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Tuesday, May 3, 2016

A to Z Reflections

When I decided to do A to Z, I thought what would it hurt if I played with this blog. It had a combination of 19 posts and pages. Each day, it was not unusual to get around 100 hits. With no feedback, I left it for teachers to get the activities. They are all popular.

I learned there is a place for a light discussion of science. I would like to say I plan to post once a week. But I will try to post about twice a month. My plan is to post an activity on the 15th of the month. I have recovered material from an old hard drive. Technology has moved quickly; but, the fundamentals of science change quite slowly. On the twenty-eighth of the month in deference to February, I will deliver a topical post.

Thanks for visiting me folks. A to Z is a great experience in that I get many insights about writing and more importantly what I should be writing. I'm gladdened when I see so many taking environmental science seriously. I walk along my driveway. The front field is overgrown and teems with life. This beautiful world needs to be saved.

Love you all.  Ann

Friday, April 29, 2016


My first science fair project, I was going to win. I had my topic ready. It was zoology. Zoology is the study of animals.

The teacher said it was too big. Too big, smig my 12 year old mind thought. What does she know? I was going to win and I had the winning topic. I loved animals.

I did the project. I didn't win. I remember putting my project out in all it's glory. It was toward the end of the row on the gym floor. This kid who I did not think was too bright had a huge project. His mom was working hard as he watched. He won, I lost.

By the time I got to ninth grade, I managed a third place. I made models of isotopes just like the World Book Encyclopedia suggested in it's science fair project presentation. The teacher told me I had a crummy project. It was a model.

The project was not that great. The ninth grade teacher was honest. Science fair projects using experimentation are preferred. The seventh grade teacher fades from my memory. If it wasn't my seventh grade science teacher. Perhaps it was a project in elementary.

Anyway, for the A to Z topic. It is perfect. And I plan to discuss one item about zoology and that is symbiosis since that has a Z sound.

I've always liked symbiosis in that two different species work together. However, mutualism where both benefit was my real preference.

Pine trees have a fungus in their roots called mycorhiza which help the pine tree absorb nutrients and of course the fungi makes food and reproduces with the pine tree's help. This is a case of mutualism.

Parasitism is also a symbiotic relationship. A successful parasite does not kill it's host. So HIV is not a successful parasite. Interesting enough viruses are thought to arise from the organism it infects. Viruses are somewhere between the living and non-living world. They cannot become active and reproduce without a host. Other than that, they are just scrap DNA in the dirt or where ever they are.

A friend of mine whose family were ethnic Germans who spent World War II in the Phillipines tells about having worms as a child. She had an uncle who had peppermints that were actually a laxative. He told her she could eat some. Being a child, she ate the whole bottle. As a result, she had diarhea and expelled the most worms. After that, she began to gain weight and wasn't so skinny. The worms were a successful parasite in that they did not kill her. Their presence weakened her.

Commensalism is where one organism benefits and the other is unaffected. Small fish swimming with sharks to eat scraps of food that escapes the sharks mouth is an example.

Domesticated dogs are put with commensalisms but it is actually a symbiotic relationship. The beginning dog was a wolf-dog that was neither a wolf or a modern dog. It was in transition. The fact that the dog benefited from living with humans is evidenced in there was a decline in the brain. When animals are benefited by another species, that brain function not used tends to be loss as the two species evolve together.

How we know that dogs benefited humans too is that humans also had a brain decline of about ten percent compared to the dog's twenty percent. Dogs got more out of the relationship.

The wolf-dog defended territory, brought home meat, helped with hunting in exchange for sitting around the campfire and being fed by the humans. I have read but have forgotten the source that without dogs, man would have probably died out. Then we would have had a real planet of the apes.

People may think the dog today does nothing. But, my dogs do alert me to strangers. The terriers efficiently hunt mice which can be a problem. And their emotional support is tremendous. I have a sister with mental illness and the dogs in our home reduced her need of medication. She still needs medication. It is a chronic disease. But the mood elevation helps her cope.
Louise hopping to flush out mice.

What do you mean I'm not supposed to be on the bed?


Never doubt that a small group of thoughtful, committed citizens can change the world; indeed, it's the only thing that ever has.        Margaret Mead

I think we all feel small when compared to the enormity of the world.

Humans are a part of the world's ecological balance. If you removed all the decomposers in the world's ecosystems, the living systems of the Earth would cease within a day. If you removed all humans, the ecosystems would become much healthier.

This is a sobering reality. But it is not the reality you should focus on in that you want positive action. You have to acknowledge human nature. This is like all those masks we wear when we deal with different people. One for children, one for the elderly, one for mom, one for the grouchy customer, you get the picture.

You have to be upbeat with your message. There are three things you have to remember.

1. Focus on one issue. If you discuss or list 20 worthy causes, you are going to get less support than if you list two. They did a study selling flavors of jams. People got to test two. In one situation, there were twenty flavors available to test two. In another there were only six available. The study with 20 flavors generated more traffic. However, sales were considerably higher when there were only six flavors.

You can overwhelm people with choices.

2. Focus on good news. People will read longer articles if they agree with the subject matter. It is pretty much like the adage, you can lead a horse to water but you cannot make them drink. This is something that people who work with the public learn. It is about communicating with people who are not going to be able to look at things outside their perspective. It is not ignorance so much as being to put yourself in someone else's shoes.

You present honest, easy to comprehend information.

3.  Discuss the successes. People like to back a winner. If you go to a political rally, they always have people that will jump up and clap and feign approval of a candidate because it is contagious.

You are selling an idea.

I got the articles for these three ideas from a CNN opinion column by CNN commentator Mel Robbins. It discussed politics so I will not produce a link. Nor does a political discussion indicate any of my own political inclinations. People feel very strongly about politics and religion and get quite passionate. That is why the world over will say, never discuss politics or religion. Taking care of the environment is the sane, nonpolitical thing to do.

Thursday, April 28, 2016


When you think of organizing a lawn so as to use plants that require minimal water, you think of people who live in arid climates. However, xeriscaping is used in most ecosystems. Georgia has plenty of rainfall. But it also has periods of drought. It taxes the water production to water lawns and gardens during periods of drought. With increased population, the cooperative services encourages people to use xeriscaping.

Native plants are good to use because they have adaptations to that particular ecosystem. Turf grasses make a great lawn and varieties such as Bermuda grass that need little water are a great choice. One friend of mine assumed the bean plants in his garden would be languishing or dead because of dry spell during his vacation. The heirloom variety were just fine.

Design garden beds with swales. Swales can be about two to three feet wide. They have a depression in the center so that rainwater will gather toward the center. Plants that need more water should be planted toward the center and more drought tolerant toward the higher ends. The size of the swale depends on the utility. I am familiar with the term turf row. But I see terracing and contour planting that employs this technique to stop run off from eroding the land. A swale is a variation of this practice on a smaller scale.

What looks like puddling of water in the middle of a pasture is actually a turf row
placed in the field to retain water and slow erosion.
Rain barrels are useful for reducing water use from a municipal supply.

Use mulch to hold water to the ground, moderate soil temperatures and provide nutrients to plants.

Planning the landscaping first enables you to plan irrigation needs. Like most things, the simpler you keep things, the more likely it will function well.

Every region needs to look for local advice. Usually a college or university has a department that delivers information to the general public. Below are two examples from the University of Georgia. Look to sources in your area.

Wednesday, April 27, 2016


A watershed is the area of land in which rainfall eventually flows into a river. The Flint river starts as a ditch running through Hartsfield-Jackson Atlanta Airport. The Ocmulgee river starts as a ditch in central Atlanta. All rivers start quite humbly. Then other rivulets of water join and a creek forms. Creeks flow into rivers.

What we as citizens need to be aware of is not to contribute to water pollution. I live in the country and I pick up my dog's poo. I live within half of a mile of the Flint river. A culvert runs under the road in front of my property to carry rainwater into the river and I do my part. Dog poo as well as excessive pesticide and fertilizer use contaminates the river.

I also do not mow where the culvert is. I allow the grass, etc to filter out problem items. After heavy rains, I pick up trash that people have tossed from cars. It is surprising how much gets hidden in the brush and is carried by water.

There are two sorts of water pollution, point and non-point.

Point pollution is where a large amount of pollution from a single source moves into a river ecosystem. Since there is usually a place this can be traced, it is easier to stop the culprit.

Roads deliver a great deal of thermal pollution. On very hot days, the pavement absorbs heat. When it rains, the water absorbs the heat and flows into the river. Thus a spike in temperature of the river occurs that can kill organisms. Hence, another reason to leave a grassy area. The water is slowed and can cool before it enters the river.

Non-pollution is much trickier. This is the cumulative problem of small pollutants from various sources. A car leaks oil or transmission fluid. This is carried to the river. This form of water pollution is harder to deal with.

In cities, storm drains can become clogged with leafs, grass clippings swept into storm drains instead of being bagged for removal.

I found this diagram on a great blog with a lot of good information. The blog is

This link will bring you to a great watershed map of Georgia and Alabama. I will post it later on my blog if the gentleman gives me permission.

Flint River Watershed of Georgia courtesy of wikimedia commons.

FlintRiver watershed

Tuesday, April 26, 2016

Volatile Organic Compounds

Volatile Organic Compounds sounds pretty dangerous. But maybe it is and maybe not. It all has to do with concentration and origin.
Pine Needles

Plants like mint, marigolds, pine, rosemary, etc have lovely strong aromas which are due to Volatile Organic Compounds (VOCs) released when you crush their leaves. I cut rosemary and put them in a vase to give my home a good smell naturally. However, too much of the aroma could cause problems for someone with asthma or lung disease.

You can distill the VOCs and they can cause problems. In cotton mills, a problem millworkers dealt with was brown lung which was caused by the inhalation of small cotton fibers. Who would think cotton which we use as a beauty product and the manufacture of quality clothing could be dangerous. Small cotton fibers are not VOC's.

Volatile Organic Compounds are called volatile because they have a high vapor pressure which means they can exist as a gas at normal temperatures. They are organic in that they originate from living organisms.

Large quantities are toxic. Some VOCs like benzene and fossil fuels such as propane are toxic. They have a low solubility in drinking water and can contaminate ground and surface water. A popular remedy for fire ants is to use gasoline. Gasoline is a VOC which can contaminate large quantities of ground water. So it may kill a fire ant nest but it's after effects on the environment is much more serious and cannot be remedied easily.

One problem of VOC's is that they may be released from common building products such as carpet, air fresheners, or photocopiers. A concentration of VOC's in a poorly ventilated building may cause "sick building syndrome" in which people who live or work there have chronic illnesses as a result.

Sunday, April 24, 2016

Umbrella Species

An umbrella species is one in which their protection enables other species to be protected.

The world is full of ironies. One of them is that some of the most adamant protectors of the natural world are hunters and sport fishermen. Degrade the environment and their hobby becomes non-existent. Many hunters spend more time watching wildlife. The strongest wildlife preservation organizations in Georgia are those concerned with hunting.

Native bamboo such as Arundianaria gigantea (River or Giant Cane), Arundianaria tecta (switch cane), Arundianaria appalachiana (hill cane) used to form thickets that allowed many species to thrive. Work has been done to re-establish these in Panola Mountain State Park and Riverbend WMA in Laurens County. Grassland birds and butterflies as well as the notorious Canebrake rattlesnake will be provided more habitat.

In planting bamboo, invasive varieties such as the Golden bamboo are not good. Where I live, the suggestion to plant bamboo is considered foolhardy because of it's invasiveness.

River Cane Goose Creek SP NC 8559 (3239220649)
River Cane - Goose Creek State Park, North Carolina courtesy of Wikimedia Commons

Switch Cane (10562026655)
Switch Cane in Hopkins South Carolina courtesy of Wikimedia Commons

Saturday, April 23, 2016

Territory and Trophic Levels

Some ecological terms define themselves. Territory is the area in which an animal will defend as theirs to live and feed. Competition between animals of the same species also includes animals of different species that feed alike.

A gentleman that did a Bird's of Prey presentation at Georgia Southern University spoke of how he was going to train a falcon to hunt with his Jack Russell. The training did not last long. The Jack Russell was unharmed from the falcon's instinct to take it down first. Species that compete for food are natural enemies.

Trophic level is the level at which an organism feeds. The first trophic level are the producers or green plants. There are a few organisms that live in the deep ocean that use chemosynthesis to produce food. They do not make nearly the amount of energy for the effort as green plants do.

The second trophic level are the herbivores.

The third trophic level are small organisms that feed on plants, animals, decaying matter or a combination of these items. Some animals are called opportunistic eaters. They eat whatever is available. Examples are bears, squirrels, opossums. There are videos of deer eating small birds. Many herbivores do eat animal matter in small quantities compared to their primary diet.

The fourth trophic level are carnivores or meat eaters. They have varying amounts of vegetative matter needs which are usually satisfied with whatever is in their herbivore's prey's stomach. When weak, sick or elderly, this group feeds more on dead and decaying organisms. This level would contain, hawks, eagles, foxes, panthers, wolves.

A truth of each level is that only ten percent of the food eaten by any organism is used to build new tissue. Ninety percent is used in day to day living of looking for another meal, maintaining body heat or reproducing. Interesting enough, a great deal of food is needed to maintain body heat.

The size of a large cat determines how much meat is needed each day. Non-domestic cats are obligate carnivores and their bodies are unable to break down plant material for the nutrients they need. A cat smaller than 40 kilograms (88 pounds or 6 stone, 4 pounds) needs about 4 percent of their body weight a day. That would be 12 pounds of meat for a approximately 14 kilogram (30 pounds or 2 stone, 2 pounds) cat  or 16 kilograms(35 pounds or 2 stones, 7 pounds) of meat for a 40 kilogram (88 pound) cat. Cats larger than 40 kilograms (88 pounds) require 1 1/2 to three percent of their body weight in meat.

An alligator needs to eat 8 to 10 percent of their body weight per week. Or about 1 to 1 3/7 percent of their body weight a day. Alligators and other reptiles are usually fed once a week. This suits their needs compared to how they would eat in the wild and their low metabolism. The drop in the amount of food needed compared to warm blooded animals should be noted. This is due to not having to maintain body heat. Like warm blooded animals, alligators decrease their food requirements with size and age.

Thursday, April 21, 2016

Sustainability and Soil

The biggest problem environmental science has is public relations. No one likes to hear about your problems, discuss their unsolvable problems ad nauseum, or just contemplate a big downer.

But environmental science is an applied science. It is taking what we know to manipulate a situation so that we maintain a great lifestyle and protect the natural world. I always loved teaching students that this is a good manipulation.

Sustainability in an ecological sense is maintaining a healthy ecosystem with diversity.

Soil is what covers a great deal of the land surface. It can be weathered rock. It can be defined by it's chemical composition. White sand beaches is made up of white quartz with a few other minerals. Black sand beaches are made of ground basalt. Basalt has a heavy iron content and contains no quartz. The moon's surface is made up of mostly basalt.

The type of soil determines what will grow in an area. Too much sand, the water drains quickly. You can have heavy rainfall; but, the hot dry days will limit plant growth to succulents and cactus.

Heavy clay soils can become very hard. The soil is clay in central Georgia. You have to break the soil up after a rain. Otherwise, it bakes in the sun and becomes very hard. Water from the next rain has a hard time penetrating this dry hardened soil.

The best soil is loam. I worked with a teacher who brought to Georgia a large jar of black soil from Ohio.  She was right about the soil being richer. Loam is made up of soil particles of various sizes and humus. Humus is made up of dead and decaying matter.

My great grandfather always talked about how bad the soil was in Northeast Alabama. The vegetables were not as tasty as the ones grown in Pennsylvania where he was a boy. My great grandfather was right. The soil influences the taste and nutrition content of vegetables. If the nutrient is not in the soil, air or water, there is no way for it to become a part of the plant. Unless the raw materials are available and the plant is able to manufacture the compound.

The funniest comment I have heard about the soil in central Georgia is that our dirt is red. It is red from an high iron oxide content. The same iron oxide which is responsible for the surface of our neighboring planet Mars being red.

What does soil and sustainability have in common. Conservation of cropland for food growth is essential for our survival. Conservation of wildlands for a\plants and animals are necessary for their survival. To accomplish this, it takes the resolve of the people and appropriate legislation to guide people to do the right thing not put their heads in the sand and hope the whole situation stops.

Some of that red dirt in Georgia. Corn is on the left. 
Field of Canola in bloom. The boxes are honeybees which are transported to fields to ensure pollination.
Pine trees planted in field. The beautiful yellow flower is Carolina Jessamine.
View from Dole Banana farm in Hawaii. 
Field of sorghum

Cotton maturing on the plant.

Reduce Reuse Recycle

The three R's of environmental science are reduce, reuse and recycle.

Nature naturally recycles everything. The recycling of nutrients happen so fast in tropical rainforests that there are very few nutrients just lying about unused. Interesting enough, when these forests are cut, their nutrients leave with them to produce poor soils that can barely sustain grass.

Reduce means reduce your consumption.
I keep my doors closed and use low consumption light bulbs. We all have our ways of contributing. This saves me money and reduces the amount of electricity used by my home.
Yard Art Created from discarded metal objects.

Recycle means to repurpose items. When you recycle an aluminum soda can, it saves 5 hours of electricity which you can use to run the lights in your home. Some items are not recycled easily because either there is no set up for the reuse or it is not profitable. I have compost from vegetable waste. It is a good fertilizer for the lucky plants that get it.

Reuse is simple. My mother will take a plastic bread bag, rinse it and put it over an object to dry to use again. Her generation was very practical and thrifty. I don't know if that can catch on unless the disposable income of people drops which I hope does not happen. In the United States, it is popular to have yard sales in which people sell unwanted household items. This produces some money for the person but also recycles the object by someone else.

Plastic soda bottles produce excellent polymers or strings of plastic to reuse. The biggest reason they are not recycled is the cost of petroleum. With the low cost of petroleum, it is just cheaper to manufacture more versus recycling what has been produced. A consumer response to plastic is that bottles of water are sold in lighter bottles. Less plastic for the landfill and a lower weight to ship to the consumer.

Cardboard dropped in prices during the last recession. The recession was world wide. China buys a great deal of cardboard for recycling to manufacture paper products and packaging to sell to themselves and the world. With the recession, there was less demand. Purchasing paper towels and toilet paper made from recycled paper encourages recycling.

My older brother is developmentally delayed and works at a workshop. The workshop found a niche in recycling newspaper, cardboard, glass, aluminum. They also have a thrift store in which they sell donated items. I am currently downsizing my home and I donate many things that we do not use. It provides a job for about 200 people in addition to the approximately 40 staff members employed.

As a classroom teacher, I told my students, one day someone is going to get rich mining landfills in this country. Reduce, reuse and recycle keeps a lot out of landfills.

Wednesday, April 20, 2016

Quiz Time

1. Which of the following is an applied science?
a. ecology       b. environmental science       c. botany        d. marine biology

2. Where an animal or plant lives?
a. habitat        b. niche        c. limiting factor       d. keystone species

3. What an animal or plant feeds on?
a. habitat        b. niche        c. sunlight         d. limiting factor

4. A factor in the environment that must be present in sufficient quantities for an organism to live and reproduce.
a.  habitat     b. niche     c. limiting factor        d. botany

5. The Flint River water crisis in Michigan is due to
a. pollution pure and simple
b. faulty duct work of delivering water
c. lack of testing of water
d. answers b and c

6.  The single biggest reason organisms become extinct is
a. development
b. pollution
c. loss of habitat
d. hunting

7. Heavy pollution will
a. cause everything to die
b. cause some organisms to become extinct
c. decrease the lifespan and increase disease of all organisms including humans
d. b and c are correct

8. All food in the food webs are created by
a. producers from sunlight
b. decomposers of dead and decaying matter
c. herbivores that eat plants only

9. Most of the energy derived from food is used for
a. building strong bodies
b. energy for day to day living
c. reproduction
d. producing more energy

10. When an environmental disaster such as a radiation spill is said to cause 1 out of 50,000 to acquire cancer, that person
a. usually already has cancer
b. would normally never get cancer
c. all cancer is caused by radiation
d. none of the answers are correct

Answers are below the picture.
Hooray, you finished

1. b       2.  a      3. b       4.  c      5.  d      6. c      7. d       8. a      9. b      10. b

Pat yourself on the back if you got any right.

Tuesday, April 19, 2016

Plankton and Producers

Plankton are microscopic organisms that may be plants, may be animals or may be a combination of the two. Many are single celled organisms. Others are very simple organisms of several cells. Most need a microscope to be seen.

In studying pond water, river water, and ocean water, you would expect to find many of these organisms. However, they are the start of the food chain and they have been consumed. They multiply rapidly and fuel the beginning of many a food chain.

Sometimes when these organisms overreproduce, they cause the food chain to come to a halt. Their overabundance clog the gills of fish which die from a lack of oxygen and a huge fish kill occurs. You can have too much of a good thing.

Which leads back to balance. There is always a balance in nature. That balance is naturally good. We tend to have the opinion that nature has the capacity to bounce back. And it does. It is just that there is a new normal which may or may not include native species to that environment.

Many think well so what. The new normal functions. That is true. But it is something that is lost as a result. Could that plant have a medicine that could produce a pharmaceutical? Will the new normal produce a drier climate or will sea levels rise and there is less land for people to live much less farm for food. We don't really know the answer. But we can make predictions on what has happened in the past.

My father was a veteran of World War II. He talked about how much oil and gas they dumped in the ocean and the ocean was able to handle it. The world's population of humans has 7.4 billion people compared to having 2.2 billion people in 1945. A three fold increase means there is a greater demand on the Earth's productivity which are dependent on diversity and healthy ecosystems.

Meanwhile innocuous plankton are busy providing food the way they should in a balanced ecosystem.

Sunday, April 17, 2016

Old Growth Forrest

Succession is the progressive growth of plants on soil and bare rock. It moves in predictable stages. The types of plants present determines the types of animals that will live there. If there is no food source or clean water, an animal will not survive.

There are some islands in the Pacific that only has species of birds which have flown there. Mammals and reptiles could not make the journey over water. On Oahu, Hawaii, we saw a mammal and we knew it was a mongoose. The mongoose was introduced to control rats.

The island of Kauai was spared the mongoose. The story is that a mongoose bit the man who was supposed to release them on the island. He threw them into the ocean to drown. There are feral rabbits, donkeys, cattle, sheep and pigs on the Hawaiian islands. However only the hoary bat is a native to Hawaii.

The island of Surtsey off the coast of Iceland is studied to observe succession. This island rose from an underwater volcano from eruptions between November 14, 1963 and June 5, 1967.

The first plants to colonize bare rock are lichens and mosses.

In time a soil will be created and quick growing annuals will grow. This will subsequently be replaced by grasses. Excessively cold temperatures like in the tundra may only progress to a heavy growth of lichens and moss.

A lack of moisture will reduce the growing season to a short quick one for annuals. Deserts are all known for the prolific blooms of flowers after short heavy rains.

Grasslands will slowly progress to a pine forest in Georgia,because there is enough rainfall to support trees. Old fields will revert to pine forests. Pine trees live for about 50 to 70 years. An understory of hardwoods will eventually replace the pine forest.

What is unique about old growth forests is the increased amount of diversity in it's many stories. The pressure for lumber and more cattle grazing land increases the amount of demand on Old Forests. Less than 3 percent of the old forests in Europe remain today.

Northern Asia still has 19 percent of it's forest, and they are the largest Boreal forests in the world. North America retains 28 percent of it's old growth forests. These are located primarily in the western states, Alaska.

South America has 35 percent with most located in Brazil. Brazil clears more land every year until it will drop considerably in the next ten to twenty years.

Old growth forests in Africa hoovers around 8 percent. South Asia retains about 7 percent of it's natural forests and the western and northern portions of provinces in Canada.

In the Southeastern United States, tree farms are planted for the harvest of timber which takes stress off deforestation.
Forest in Alaska South of Anchorage

Grassland with grazing wild Buffalo in North Dakota

Waimea Canyon in Kauai, Hawaii

Understory of Oaky Woods, Georgia, USA

Canopy of old forest - Oaky Woods, Georgia USA

Canopy of Oaky Woods, Georgia, USA
Oaky Woods is in danger of development.

Saturday, April 16, 2016


Niche is what an organism does to make a living.

Fungi feed on dead and decaying organic matter.

Green plants are producers. They change sunlight into food energy. They do require a certain amount of water and nutrients from the soil to do this.

Opossums are opportunistic eaters. They eat plants, they kill and eat small animals, they scavenge from carcasses.

Carnivores are at the top of the food chain. They eat meat.

Herbivores eat plants.

Omnivores eat plants and animals.

We talk about the food chain but it is actually a web. The more connections a food web has, the healthier it is. It is sort of like Ireland during the Potato famine as it is known in the United States or the Hunger as it is known in Ireland. Plenty of food was grown and exported. However, the peasants only ate potatoes.

When the blight affected the potato harvest for several years, many people starved. Others emigrated. Ireland's population was at a historic high of approximately 8 million in 1841. Today the population is slightly over 6 million today.

So when ecologist discuss that an ecosystem does not have enough diversity. This is why it has a problem. If there is one organism that the entire ecosystem revolves around, it's loss will devastate the ecosystem.

The Chestnut blight still affects North American forests. At one time Chestnuts fed people and animals. When the tree virtually disappeared, there are a few that have survived, it left the ecosystem dependent on acorns, pecans, walnuts, hickory nuts to make up for it's loss. Some years they are not enough.

It takes 1000 pounds of vegetable matter to convert to 100 pounds of animal matter. 900 pounds is lost in the energy of day to day living. 100 pounds of herbivore will produce 10 pounds of carnivores. This is why there are much fewer cougars, bobcats, coyotes, wolves compared to herbivores such as deer and rabbits.
I post this picture too many times. But I love how the spiders get busy and build webs in an overgrown field.
You don't notice the webs during the day. The morning dew on them makes them more visible.

Friday, April 15, 2016

Mass Extinctions

I'll post at the end of the challenge the stats on how many people click this link compared to the other 25. It will be remarkably lower. This post is what I consider adult content. Children need to be taught hope. Adults know that hope is real. Life is real. Life has no guarantees. And so Adults, lets look at the reality of mass extinctions.

Geologic Eras are marked by mass extinctions. 600 million years ago, invertebrates ruled the Earth. Dinosaurs roamed the Earth 150 million years ago. They have posited that a massive cooling of the Earth and Cloud of Dust from an asteroid strike could have caused the extinction of dinosaurs.

A few species of large reptiles live on such as alligators and dinosaurs. We are all enamored with dragons. Were there large reptiles in man's history that fuel the almost worldwide concept of the dragon? We will never know. But what we do know is that the world is experiencing mass extinctions of flora and fauna. This truly in geologic time is the end of the Cenozoic Era.

What can one person do? They can do very little. You can change your habits and reduce your consumption of energy. You can approach household items with the adage, reduce, reuse and recycle. You can reduce your use of pesticides and herbicides and promote the formation locally of natural areas.

What you can do on a larger scale is not repeat the scoffing that environmental problems are just a tree-huggers baloney. I come from very humble roots in the United States. My predecessors are what were called rednecks. They acquired a rough leathery neck from working in the sun. My lineage does not lend me to some ivory tower holier than thou environmental fanatic. It does give me the humility to know I am just part of the world not it's controller.

Psychologically I understand not acknowledging a problem because it's solution is so immense. I don't believe in teaching children the gloom and doom aspect of environmental science. You teach them that we can find solutions if we are so determined.

I also believe you teach children there is a trade-off for everything. Everything has a price. Does the short term satisfaction merit the long term detriment.

We feel sad that lions, the great Apes, tigers and large mammals are endangered. We pat ourselves on the back that the Bald Eagle population is increasing. We don't acknowledge that the acidification of the world's oceans along with overfishing may decimate all salt water vertebrate species by 2048.

With not acknowledging how humans affect the environment, we don't acknowledge the environment's affect on humans. In that by not protecting the environment better. Humans are also on the extinction list.

Wednesday, April 13, 2016

Limiting Factor

The population of any organism will increase exponentially until a limiting factor comes into play. You think the limiting factors would be sunlight, temperature, amount of water. But these factors affect the type of organisms in an environment. Organisms best suited for the amount available for all of these will be more likely to reproduce.

All populations are limited by limiting factors. There are density dependent and there are density independent limiting factors.

An increase in density will cause more stress on the organism in addition to problems living close together such as the transmission of disease being more easily facilitated. Competition between organisms may make some organisms limited to territories with less food resources. With less food, reproduction and/or the nurturing of offspring is less successful. Higher populations of organisms may make them more vulnerable for predation.

Disease, competition and predation are density dependent limiting factors. These are biotic or living factors.

Food/nutrient availability, weather, natural disasters (earthquakes, tornadoes, hurricanes, volcanos, weather shifts, droughts) or pollutants are density independent limiting factors. These are abiotic or non-living factors.

Excessive pollution does not kill off a population. It reduces the number of individuals in addition to the longevity of the individuals. We think of humans when we consider populations. But non-human species are affected. The increase of acidity in water in the Southeast weakens the native Dogwood tree to the affects of the anthracnose fungi. As a result the population of Dogwood trees will have a slow decline in numbers as the anthracnose is spread. Hence a density independent factor enhances a density dependent factor.

This plant is called Carolina Jessamine. It's flowers resemble honeysuckle. There are cases of poisoning from people who
attempt to drink the alkaline nectar produced by this plant. The honey bee which is not native to North America will
be poisoned by this plant's nectar. However, bees native to North America are not affected. 

Tuesday, April 12, 2016

Keystone Species

Try balancing on one foot. You may do it well on first try. At my age, part of my daily exercise routine is to alternately stand on one foot along with getting on the floor and getting back up. That balance improves my overall functioning. A keystone species works the same in the functioning of an ecosystem. The loss of a keystone species changes the dynamics of an ecosystem much like losing your balance affects your day to day activities.

As ecosystems are stressed by human activities, there is a greater need to protect keystone species. A keystone species protects an ecosystems health by it's activities. The keystone species is usually a predator.

Coyote in forestWhere I live, coyotes are considered a problem and there is no limit on how many people can hunt. However, coyotes do have their benefits. They are very adaptive animals and are found in urban areas such as Atlanta, GA.

Coyotes keep the population of rabbits, mice and other small animals down. On the sad side, they love cats. Near my home there have been some short-lived cat colonies. They were short lived in that coyotes love to eat them. I have one cat who lives in the house for obvious reasons.

It sounds cruel that the coyotes eat the beautiful bunnies, rascally squirrels, harmless field mice; but, eat of these species can overpopulate and become a problem. And this goes back to balance. When a population overpopulates they can destroy their own food supply and make room for invasive species that would not fill the void.

There are other predators present such as the bobcat, fox and a few bears in the Southern pine forests. Move to rivers and creeks and you will find alligators.

When sea otters were over hunted in the Pacific Northwest, their food source the sea urchin overpopulated. The sea urchins ate the kelp forests underwater which provided food and protection for many species. The kelp forest ecosystem was unstable and began disappearing. Fortunately, sea otters have made a comeback.

Hummingbirds are a keystone species in the Sonoran desert. Their feeding activities pollinates many desert plants that would not have a pollinator otherwise.

Although they are herbivores, elephants are a keystone species to the African Savannah. They eat and pull up the acacia tree. Otherwise the trees would grow until a forest occurred which would be detrimental to the many migrating grazing species such as the wildebeest, antelopes and zebras.

I've taken some of this information from the following National Geographic link.

Monday, April 11, 2016


A jungle is an undeveloped forest in a tropical climate with high humidity. This environment spawns a great diversity of species. When these forests are cleared to produce land for grazing animals or places to live, the nutrients quickly leave. The nutrients are constantly in a state of use by the animals and plants. They are better known as tropical rain forests.

The names of forests change depending on the climate and the amount of rainfall. All forests have plenty of rain. Trees only grow where there is adequate moisture. When there is not enough rain for trees, the land is covered in grasses. The grasses of the plain states were so tall, men on horseback could just see over the grass as they traveled.

With less rainfall, plants change to those that cope with dry conditions such as succulents and cactus. In extreme desert conditions, plant growth is minimal to non-existent.

On the west coast of North America in Canada and Alaska, the forests are called temperate rain forests. They are called rain forests in that they receive a great deal of rain. Although the latitude of Alaska is much further North than the latitude where most Canadians live in Canada, the weather is milder due to warm ocean currents.  The interior provinces of Saskatchewan and Manitoba are much colder than British Columbia. They are further from this warm moist air.

England does not get a lot of snow. The warm Gulf Stream that originates in the Caribbean warms the British Isles. We associate harsh weather with the highlands of Scotland. Scotland is buffered from the warmth by Ireland.The higher elevations found in Scotland creates a colder climate.

The coniferous forests of central Canada is called a taiga or boreal forest. Tall evergreen trees are able to allow snow to fall on the ground versus weighing down their branches.

Much of the eastern United States and Canada have deciduous broad leaf forests. These forests have hardwood trees which lose their leaves in the winter months to return in spring for the summer months. The Southeastern Coastal Plain of the United States has Southern Pine Forests in nutrient weak, sandy soil.

There are many names for the different forests in the world in addition to the different ecosystems. In mountainous regions, the ecosystems change rapidly as you go higher in elevation.

So we think of any heavily forested area that is heavily vegetated as a jungle. But not all jungles and forests are alike. They are affected by temperature, elevation, ocean currents and rainfall to create their particular ecosystem.

Southern Pine Forest along  Cedar Creek in Georgia USA during winter
Coniferous forest along highway through Denali National Forest in Alaska, USA summer

Forested area of Alaska between Anchorage and Seward - summer

Waterfall in Rain forest in Hawaii

Sunday, April 10, 2016

Environmental Impact

Massive constructions, road building,reservoir creation, dam building, any major change in the environment requires an environmental impact study.

 A culvert that drains run-off in front of my home goes directly into the Flint river. I do not farm my property so I do not have to comply with environmental problems. One of the chief problems I could create with farming is excessive fertilizer or animal waste into the Flint River. Due to that there are county municipal codes I would have to follow. These codes are not recent, they have been around awhile to protect the environment.

Environmental scientists and/or engineers do these studies. There is a population of bears in Central Georgia. As a result, a new road widening will include tunnels for bears and other wildlife to use close to the Ocmulgee river. The design is due their work.

There are many careers which are environment related.

Forest rangers are law enforcement officers. They train to protect people and maintain natural areas. They keep logs of wildlife and flora present. Records of problems with invasive species are maintained. They monitor the activities of recreational hunters and fishermen.

Foresters work with commercial forests. Timber production has increased the amount of forested land in Georgia. People equate logging with the destruction of forests. Ironically, the growth of forest for wood production causes more land to be planted with trees and more habitat produced.

Below are photos of runoff in front of my home. Beneath the photos are some of the many environmental science related careers.

Runoff from heavy rain

The following are a few environmental science careers.

  1. arborist
  2. ecologist
  3. entomologist
  4. farmer
  5. fisheries manager
  6. forest engineer
  7.  forest pathologist
  8. forest supervisor
  9. park ranger or manager
  10.  plant physiologist
  11. technical writer
  12. wildlife manager
  13.  environmental educator
  14. environmental engineer
  15. environmental lobbyist
  16. museum curator or naturalist
  17.  parks ranger or naturalist
  18. recycling management
  19. waste disposal management
  20.  agricultural agent
  21. biochemist
  22. chemical engineer
  23. ecologist
  24. environmental activist
  25.  environmental consultant
  26. environmental researcher
  27. environmental scientist
  28. environmental lawyer
  29. government regulator
  30. microbiologist
  31. parasitologist
  32.  pollution engineer
  33. range manager
  34. soil scientist
  35.  toxicologist
  36. embryologist
  37. geneticist
  38. geochemist
  39. geologist
  40. oceanographer
  41. political scientist
  42. research scientist

Saturday, April 9, 2016


Habitat is where an organism lives. The temperature, water, sunlight, food source needed is available.

I planted grapefruit trees in my yard. They were supposed to be tolerant of temperatures to 22 degrees Fahrenheit or -10 Celsius. They weren't. They died promptly after the first freeze.

I have plans to purchase the variety of banana plants called cohol veinte. They are supposed to set fruit that mature before the plant freezes back each year. It is best to grow what is suitable for your climate.

About ten miles as the crow flies, there is a great deal of sand. There is a road in the area called cactus hill. There is plenty of rain but the sandy soil doesn't hold onto the water. So you have cactus.

The greatest predictor of extinction of a species is loss of habitat.

I'm a bit cynical about this. Whenever a developer wants a piece of land, they may be delayed but eventually the land will be developed. So many of our natural areas are in undesirable locations for people to live. The nuclear disaster at Chernobyl has produced a natural wonderland for flora and fauna.

This is why I never enjoyed teaching environmental science. People will support protecting the environment. But economics make a lot of decisions. When the knowledge that many dolphins were killed during tuna fishing, sales of tuna dropped dramatically. This demonstrates the general public is in favor or protecting species. Tuna companies began advertising their tuna was caught with dolphin safe nets to encourage sales.

I don't develop my small piece of property. No insecticides or herbicides are used. It is not a big natural area but it is my part. I love a late evening walk and hearing the birds settling into the deep grass for a short night's sleep.
Westward View from my Front Yard. 

Friday, April 8, 2016


A well supplies the water to my house. There are many sources of freshwater that we use. It can be from nearby rivers and lakes created to provide water or an aquifer deep within the ground. My well is deeper than 300 feet. I would like to get a solar powered pump. However, when I looked into it ten years ago, I was told my well was too deep to be serviced with solar power.

Withdrawing water for agriculture is a contentious issue. Some states particularly in the west have regulations regarding withdrawing water from wells for a region. Excessive use can deplete an aquifer or lower the water table.

NPR article of overuse of groundwater by Saudi Arabian farm in Arizona

Although approximately 70 percent of the Earth is covered with water, only about 3 percent is freshwater. All of my percentages are rounded off. Precise percentages can be found in the following two sources.

Wikipedia breakdown of world's water

USGS water resource

Of the three percent freshwater, about 1.5 percent is groundwater and 1.5 percent is glacial ice and snow. About 1/10 of a percent is the world's lakes, rivers, streams, swamps, humidity. Water is a finite resource.

Some ground water is salt water. Excessive removal of freshwater along the coastline produce an encroachment of salt water into freshwater sources.

The Flint river which is about 2/10 of a mile or about a 1/4 of a kilometer from my house as the crow flies biggest problem is water flow. It is a relatively clean river free of pollutants. However excessive removal of groundwater and surface water affects its health. A great deal of the water that flows in the Flint is due to springs and underground water coming to the surface.  

Excessive irrigation for farming causes some land to become so salty that it cannot support farming and most plant life. Minerals are dissolved in water. Repeated watering causes a buildup of minerals. Water leaves by run-off, plant use or evaporation. The minerals are left behind.

Thursday, April 7, 2016


Salmon fishery in Alaska. Note the man-made ladder of the salmon run.
Environmental Science includes the study of best practices of natural resource management. This includes urban planning, wetland management, agroecology, fisheries, agroculture, forestry and other disciplines.

Ninety percent of the fish consumed by people are salt water fish. Fisheries can be the introduction of small fish into an ecosystem. In the fishery pictured in Alaska, they take the eggs and sperm of caught salmon and stir them together to produce small fry to reintroduce. This is called fry farming. At one time the fry would be lost in the salmon harvest.

Aquaculture is a very old practice. Oysters have been cultivated as far back as one century before the common era in the Roman Empire. Jack London wrote a short story about Oyster Pirates. East Coast Oysters were cultivated off the coast of California. Pirates would sneak in and steal the oysters to sell at much lower prices in the marketplaces.

Fish are grown and harvested in ponds, tanks and indoors in some locations. The technology needed to provide nutrients and recycle water are problems solved in these operations. India has a system of ponds in which six species of fish are grown. Some feed off algae and others feed off other components in the pond. Some fisheries have large cages submerged in the water to protect the fish from predation and for easy harvest when the fish are an appropriate size.

Wednesday, April 6, 2016


This is a sensitive topic. Everybody enjoys living in a developed country.

One reason guest workers from Mexico like living in the United States is the infrastructure. My family has a joke that once you get used to Central Heat and Air, you never want to go back.

We know that for a fact. The Southeastern United States has been traditionally poorer than the rest of the country. Add to that, the advent of air conditioning between the 1960s and 1990s. When I first taught school, most schools were not air conditioned. By 1990, most schools were air conditioned.

Why am I talking about air conditioning? It is something you don't have to have. But it makes life much better. I never air conditioned my home until about 1990. It just took one summer to make the change. To maintain the lifestyle we have, we have to use energy well.

A combination of energy sources is needed. No one energy source has no problems. Some have more than others. We love gasoline. It fuels our automobiles. I have a moderate sized SUV. I have always been careful to not buy a gas guzzler. But like my dad, as long as I have money, I am driving.

So we are all dependent on gasoline producers. If you will notice, we have periods of high prices with dramatic drops in prices. The Saudi Arabians and other oil rich nations are very mindful of retaining their customers. I can't criticize them. But I can criticize developed countries who do not maintain policies to develop alternative energy.

Adding solar panels to your roof is expensive and it is hard to find a contractor. However, if we all did, we would be less dependent on coal burning power plants. There are problems with recycling solar equipment. However use of solar equipment would be like televisions. They would improve the technology over time.

When I was a kid, cars got between 6 and 12 miles per gallon of gas. Today laws requiring automobiles have better gas mileage have improved this and reduced our need on gasoline. When I lived in the South metro Atlanta area, I attended Georgia State University during the summer of 1984. I rode MARTA. It was so convenient. I did most of my required reading on the buses and trains.

I spent a few days riding the trains to all the destinations just to look out the windows. I recommend touring Oahu by riding "The Bus". It is a great way to see the island. I have a friend who has ridden Greyhound all through Appalachia just to look at the scenery, people and sights as she travels from Georgia to Virginia Tech where her daughter works.

Mass transit over well traveled routes would benefit Americans. Our big problem is we are an independent lot. As I get older, I get excited about self driving cars. I know there will be a day I am not a safe driver. Mass transit would be of great benefit for me as I get older.

There are two sorts of energy, renewable and nonrenewable.

Sunlight, Wind, Hydroelectric, Tidal Turbines are examples of renewable.

Fossil fuels are not considered renewable. It takes too many millions of years for them to be replenished. Fossil fuels are petroleum, oil, or coal. Natural Gas is a fossil fuel but it is produced in old landfills and by organic means.

I asked a man in the tree industry about ethanol for automobiles being made from trees. He said that was not practical in that they needed very clean pellets. So ethanol is a product of the corn industry.

A reality of life is you can't have your cake and eat it too. This describes the problems with energy use all over the world. New supplies of energy are often clumsy and inefficient. But that is how everything is started. Fossil fuels are used heavily because this is what we are familiar with.

Tuesday, April 5, 2016



I love Dandelions. I love how they grow close to the ground in early spring with a bright yellow flower. Mixed with various colors of blue of Viola, Wild Violets, Bluetts and other wildflowers. Living in the country, I can enjoy them spring their tall heads in the middle of the summer before I mow them down that week.

I have had the patience to pick the toothy edged dandelion leaves. They aren't that bad. Sort of like eating Kale with a little bitterness. My grandmother used to gather wild leaves to make wild salad which I have tried to recreate.  I have not eaten the roots.

To make dandelion wine with the flowers, you have to add sugar. I don't know of anyone who has made any dandelion wine. I think that is just a romantic notion. Why would you do that when there are plenty of wild muscadines or blackberries to do the job.

Now what does Dandelions have to do with Ecology. They are naturalized plants. A naturalized organism is an introduced species that has developed a sustainable population but has not become invasive by crowding out native species.

The story is that Indians called dandelions white man's footprints. We think of North America colonized in the 1600's by the English. But the Spanish were first. The WPA built a small Spanish style fort they called Coronado Heights near Lindsborg, Kansas to commemorate Coronado passing through the area in the 1600's. The first Spanish settlement was in St. Augustine, Florida in September 8, 1565.

Who can forget Hernando DeSoto's brutal exploration of the Southeast in 1539 culminating with his death along the Mississippi River in 1542. The complex Kingdoms described by the Spanish were gone when the English came. Disease decimated the Native American populations.

There are similar plants in North America and Europe in that both continents broke apart in geologic history which is quite a long time compared to our lives and the history of man but a short time in the changes of a species.

The introduction of potatoes from the New World to the Old World increased the Old World's population because it was such a hardy food source. The receipt of deer during the first Thanksgiving was an incredible gift by English standards. North America offered meat on a regular basis for the colonist. The 1600s was a hard scrabble time for colonist but probably a better situation that what they left behind in England, Scotland and Ireland.

There have been accidental introductions of species and intentional introductions. Some have greater effects than others. Some have happened so long ago, we really don't know how they affected the ecosystem. This is true for the dandelion. It had traveled from the East Coast to the West Coast by the end of the 1600's.

Today, we have wild hogs, horses, trees, herbaceous plants that have become part of our ecosystems whether we like it or not. These organisms are not considered a problem if they are not invasive. The lawn perfectionist may hate seeing you blow the white billowy seeds of the dandelion; but, blow away, dandelions are part of our natural world.

Sunday, April 3, 2016

Climate Change

Climate Change is real. It is caused by an increase of Carbon Dioxide in the atmosphere due to human activities.

One problem with climate change is understanding what the difference between climate and weather is. Weather is a day to day phenomenon. Climate occurs over decades and centuries. A rise of 2 degrees in average temperature changes an ecosystem greatly. We don't think of our towns and suburbs being part of an ecosystem but they are.

They have studied how people react to bad news such as ecological problems. Most people feel overwhelmed by the problem and a good way to cope is to ignore or deny the problem. Add to that people confuse opinions with facts. Climate change has become political; which is curious in that it should not be.

Gordon Rogers who is the Flint Riverkeeper in Georgia will never talk politics. His point is the health of the Flint River. He brokers deals with everyone. One battle he fought was saved by a tea party constituent who you would not associate with environmental progress. Environmentalist come from every political bend.

For the record, I am not a member of the tea party or advocate it's policies. I do not know Gordon Roger's opinion on climate change or the tea party. Since he is essentially a lobbyist for the protection of the Flint River, I doubt he would have a public opinion. He is negotiating for good water quality of the Flint River.

Like it or not, legislators may have strong opinions which are contradicted by their actions. They may say climate change is not real. Then vote to address the problem of climate change. Or vote on a bill to get someone to vote on their bill. What a legislator wants most is to be re-elected. If the electorate advocates for climate change to be addressed. They will say that is something they think is important. Your opinion makes a bigger difference than you think. However opinion is still not fact. But it is good to base opinion on fact when you can.

It is true that politicians are influenced by their donors. It takes money to run an election campaign.
Donors have different priorities. Your opinion can influence how much that money talks. It is a two edged sword to be elected, donations and voters.
Steam emerging from Kilauea on the Big Island of Hawaii

Saturday, April 2, 2016

Bradford Pear Trees

My dad believed in planting a tree that makes food. When I first bought a house, people said get a Bradford Pear Tree. My sister told my mom she was planting a Bradford Pear Tree. Mom says, "Great. I love pears." My sister shook her head.
Wild Ripe Persimmons which are native to Georgia

Bradford Pear is a cultivar loaded with white blossoms and leaves that turned lovely reds, oranges and purples each fall. Add to that it grew quickly, who could complain. Each fall it would be loaded with tiny, woody pears that softened with freezing temperatures. Birds ate freely and there was no worry about an unwanted invasive species. The seeds were sterile.

Then the soft wood cracked in the winter time and a beautifully shaped tree became misshapen. People trimmed them so that it did not branch so much from the base. The tree still rarely lives more than 25 years. Large oaks grace the neighborhood I grew up. An adjoining neighborhood smiles with dogwoods and azaleas every spring.

You don't see old Bradford Pears in neighborhoods. The rumors that they grow into stately trees one day is just a myth. However, you go by unused fields and you see sprigs of white flowers of volunteer Bradfords. Wait, they are supposed to be sterile.

It gets worse, they revert to Callory Pears which grow into thick thickets like wild plums that are native to North America. Callory Pears are native to China. These thickets of trees have four inch thorns that will easily puncture the tire of a tractor. It takes a tractor with steel tread to travel over a thicket and destroy them.

Pears are not native to North America. Peach trees are not native. We grow a lot of plants that are not native. The problem is whether they become invasive. Fireblight attacks Pear trees in the humid East. So commercially, they are grown in the Northwest. Callory Pear roots are used to produced many grafted varieties of Pears.

I'll be cutting my Pear trees down in the backyard. I was slack and I allowed a few suckers to grow. They actually did better than the original tree. The original trees were destroyed by blight. One tree is one side small knotty Bradford pears and the other nice large eating Pears. We enjoy watching the deer eat them. And this is why I will cut them down. Those small pears mate with the large pears. The deer eat the large pears. Everywhere they defecate, more Callory Pear trees will eventually grow. It might take ten years for enough generations to turn over to Callory; but, they will be there.

If you grow a Bradford in proximity to a European  or Asian Fruit Pear tree, you are producing viable seed that will eventually revert to the original Callery Pear. It is an invasive species which is as bad as Chinese Privet and Kudzu.

So those old opinions to grow a native plant or something you can eat is something to heed. I have planted some more Pear trees. I'll watch for suckers this time. With the blight attacking the other trees, I don't have much hope for the new trees.  Fortunately, I have planted many Apple trees. You don't want the deer to go hungry. They also enjoy the Persimmons and other native plant fruits.

I plan to plant some common pear trees that are not invasive.

Links for further study.

Article merely warns people that Bradford Pear is not a reliable ornamental tree and suggests a Native plant.

Picture of Callery Pear fruit.

University of Florida discussion of Bradford Pear without mention of invasive tendencies.

Clemson University in South Carolina discusses invasive problems of Callery Pear.

University of Georgia publication warning of the Bradford Pear's invasiveness

Greenville, South Carolina article by Durant Ashmore discussing the future problems of Bradford Pears