Thursday, November 14, 2013

Community Gardens

A community garden may refer to a piece of land that is used for growing local crops. These gardens are important because they encourage community development, and provide access to fresh vegetables. The American Community Gardening Association (ACGA) prides itself on being supportive of community involvement in the United States, Canada, and seven other countries. ACGA is active in helping people learn how to grow their own food. Watch the video below to learn more about the work ACGA is doing.

Sunday, November 10, 2013

Soil Classification

When I was growing up in Liberia, I always heard my dad talk about top soil. As I grew older, I learned how to identify a good agricultural soil; However, I had no idea about the many different types of soils in the world.

Soils may be grouped based on their composition, color, porosity, texture, and many other characteristics. Soils are classified into 12 categories called orders.

The images below represent the 12 soil orders of the world. Ultisols is the most prominent soil in Georgia. Click on each image to read more about the corresponding soil.

Sunday, October 27, 2013

Trees Identification

Trees are very important to our environment. They are an essential source of food, oxygen, and medicine. Some trees may be more useful than others in terms of its use for medicine, food, and decoration. During our environment biology lab, we learned about some of the most amazing trees in the US. Of the many trees we saw that day, these are my favorites:

Platanus occidentalis (Sycamore)

Figure 1: Platanus occidentalis 

Sycamore is a huge tree native to eastern North America. It typically grows between 75 -100 feet in height. It grows better in lowland areas, and usually reaches its largest size along streams and rivers. Sycamore is commonly found throughout the State of Missouri. It has a brown bark which shed in irregular pieces to reveal creamy white inner bark. It has yellowish Male flowers and reddish female flowers. The wood of this tree has been used for making furniture, cabinets, barrels and crates; the tree itself is usually used as a shade tree.

Gingko biloba (Gingko or Maidenhair Tree)

Figure 2: Gingko biloba

Ginkgo, the maidenhair tree, is known to be one of the ancient plants that inhabited the earth about 150 million years ago. It typically grows between 40 to 50 feet tall. Ginkgoes can be either male or female and they are native to China. This tree can be used for medicinal purposes or as a source of food. A female Gingko tree is undesirable because it produces seeds which can be messy, and can produce an unpleasant odor. Male Gingko trees are more popular today because they are fruitless. The leaves of Gingko biloba turn golden yellow in autumn, and form a golden carpet around the tree when they fall. Though it can tolerant a wide range of soil conditions, Gingko grows better in moist, sandy, well-drained soils.

Prunus yedoensis (Yoshino Cherry)

Prunus yedoensis

Yoshino cherry is a flowering cherry tree that typically grows 30 to 40 feet tall. This tree can tolerate heat and humidity, and it is adaptable to a wide range of soil, but it does not do well in drought. Yoshino cherry is a hybrid cherry of unknown origin. Its flowers has small black cherries which are unpleasant to humans. This hybrid cherry is one of the most popular flowering cherry trees planted in Washington D.C. It is typically used as a shade or street tree.

Topograpic Map, Mount Kilimanjaro

Mount Kilimanjaro is a dormant volcanic mountain in Tanzania.  It has three volcanic cones: Kibo, Mawenzi, and Shira. Mt. Kilimanjaro It is the highest mountain in Africa, and the highest free standing mountain in the world (at 5,895 meters or 19,341 feet above sea level). The image below represents a typographic map of mt. Kilimanjaro. 

Thursday, September 26, 2013

Ocmulgee River

A graphical representation of the elevation in the Ocmulgee River
The Ocmulgee River is an important source of drinking water for the people of Macon. The river provides clean water for homes and business, and its waterfront is a recreational area for many. Our class visited this river to measure the elevation and flow rate on either side of the sandbar. We used two poles and a string to measure the elevation in the river. We dropped an orange in the river, on each side of the sandbar, and timed it to measure the flow rate.

It was very interesting for me to know that some Mercer students advocated for the construction of the Ocmulgee Heritage Trail which is the only riverside trail and park system in Middle Georgia.

This transformed environment has become suitable for walking, biking, boating, bird watching and other activities.

Tuesday, September 24, 2013

A Reflection on the Mystery of Mega-floods

For our Environmental Biology lab on September 11, we watch a documentary that reveals the power of nature. In the video "Mystery of the Mega-floods", we saw that nature has changed our planet in many ways: It is believed that great land marks, including those of  the channel scabland of eastern Washington State and the Grand Canyon in Arizona, were formed by mega-floods.

According to the video, the potholes, ripples, and giant stones found in the channel scabland made scientist to wonder about the cause of such an unusual landscape.

The geologist Harlen Bretz was the first to mention that such landscape was caused by giant floods; however, he could not prove where the flood may have come from.

Later in the years, scientists agreed that the unusual land marks in the channel scabland was formed by floods from Glacial Lake Missoula. By checking the age of different ash layers, it was believed that the unusual landscape of the channel scabland was actually formed by more than a single flood. This land was hit by mega floods many times.

According to the theory explained in the video, large ice dams can block rivers and cause the formation of lakes. As water bubbles make way through cracks in an ice dam, super cooled water can cause friction which cause bigger cracks in ice sheets. As this process continues, ice dams may collapse and give way to a huge volume of water. Such water body can move at very high spread, carrying rocks and carving up cliffs. Under water tornadoes can cause bobbles of water to penetrate the soil and create enormous pot holes. This is the explanation given for the unusual landscape seen in channel scabland of eastern Washington State.