This study was conducted in Dr. Ahn’s wetland mesocosm on West Campus at George Mason University. Inside there are 40 wetland mesocosms that were created in 2012. The mesocosms were initially planted with 0 to 4 different native wetland species. Since COVID-19, maintenance halted which allowed the colonization of invasive species for the past three to five years. The goal of this study was to determine the amount of soil organic matter in each mesocosm after the colonization of invasive species. The hypothesis was that because there were more plants than there were previously, there will be a higher amount of soil organic matter in these mesocosms. The soil organic matter percentage was processed using the loss on ignition method. It was found that mesocosms that had sparsely spread, or no plants had the lowest soil organic matter while overgrown and dense mesocosms had the highest soil organic matter. After about 10 years, soil organic matter seemed to increase from a range of 2.36% to 2.59% to now a range of 4.15% to 6.21%. In the future a soil bulk density will be processed to analyze how soil porosity or compaction correlates with the soil organic matter found within the mesocosms. Also, plant identification will be conducted for all 40 mesocosms.

Hello, my name is Trinity Lavenhouse, and I am presenting my research on assessing soil organic matter in a legacy wetland mesocosm after the colonization of invasive species. My mentor is Dr. Changwoo Ahn.
So, to start off I am going to explain the importance of measuring soil organic matter! Soil organic matter is made up of decomposed plant and animal material. They contain quite a lot of organic compounds and are full of nutrients that help plants grow. So in general, it is important to measure the amount of soil organic matter that is present because it can indicate how healthy and fertile the soil is for plants to grow.
This study was conducted in Dr. Ahn’s wetland mesocosm on West campus in George Mason University. Inside there are 40 wetland mesocosms that were created in 2012. The mesocosms were initially planted with 0 to 4 different native wetland species. This picture is from 2014 after 2 growing seasons. Since COVID-19, maintenance halted. Unwanted plants weren’t removed and the water levels weren’t monitored like they use to be. This allowed the colonization of invasive species for the past three to five years. So, the goal of this study was to determine the amount of soil organic matter in each mesocosm after the colonization of invasive species. The hypothesis was that since there were more plants than there were previously, there will be a higher amount of soil organic matter in these mesocosms.
To take samples the mesocosms were split into 5 sections and one sample was taken from each section within the top 20 centimeters where organic matter is the most present, because soil organic matter decreases as you go further down. This was repeated for all 40 mesocosms. The soil organic matter percentage was processed using the loss on ignition method. To carry this out each sample was dried at 105°C for two days. After they were completely dry, they stayed in a desiccator to cool and were then crushed in with a mortar and pestle and sieved through a 2mm filter to get everything that is too big to go into the crucibles. The fine dirt was then placed in crucibles and fired at 360 Celsius for two hours and they were placed back into the desiccator to cool. Soil organic matter percentage is the percentage change of mass.
The results were all collected and all five of the samples were compiled and averaged represent the one mesocosm. It was found that mesocosms that had sparsely spread, or no plants had the lowest soil organic matter while overgrown and dense mesocosms had the highest soil organic matter. The standard error bars are large in mesocosms that had more plants or organic matter in a section than other sections. The mesocosms were then grouped by the initial number of species planted. There seems to be no significant difference across the board and the reason for that will be analyzed further.
In a previous study conducted by another person in this lab named Mary Means, they measured the total carbon content of all of the 34 planted mesocosms in 2014. Total carbon content is a is about 58% of soil organic matter so that conversion was used to estimate what the soil organic matter content was back in 2014. About ten years until now, later soil organic matter seemed to increase from a range of 2.36% to 2.59% to now a range of 4.15% to 6.21%. In the future a soil bulk density will be processed to analyze how soil porosity or compaction correlates with the soil organic matter found within the mesocosms. Also, plant identification will be conducted for all 40 mesocosms as when these samples were initially taken most of the plants were dead because it was the end of the winter.
Thank you for listening!

The climate of the current workplace has changed drastically within the past few years, as a result of many jobs moving to remote work. Many employees have had to learn how to adjust to dealing with the physical separation of leadership, as well as balance their own basic psychological needs in a new environment. These three needs, autonomy, competence, and relatedness, are important workplace predictors that still need further exploration in the remote workplace. This study samples from both remote and in-person workers, providing a clear comparison of how the change in workplace setting impacts an employee’s perception of leader-member quality, as well as their basic psychological needs. We hypothesized that LMX would have a significant and positive impact on each basic psychological need. We also hypothesized that remote work will moderate the relationship between LMX and each basic psychological need, such that the positive relationship will be stronger for non-remote workers than remote workers. Participants consisted of 241 full-time employees, 123 in-person workers and 118 remote workers. Results show that while the correlation between LMX and each basic psychological need were significant, they were not statistically different between work locations. This has implications for how the basic psychological needs can be fulfilled in the remote environment, challenging the assumption that the in-person environment is better at fostering better leader relationships and significance of the impact on the employee.

Hi everyone! My name is Jessica Luther and this is my project, Evaluating Basic Psychological Needs in Full-Time Employees. This study was done with the help of Dr. Kuykendall, and represents my research conducted for the third semester of the Honors in Psychology program. Since COVID, there’s been more flexibility in allowing employees to have part-time and full-time positions working remotely. Prior research shows that perception of leader quality is a predictor for employee well-being which has been studied in both the in-person and remote environments. The perception of someone’s basic psychological needs has also been seen to change the remote environment, a result of whether it be not seeing people, or whether it be feelings of social isolation. Basic psychological need perception has also changed. Connecting these three topics, since COVID we have seen a lot of people moving to remote positions, and a lot of the recent research in remote work kind of reflects how leader quality or leadership styles are impacting employees, specifically, the outcomes such as autonomy, motivation, a lot of stress-related outcomes as well. So, for this study to provide a direct comparison between in-person and remote employees we looked at how leader member exchange, which is noted as LMX, or also known as the perception of leader quality, is moderated by remote work and how remote work changes the relationship that someone might have with their leader or the perception of the quality they have with their leader and how that impacts their three basic psychological needs, which are autonomy, competence, and relatedness. My hypotheses are split into two parts, you have hypotheses 1a through 1c. This deals with direct associations between LMX and autonomy, LMX and competence, and LMX and relatedness. Prior research shows LMX is positively related to autonym, competence and relatedness, so we assume the same thing for this study. Hypotheses 2a, 2b, and 2c are where my contribution to the research comes in. It suggests that remote work moderates this relationship so remote work will moderate the relationship between LMX and each basic psychological need, such that the positive relationship will be stronger for no-remote workers than remote workers. Basically, insinuating that we will see that autonomy, competence and relatedness are both significant and stronger for in-person employees rather than remote employees. So, my participants were 241 full-time employees, 51% worked in-person, 49% worked remotely. We did not include any hybrid workers or anyone who worked part-time just to have a more balanced sample of who we were sampling from so full-time in this case was defined as working 35 plus hours per week. 42.3% were male, 55.2% were female, and 2.5% identified as non-binary. They were excluded if they worked part-time, were hybrid workers, or resided somewhere other than the U.S.. So, the methodology for this was that they were recruited on Prolific, which is an anonymous survey taking website, and the survey itself took place on Qualtrics. The two instruments used were the LMX-7, which measures perceived leader-member quality, or leader-member exchange, and Self Determination Theory 21, or SDT-21 Basic Psychological Needs at Work Scale, which measures each basic psychological need through statements that were tested using a Likert scale. Participants, for their participation, were compensated 2.85%. So, for the results, we ran a correlational analysis between LMX and SDT, separating remote participants from in-person participants, so that we would be able to directly compare their results. We actually found that each component of self-determination theory, autonomy, competence, and relatedness, was significant with LMX in both groups. So Hypotheses 1a-1c were supported, which was expected because we’ve already seen this in prior research, However, Hypotheses 2a-2c were not supported. Even though each component was significant for in-person, through further testing we found that while everything was significant, they were significantly different so the correlations between LMX and SDT of in-person workers was not significantly different than LMX and SDT of remote workers. That suggests that these needs can be filled in both environments. The implications for this show how leadership perceptions might not really change based on environments, and even then, it’s not statistically significant between the two environments themselves, and actually remote work can still be a supporting environment, given that people have supportive leadership roles and supportive leaders that they can count on. One of the studies that I read noted that social isolation was a really really big concern, which could really damage someone’s feelings of relatedness. However, as seen in the table, relatedness was still significant in remote workers using LMX, so having that supportive leadership role really can help fill the need for relatedness. Further research should take into account what hybrid work or part time work might reveal because those are really samples as well. Knowing how different samples perceive different leadership styles is really important to understanding how leaders can support their employees and how leaders can really help fulfill some of these psychological needs. For my acknowledgements, I wanted to say that this couldn’t have been done without OSCAR funding, it was used to help compensate the participants for their participants, and I also wanted to thank Dr. Brielmaier, Dr. Zaccaro, and Dr. Z for all their help in my project as well. Thank you.