Merritt Island 1 Group 4

THE OBJECTIVE OF THE EXPERIMENT WAS TO TEST THE EFFECTS OF A CONTROLLED FIRE ON THE NITRATE LEVELS IN THE SOIL AND THE EFFECTS ON THE LOCAL BRAZILIAN PEPPER TREE POPULATION.

Objective

It is a very aggressive, invasive speciesCan cause dermatitis and reparatory problems•Native to Argentina, Paraguay, and Brazil.•Introduced to Florida in the 1840s as a cultivated ornamental plant•Partly responsible for the deterioration of native biotic communities in Florida•Invades aquatic and terrestrial habitats•They grow rapidly and have high germination rates•To control the population, that entire plant including the root system should be removed. Following a fire, the seeds will not germinate, but the plant may still be able to re-sprout from the roots

Brazilian Pepper-treeSchinus terebinthifolius

FIRE MANAGEMENT

Purpose:

• Improve or restore wildlife habitat

•Reduce hazardous fuel loads

•Reduce encroachment of woody vegetation

•Replenish nutrients to the soil

Nitrogen is very important to organisms, as it is required to make amino acids and DNA. It is a large part of the atmosphere, but is in a form is not usable by plants or animals. Nitrogen is released into the soil when an organism decomposes. Bacteria in soil "fix" nitrogen into nitrate, which is the primary source for nitrogen in a plant.

Role of Nitrate in Ecosystems

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The Nitrogen Cycle & Controlled Burns

HypothesisIt is hypothesized that there will be a decrease in Nitrate in soil due to volatization of of nitrate from the heat of the fire. it is hypothesized that there will be no effect on the amount of Brazilian pepper trees in the first year but an increase after one year due to less competition and the Brazilian pepper trees resistance to fire.Alternative: As time after a controlled burn increases, the pepper plant population will increase due to an abundance of nitrate in the soil released from the ash of the fire and then plateau out as nitrogen is used up.

Null: If the time after a controlled burn is increased, the Brazilian Pepper plant population will stay the same and nitrate levels will remain the same.

Procedure

We went into the MI Wildlife refuge, equipped with the following supplies

Pre-randomized coordinatesMarked Transect LinesPVC Pipes, used for collecting soilA meter stick10 collection containers for the soilLog Book for DataA rubber Mallet

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We placed our transect lines along the random coordinates. We planned to count the Brazilian Pepper plants that touched, however we were not able to find any along the lines. We took soil samples at those random points and included an additional sample from an area of concentrated Brazilian Pepper plants and counted 6 plants there. We took 3 additional samples from the Brazilian Pepper plant soil. On the other site we did not find any Pepper plants and took samples from our other 5 random points

SAMPLING TECHNIQUES

Materials:Beakers, Distilled Water, Balance, Soil Samples, Nitrate strips,

Coffee Filters

Work at the lab

We measured our 5 g of soil from each sample and diluted it in 250 mL of water..

... Then poured the solution through a coffee filter and placed 3 nitrate strips into the filtered solution. We read the strips and compared them to the nitrate color sale to determine the nitrate level.

RESULTS

The nitrate tests revealed that there was an indetectable amount of nitrate in the soil(<1 ppm)

Sandier samples had water filter quicker, while

thicker and more moist samples took

longer.

No pepper trees were spotted in the

most recent controlled burn.

Brazilian peppers trees were spotted along the coast of

a river in oldest burn site.

There was a strong sulfur smell near the coast of the

river.

Soil samples collected had

different textures and colors.

When soil samples were filtered, water

seeped through each sample at different rates

depending on their textures.

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Observations

Conclusion• Changes in nitrate levels could not be determined due to the

lack of nitrate in both sites. All that can be concluded is that the fire did not cause an increase in nitrate levels.

• Effects of fire on Brazilian pepper tree population could not be determined because no pepper trees were found on the tested locations. No conclusions are possible to be drawn on this as it was learned there was a Brazilian Pepper tree eradication program going on at the sites that would make any results useless due to the bias that comes with the eradication program.

• Nitrate is very scarce in Florida soil due to rapid plant growth, climate, and the composition and texture of the soil, which causes nitrate to leach underground where it is unusable.

• Thus our null hypothesis is proven

• "Merritt Island National Wildlife Refuge." Www.fws.gov. U.S. Fish and Wildlife Service Home, 22 Jan. 2012. Web. 22 Jan. 2012. <http://www.fws.gov/merrittisland/Firemanagement.html>.

• "G9804 Nitrate in Soils and Plants." University of Missouri Extension Home. University of Missouri, 1993. Web. 22 Jan. 2012. <http://extension.missouri.edu/p/G9804>.

• Soil Survey of Brevard County, FL. Gainesville, Florida: United States Department of Agriculture, 1973. PDF.

Works Cited