Trina Ming 1, Darrell Patterson 4, Randy Peterson 3, Conni Stuehler 4, Samantha Lough 1, Nancy Ko 2,...
1
Trina Ming 1 , Darrell Patterson 4 , Randy Peterson 3 , Conni Stuehler 4 , Samantha Lough 1 , Nancy Ko 2 , Jade Dean 4 , Koang KC Chea 5 , Brian Nagy 4 , Dr. Chrys Rodrigue 4 , Dr. Paul Laris 4 Geosciences Diversity Enhancement Program, California State University Long Beach 1: Lakewood High School, 2: Los Alamitos High School, 3: Wilson High School, 4: California State University Long Beach , 5. UC Riverside Does Size Matter? An extensive study on different soil textures within the coastal foothills and its effect on the distribution of grass and shrub species Introduction The California coastal foothills are the home for California Sage Scrub (CSS), an important native vegetation that is being lost to invasion by non-native grass species. Only about 10 – 15% of original CSS is left in Southern California. This habitat, which is a biodiversity hotspot, is important because it is home to unique plant and animal life (such as the endangered California Gnatcatcher) that can only exist in this area. The reasons why these invasive grasses persist in a way that prevents native plants from recovering is still unclear. We are still unsure if the areas were originally home to perennial grasses that were taken over by invasive grasses. It could be that CSS prefers higher slopes and rocky soil while grasses prefer flat, fine soil. Alternatively, too frequent fires could prevent CSS from recovering fast enough before invasive plants take over. Carbon and nitrogen amounts can contribute to growth patterns (Patterson 2010). Another possibility is overgrazing left the plants unable to grow back (Freudenberger 1987). Mechanical disturbances such as homes being built on the CSS habitat or plowing of the land can also inhibit growth. The purpose is to determine that factors that could be helping or inhibiting the native plants from advancing into the grasslands in order to figure out how to get the California Sage Scrub habitat to recover. Van Dam (2002) says that the amount of organic matter within the soil affect the amount of water retained by it. The specific purpose of this experiment was to find the percentages of sand, silt, and clay in each soil sample. These percentages will then be compared to see if there is a significant difference between grain size in grasses versus CSS and stable versus moving boundaries. Soil samples taken with augers Acknowledgements My thanks go to: Gabby Valenzuela for accepting me into the GDEP program even though my essay was kind of sporadic, you had no idea who you decided to hire. To Paul Laris, Chrys Rodrigue, and Randy Peterson for being the “adults” and “teachers” during this program. We couldn’t have done it without you guys. (Well maybe we could have but only in a super desperate situation and I bet it would not have been as fun). To Jade Dean, KC Chea, Sam Lough, Nancy Ko, and Darrell Patterson for putting up with the complaining that I did. The. Whole. Time. And for putting up with my total lack of knowledge of everything. And for being amazing coworkers for the whole six weeks. To Lora Stevens and Conni Stuehler the toughest soil scientists I know. To the random people working in the lab with me. Your work was completely unrelated to mine but, hey, you guys made great lab company. To Brian Nagy, the best GIS and GPS expert that ever lived. To Rich Gossett & Andrew Hamilton in IIRMES. To Excel, thanks for turning my pie charts blue. To people who I may have neglected to thank, THANKS! Methods The biogeography group in GDEP hiked into La Jolla Valley and took soil samples in areas [figure 2] that showed a transition between native plants, into a transition zone, and into invasive grasses. Three of those areas were stable areas and three other samples were taken at places with a moving boundary. We took soil samples at 10M and 5M into the CSS (or native plants), one at the 0M point (at the transition zone), and a 10M and 5M into the grasses. [See figure 1]. An upper and lower sample was taken but only two of the lower samples were tested because we did not believe that the soil depth would be a factor. The two were tested anyway just in case it would. Procedure: 1. Weigh out about 30 grams of soil from the sample (Note that six soil samples were weighed to 20 g and soil sample sizes were then increased to 30g.) [Figure 3] 2. Pour in 60 mL of 10% hydrogen peroxide solution (turns organic matter in soil into carbon dioxide) 3. Added additional 40 mL of hydrogen peroxide 4. Once reaction with organic matter ceases, sieve remaining soil through 2 phi (63 micron) sieve (using a spray bottle) to separate the clay and silt from sand. [Figure 4] To find the percentages of the sand, silt, and clay within 30 grams of the soil sample, it had to be sifted. Sand is the biggest grain size so it was caught in a 63 micron sieve while the silt and clay was washed through. The sand collected was the total amount out of sand from the 30 grams so it’s weight can be divided by the total weight of the sample to find the percentage. The clay and silt mixture placed in the cylinder [figure 5] was mixed and 20 mL was collected after 20 seconds. That mixture was the amount of clay plus silt. After 2 hours, the 20 mL collected was the amount of clay because by then, all the silt would have sunk to the bottom. In order to find the percent of clay, the weight of the 2 hour sediment was subtracted by 0.05, divided by the total weight (sand + clay + silt) and multiplied by 100. The percent of the fines was found by taking the 20 second weight, divided by total and multiplied 100. The percent of clay subtracted by the percentage of fines will equal the percentage of silt. The total weight of the sand, silt, and clay did not add up to 30 grams because the organic matter was removed by the hydrogen peroxide. The organic carbon reacted with the hydrogen peroxide (H 2 O 2 ) to create C0 2 and H 2 . Graduated cylinders w/ silt and clay Conclusion Soil texture is another factor that has been disproven. It does not affect the CSS’s inability or ability to grow back in certain area. Fire and carbon/nitrogen amounts are disproven as well. Grain size is one less theory that need to be tested. Further ideas to study are looking at the organic matter amounts and the pH of soil with a stable boundary versus the soil of advancing CSS boundaries. If a factor can be proven that it helps CSS grow back, it will be important because we might be able to give CSS the advantage over invasive species and help it recover. Abstract The purpose of our study was to compare the boundaries between the California Sage Scrub (CSS) and invasive grasslands in Southern California in order to restore CSS because it holds endangered species. Soil was taken from CSS and grass boundaries that were either stable or the CSS was advancing into the grasslands. The soil was tested to see the percentages of sand, silt, and clay. Those percentages of the soil in stable boundaries and percentages of advancing (or recovering) boundaries were then compared using a chi square test. The difference of the expected and observed results did not provide a large enough of a difference that it can be said that grain size affects the rate of CSS recovery. Results The percentages of sand, silt, and clay were averaged for all transects with a stable boundary and a separate average for the ones with CSS advancing. Those averages were then compared, they showed no big difference between the two different data sets. [Figure 6]. We decided to use the chi square method to test if our difference is significant because it calculates the difference in an observed event versus an expected event, and whether it is due to randomness or because there is a significant reason behind it. When placed in a multiple chi square analysis, the probability of the difference being significant was 0.78. In order for a difference to be significant, it must be less than 0.05 because the difference has to be very extreme. Since it is not smaller than 0.05, the results show our results are due to random chance. Soil sieve Scal e References Chang, A. No date. Multiple proportions and post hoc analysis. StatTools < http://www.amchang.net/StatTools/Multiprop_Pgm.php > Freudenberger, D.O.; Fish, B.E.; Keeley, J.E. 1987. Distribution and stability of grasslands in the Los Angeles Basin. Bull. Southern California Acad. Sci 86, 1: 13 – 26 Patterson, D. 2010. Is carbon and nitrogen the reason in season?. GDEP Research Symposium (CSULB). Van Dam, R.L.; Van Den Burg, E.H.; Kasse C. et al 2002. Influence of organic matter in soils on radar-wave reflection: Sedimentological implications. Journal of Sedimentary Research. 72, 3: 341 – 352 Discussion These findings show that grain size does not influence or inhibit the growth of CSS. Freudenberger’s (1987) hypothesis of overgrazing can still be valid. Patterson’s (2010) experiment shows that nitrogen and carbon amounts do not cause the type of boundary found. Since that result plus grain size are not significant, we can expand the experiment using Van Dam’s (2002) work. His work states that organic matter has the ability to hold water. Since my experiment focused solely on grain size, the organic matter had to be removed. The grasses or shrubs could be living in the areas that they are because of a difference in organic matter. The grain size factor has been ruled out which gives us a better idea of why the boundaries are different. Figure 1 Figure 2 Figure 3 Figure 4 Figure 6 Figure 5 Figure 1
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Transcript of Trina Ming 1, Darrell Patterson 4, Randy Peterson 3, Conni Stuehler 4, Samantha Lough 1, Nancy Ko 2,...
Trina Ming1, Darrell Patterson4, Randy Peterson3, Conni Stuehler4, Samantha Lough1, Nancy Ko2, Jade Dean4, Koang KC Chea5, Brian Nagy4, Dr. Chrys Rodrigue4, Dr. Paul Laris4
Geosciences Diversity Enhancement Program, California State University Long Beach1: Lakewood High School, 2: Los Alamitos High School, 3: Wilson High School, 4: California State University Long Beach , 5. UC Riverside
Does Size Matter?An extensive study on different soil textures within the coastal foothills and its effect on the
distribution of grass and shrub species
Introduction The California coastal foothills are the home for California Sage Scrub (CSS), an important native vegetation that is being lost to invasion by non-native grass species. Only about 10 – 15% of original CSS is left in Southern California. This habitat, which is a biodiversity hotspot, is important because it is home to unique plant and animal life (such as the endangered California Gnatcatcher) that can only exist in this area. The reasons why these invasive grasses persist in a way that prevents native plants from recovering is still unclear. We are still unsure if the areas were originally home to perennial grasses that were taken over by invasive grasses. It could be that CSS prefers higher slopes and rocky soil while grasses prefer flat, fine soil. Alternatively, too frequent fires could prevent CSS from recovering fast enough before invasive plants take over. Carbon and nitrogen amounts can contribute to growth patterns (Patterson 2010). Another possibility is overgrazing left the plants unable to grow back (Freudenberger 1987). Mechanical disturbances such as homes being built on the CSS habitat or plowing of the land can also inhibit growth. The purpose is to determine that factors that could be helping or inhibiting the native plants from advancing into the grasslands in order to figure out how to get the California Sage Scrub habitat to recover. Van Dam (2002) says that the amount of organic matter within the soil affect the amount of water retained by it. The specific purpose of this experiment was to find the percentages of sand, silt, and clay in each soil sample. These percentages will then be compared to see if there is a significant difference between grain size in grasses versus CSS and stable versus moving boundaries.
Soil samples taken with augers
AcknowledgementsMy thanks go to: Gabby Valenzuela for accepting me into the GDEP program even though my essay was kind of sporadic, you had no idea who you decided to hire. To Paul Laris, Chrys Rodrigue, and Randy Peterson for being the “adults” and “teachers” during this program. We couldn’t have done it without you guys. (Well maybe we could have but only in a super desperate situation and I bet it would not have been as fun). To Jade Dean, KC Chea, Sam Lough, Nancy Ko, and Darrell Patterson for putting up with the complaining that I did. The. Whole. Time. And for putting up with my total lack of knowledge of everything. And for being amazing coworkers for the whole six weeks. To Lora Stevens and Conni Stuehler the toughest soil scientists I know. To the random people working in the lab with me. Your work was completely unrelated to mine but, hey, you guys made great lab company. To Brian Nagy, the best GIS and GPS expert that ever lived. To Rich Gossett & Andrew Hamilton in IIRMES. To Excel, thanks for turning my pie charts blue. To people who I may have neglected to thank, THANKS!
Methods The biogeography group in GDEP hiked into La Jolla Valley and took soil samples in areas [figure 2] that showed a transition between native plants, into a transition zone, and into invasive grasses. Three of those areas were stable areas and three other samples were taken at places with a moving boundary. We took soil samples at 10M and 5M into the CSS (or native plants), one at the 0M point (at the transition zone), and a 10M and 5M into the grasses. [See figure 1]. An upper and lower sample was taken but only two of the lower samples were tested because we did not believe that the soil depth would be a factor. The two were tested anyway just in case it would.
Procedure:1. Weigh out about 30 grams of soil from the sample (Note that six soil samples were weighed to 20 g and soil sample sizes were then increased to 30g.) [Figure 3]2. Pour in 60 mL of 10% hydrogen peroxide solution (turns organic matter in soil into carbon dioxide)3. Added additional 40 mL of hydrogen peroxide4. Once reaction with organic matter ceases, sieve remaining soil through 2 phi (63 micron) sieve (using a spray bottle) to separate the clay and silt from sand. [Figure 4]
To find the percentages of the sand, silt, and clay within 30 grams of the soil sample, it had to be sifted. Sand is the biggest grain size so it was caught in a 63 micron sieve while the silt and clay was washed through. The sand collected was the total amount out of sand from the 30 grams so it’s weight can be divided by the total weight of the sample to find the percentage. The clay and silt mixture placed in the cylinder [figure 5] was mixed and 20 mL was collected after 20 seconds. That mixture was the amount of clay plus silt. After 2 hours, the 20 mL collected was the amount of clay because by then, all the silt would have sunk to the bottom. In order to find the percent of clay, the weight of the 2 hour sediment was subtracted by 0.05, divided by the total weight (sand + clay + silt) and multiplied by 100. The percent of the fines was found by taking the 20 second weight, divided by total and multiplied 100. The percent of clay subtracted by the percentage of fines will equal the percentage of silt. The total weight of the sand, silt, and clay did not add up to 30 grams because the organic matter was removed by the hydrogen peroxide. The organic carbon reacted with the hydrogen peroxide (H2O2) to create C02 and H2.
Graduated cylinders w/ silt and clay
Conclusion Soil texture is another factor that has been disproven. It does not affect the CSS’s inability or ability to grow back in certain area. Fire and carbon/nitrogen amounts are disproven as well. Grain size is one less theory that need to be tested. Further ideas to study are looking at the organic matter amounts and the pH of soil with a stable boundary versus the soil of advancing CSS boundaries. If a factor can be proven that it helps CSS grow back, it will be important because we might be able to give CSS the advantage over invasive species and help it recover.
AbstractThe purpose of our study was to compare the boundaries between the California Sage Scrub (CSS) and invasive grasslands in Southern California in order to restore CSS because it holds endangered species. Soil was taken from CSS and grass boundaries that were either stable or the CSS was advancing into the grasslands. The soil was tested to see the percentages of sand, silt, and clay. Those percentages of the soil in stable boundaries and percentages of advancing (or recovering) boundaries were then compared using a chi square test. The difference of the expected and observed results did not provide a large enough of a difference that it can be said that grain size affects the rate of CSS recovery.
Results The percentages of sand, silt, and clay were averaged for all transects with a stable boundary and a separate average for the ones with CSS advancing. Those averages were then compared, they showed no big difference between the two different data sets. [Figure 6]. We decided to use the chi square method to test if our difference is significant because it calculates the difference in an observed event versus an expected event, and whether it is due to randomness or because there is a significant reason behind it. When placed in a multiple chi square analysis, the probability of the difference being significant was 0.78. In order for a difference to be significant, it must be less than 0.05 because the difference has to be very extreme. Since it is not smaller than 0.05, the results show our results are due to random chance.
Soil sieve
Scale
ReferencesChang, A. No date. Multiple proportions and post hoc analysis. StatTools <
http://www.amchang.net/StatTools/Multiprop_Pgm.php> Freudenberger, D.O.; Fish, B.E.; Keeley, J.E. 1987. Distribution and stability of grasslands in the Los
Angeles Basin. Bull. Southern California Acad. Sci 86, 1: 13 – 26Patterson, D. 2010. Is carbon and nitrogen the reason in season?. GDEP Research Symposium (CSULB).
Van Dam, R.L.; Van Den Burg, E.H.; Kasse C. et al 2002. Influence of organic matter in soils on radar-wave reflection: Sedimentological implications. Journal of Sedimentary Research. 72, 3: 341 – 352
Discussion These findings show that grain size does not influence or inhibit the growth of CSS. Freudenberger’s (1987) hypothesis of overgrazing can still be valid. Patterson’s (2010) experiment shows that nitrogen and carbon amounts do not cause the type of boundary found. Since that result plus grain size are not significant, we can expand the experiment using Van Dam’s (2002) work. His work states that organic matter has the ability to hold water. Since my experiment focused solely on grain size, the organic matter had to be removed. The grasses or shrubs could be living in the areas that they are because of a difference in organic matter. The grain size factor has been ruled out which gives us a better idea of why the boundaries are different.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 6
Figure 5
Figure 1
