Draft 1 : Soil pH and Various Factors Concerning Trees in Oxford

This topic submitted by Jason Fox, Carl Marsh, Jennifer Swing ( marshcd@muohio.edu ) on 10/9/03 .

Natural Systems 1 Syllabus---Western Program---Miami University

Proposal
Dr. Chris Meyers
October 9, 2003
Jason Fox, Carl Marsh, Jennifer Swing
Section E
Soil pH and Various Factors Concerning the Trees in Oxford
Questions:
The questions we want to answer in our lab is threefold:
How is the soil pH affected by the decomposition of leaves of 4 key tree species?
Does our soil contain a limestone buffer that negates any possible pH changes?
Is there any statistically significant evidence that leaf pH functions as an allelopathy, affecting seed growth, as well as inhibiting growth under our key tree species? (This will be measured directly by the number of plants growing under these species. We will also measure this indirectly by looking at seed dispersal.

Hypothesis:
Our hypothesis is that there will be a significant difference in the soil pH underneath our key species before and after the major leaf fall. We also that there each of the species will have different levels of pH difference. The most significant will be that of the pine, as its needles are much more acidic than the leaves of the oak, cedar, or maple trees.
Because of this difference of soil pH, there will be a lack of other species that are growing within a certain radius of the base of the tree. This difference will also have an effect on each treeÕs next generation. While seeds that fall near the tree will not be able to grow, those that fall farther away from the parent will do much better, depending on how far they travel. This cycle will then continue with the next generations.
However, should there not be a significant difference in soil pH, and our hypothesis is rejected, there is a plausible explanation. The soil may contain a measurable concentration of limestone that comes from the local bluffs in Pfeffer Park. Because of the inherent basic properties of the limestone, it would absorb the acidity from the leaf litter. Because of this limestone buffer, there would be an insignificant, if any, difference in the pH of the soil. This would in turn, affect the growth of other species around the base of the tree. There would be no difference in the next generation of trees from the seed dispersal.

Introduction:
Our experiment will be examining the role leaf litter plays in fluctuating pH levels in soil and the importance of pH similar to the experiments: Th Development of a Bioindicator System for Soil Acidity based on Arthropod pH Preferences, Tansley review No. 104 Calcium Physiology and Terrestrial Ecosystem Processes, Factors Regulated Nitrification in Primary and Secondary Succession, Selection of Substrate pH by Salamanders, Seasonal Differences in the Availability of Nutrients Down a Podzolic Profile, Phosphate Solubilization by Organic Anion Excretion from Rice growing in Aerobic Soil: Rates of Excretion and Decomposition, Effects on Rhizosphere pH and effects on Phosphate Solubility and Uptake, Plant-Induced Changes in the Rhizosphere of Rape Seedlings-Origin of pH change, Anatomical Characteristics of Roots of Citrus Rootstocks that Vary in Specific Root Length Population Dynamics of Indigenous and Genetically Modified Rhizobia the Field, Influence of a Potassium-Channel Blocker and Metabolic and ATPase Inhibitors on Potassium and Malate Content, H+ Extrusion and Organic-Acid Synthesis in N2-Fixing Symbioses Involving Vascular Plants, Tansley Review no. 47. Interactions of Fungi with Toxic metals, The Effect of Abscisic Acid and Fusicoccin on Mailc Acid Concentration in Pulvini of Phaseolus coccineus L. Also, our experiment tests natural soil buffers from limestone similar to the Development of a Bioindicator System for Soil Acidity based on Arthropod pH Preferences experiment. Like allelopathic plants who drop chemicals to poison competition, trees drop their leaves and if the litter fluctuates the ph, may also act as a allelopath as discussed in factors Regulated Nitrification in Primary and Secondary Succession. This property might influence the dispersal of seeds and seed form. This experiment is vital in exploring the relationship of trees seasonal adjustment adaptations and their relation to affecting overall soil health as it effects the human race as in: An Experimental Approach to Part of the Calcicole Problem, Conservation Tillage, American Journal of Botany Vol. 81 & 82 No. 6, The Effects of Fire on Factors Controlling Plant Growth in Adenostoma Chaparral, and Phosphate Solubilization by Organic Anion Excretion from Rice Growing in Aerobic Soil.

Method:

Part I:
1.) Establish four sites of contrasting varieties of trees (two conifers and two deciduous i.e. maple, oak, pine, and cedar).
2.) At the designated sites observe and count the number of at least 12 inch seedlings under the trees canopies.
3.) Calculate the percentage of seedlings which are the same species as the canopy theyÕre under.

Part II
4.) In the lab (separately researched) observe the method of seed dispersal (i.e. size,
structural adaptations, etc.) to determine whether or not the species ÔintendÕ for seedlings to germinate underneath their canopies, or do they travel, by wind or otherwise?

Part III
5.) After all observations have been made in the undisturbed, designated sites take a minimum of 28 samplings of 0.5 g of each native soil and of a potting soil control*.
6.) Mark the areas where the samples were taken
7.) In the lab bring the 0.5g samples into contact with 50ml of distilled* water for at least 24 hours.
NOTE: Do not disturb samples during this period, so as to not mix sediment into the water.
8.) Test the water from the soil/water contacts with a pH tester.
9.) Record Data in Tables (before section)

Part IV
10.) Before a substantial amount of new leaf litter has fallen secure the designated testing sites of native soil.
11.) Secure one baking pan ² full with control potting soil under the canopy per each site for a non buffered comparison.
12.) After the pans/soil is covered with leaf litter, has set (undisturbed), and decomposition has begun (apx. 3-5weeks) return to sites.
13.) Take another set of samples from each site from both the topsoil (native) and the potting soil (alien microcosm).
14.) In the lab place the 0.5g samples in 50ml of the distilled water
15.) Let the samples set for the 24 hour period
16.) Take the pH tests of all samples.
17.) Record the data in the second half (after)

NOTE: Compare the native soilÕs pH test results to itself before and after to see if there is any measurable change.
Compare the native soilÕs tests to the potting soilÕs tests of before and after.

Draw Inferences of: possible allelopathic-like qualities, evidence of natural buffer in soil, relationship between seed dispersal and pH results and seedling counts.

*Terms:
Potting soil control- the native soil in Oxford is rich in limestone, therefore is influenced by a natural buffer (acid neutralizer). The potting soil acts as a comparison for this variable especially, but for other unaccountable variables.

Distilled water- distilling the water to be used to the pH is imperative because water, the universal solvent, is easily contaminated with minerals and nutrients that might influence the results. For an accurate comparison pure water is needed so that the results reflect the differences in the soils, not water quality.

Our Day:
The class would begin off with a demonstration of a familiar reaction caused by differences in pH, the baking soda/vinegar volcano demo. Then we will do hands on pH tests possibly using red cabbage juice and other mediums, demonstrating similar tests we will be doing on the soil.
WeÕll lead the class through a fun exercise on seed distribution. The exercise will start out with the class drawing Òa seedÓ on a piece of paper. This will explore their pre-conceived notion of what seeds look like. Then WeÕll ask them to explain how their seeds are distributed.. After they draw, color, and write their stories about their seed weÕll explain how seed distribution is valid in our experiment and how it pertains to the pH of leaf litter.
Overall our day will incorporate creative, hands-on interactive activities with lecture and over head slides..

Results:
After collecting the data, we will determine if the pH level of the top soil around various types of trees is the result of the falling leaves or if the pH level was present and remained at a consistent level regardless of the amount and type of leaf that had fallen. If the pH level is changed, we will establish which of our sample trees create the biggest difference in pH levels. We will determine if the pH level around the trees that changed the soilÕs acidity, allow only the treeÕs own offspring to grow or if other types of plants can grow as well. Our point of comparison will be with our control soil, which is purchased potting soil that is not contaminated with local soil.

Conclusion:
We are observing the change, if any, in pH levels around various types of trees and if the level of pH varies from trees with heavy seeds versus trees with lighter seeds that travel a farther distance from the tree. There is a possibility trees do not change the soil around them every year, but there is a relatively consistent pH level around Western Campus.

Bibliography:
Van Straalen, Nico M.; Verhoef, Herman A. ÒThe Development of a Bioindicator System for Soil Acidity Based on Arthropod pH PreferencesÓ Jstor: 217 pp. 7 October 2003 McLaughlin, S. B.; Wimmer, R. ÒTansley Review No. 104 Calcium Physiology and Terrestrial Ecosystem ProcessesÓ Jstor: 373 pp. 7 October 2003 Robertson, Philip G. ÒFactors Nitrification in Primary and Secondary SuccessionÓ Jstor: 1561 pp. 7 October 2003 Mushunsky, Henry R. ÒSelection of Substrate pH by SalamandersÓ Jstor: 440 pp. 7 October 2003 Gupta, P.L. ÒSeasonal Differences in the Availability of Nutrients Down a Podzolic ProfileÓ Jstor: 521 pp. 7 October 2003 American Journal of Botany, Vol. 82, No.6, Supplement: Program with Abstracts of Papers, Posters and Symposia to be Presented at the Annual Meeting of the Botanical Society of America with Other Affiliated Societies, Town and Country Hotel, San Diego, California 6-10 August 1995. (Jun.,1995), pp.1. 7 October 2003 American Journal of Botany, Vol. 81, No.6, Supplement: Program with Abstracts of Papers, Posters and Symposia to be Presented at the Annual Meeting of the Botanical Society of America with Other Affiliated Societies, University of Tennessee/Knoxville Knoxville, TN 7-11 August 1994. (Jun.,1994), pp.1. 7 October 2003 Christensen, Norman L.; Muller, Cornelius H. ÒEffects of Fire Factors Controlling Plant Growth in Adenostoma ChaparralÓ Jstor: 29-30 pp. 7 October 2003Kirk, G.J.D.; Santos E.E.; Santos M.B. ÒPhosphate Solubilization by Organic Anion Excretion from Rice Growing in Aerobic Soil: Rates of Excretion and Decomposition, Effects on Rhizosphere pH and Effects on Phosphate Solubility and UptakeÓ Jstor: 185 pp. 7 October 2003 Hedley, M. J.; Nye, P.H.; White, R.E. ÒPlant-Induced Changes n the Rhizosphere of Rape Seedlings; Orgin of the pH ChangeÓ Jstor: 31 pp. 7 October 2003 Achor, D.S.; Eissenstat, D. M. ÒAnatomical Characteristics of Roots of Citrus Rootstocks that Vary in Specific Root LengthÓ Jstor: 309 pp. 7 October 2003 Hirsch, Penny R. ÒPopulation Dynamics of Indigenous and Genetically Modified Rhizobia in the FieldÓ Jstor: 159 pp. 7 October 2003 Clymo, R.S. ÒAn Experimental Approach to Part of the Calcicole ProblemÓ Jstor: 707 pp. 7 October 2003 Bialczyk, Jan ÒInfluence of a Potassium-Channel Blocker and metabolic and ATPasse Inhibitors on Potassium and Malate Content of Phaseolus coccineus L. PulviniÓ Jstor: 595 pp. 7 October 2003 Gebhardt, Maurice R.; Daniel, Tommy C.; Scheizer, Edward E.; Allmaras, Raymond R. ÒConservation TillageÓ Jstor: 625 pp. 7 October 2003 Raven, John A.; Franco, Antonio A.; Eli Lino de Jesus; Jorge Jacob, Neto ÒH+ Extrusion and Organic-Acid Synthesis in N2-Fixing Symbioses Involving Vascular PlantsÓ Jstor: 396 pp. 7 October 2003 Gadd, G. M. ÒTansley Review No. 47. Interactions of Fungi with Toxic MetalsÓ Jstor: 25 pp. 7 October 2003 Bialcyk, Jan; Lechowski, Zbigniew ÒThe Effect of Abscisic Acid and Fusicoccin on Malic Acid ConcentrationÓ Jstor: 469 pp. 7 October 2003 Does not look like I can paste the data sheets into this text box. If needed I can give you a hard copy.