The Effect of Soil Moisture Levels on Bacterial Species Richness

The Effect of Soil Moisture Levels on Bacterial Species Richness Yusuf Shawky, Kyuwon Jung, Muhammad Abdullah, Eshaan Sandhu The University of Western Ontario 1151 Richmond Street, London, ON N6A 3K7 Moisture level on bacterial diversity Discussion and Practical Applications of Research Findings Bacter ia • Essential f or soil ecosyste m and nutrient cycle ​ Ob jective • Determine the relationship be tween soil m oisture levels and ba cte ria l colony diversity Fig .1.Samp ling locations for Site 1 (wet s oil), Site 2 (mois t s oil), and Site 3 (dry s oil), shown fro m right to left. Moist environment Dry environment Results Bacter ial dive rsity • Influe nce d by m oisture level and soil composition (Sm ith et al., 2020) • Ref lec t a critic al role in soil health and microbial ecology (Johnson & Lee 2018) Hypothesis • Soil moisture leve ls influence bac ter ial dive rsity. Prediction • Soil with higher moisture conte nt will exhibit gr eater bacterial diversity Methods Stu dy Locat ion and Samp ling Sites Soil sam ples were collected along the Tha mes River fr om thre e distinct locations, selected to r epr ese nt varying m oisture levels: • Sample 1: Shoreline ( wet soil). • Sample 2: Approxim ate ly 5 m ete rs from the shore (moist soil). • Sample 3: Approxim ate ly 10 meters f rom the shore (dr y soil). The sampling area wa s shaded, with no dire ct sunlight e xposure. All samples were collec ted f rom a depth of 1 inch, avoiding orga nic m atter such a s lea ves or roots to ensure consistency acr oss sample s. Var iables • Indepe ndent Variable: Soil moisture leve ls (wet, moist, dry). • Depend ent Variable: Bac ter ial dive rsity, me asured a s the number of morphologically distinct ba cte ria l colonies. Sampling Procedu re Soil was c ollected using sterile tablespoons, with a new sterile spoon used for ea ch sample to pr eve nt cr oss-contam ination. Eac h soil sam ple was placed into an a irtight pla stic bag immediately a fte r collec tion to preserve its moistur e content dur ing transportation. Microbial Culturing and Analysis The collected soil samples were processed to separate microorganism s, which were the n plated onto nutrient-rich agar to promote bacterial gr owth. Plates we re incubated at room tem per ature for one week. After incubation, ba cte ria l diversity was determined by c ounting the number of distinct colony morphologie s observed on eac h plate. Statistic al Analysis To evaluate the ef fect of soil m oisture on bacterial diversity, da ta we re analyzed using a one-way ANOVA to test for ove rall differ enc es among moisture leve ls. Posthoc two-sample t-tests were conducte d to identify significant pairwise differences betwee n tre atm ents. Fig. 2. Me an ba cte ria l species richne ss (±SE) a cross four soil treatments: wet soil, moist soil, dry soil, a nd distilled water. Wet and moist soils supported greater ba cte ria l diversity compared to distilled wate r, while dry soil e xhibited interm ediate species richne ss. Bars sha ring the same letter a re not significantly diff erent. A one-way ANOVA was c onducted to asse ss the eff ect of soil moisture levels on bacterial species richness. This test revealed a statistically significant dif ference among the four treatments (wet soil, moist soil, dr y soil, and control) (F = 39.46, df = 3, 8, p < 0.001). These r esults indicate that soil moisture levels ha ve an ef fect on bacterial diversity. Post-hoc pair wise comparisons were c onducted using twosample t-tests to dete rmine which treatments we re signif ica ntly differ ent. The results wer e as follows: Wet soil and moist soil showed no significant dif ference in ba cte ria l species richne ss (p = 0.057). Wet soil had significantly more ba cte ria l species tha n dry soil (p = 0.002). Wet soil had significantly more ba cte ria l species tha n the control (p < 0.001). Moist soil had significantly more ba cte ria l species tha n the control (p = 0.002). Dry soil had significantly more ba cte ria l species tha n moist soil ( p = 0.007). Dry soil and the control showed no significant dif ference in ba cte ria l species richne ss (p = 0.116). This study investigate d how soil moisture levels influe nce bacterial diversity, addressing the hypothe sis that soil m oisture im pa cts bacterial comm unity c om position. The results supported this hypothesis, showing tha t wetter soils foster greater bacterial diversity, while dry conditions re strict it. Biological Con text for t he Results • Nutrient Availability: Increa sed m oisture enhances nutr ient dissolution, ma king nutrie nts more accessible to support bacterial growth and metabolism . • Oxyge n Levels: Moisture a lters oxygen availa bility, influencing the balance betwee n aerobic and a nae robic bacterial popula tions. • Microbial Compe tit ion and In teraction s: Variability betwe en Samples 1 and 2 indicates that f actors such as microbia l com pe tition and nutrient a vailability pla y a role in shaping bacterial diversity. Sample 3's reduce d diversity highlights the diff iculty of bac ter ial survival under arid conditions, where resour ces are limited. Comparison with Pr evious Stud ies • Zha ng et a l. (2020) found that soil moisture promote s bac ter ial m etabolic diversity, which aligns with our findings of incr eased diversity in we tter environments. • BBC Bite size (2024) reports that bacteria requir e moisture f or nutrient absorption and growth, suppor ting our obse rva tion of reduc ed diversity in dr y soils (Sam ple 3). Broader Implicat ions • Soil Healt h: Bac ter ial dive rsity is c ruc ial f or maintaining soil health, nutrient cycling, a nd disea se suppr ession. Prote cting microbial diver sity ensures ecosystem resilienc e and agricultur al pr oductivity. • Climate Change Impac ts: Changing rainf all patterns due to climate change are likely to affect soil e cosystem s. Understanding how ba cte ria l com munitie s respond to moistur e variability ca n help mitigate a dverse e ffects on biodiversity and soil productivity. Future Dire ctions • Investiga te the com bined effe cts of soil pH, nutrie nt availability, a nd m icr obial competition on bacterial diversity. • Explor e seasonal variations in bacterial comm unities to understand tem poral dynam ics. • Exa mine how soil types and the ir moistur e retention capacities inte ract to inf luence bacterial diver sity. References BBC Bite siz e. “Conditions Ne eded for Bacte ria l G rowth - Food Safety – CCEA - GCSE Home Economics: Food a nd Nutrition (CCEA ) Revision.” BBC Bite size, 2021, ww w.bbc .c o.uk/bite siz e/guides/z 77v3k7/revision/1 . Z ha ng, Hongying, et al. “Soil Bacte rial D ive rsity a nd Its Rela tionship with Soil CO2 and M inera l Composition: A Case Study of the Laiwu Experime nta l Site.” Inte rnational Journal of Environm ental R esearch and P ublic H ealth, vol. 17, no. 16, 7 A ug. 2020, p. 5699, https://doi.org/10.3390/ijerph17165699. Smith, J., D oe , A ., & Green, L. (2020). The impact of soil moisture on m icrobial div ersity: A case study of riparian zones. Journa l of Environmental M icrobiology, 34(2), 123–134. https://doi.org/10.1016/j.jenvmic ro.2020.02.003 Johnson, R., & Lee , T. (2018). Mic robial activ ity in v arying soil moisture c onditions: Insights into nutrie nt cy cling. Soil Ecology Journa l, 29(3), 456–467. https://doi.org/10.1080/soilecoj.2018.456 Acknowledgments This study wa s made successf ul thanks to the guidance and support provided by the teaching assistants, Hossein Asgari a nd Ca rson Mitchell, during the lab period. They both provided im mense help by sharing their knowledge on the be st equipme nt ma ter ials to use as we ll as strategies on how to collec t data and implement str ate gies, greatly contributing to the success of this projec t. Also, Dr. Tim Ha in, the c ourse coordinator pr ovided c ontinued support and assistanc e thr oughout the r ese arch process. The Effect of Soil Moisture Levels on Bacterial Species Richness Yusuf Shawky, Kyuwon Jung, Muhammad Abdullah, Eshaan Sandhu The University of Western Ontario 1151 Richmond Street, London, ON N6A 3K7 Moisture level on bacterial diversity Discussion and Practical Applications of Research Findings Bacter ia • Essential f or soil ecosyste m and nutrient cycle ​ Ob jective • Determine the relationship be tween soil m oisture levels and ba cte ria l colony diversity Fig .1.Samp ling locations for Site 1 (wet s oil), Site 2 (mois t s oil), and Site 3 (dry s oil), shown fro m right to left. Moist environment Dry environment Results Bacter ial dive rsity • Influe nce d by m oisture level and soil composition (Sm ith et al., 2020) • Ref lec t a critic al role in soil health and microbial ecology (Johnson & Lee 2018) Hypothesis • Soil moisture leve ls influence bac ter ial dive rsity. Prediction • Soil with higher moisture conte nt will exhibit gr eater bacterial diversity Methods Stu dy Locat ion and Samp ling Sites Soil sam ples were collected along the Tha mes River fr om thre e distinct locations, selected to r epr ese nt varying m oisture levels: • Sample 1: Shoreline ( wet soil). • Sample 2: Approxim ate ly 5 m ete rs from the shore (moist soil). • Sample 3: Approxim ate ly 10 meters f rom the shore (dr y soil). The sampling area wa s shaded, with no dire ct sunlight e xposure. All samples were collec ted f rom a depth of 1 inch, avoiding orga nic m atter such a s lea ves or roots to ensure consistency acr oss sample s. Var iables • Indepe ndent Variable: Soil moisture leve ls (wet, moist, dry). • Depend ent Variable: Bac ter ial dive rsity, me asured a s the number of morphologically distinct ba cte ria l colonies. Sampling Procedu re Soil was c ollected using sterile tablespoons, with a new sterile spoon used for ea ch sample to pr eve nt cr oss-contam ination. Eac h soil sam ple was placed into an a irtight pla stic bag immediately a fte r collec tion to preserve its moistur e content dur ing transportation. Microbial Culturing and Analysis The collected soil samples were processed to separate microorganism s, which were the n plated onto nutrient-rich agar to promote bacterial gr owth. Plates we re incubated at room tem per ature for one week. After incubation, ba cte ria l diversity was determined by c ounting the number of distinct colony morphologie s observed on eac h plate. Statistic al Analysis To evaluate the ef fect of soil m oisture on bacterial diversity, da ta we re analyzed using a one-way ANOVA to test for ove rall differ enc es among moisture leve ls. Posthoc two-sample t-tests were conducte d to identify significant pairwise differences betwee n tre atm ents. Fig. 2. Me an ba cte ria l species richne ss (±SE) a cross four soil treatments: wet soil, moist soil, dry soil, a nd distilled water. Wet and moist soils supported greater ba cte ria l diversity compared to distilled wate r, while dry soil e xhibited interm ediate species richne ss. Bars sha ring the same letter a re not significantly diff erent. A one-way ANOVA was c onducted to asse ss the eff ect of soil moisture levels on bacterial species richness. This test revealed a statistically significant dif ference among the four treatments (wet soil, moist soil, dr y soil, and control) (F = 39.46, df = 3, 8, p < 0.001). These results indica te that soil moisture levels ha ve an effe ct on bacterial diver sity. Post-hoc pair wise comparisons were c onducted using twosample t-tests to dete rmine which treatments we re signif ica ntly differ ent. The results wer e as follows: Wet soil and moist soil showed no significant dif ference in ba cte ria l species richne ss (p = 0.057). Wet soil had significantly more ba cte ria l species tha n dry soil (p = 0.002). Wet soil had significantly more ba cte ria l species tha n the control (p < 0.001). Moist soil had significantly more ba cte ria l species tha n the control (p = 0.002). Dry soil had significantly more ba cte ria l species tha n moist soil ( p = 0.007). Dry soil and the control showed no significant dif ference in ba cte ria l species richne ss (p = 0.116). This study investigate d how soil moisture levels influe nce bacterial diversity, addressing the hypothe sis that soil m oisture im pa cts bacterial comm unity c om position. The results supported this hypothesis, showing tha t wetter soils foster greater bacterial diversity, while dry conditions re strict it. Biological Con text for t he Results • Nutrient Availability: Increa sed m oisture enhances nutr ient dissolution, ma king nutrie nts more accessible to support bacterial growth and metabolism . • Oxyge n Levels: Moisture a lters oxygen availa bility, influencing the balance betwee n aerobic and a nae robic bacterial popula tions. • Microbial Compe tit ion and In teraction s: Variability betwe en Samples 1 and 2 indicates that f actors such as microbia l com pe tition and nutrient a vailability pla y a role in shaping bacterial diversity. Sample 3's reduce d diversity highlights the diff iculty of bac ter ial survival under arid conditions, where resour ces are limited. Comparison with Pr evious Stud ies • Zha ng et a l. (2020) found that soil moisture promote s bac ter ial m etabolic diversity, which aligns with our findings of incr eased diversity in we tter environments. • BBC Bite size (2024) reports that bacteria requir e moisture f or nutrient absorption and growth, suppor ting our obse rva tion of reduc ed diversity in dr y soils (Sam ple 3). Broader Implicat ions • Soil Healt h: Bac ter ial dive rsity is c ruc ial f or maintaining soil health, nutrient cycling, a nd disea se suppr ession. Prote cting microbial diver sity ensures ecosystem resilienc e and agricultur al pr oductivity. • Climate Change Impac ts: Changing rainf all patterns due to climate change are likely to affect soil e cosystem s. Understanding how ba cte ria l com munitie s respond to moistur e variability ca n help mitigate a dverse e ffects on biodiversity and soil productivity. Future Dire ctions • Investiga te the com bined effe cts of soil pH, nutrie nt availability, a nd m icr obial competition on bacterial diversity. • Explor e seasonal variations in bacterial comm unities to understand tem poral dynam ics. • Exa mine how soil types and the ir moistur e retention capacities inte ract to inf luence bacterial diver sity. References BBC Bite siz e. “Conditions Ne eded for Bacte ria l G rowth - Food Safety – CCEA - GCSE Home Economics: Food a nd Nutrition (CCEA ) Revision.” BBC Bite size, 2021, ww w.bbc .c o.uk/bite siz e/guides/z 77v3k7/revision/1 . Z ha ng, Hongying, et al. “Soil Bacte rial D ive rsity a nd Its Rela tionship with Soil CO2 and M inera l Composition: A Case Study of the Laiwu Experime nta l Site.” Inte rnational Journal of Environm ental R esearch and P ublic H ealth, vol. 17, no. 16, 7 A ug. 2020, p. 5699, https://doi.org/10.3390/ijerph17165699. Smith, J., D oe , A ., & Green, L. (2020). The impact of soil moisture on m icrobial div ersity: A case study of riparian zones. Journa l of Environmental M icrobiology, 34(2), 123–134. https://doi.org/10.1016/j.jenvmic ro.2020.02.003 Johnson, R., & Lee , T. (2018). Mic robial activ ity in v arying soil moisture c onditions: Insights into nutrie nt cy cling. Soil Ecology Journa l, 29(3), 456–467. https://doi.org/10.1080/soilecoj.2018.456 Acknowledgments This study wa s made successf ul thanks to the guidance and support provided by the teaching assistants, Hossein Asgari a nd Ca rson Mitchell, during the lab period. They both provided im mense help by sharing their knowledge on the be st equipme nt ma ter ials to use as we ll as strategies on how to collec t data and implement str ate gies, greatly contributing to the success of this projec t. Also, Dr. Tim Ha in, the c ourse coordinator pr ovided c ontinued support and assistanc e thr oughout the r ese arch process. The Effect of Soil Moisture Levels on Bacterial Species Richness Yusuf Shawky, Kyuwon Jung, Muhammad Abdullah, Eshaan Sandhu The University of Western Ontario 1151 Richmond Street, London, ON N6A 3K7 Moisture level on bacterial diversity Discussion and Practical Applications of Research Findings Bacter ia • Essential f or soil ecosyste m and nutrient cycle ​ Ob jective • Determine the relationship be tween soil m oisture levels and ba cte ria l colony diversity Fig .1.Samp ling locations for Site 1 (wet s oil), Site 2 (mois t s oil), and Site 3 (dry s oil), shown fro m right to left. Moist environment Dry environment Results Bacter ial dive rsity • Influe nce d by m oisture level and soil composition (Sm ith et al., 2020) • Ref lec t a critic al role in soil health and microbial ecology (Johnson & Lee 2018) Hypothesis • Soil moisture leve ls influence bac ter ial dive rsity. Prediction • Soil with higher moisture conte nt will exhibit gr eater bacterial diversity Methods Stu dy Locat ion and Samp ling Sites Soil sam ples were collected along the Tha mes River fr om thre e distinct locations, selected to r epr ese nt varying m oisture levels: • Sample 1: Shoreline ( wet soil). • Sample 2: Approxim ate ly 5 m ete rs from the shore (moist soil). • Sample 3: Approxim ate ly 10 meters f rom the shore (dr y soil). The sampling area wa s shaded, with no dire ct sunlight e xposure. All samples were collec ted f rom a depth of 1 inch, avoiding orga nic m atter such a s lea ves or roots to ensure consistency acr oss sample s. Var iables • Indepe ndent Variable: Soil moisture leve ls (wet, moist, dry). • Depend ent Variable: Bac ter ial dive rsity, me asured a s the number of morphologically distinct ba cte ria l colonies. Sampling Procedu re Soil was c ollected using sterile tablespoons, with a new sterile spoon used for ea ch sample to pr eve nt cr oss-contam ination. Eac h soil sam ple was placed into an a irtight pla stic bag immediately a fte r collec tion to preserve its moistur e content dur ing transportation. Microbial Culturing and Analysis The collected soil samples were processed to separate microorganism s, which were the n plated onto nutrient-rich agar to promote bacterial gr owth. Plates we re incubated at room tem per ature for one week. After incubation, ba cte ria l diversity was determined by c ounting the number of distinct colony morphologie s observed on eac h plate. Statistic al Analysis To evaluate the ef fect of soil m oisture on bacterial diversity, da ta we re analyzed using a one-way ANOVA to test for ove rall differ enc es among moisture leve ls. Posthoc two-sample t-tests were conducte d to identify significant pairwise differences betwee n tre atm ents. Fig. 2. Me an ba cte ria l species richne ss (±SE) a cross four soil treatments: wet soil, moist soil, dry soil, a nd distilled water. Wet and moist soils supported greater ba cte ria l diversity compared to distilled wate r, while dry soil e xhibited interm ediate species richne ss. Bars sha ring the same letter a re not significantly diff erent. A one-way ANOVA was c onducted to asse ss the eff ect of soil moisture levels on bacterial species richness. This test revealed a statistically significant dif ference among the four treatments (wet soil, moist soil, dr y soil, and control) (F = 39.46, df = 3, 8, p < 0.001). These results indica te that soil moisture levels ha ve an effe ct on bacterial diver sity. Post-hoc pair wise comparisons were c onducted using twosample t-tests to dete rmine which treatments we re signif ica ntly differ ent. The results wer e as follows: Wet soil and moist soil showed no significant dif ference in ba cte ria l species richne ss (p = 0.057). Wet soil had significantly more ba cte ria l species tha n dry soil (p = 0.002). Wet soil had significantly more ba cte ria l species tha n the control (p < 0.001). Moist soil had significantly more ba cte ria l species tha n the control (p = 0.002). Dry soil had significantly more ba cte ria l species tha n moist soil ( p = 0.007). Dry soil and the control showed no significant dif ference in ba cte ria l species richne ss (p = 0.116). This study investigate d how soil moisture levels influe nce bacterial diversity, addressing the hypothe sis that soil m oisture im pa cts bacterial comm unity c om position. The results supported this hypothesis, showing tha t wetter soils foster greater bacterial diversity, while dry conditions re strict it. Biological Con text for t he Results • Nutrient Availability: Increa sed m oisture enhances nutr ient dissolution, ma king nutrie nts more accessible to support bacterial growth and metabolism . • Oxyge n Levels: Moisture a lters oxygen availa bility, influencing the balance betwee n aerobic and a nae robic bacterial popula tions. • Microbial Compe tit ion and In teraction s: Variability betwe en Samples 1 and 2 indicates that f actors such as microbia l com pe tition and nutrient a vailability pla y a role in shaping bacterial diversity. Sample 3's reduce d diversity highlights the diff iculty of bac ter ial survival under arid conditions, where resour ces are limited. Comparison with Pr evious Stud ies • Zha ng et a l. (2020) found that soil moisture promote s bac ter ial m etabolic diversity, which aligns with our findings of incr eased diversity in we tter environments. • BBC Bite size (2024) reports that bacteria requir e moisture f or nutrient absorption and growth, suppor ting our obse rva tion of reduc ed diversity in dr y soils (Sam ple 3). Broader Implicat ions • Soil Healt h: Bac ter ial dive rsity is c ruc ial f or maintaining soil health, nutrient cycling, a nd disea se suppr ession. Prote cting microbial diver sity ensures ecosystem resilienc e and agricultur al pr oductivity. • Climate Change Impac ts: Changing rainf all patterns due to climate change are likely to affect soil e cosystem s. Understanding how ba cte ria l com munitie s respond to moistur e variability ca n help mitigate a dverse e ffects on biodiversity and soil productivity. Future Dire ctions • Investiga te the com bined effe cts of soil pH, nutrie nt availability, a nd m icr obial competition on bacterial diversity. • Explor e seasonal variations in bacterial comm unities to understand tem poral dynam ics. • Exa mine how soil types and the ir moistur e retention capacities inte ract to inf luence bacterial diver sity. References BBC Bite siz e. “Conditions Ne eded for Bacte ria l G rowth - Food Safety – CCEA - GCSE Home Economics: Food a nd Nutrition (CCEA ) Revision.” BBC Bite size, 2021, ww w.bbc .c o.uk/bite siz e/guides/z 77v3k7/revision/1 . Z ha ng, Hongying, et al. “Soil Bacte rial D ive rsity a nd Its Rela tionship with Soil CO2 and M inera l Composition: A Case Study of the Laiwu Experime nta l Site.” Inte rnational Journal of Environm ental R esearch and P ublic H ealth, vol. 17, no. 16, 7 A ug. 2020, p. 5699, https://doi.org/10.3390/ijerph17165699. Smith, J., D oe , A ., & Green, L. (2020). The impact of soil moisture on m icrobial div ersity: A case study of riparian zones. Journa l of Environmental M icrobiology, 34(2), 123–134. https://doi.org/10.1016/j.jenvmic ro.2020.02.003 Johnson, R., & Lee , T. (2018). Mic robial activ ity in v arying soil moisture c onditions: Insights into nutrie nt cy cling. Soil Ecology Journa l, 29(3), 456–467. https://doi.org/10.1080/soilecoj.2018.456 Acknowledgments This study wa s made successf ul thanks to the guidance and support provided by the teaching assistants, Hossein Asgari a nd Ca rson Mitchell, during the lab period. They both provided im mense help by sharing their knowledge on the be st equipme nt ma ter ials to use as we ll as strategies on how to collec t data and implement str ate gies, greatly contributing to the success of this projec t. Also, Dr. Tim Ha in, the c ourse coordinator pr ovided c ontinued support and assistanc e thr oughout the r ese arch process. The Effect of Soil Moisture Levels on Bacterial Species Richness Yusuf Shawky, Kyuwon Jung, Muhammad Abdullah, Eshaan Sandhu The University of Western Ontario 1151 Richmond Street, London, ON N6A 3K7 Moisture level on bacterial diversity Discussion and Practical Applications of Research Findings Bacter ia • Essential f or soil ecosyste m and nutrient cycle ​ Ob jective • Determine the relationship be tween soil m oisture levels and ba cte ria l colony diversity Fig .1.Samp ling locations for Site 1 (wet s oil), Site 2 (mois t s oil), and Site 3 (dry s oil), shown fro m right to left. Moist environment Dry environment Results Bacter ial dive rsity • Influe nce d by m oisture level and soil composition (Sm ith et al., 2020) • Ref lec t a critic al role in soil health and microbial ecology (Johnson & Lee 2018) Hypothesis • Soil moisture leve ls influence bac ter ial dive rsity. Prediction • Soil with higher moisture conte nt will exhibit gr eater bacterial diversity Methods Stu dy Locat ion and Samp ling Sites Soil sam ples were collected along the Tha mes River fr om thre e distinct locations, selected to r epr ese nt varying m oisture levels: • Sample 1: Shoreline ( wet soil). • Sample 2: Approxim ate ly 5 m ete rs from the shore (moist soil). • Sample 3: Approxim ate ly 10 meters f rom the shore (dr y soil). The sampling area wa s shaded, with no dire ct sunlight e xposure. All samples were collec ted f rom a depth of 1 inch, avoiding orga nic m atter such a s lea ves or roots to ensure consistency acr oss sample s. Var iables • Indepe ndent Variable: Soil moisture leve ls (wet, moist, dry). • Depend ent Variable: Bac ter ial dive rsity, me asured a s the number of morphologically distinct ba cte ria l colonies. Sampling Procedu re Soil was c ollected using sterile tablespoons, with a new sterile spoon used for ea ch sample to pr eve nt cr oss-contam ination. Eac h soil sam ple was placed into an a irtight pla stic bag immediately a fte r collec tion to preserve its moistur e content dur ing transportation. Microbial Culturing and Analysis The collected soil samples were processed to separate microorganism s, which were the n plated onto nutrient-rich agar to promote bacterial gr owth. Plates we re incubated at room tem per ature for one week. After incubation, ba cte ria l diversity was determined by c ounting the number of distinct colony morphologie s observed on eac h plate. Statistic al Analysis To evaluate the ef fect of soil m oisture on bacterial diversity, da ta we re analyzed using a one-way ANOVA to test for ove rall differ enc es among moisture leve ls. Posthoc two-sample t-tests were conducte d to identify significant pairwise differences betwee n tre atm ents. Fig. 2. Me an ba cte ria l species richne ss (±SE) a cross four soil treatments: wet soil, moist soil, dry soil, a nd distilled water. Wet and moist soils supported greater ba cte ria l diversity compared to distilled wate r, while dry soil e xhibited interm ediate species richne ss. Bars sha ring the same letter a re not significantly diff erent. A one-way ANOVA was c onducted to asse ss the eff ect of soil moisture levels on bacterial species richness. This test revealed a statistically significant dif ference among the four treatments (wet soil, moist soil, dr y soil, and control) (F = 39.46, df = 3, 8, p < 0.001). These results indica te that soil moisture levels ha ve an effe ct on bacterial diver sity. Post-hoc pair wise comparisons were c onducted using twosample t-tests to dete rmine which treatments we re signif ica ntly differ ent. The results wer e as follows: Wet soil and moist soil showed no significant dif ference in ba cte ria l species richne ss (p = 0.057). Wet soil had significantly more ba cte ria l species tha n dry soil (p = 0.002). Wet soil had significantly more ba cte ria l species tha n the control (p < 0.001). Moist soil had significantly more ba cte ria l species tha n the control (p = 0.002). Dry soil had significantly more ba cte ria l species tha n moist soil ( p = 0.007). Dry soil and the control showed no significant dif ference in ba cte ria l species richne ss (p = 0.116). This study investigate d how soil moisture levels influe nce bacterial diversity, addressing the hypothe sis that soil m oisture im pa cts bacterial comm unity c om position. The results supported this hypothesis, showing tha t wetter soils foster greater bacterial diversity, while dry conditions re strict it. Biological Con text for t he Results • Nutrient Availability: Increa sed m oisture enhances nutr ient dissolution, ma king nutrie nts more accessible to support bacterial growth and metabolism . • Oxyge n Levels: Moisture a lters oxygen availa bility, influencing the balance betwee n aerobic and a nae robic bacterial popula tions. • Microbial Compe tit ion and In teraction s: Variability betwe en Samples 1 and 2 indicates that f actors such as microbia l com pe tition and nutrient a vailability pla y a role in shaping bacterial diversity. Sample 3's reduce d diversity highlights the diff iculty of bac ter ial survival under arid conditions, where resour ces are limited. Comparison with Pr evious Stud ies • Zha ng et a l. (2020) found that soil moisture promote s bac ter ial m etabolic diversity, which aligns with our findings of incr eased diversity in we tter environments. • BBC Bite size (2024) reports that bacteria requir e moisture f or nutrient absorption and growth, suppor ting our obse rva tion of reduc ed diversity in dr y soils (Sam ple 3). Broader Implicat ions • Soil Healt h: Bac ter ial dive rsity is c ruc ial f or maintaining soil health, nutrient cycling, a nd disea se suppr ession. Prote cting microbial diver sity ensures ecosystem resilienc e and agricultur al pr oductivity. • Climate Change Impac ts: Changing rainf all patterns due to climate change are likely to affect soil e cosystem s. Understanding how ba cte ria l com munitie s respond to moistur e variability ca n help mitigate a dverse e ffects on biodiversity and soil productivity. Future Dire ctions • Investiga te the com bined effe cts of soil pH, nutrie nt availability, a nd m icr obial competition on bacterial diversity. • Explor e seasonal variations in bacterial comm unities to understand tem poral dynam ics. • Exa mine how soil types and the ir moistur e retention capacities inte ract to inf luence bacterial diver sity. References BBC Bite siz e. “Conditions Ne eded for Bacte ria l G rowth - Food Safety – CCEA - GCSE Home Economics: Food a nd Nutrition (CCEA ) Revision.” BBC Bite size, 2021, ww w.bbc .c o.uk/bite siz e/guides/z 77v3k7/revision/1 . Z ha ng, Hongying, et al. “Soil Bacte rial D ive rsity a nd Its Rela tionship with Soil CO2 and M inera l Composition: A Case Study of the Laiwu Experime nta l Site.” Inte rnational Journal of Environm ental R esearch and P ublic H ealth, vol. 17, no. 16, 7 A ug. 2020, p. 5699, https://doi.org/10.3390/ijerph17165699. Smith, J., D oe , A ., & Green, L. (2020). The impact of soil moisture on m icrobial div ersity: A case study of riparian zones. Journa l of Environmental M icrobiology, 34(2), 123–134. https://doi.org/10.1016/j.jenvmic ro.2020.02.003 Johnson, R., & Lee , T. (2018). Mic robial activ ity in v arying soil moisture c onditions: Insights into nutrie nt cy cling. Soil Ecology Journa l, 29(3), 456–467. https://doi.org/10.1080/soilecoj.2018.456 Acknowledgments This study wa s made successf ul thanks to the guidance and support provided by the teaching assistants, Hossein Asgari a nd Ca rson Mitchell, during the lab period. They both provided im mense help by sharing their knowledge on the be st equipme nt ma ter ials to use as we ll as strategies on how to collec t data and implement str ate gies, greatly contributing to the success of this projec t. Also, Dr. Tim Ha in, the c ourse coordinator pr ovided c ontinued support and assistanc e thr oughout the r ese arch process. The Effect of Soil Moisture Levels on Bacterial Species Richness Yusuf Shawky, Kyuwon Jung, Muhammad Abdullah, Eshaan Sandhu The University of Western Ontario 1151 Richmond Street, London, ON N6A 3K7 Moisture level on bacterial diversity Discussion and Practical Applications of Research Findings Bacter ia • Essential f or soil ecosyste m and nutrient cycle ​ Ob jective • Determine the relationship be tween soil m oisture levels and ba cte ria l colony diversity Fig .1.Samp ling locations for Site 1 (wet s oil), Site 2 (mois t s oil), and Site 3 (dry s oil), shown fro m right to left. Moist environment Dry environment Results Bacter ial dive rsity • Influe nce d by m oisture level and soil composition (Sm ith et al., 2020) • Ref lec t a critic al role in soil health and microbial ecology (Johnson & Lee 2018) Hypothesis • Soil moisture leve ls influence bac ter ial dive rsity. Prediction • Soil with higher moisture conte nt will exhibit gr eater bacterial diversity Methods Stu dy Locat ion and Samp ling Sites Soil sam ples were collected along the Tha mes River fr om thre e distinct locations, selected to r epr ese nt varying m oisture levels: • Sample 1: Shoreline ( wet soil). • Sample 2: Approxim ate ly 5 m ete rs from the shore (moist soil). • Sample 3: Approxim ate ly 10 meters f rom the shore (dr y soil). The sampling area wa s shaded, with no dire ct sunlight e xposure. All samples were collec ted f rom a depth of 1 inch, avoiding orga nic m atter such a s lea ves or roots to ensure consistency acr oss sample s. Var iables • Indepe ndent Variable: Soil moisture leve ls (wet, moist, dry). • Depend ent Variable: Bac ter ial dive rsity, me asured a s the number of morphologically distinct ba cte ria l colonies. Sampling Procedu re Soil was c ollected using sterile tablespoons, with a new sterile spoon used for ea ch sample to pr eve nt cr oss-contam ination. Eac h soil sam ple was placed into an a irtight pla stic bag immediately a fte r collec tion to preserve its moistur e content dur ing transportation. Microbial Culturing and Analysis The collected soil samples were processed to separate microorganism s, which were the n plated onto nutrient-rich agar to promote bacterial gr owth. Plates we re incubated at room tem per ature for one week. After incubation, ba cte ria l diversity was determined by c ounting the number of distinct colony morphologie s observed on eac h plate. Statistic al Analysis To evaluate the ef fect of soil m oisture on bacterial diversity, da ta we re analyzed using a one-way ANOVA to test for ove rall differ enc es among moisture leve ls. Posthoc two-sample t-tests were conducte d to identify significant pairwise differences betwee n tre atm ents. Fig. 2. Me an ba cte ria l species richne ss (±SE) a cross four soil treatments: wet soil, moist soil, dry soil, a nd distilled water. Wet and moist soils supported greater ba cte ria l diversity compared to distilled wate r, while dry soil e xhibited interm ediate species richne ss. Bars sha ring the same letter a re not significantly diff erent. A one-way ANOVA was c onducted to asse ss the eff ect of soil moisture levels on bacterial species richness. This test revealed a statistically significant dif ference among the four treatments (wet soil, moist soil, dr y soil, and control) (F = 39.46, df = 3, 8, p < 0.001). These results indica te that soil moisture levels ha ve an effe ct on bacterial diver sity. Post-hoc pair wise comparisons were c onducted using twosample t-tests to dete rmine which treatments we re signif ica ntly differ ent. The results wer e as follows: Wet soil and moist soil showed no significant dif ference in ba cte ria l species richne ss (p = 0.057). Wet soil had significantly more ba cte ria l species tha n dry soil (p = 0.002). Wet soil had significantly more ba cte ria l species tha n the control (p < 0.001). Moist soil had significantly more ba cte ria l species tha n the control (p = 0.002). Dry soil had significantly more ba cte ria l species tha n moist soil ( p = 0.007). Dry soil and the control showed no significant dif ference in ba cte ria l species richne ss (p = 0.116). This study investigate d how soil moisture levels influe nce bacterial diversity, addressing the hypothe sis that soil m oisture im pa cts bacterial comm unity c om position. The results supported this hypothesis, showing tha t wetter soils foster greater bacterial diversity, while dry conditions re strict it. Biological Con text for t he Results • Nutrient Availability: Increa sed m oisture enhances nutr ient dissolution, ma king nutrie nts more accessible to support bacterial growth and metabolism . • Oxyge n Levels: Moisture a lters oxygen availa bility, influencing the balance betwee n aerobic and a nae robic bacterial popula tions. • Microbial Compe tit ion and In teraction s: Variability betwe en Samples 1 and 2 indicates that f actors such as microbia l com pe tition and nutrient a vailability pla y a role in shaping bacterial diversity. Sample 3's reduce d diversity highlights the diff iculty of bac ter ial survival under arid conditions, where resour ces are limited. Comparison with Pr evious Stud ies • Zha ng et a l. (2020) found that soil moisture promote s bac ter ial m etabolic diversity, which aligns with our findings of incr eased diversity in we tter environments. • BBC Bite size (2024) reports that bacteria requir e moisture f or nutrient absorption and growth, suppor ting our obse rva tion of reduc ed diversity in dr y soils (Sam ple 3). Broader Implicat ions • Soil Healt h: Bac ter ial dive rsity is c ruc ial f or maintaining soil health, nutrient cycling, a nd disea se suppr ession. Prote cting microbial diver sity ensures ecosystem resilienc e and agricultur al pr oductivity. • Climate Change Impac ts: Changing rainf all patterns due to climate change are likely to affect soil e cosystem s. Understanding how ba cte ria l com munitie s respond to moistur e variability ca n help mitigate a dverse e ffects on biodiversity and soil productivity. Future Dire ctions • Investiga te the com bined effe cts of soil pH, nutrie nt availability, a nd m icr obial competition on bacterial diversity. • Explor e seasonal variations in bacterial comm unities to understand tem poral dynam ics. • Exa mine how soil types and the ir moistur e retention capacities inte ract to inf luence bacterial diver sity. References BBC Bite siz e. “Conditions Ne eded for Bacte ria l G rowth - Food Safety – CCEA - GCSE Home Economics: Food a nd Nutrition (CCEA ) Revision.” BBC Bite size, 2021, ww w.bbc .c o.uk/bite siz e/guides/z 77v3k7/revision/1 . Z ha ng, Hongying, et al. “Soil Bacte rial D ive rsity a nd Its Rela tionship with Soil CO2 and M inera l Composition: A Case Study of the Laiwu Experime nta l Site.” Inte rnational Journal of Environm ental R esearch and P ublic H ealth, vol. 17, no. 16, 7 A ug. 2020, p. 5699, https://doi.org/10.3390/ijerph17165699. Smith, J., D oe , A ., & Green, L. (2020). The impact of soil moisture on m icrobial div ersity: A case study of riparian zones. Journa l of Environmental M icrobiology, 34(2), 123–134. https://doi.org/10.1016/j.jenvmic ro.2020.02.003 Johnson, R., & Lee , T. (2018). Mic robial activ ity in v arying soil moisture c onditions: Insights into nutrie nt cy cling. Soil Ecology Journa l, 29(3), 456–467. https://doi.org/10.1080/soilecoj.2018.456 Acknowledgments This study wa s made successf ul thanks to the guidance and support provided by the teaching assistants, Hossein Asgari a nd Ca rson Mitchell, during the lab period. They both provided im mense help by sharing their knowledge on the be st equipme nt ma ter ials to use as we ll as strategies on how to collec t data and implement str ate gies, greatly contributing to the success of this projec t. Also, Dr. Tim Ha in, the c ourse coordinator pr ovided c ontinued support and assistanc e thr oughout the r ese arch process. The Effect of Soil Moisture Levels on Bacterial Species Richness Yusuf Shawky, Kyuwon Jung, Muhammad Abdullah, Eshaan Sandhu The University of Western Ontario 1151 Richmond Street, London, ON N6A 3K7 Moisture level on bacterial diversity Discussion and Practical Applications of Research Findings Bacter ia • Essential f or soil ecosyste m and nutrient cycle ​ Ob jective • Determine the relationship be tween soil m oisture levels and ba cte ria l colony diversity Fig .1.Samp ling locations for Site 1 (wet s oil), Site 2 (mois t s oil), and Site 3 (dry s oil), shown fro m right to left. Moist environment Dry environment Results Bacter ial dive rsity • Influe nce d by m oisture level and soil composition (Sm ith et al., 2020) • Ref lec t a critic al role in soil health and microbial ecology (Johnson & Lee 2018) Hypothesis • Soil moisture leve ls influence bac ter ial dive rsity. Prediction • Soil with higher moisture conte nt will exhibit gr eater bacterial diversity Methods Stu dy Locat ion and Samp ling Sites Soil sam ples were collected along the Tha mes River fr om thre e distinct locations, selected to r epr ese nt varying m oisture levels: • Sample 1: Shoreline ( wet soil). • Sample 2: Approxim ate ly 5 m ete rs from the shore (moist soil). • Sample 3: Approxim ate ly 10 meters f rom the shore (dr y soil). The sampling area wa s shaded, with no dire ct sunlight e xposure. All samples were collec ted f rom a depth of 1 inch, avoiding orga nic m atter such a s lea ves or roots to ensure consistency acr oss sample s. Var iables • Indepe ndent Variable: Soil moisture leve ls (wet, moist, dry). • Depend ent Variable: Bac ter ial dive rsity, me asured a s the number of morphologically distinct ba cte ria l colonies. Sampling Procedu re Soil was c ollected using sterile tablespoons, with a new sterile spoon used for ea ch sample to pr eve nt cr oss-contam ination. Eac h soil sam ple was placed into an a irtight pla stic bag immediately a fte r collec tion to preserve its moistur e content dur ing transportation. Microbial Culturing and Analysis The collected soil samples were processed to separate microorganism s, which were the n plated onto nutrient-rich agar to promote bacterial gr owth. Plates we re incubated at room tem per ature for one week. After incubation, ba cte ria l diversity was determined by c ounting the number of distinct colony morphologie s observed on eac h plate. Statistic al Analysis To evaluate the ef fect of soil m oisture on bacterial diversity, da ta we re analyzed using a one-way ANOVA to test for ove rall differ enc es among moisture leve ls. Posthoc two-sample t-tests were conducte d to identify significant pairwise differences betwee n tre atm ents. Fig. 2. Me an ba cte ria l species richne ss (±SE) a cross four soil treatments: wet soil, moist soil, dry soil, a nd distilled water. Wet and moist soils supported greater ba cte ria l diversity compared to distilled wate r, while dry soil e xhibited interm ediate species richne ss. Bars sha ring the same letter a re not significantly diff erent. A one-way ANOVA was c onducted to asse ss the eff ect of soil moisture levels on bacterial species richness. This test revealed a statistically significant dif ference among the four treatments (wet soil, moist soil, dr y soil, and control) (F = 39.46, df = 3, 8, p < 0.001). These results indica te that soil moisture levels ha ve an effe ct on bacterial diver sity. Post-hoc pair wise comparisons were c onducted using twosample t-tests to dete rmine which treatments we re signif ica ntly differ ent. The results wer e as follows: Wet soil and moist soil showed no significant dif ference in ba cte ria l species richne ss (p = 0.057). Wet soil had significantly more ba cte ria l species tha n dry soil (p = 0.002). Wet soil had significantly more ba cte ria l species tha n the control (p < 0.001). Moist soil had significantly more ba cte ria l species tha n the control (p = 0.002). Dry soil had significantly more ba cte ria l species tha n moist soil ( p = 0.007). Dry soil and the control showed no significant dif ference in ba cte ria l species richne ss (p = 0.116). This study investigate d how soil moisture levels influe nce bacterial diversity, addressing the hypothe sis that soil m oisture im pa cts bacterial comm unity c om position. The results supported this hypothesis, showing tha t wetter soils foster greater bacterial diversity, while dry conditions re strict it. Biological Con text for t he Results • Nutrient Availability: Increa sed m oisture enhances nutr ient dissolution, ma king nutrie nts more accessible to support bacterial growth and metabolism . • Oxyge n Levels: Moisture a lters oxygen availa bility, influencing the balance betwee n aerobic and a nae robic bacterial popula tions. • Microbial Compe tit ion and In teraction s: Variability betwe en Samples 1 and 2 indicates that f actors such as microbia l com pe tition and nutrient a vailability pla y a role in shaping bacterial diversity. Sample 3's reduce d diversity highlights the diff iculty of bac ter ial survival under arid conditions, where resour ces are limited. Comparison with Pr evious Stud ies • Zha ng et a l. (2020) found that soil moisture promote s bac ter ial m etabolic diversity, which aligns with our findings of incr eased diversity in we tter environments. • BBC Bite size (2024) reports that bacteria requir e moisture f or nutrient absorption and growth, suppor ting our obse rva tion of reduc ed diversity in dr y soils (Sam ple 3). Broader Implicat ions • Soil Healt h: Bac ter ial dive rsity is c ruc ial f or maintaining soil health, nutrient cycling, a nd disea se suppr ession. Prote cting microbial diver sity ensures ecosystem resilienc e and agricultur al pr oductivity. • Climate Change Impac ts: Changing rainf all patterns due to climate change are likely to affect soil e cosystem s. Understanding how ba cte ria l com munitie s respond to moistur e variability ca n help mitigate a dverse e ffects on biodiversity and soil productivity. Future Dire ctions • Investiga te the com bined effe cts of soil pH, nutrie nt availability, a nd m icr obial competition on bacterial diversity. • Explor e seasonal variations in bacterial comm unities to understand tem poral dynam ics. • Exa mine how soil types and the ir moistur e retention capacities inte ract to inf luence bacterial diver sity. References BBC Bite siz e. “Conditions Ne eded for Bacte ria l G rowth - Food Safety – CCEA - GCSE Home Economics: Food a nd Nutrition (CCEA ) Revision.” BBC Bite size, 2021, ww w.bbc .c o.uk/bite siz e/guides/z 77v3k7/revision/1 . Z ha ng, Hongying, et al. “Soil Bacte rial D ive rsity a nd Its Rela tionship with Soil CO2 and M inera l Composition: A Case Study of the Laiwu Experime nta l Site.” Inte rnational Journal of Environm ental R esearch and P ublic H ealth, vol. 17, no. 16, 7 A ug. 2020, p. 5699, https://doi.org/10.3390/ijerph17165699. Smith, J., D oe , A ., & Green, L. (2020). The impact of soil moisture on m icrobial div ersity: A case study of riparian zones. Journa l of Environmental M icrobiology, 34(2), 123–134. https://doi.org/10.1016/j.jenvmic ro.2020.02.003 Johnson, R., & Lee , T. (2018). Mic robial activ ity in v arying soil moisture c onditions: Insights into nutrie nt cy cling. Soil Ecology Journa l, 29(3), 456–467. https://doi.org/10.1080/soilecoj.2018.456 Acknowledgments This study wa s made successf ul thanks to the guidance and support provided by the teaching assistants, Hossein Asgari a nd Ca rson Mitchell, during the lab period. They both provided im mense help by sharing their knowledge on the be st equipme nt ma ter ials to use as we ll as strategies on how to collec t data and implement str ate gies, greatly contributing to the success of this projec t. Also, Dr. Tim Ha in, the c ourse coordinator pr ovided c ontinued support and assistanc e thr oughout the r ese arch process.