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Introduction to Natural History

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1 Introduction to Natural History
Master Naturalist Program University of Maryland Extension Author: Sylvan Kaufman

2 What is Natural History?
The study of the natural world Plants, animals, rocks, planets, weather, … Naturalists observe and study natural objects. They want to learn more about the inhabitants, patterns and processes of the natural world. What are your interests in natural history? - geology, climate change, bird watching, butterflies, animal behavior, plant adaptations Illustration from Mark Catesby’s Natural History of Carolina, Florida and the Bahama Islands

3 Geology The Earth’s physical structure Sideling Hill
Geologists study Earth’s materials, structures and processes. This image of Sideling Hill in Washington Co., MD shows layers of rocks of different colors. The layers reflect different rock materials that formed over hundreds of thousands of years. The layers buckled as the Appalachian Mountains formed. Geology of a location can influence the plant and animal communities that form there. Sideling Hill Photo by Paul Breeding,

4 Formation and Structure of the Earth
To understand the events that formed the geology of Maryland, you have to understand something about how Earth was formed. After our universe was came to be, there was a swirling cloud of gases and materials called a solar nebula. Collisions within the nebula began forming proto-planets and the Sun. The Earth started out as a molten ball of materials and gases about 4.6 billion years ago. Gradually layers formed including: - A super-hot solid inner core composed mostly of nickel and iron - A liquid outer core whose movements contribute to producing the Earth’s magnetic field A semi-molten mantle, and The Earth’s thin, solid crust The lithosphere is made up of the crust and uppermost part of the mantle.

5 Movement of Continents
The lithosphere is divided into about 12 large plates that move very slowly over the viscous mantle. About 250 million years ago all of the continents were joined together into a land mass known as Pangaea. The continents are on different plates though, and as the plates drift, the continents drift with them. Evidence for Pangaea comes from similarities among fossils and rock formations found on once adjoining continents.

6 Plate Tectonics The study of the movement of the plates is called “plate tectonics”. Here you can see the approximate boundaries of the plates and how they move in relation to eachother. Where the plates collide you get the formation of mountains and volcanoes, e.g. the Andes mountains where the Nazca and South American plates collide. Along California’s coast you can see that two plates are slipping against eachother – this often causes earthquakes. Where plates spread apart, such as between the North American and Eurasian plates, you get deep trenches in the ocean floor.

7 Formation of the Appalachians
The rocks that make up the Appalachian Mountains began to form 750 million years ago. A shallow sea covered portions of the area creating layers of limestone and sandstone over time. Volcanoes erupted in what is now Virginia and the Carolinas creating layers of volcanic rocks. The layers of bedrock were upthrust into mountains when the North American and African plates collided repeatedly between 470 – 220 million years ago. Rivers cut valleys through the different layers of bedrock eroding softer layers more quickly.

8 Types of Rocks Igneous – from volcanic activity
Sedimentary – from erosion, deposition Metamorphic – from heat and/or pressure Rocks are classified by their mineral and chemical composition, particle size and texture, and permeability to air and water. There are three main types of rocks: Igneous, sedimentary and metamorphic. Metamorphic rocks form when igneous or sedimentary rocks undergo intense heat or pressure.

9 Maryland’s Physiographic Provinces
Maryland can be divided into 5 major provinces based on its geology. Coastal plain – deposition of sediments from rivers and the ocean Piedmont – eastern Piedmont bedrock of volcanic origin, western Piedmont mixed volcanic and sedimentary origin. Blue Ridge – Granitic rocks over sedimentary rocks Ridge and Valley – long parallel folds of rocks, mostly sedimentary Appalachian Plateau – underlain by sedimentary rock with rugged channels carved by streams.

10 Geologic Time Geologists can link characteristics they see in different rock formations with events that happened millions of years ago. Rocks can be dated using radiometric dating (measures changes in isotope levels of different elements) to discover how old they are. The type of rock gives clues about climate and whether there were seas or volcanic activity. Fossils and carbon in the rock tell what life forms were around at a certain point in history. See interactive timelines at

11 Important Events for Maryland
Formation of Earth 4.56 bya one-celled organisms Chesapeake Bay bolide lands Insects, mollusks, fish, amphibians, primitive plants Pangaea forms 3.5 bya 1.8bya 500 mya oxygen increasing in atmosphere Precambrian 3.5-1bya Paleozoic mya 230mya 35 mya Mesozoic mya Pangaea breaks apart Dinosaurs, birds, first mammals, seed plants Cenozoic 65 mya - present North America splits from Laurasia 65mya Mammals dominate on land 18000 ya 2mya Glaciation periods, spruce forests, tundra, grasslands End of Wisconsin glaciation Appalachians forming 50mya Extinction of dinosaurs 10000ya Humans settle eastern North America Chesapeake Bay forms (not to scale) This timeline gives you an idea of when certain geologic events happened in relation to when different organisms appeared. The major geologic eras are listed across the top.

12 Atmosphere
Above the Earth’s crust lies the atmosphere. The composition of Earth’s atmosphere changes over time. The evolution of photosynthesis in bacteria and then plants led to an increase in oxygen levels. The atmosphere is divided into layers just as the Earth is. Look at the diagram to see what happens in different layers of the atmosphere. The atmosphere not only holds oxygen for us to breathe, but it also provides a protective layer that reduces solar radiation and reduces impacts by meteors and other objects.

13 Climate Our climate is shaped not only by the atmosphere, but also by the tilt of the Earth and our proximity to the Sun, vegetation and land surface types, oceans, glaciers, wind patterns, and human activities. Climate is the average weather over time.

14 Historic climate change
Scientists use data on climate collected from ice cores to look at changes in climate over hundreds of thousands of years. Temperature shows a strong correlation with carbon dioxide levels over time. You can see that climate fluctuates considerably over long time periods. After the industrial revolution carbon dioxide levels began to increase rapidly and now atmospheric carbon dioxide levels are above any ever recorded before. Image from:

15 Recent climate change Temperatures have increased correspondingly. This map shows the change in hardiness zones (measured by average annual minimum winter temperatures) in the United States between 1990 and 2012.

16 Future climate change Warmer winters and summers
Wetter autumns and springs, drier summers Increase in storm severity Sea level rise Expected effects of climate change in Maryland include the above.

17 Weather Weather describes day to day temperatures, winds and precipitation. Weather can be determined by many factors. Cold and warm fronts form depending on wind patterns, temperatures, and moisture content in the air. If you live on the coast, you might get shifts in wind most days in summer because water gains and loses heat more slowly than the land. Mountain ranges can also affect the movement of storms.

18 Maryland Watersheds We’ve been talking about the basics of geology, climate and weather, and now we will shift to focus more specifically on Maryland and how people’s actions affect our natural areas and natural resources. A watershed is a drainage basin or area of land where all the water on or under it flows to the same place. This map shows the major Maryland Watersheds. Which one do you live in? What do you think your sub-watershed would be (based on what river you live closest to)? In Maryland, all the watersheds except for the Youghiogheny are part of the Chesapeake Bay watershed. The Youghiogheny is part of the Ohio and Mississippi watershed.

19 Chesapeake Bay
Because most of Maryland’s watersheds flow to the Chesapeake Bay, the state puts a lot of emphasis on the health of the Bay. The Chesapeake Bay is one of the largest and most productive estuaries in the world. This diagram shows attributes of the Bay monitored by MD DNR. Runoff from the land, waste discharge from urban areas, and atmospheric deposition from autos and industrial processes all pollute the waters of our rivers and the Bay.

20 Formation of Dead Zones
In shallow waterways like the Chesapeake Bay and many lakes, a layer of warm water forms over a layer of colder water in summer. The warm water may get some oxygen from the air above it, but the water in the lower layer becomes starved of oxygen. In fall as the upper layer of water cools, the layers mix oxygenating the water at the bottom. When there are high nutrient inputs into waterways (nitrogen and phosphorous are the two major nutrients of concern), algae blooms often occur in summer. When the algae dies oxygen in the water is used up as the algae decays. Dead zones in the Chesapeake Bay tend to form in areas where the bottom is bowl-shaped effectively preventing mixing. Shellfish and fish can’t survive in these low-oxygen waters.

21 Native Americans in Maryland
Paleo Indians Archaic period Woodland Period Humans have occupied this region for the last 10,000 to 20,000 years. The original settlers, the Paleo Indians were hunter-gatherers that probably lived in relatively small, nomadic groups. Between 9,000 and 2,000 years ago during the Archaic period, the climate warmed and forests grew thicker in Maryland. The Chesapeake Bay began to assume its current shape. Native Americans began forming small settlements and their populations grew. During the Woodland period, 2,000 – 400 years ago, villagers began small-scale farming, clearing and burning forests to create fields. There may have been as many as 50,000 Native Americans living in the Chesapeake Bay region by Native American populations declined rapidly after European exploration and settlement began mainly because of introduced diseases. The abundant game and dense thickets observed and recorded by early settlers may be attributed to the abandoned villages and sudden loss of population. This map depicts the tribes and villages recorded by John Smith during is voyage up the Chesapeake in 1608. Human populations increased rapidly again once Europeans began settling in the region. By 1700 the population of Maryland was estimated at 25,000 – 32,000. In the next few slides we will see what effects human population growth has had on natural processes and natural resources in Maryland.

22 Human Population Growth
Human populations have been increasing almost exponentially worldwide. In the United Sates the population is now above 300 million people. Maryland has nearly 6 million people. People require resources such as water, food, fuel, and space to live, so we have a tremendous impact on the environment around us. Year

23 Hydrological Cycle Only 3% of Earth’s water is fresh water, the water people need to survive. Review the hydrological cycle. In Maryland most of our fresh water comes from lakes, rivers and groundwater. Even though Maryland is a relatively water-rich state with 1/5 of the state covered by water and an average of 42” of rainfall a year, we still face water shortages during drought years. Sea level rise and overuse of groundwater has led to some groundwater supplies becoming contaminated by salt water. Groundwater and surface waters also have to be protected from pollutants. It can take hundreds of years for groundwater to be replenished from surface waters.

24 Soils Healthy soils store air and water, resist erosion, and store organic matter in addition to supporting plants and animals. Human actions that threaten soil health include: Disturbance – increases erosion, loss of topsoil, releases stored carbon dioxide Compaction – decreases spaces for air and water within soil Pollution – harms soil biota, changes soil chemistry Introduced species – Nitrogen fixing plants change soil chemistry, introduced earthworms destroy leaf litter Figure from:

25 Industrial Mining Mine tailings in the Savage River
Maryland has a wealth of natural resources. Some of its mined and quarried resources include coal, oil and natural gas, stone, sand and gravel and cement. Small scale mining for iron and gold began in the early 1700s. Large coal mines and quarries for stone and other materials still exist. Once a mine or quarry was exhausted it used to be abandoned. Now there are regulations requiring restoration, and old mine sites are gradually being restored as well. Mines often leave a legacy of toxic waste that has to be cleaned up. Mine tailings can be very acidic for example, and mining for some minerals requires use of toxic chemicals that last for years in the soil. Forests and other vegetation are stripped away and are difficult to re-establish since the topsoil is gone. What sorts of mines and quarries exist in your region? Mine tailings in the Savage River Image from Limestone quarry in Cockeysville, MD

26 Forest Products Building lumber Shipping crates and pallets
Shelves and furniture Chips for fuel pellets Mulch Pulp for paper Forests used to cover 90% of Maryland, but now cover only about 40%. First trees were cut mainly to clear land for farming, but as the demand for timber products grew, forest clearing increased into mid 1800s. After the Civil War and the Great Depression, forest cover increased as people moved to urban areas abandoning marginal farmland. Now the biggest loss of forest in Maryland is due to development. At greatest risk are old growth forests, forests with many old trees, because there are relatively few of these unique forests left in the state. The forest industry is the 5th largest industry in Maryland according to the Maryland Department of Natural Resources. Forests provide important wildlife habitat, they store carbon, stabilize soils, absorb stormwater runoff and pollutants, and provide numerous recreational opportunities.

27 Wildlife – Hunting and Fishing
Deer Black bear Rabbits Muskrats Squirrels Game birds Waterfowl Fish Shellfish Hunting and fishing are popular recreational pastimes in Maryland and many conservation efforts are related to wildlife and fisheries management. Deer hunting is now used to control overpopulations of deer. Limits on oyster harvests and oyster reef building help to increase populations of this important shellfish. Oysters help to filter waters in our rivers and bays. Creating large meadows helps provide habitat for bobwhite quail, a popular game bird. Shallow freshwater ponds and other wetland creation helps to replace wetlands lost to farming and development and provides habitat for migrating waterfowl. Image from:

28 Loss of Habitat In this aerial photo of the area around Bethesda, MD, you can see how forest habitat has been fragmented by roads, housing developments, urban corridors, and golf courses. The undeveloped area in the lower right is Rock Creek Park. Fragmentation of habitat makes remaining habitat more vulnerable to disturbances and invasion by non-native species. Some animals such as the scarlet tananger and bobcat need large forested areas to survive. Providing corridors of habitat that connect large intact patches can help reduce the impact of fragmentation. Making home and commercial landscapes wildlife friendly can also knit back together our fragmented landscape.

29 Skills for Naturalists
Observation Recording Research Reporting Just because we live in human-dominated landscapes, doesn’t mean that there aren’t still wonderful opportunities to study nature. Even in the most urbanized landscape you can find wild animals, native plants, insects, and the influences of geology on the layout of a city. The skills that a naturalist needs are: Observation – use all your senses to observe what is happening in the world around you. Recording – whether you prefer to write, draw, or sing, recording your observations will help you remember and make links to past and future observations. You may leave a lasting legacy of observations for future naturalists to enjoy as well. The image here shows a page from a nature journal where the author combines words and drawings about what she observed one day including background information about the location and weather that day. Research – learn to use library and online resources to identify what you see and learn more about different natural processes. Think of a research project you might want to collect data on. Reporting – Share what you learn with others. As a Master Naturalist you will have lots of opportunities to lead a walk, write an article, teach a class or to share data with others. Nature journal page from Margan Glover, used with permission from the author.

30 Famous Maryland Naturalists – You could be next!
Benjamin Banneker Rachel Carson Maryland has many people who have contributed to an understanding of Maryland’s natural history. Rachel Carson is one of the most famous Maryland Naturalists. She worked for the US Bureau of Fisheries as an aquatic biologist and later authored Silent Spring about the effect of DDT on wildlife. Charles Wilson Peale was born in Chester, MD in He became an artist and natural historian opening the first public art and science museum in Philadelphia, PA. Benjamin Banneker was born free in Baltimore County in 1731 and educated himself in the sciences. He wrote a series of almanacs that predicted astronomical events and weather. Mary Elizabeth Banning was born in Oxford, MD in She authored the Fungi of Maryland which included her drawings of 123 species of fungi and descriptive notes. It was the first guide to fungi for the United States. Chan Robbins is an amazing ornithologist who at age 95 is still an active birder in Maryland. He developed the methodology for the Breeding Bird Survey which is conducted across the United States to monitor the health of bird populations. What other amazing naturalists do you know in Maryland? Charles Wilson Peale Mary Elizabeth Banning Chandler S. Robbins

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