa ends up as soil nutrients in the tropical rain forests of the Amazon River basin and particles of toxic air pollutants in Florida and the Caribbean Weather and pollution are global issues! In terrestrial systems precipitation, temperature and soil are the major determinants of biomes. In aquatic zones, light penetration, water currents and dissolved nutrient concentrations (especially N and P) are usually the most important factors in determining composition and structure. The path of this storm represents the flow of trade winds resulting from the Coriolis effect. Columbus took this trade wind to the West Indies. He returned on the Gulf Stream and North American currents.

What factors determine weather and climate and aquatic conditions?
TOPICS FOR CHAPTER 6 What factors determine weather and climate and aquatic conditions? How do biomes develop in response to climate and soil? What are and how do humans impact desert and grassland biomes? What are and how do humans impact forest and mountain biomes What are and how do humans affect saltwater life zones? What are and how do humans affect freshwater life zones

© 2004 Brooks/Cole – Thomson Learning Average Precipitation
Climate is the average weather patterns for an area over a long period of time (30 - 1,000,000 years). It is determined by Average Precipitation and Average Temperature which are influenced by This is a flow chart showing how climate is defined and created and then interacts with humans. Climate is an average for a set time. Obviously, average precipitation and and temperature are important to living organisms, but also extremes of these 2 variables determine species distributions and abundances. Climate, in turn, is one of the most important factors in soil development (pedogenesis). Position north or south of the equator (latitude) are important due to the sun's direct impact. This solar impact is a function of the length of day and the angle at which the sun's rays hit the earth as it wobbles about in its orbit. Generally, temperatures decrease and precipitation increases as altitude increases. Ocean currents moderate continents based on where they come from. You should know the definition of climate. Climate is determined mostly by average ppt. and temperature. You should understand how latitude, altitude and ocean currents affect climate and how all these interact together with soil to form the worlds biomes and aquatic life zones. latitude altitude ocean currents and affects Figure 6-2 Page 107 what they grow and eat where people live how people live

This is a map of global climate zones and major ocean currents
This is a map of global climate zones and major ocean currents. Note that there are 2 strips of desert at similar latitudes at the Tropics of Cancer and Capricorn. There is considerably more land mass in the northern than in the southern hemisphere. This particular map projection makes land above or below 70 degrees latitude look much larger than it actually is. For example, Anartica, Russia, Iceland and Canada appear about 2Xs bigger than they really are. Ocean currents have a profound effect on continental climate and ocean productivity. Currents can change over time and season. The Gulf Stream runs from the equator into the Gulf of Mexico and then up the east coast of North America before finally warming northwestern Europe which would otherwise be subarctic. Ocean currents mix ocean waters and distribute nutrients and dissolved oxygen to aquatic organisms. When deep cold waters surface and displace warmer surface waters as happens with La Nina off the west coast of South America an upwelling of nutrients occurs. One can imagine that when Columbus left Portugal he flowed with the Canaries Current into the trade winds west picking up the South equatorial current and Caribbean current. Polar (ice) Warm temperate Highland Warm ocean current Subarctic (snow) Dry Major upwelling zones Cold ocean current Figure 6-3 Page 108 Cool temperate Tropical River

Uneven heating of the earth's surface
Temperature and precipitation patterns that cause different climates within the earth's troposphere are caused by air circulation over the earth's surface. Five factors determine these global air circulations. These factors plus ocean density create warm and cold ocean currents. Uneven heating of the earth's surface Seasonal changes in temperature and precipitation as earth wobbles causes seasons to flip flop N to S Rotation of earth on its axis causes air at equator to move faster than air at poles resulting in 6 convection cells that mix the earth's air and moisture (called Hadley cells) resulting in prevailing winds Long term variations in sun intensity due to changes in solar output and planetary shifts (the Siberian Milankovitch first described these cycles in the 1920's). Properties of air and water such as heat causing water to evaporate and transfer its heat to the air Ocean currents redistribute heat and so influence climate and vegetation, especially near coastal areas.

(sun aims directly at equator)
23.5º Spring (sun aims directly at equator) Winter (northern hemisphere tilts away from sun) Solar radiation Summer (northern hemisphere tilts toward sun) Figure 6-4 Page 108 Fall (sun aims directly at equator)

Milankovitch cycles Some of this variation is considered to to be due to Milankovitch cycles which occur because of changes in the Earth's orbit, a shifting of the tilt of the Earth's axis, and wobble that occurs along the Earth's axis. Of course, all of these changes would result substantial changes in the Earth's climate.

There are many layers to the earth's atmosphere
There are many layers to the earth's atmosphere. For now, we need to know the difference between the troposphere (where weather occurs) and the stratosphere. Note that temperature and altitude do not change in a linear fashion. The atmosphere itself is composed of four distinctive zones divided by contrasting temperatures due to different amounts of absorption of solar energy. These zones include the troposphere which is the zone that humans live in, ranging from sea level to about 11 km, the stratosphere which ranges from about kilometers, the mesosphere which ranges from about km, and the thermosphere which ranges above 83 km in attitude. The pressure exerted by the atmosphere decreases very rapidly above sea level and is essentially zero at 20 to 30 kilometers above the earth's surface. So far in this class we are focused on the tropopause and troposphere. Note that there is a warming of the air in the stratosphere and this temperature cap keeps the surface troposphere air from mixing with the upper air. Ozone shielding occurs in the stratosphere.

It is fortunate that these convection systems exist (fortunate for people living in polluted areas) because they act to distribute and disperse substances more widely on the earth than would otherwise occur. These movements of winds create pressure differentials that also distribute rain and weather more evenly throughout the earth than would otherwise occur.

Convection and Atmospheric Pressure
Evaporation Latent heat Condensation Convection currents Air pressure differences Coriolis effect Here we have integrated latitude and longitude with atmospheric pressure. The movement of the atmosphere of the earth has a reproducible general pattern caused by the spinning of the earth, and the heating and cooling at the cooler north and south poles relative to the warmer equator. These conditions produce movement of air around the earth through convection, the different zones of which are referred to as Hadley cells. Dominant winds, including the Westerlies and the Trade Winds, occur within these convection cells. These forces dictate to a large extent the movement and dispersal of pollutants and other substances through the atmosphere. Historically, trade that relied on air power could only occur well in the direction these winds and ocean currents dictated.

Jet Stream The polar jet stream greatly influences the weather in some parts of the world. It is particularly important than the Pacific Northwest as the position of the jet stream often dictates the temperature and power of wind in areas near Seattle. When the jet stream dips into the Seattle area it typically becomes very windy and cold.

Circumpolar winds transport air pollution from heavily industrialized regions to the Arctic, where high levels of smog accumulate. Heating of the Earth's atmosphere in tropical regions causes air to rise and eventually circulate to polar regions of the earth. Long-range transport of the air that circulates at the poles can result in the accumulation of pollutants in these polar regions. Air transport can be very rapid; for instance, the average transit time of pollution from Russia to Canada is about three days. While I was working at Oak Ridge National Laboratory during the Chernobyl incidence, physicists at the laboratory asked us to mow our lawns and bring the grass clippings into the lab for analysis for radioactive substances. Within about a week, fallout from Chernobyl releases had arrived in Tennessee. This also shows how rapidly air distribution can transport pollutants and how global their distribution is likely to be.

Seasonal Winds and Monsoons
The seasonality of weather is also a very important aspect of how weather influences the environment and people. For instance, in India, Society has depended on the timing and degree of monsoon rains that occur when warm, wet air from the Indian Ocean is drawn into the Indian subcontinent and releases rainfall as it rises and cools over the Himalayan mountains. Lack of monsoon rain due to different weather patterns sometimes causes drought, starvation, and death to people living in the region as well as to their animals, crops, and other organisms that depend on seasonal rainfall.

Wind Upwelling Nutrients
Movement of surface water Wind Diving birds Fish Upwelling Zooplankton Phytoplankton Shore upwelling (cold, deep and nutrient-laden water convection from the bottom up replacing warmer surface water) is where ocean productivity is usually highest. It creates a major fishing area off the coast of South America during normal La Nina weather patterns. The fishing goes sour when El Nino Southern Oscillation conditions (currents) set in. Nutrients Figure 6-6 Page 110

Some cycles have a particularly important impact on the Pacific Northwest. For instance, the El Niño/La Niña/Southern Oscillation cycle directly impacts trade winds that normally push warm water west toward Indonesia and allow the water to flow toward the coast of South America. Typically, El Niño results in warmer weather along the coast and significant climatic impacts such as increased rain and flooding in California. It causes warmer, drier weather in Oregon, Washington and British Columbia.

Warm water Thermocline Cold water Normal Conditions
Surface winds blow westward EQUATOR Warm waters pushed westward SOUTH AMERICA AUSTRALIA Warm water Normal conditions are called La Nina Thermocline Cold water Figure 6-7 (1) Page 110 Normal Conditions

Warm water Thermocline Cold water El Niño Conditions
Winds weaken, causing updrafts and storms Drought in Australia and Southeast Asia EQUATOR Warm water flow stopped or reversed SOUTH AMERICA AUSTRALIA Warm water deepens off South America Warm water Thermocline Cold water Figure 6-7 (2) Page 110 El Niño Conditions

El Niño Drought Unusually high rainfall Unusually warm periods
El Nino is the unusual situation. What is most interesting is that this current pattern and its more common variant (La Nina) have a global impact on the weather of the northern hemisphere. Drought Unusually high rainfall Unusually warm periods Figure 6-8 Page 111

GLOBAL WARMING IS CAUSED BY GREENHOUSE GASES CAPTURING THE ENERGY OF LONGER WAVELENGTHS OF LIGHT WITH THEIR CHEMICAL BONDS Water vapor is a greenhouse gas. The greenhouse effect is necessary to maintain life as we know it on earth. Rapidly changing the concentration of greenhouse gases and major development along the coastlines are not normal conditions of the earth. Figure 6-9 Page 111

For instance, these figures show the variation in temperature during both the last million years and the last hundred years. Note that there were relatively large fluctuations in the average temperature of the earth including warmer periods and cooler periods than the present that lasted thousands of years. Note also that over the last hundred years the Earth's average temperature has been increasing.

Carbon dioxide levels are increasing and oscillate with seasons of northern hemisphere
This figure, for instance, shows the measurement of carbon dioxide at the Mauna Loa observatory in Hawaii. The amount of carbon dioxide has been increasing steadily. Note also the annual changes in carbon dioxide that give the curve a saw tooth appearance. These seasonal changes are due to the difference between respiration in the Spring and Summer in northern temperate areas, which has a much larger land surface area than the southern temperate areas.

Greenhouse gases animation.
In 1895, Svante Arrhenius hypothesized that carbon dioxide released to the atmosphere from the burning of coal could cause global warming. The first hard evidence that carbon dioxide atmospheric concentration was increasing came from the observatory atop the Mauna Loa volcano in Hawaii. Results here showed carbondioxide levels increasing 0.5 percent per year rising from 315 ppm in 1958 to 372 ppm in 2002.Northern hemisphere springs cause the annual drops in carbon dioxide air concentrations as the plants on the larger northern hemisphere land mass take up more carbon dioxide. Levels rise during northern winters as plant respiration releases carbon dioxide. Double and triple covalent bonds are good at capturing long wavelengths of light.which is what this video is about. Click to view animation.

RELATIONSHIP OF BIOMES TO HADLEY CELLS AND LATITUDE
Cell 3 North Cold, dry air falls Moist air rises — rain Polar cap Cell 2 North Arctic tundra Evergreen coniferous forest RELATIONSHIP OF BIOMES TO HADLEY CELLS AND LATITUDE 60° Cool, dry air falls Temperate deciduous forest and grassland Cell 1 North Desert 30° Tropical deciduous forest Moist air rises, cools, and releases moisture as rain Tropical rain forest 0° Equator Tropical deciduous forest 30° Desert Cell 1 South Our text gives a simplified version of the 6 north-to-south weather cells of the earth. Please not the locations of precipitation, deserts and biomes. This is from our text. Temperate deciduous forest and grassland Cool, dry air falls 60° Cell 2 South Polar cap Figure 6-5 Page 109 Cold, dry air falls Moist air rises — rain Cell 3 South

Figure 6-11 Page 113 Tropic of Cancer Equator Tropic of Capricorn
If we slice the globe open and lay it flat, we can see the pattern of biomes of the earth. Note the location of deserts north and south of the Tropics of Cancer and Capricorn and the lush vegetation at the tropics and at mid-latitudes north and south. Another important thing to note is that most of the land is in the northern hemisphere. Semidesert, arid grassland Arctic tundra (polar grasslands) Desert Boreal forest (taiga), evergreen coniferous forest (e.g., montane coniferous forest) Tropical rain forest, tropical evergreen forest Mountains (complex zonation) Temperate deciduous forest Tropical deciduous forest Ice Figure 6-11 Page 113 Temperate grassland Tropical scrub forest Dry woodlands and shrublands (chaparral) Tropical savanna, thorn forest

COMPARISON OF VEGETATION CHANGE WITH ALTITUDE AND LATITUDE
COMPARISON OF VEGETATION CHANGE WITH ALTITUDE AND LATITUDE. NOTE THAT LOW LATITUDE DESERTS ARE MISSING IN THIS FIGURE Altitude Mountain Ice and snow Tundra (herbs, lichens, mosses) Coniferous Forest Deciduous Forest Latitude Tropical Forest Along with the latitudinal variation in vegetation biomes is that of altitude. This figure is missing deserts! Tropical Forest Deciduous Forest Coniferous Forest Tundra (herbs, lichens, mosses) Polar ice and snow Figure 6-13 Page 114

MAJOR IMPACTS ON DESERTS Large desert cities
Soil destruction by vehicles and urban development Soil salinization from irrigation Depletion of underground water supplies Land disturbance and pollution from mineral extraction Storage of toxic and radioactive Wastes Large arrays of solar cells and solar collectors used to produce electricity You should be familiar with the major human impacts on all the biomes given in this powerpoint presentation. We will explain many of these impacts in chapters 7-10. Figure 6-15 Page 116

HUMAN IMPACTS ON GRASSLANDS Conversion of savanna and temperate
grassland to cropland Release of CO2 to atmosphere from burning and conversion of grassland to cropland Overgrazing of tropical and temperate grasslands by livestock Damage to fragile arctic tundra by oil production, air and water pollution, and vehicles Natural grasslands have many (often large) ungulates such as buffalo, zebras and gazelles. The savannas of Africa have the best developed system of ungulates. Figure 6-19 Page 119

STRUCTURE OF TROPICAL RAIN FOREST
45 Emergent layer Harpy eagle 40 35 Toco toucan Canopy 30 Height (meters) 25 20 Understory Wooly opossum 15 Include vines and epiphytes in your structural vision of tropical rain forests. You are responsible for knowing the physical structure of a tropical rain forests. This system is highly productive but not resilient. One major reason for the low resilence is that most of the necessary life sustaining nutrients are tied up in the above ground organisms and the soil's ability to recycle is damage when the area is deforested and cultivated or grazed afterwards. Nitrogen pools are very low in this system. 10 Brazilian tapir Shrub layer 5 Black-crowned antpitta Ground layer Figure 6-21 Page 121 STRUCTURE OF TROPICAL RAIN FOREST

HUMAN IMPACTS ON FORESTS Clearing and degradation of tropical
forests for agriculture, livestock grazing, and timber harvesting Clearing of temperate deciduous forests in Europe, Asia, and North America for timber, agriculture, and urban development Clearing of evergreen coniferous forests in North America, Finland, Sweden, Canada, Siberia, and Russia Conversion of diverse forests to less biodiverse tree plantations The impact on tropical forests is very different than that of coniferous forests, although problems with erosion, road building, flooding and landslides are similar. Figure 6-24 Page 124

AQUATIC LIFE ZONES Lakes Rivers Coral reefs Mangroves
Mangrove forests and coral reefs are subjected to heavy degradation and abuse currently from human exploitation. We will discuss these problems later in the class. Lakes AQUATIC LIFE ZONES Rivers Coral reefs Figure 6-26 Page 125 Mangroves

© 2004 Brooks/Cole – Thomson Learning
Marine Systems Ecological Services Economic Services • Climate moderation • CO2 absorption • Nutrient cycling • Waste treatment and dilution • Reduced storm impact (mangrove, barrier islands, coastal wetlands) • Habitats and nursery areas for marine and terrestrial species • Genetic resources and biodiversity • Scientific information • Food • Animal and pet feed (fish meal) • Pharmaceuticals • Harbors and transportation routes • Coastal habitats for humans • Recreation • Employment • Offshore oil and natural gas • Minerals • Building materials Aquatic systems have been taken for granted until the last half of the 20th century. This obviously was a gigantic mistake. Figure 6-29 Page 127

High tide Depth in meters Sun Low tide Coastal Zone Open Sea Sea level 50 Euphotic Zone Photosynthesis Estuarine Zone 100 Continental shelf 200 500 Bathyal Zone Twilight 1,000 1,500 2,000 Abyssal Zone 3,000 We are now finding life in the ocean much more complex, at deeper depths and more diverse than we ever even came close to suspecting. These organisms are just as sensitive as terrestrial ones, if not more so. 4,000 Darkness 5,000 10,000 © 2004 Brooks/Cole – Thomson Learning Figure 6-30 Page 128

MADAGASCAR ESTUARY Figure 6-31 Page 128
The Puget Sound is an estuary. Estuaries are one of the most productive and diverse life zones because of the mixing of nutrients and the flushing of the water with tides. Unfortunately, nutrient overload and sedimentation from agriculture and logging have caused major problems with reproduction and aeration of these systems and the problems extend out into the gulfs and even the open ocean. Here, we have anoxia (lack of oxygen) so bad in the Hood Canal that the whole system is almost dead. The problem seems to be in large part related to septic tank pollution (a problem that can easily be solved). Figure 6-31 Page 128

Algae growth from fertilizer runoff Mangrove destruction
MAJOR IMPACTS TO CORAL Ocean warming Soil erosion Algae growth from fertilizer runoff Mangrove destruction Coral reef bleaching Rising sea levels Increased UV exposure from ozone depletion Using cyanide and dynamite to harvest coral reef fish Coral removal for building material, aquariums, and jewelry Damage from anchors, ships, and tourist divers Along with estuaries, coral reefs are highly productive and diverse, and unfortunately being vastly abused by humans. We even used atolls (a type of reef developed around exploding, stratolayer oceanic volcanoes) as sites for nuclear bomb tests. Often problems from estuary pollutants and sediment bleed out onto coral reefs. This is happening with the Mississippi River in the Gulf of Mexico. Figure 6-36 Page 133

MAJOR IMPACTS TO MARINE SYSTEMS Half of coastal wetlands lost to
agriculture and urban development Over one-third of mangrove forests lost since 1980 to agriculture, development, and aquaculture shrimp farms About 10% of world’s beaches eroding because of coastal development and rising sea level Ocean bottom habitats degraded by dredging and trawler fishing boats Over 25% of coral reefs severely damaged and 11% have been destroyed We've already discussed and visited some urban wetlands. One-third of all organisms on this planet require wetlands at some stage of their life cycle. There role in purifying water and flood control is one of the most under-appreciated aspects of our society. There are many, many types of wetlands. Figure 6-37 Page 133

Freshwater Systems Ecological Services Economic Services • Climate moderation • Nutrient cycling • Waste treatment and dilution • Flood control • Groundwater recharge • Habitats for aquatic and terrestrial species • Genetic resources and biodiversity • Scientific information • Food • Drinking water • Irrigation water • Hydroelectricity • Transportation corridors • Recreation • Employment The first cut in classifying aquatic ecosystems is freshwater vs. saltwater with estuaries and coastal wetlands lying somewhere in between the two. What happens in fresh water is very different than saltwater. Freshwater is very limited upon the earth's surface and will soon be more valuable than fossil fuel. Wars in the mid-east and northern Africa are already being waged over water rights. Figure 6-39 Page 133

OLIGOTROPHIC (CLEAN) VS. EUTROPHIC (POLLUTED) BODIES OF WATER
Sunlight OLIGOTROPHIC (CLEAN) VS. EUTROPHIC (POLLUTED) BODIES OF WATER These slides contrast oligotrophic with eutrophic lakes, but this terminology can be applied to rivers and saltwater systems Narrow littoral zone Little shore vegetation Low concentration of nutrients and plankton Limnetic zone Sparse fish population Sleepily sloping shorelines Profundal zone Sand, gravel, rock bottom Oligotrophic lake Sunlight You should know the differences between oligotrophic and eutrophic lakes and how they fit into successional and environmental frameworks. Oligotrophic bodies are often made eutrophic with the addition of N and P. Phosphorous detergents, pet waste and fertilizers often pollute freshwater systems since P is limiting. Nitrogen often causes eutrophication of saltwater systems. It is a natural process for lakes to gradually move from oligotrophic to eutrophic conditions. For humans, oligotrophic conditions are better. Green Lake is eutrophic, Lake Washington is marginal between oligotrophic and eutrophic. Eutrophic aquatic systems are bad for salmon due to the heat, sedimentation and paucity of oxygen in the water. Much shore vegetation Wide littoral zone High concentration of nutrients and plankton Dense fish population Limnetic zone Gently sloping shorelines Figure 6-41 Page 136 Profundal zone Silt, sand, clay bottom Eutrophic lake

IT IS LONG, BUT VERY IMPORTANT!
THIS ENDS CHAPTER 6 IT IS LONG, BUT VERY IMPORTANT!

CLIMATE AND TERRESTRIAL AND AQUATIC BIODIVERSITY

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