This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Linguistic analysis of 2,206 letters of recommendation compared gender bias in two disciplines di... more Linguistic analysis of 2,206 letters of recommendation compared gender bias in two disciplines differing in women’s representation: experimental particle physics (EPP, <15% female) and social science (>60% female). Standard lexical measures (e.g., “communal,” “agentic,” and “standout”) did not show bias against women in either discipline. On the contrary, in letters about women, female physicists used more positive-affect words, while male physicists used fewer negative-affect words as well as more references to hard work/effort. Neither discipline showed gender differences in the rank of letter writers, but social scientists wrote longer letters about women and wrote more often for candidates of their own gender. However, standard lexical measures assess only overt expressions of bias and may miss more subtle gendered language. We therefore developed a novel, open-ended measure of gendered usages. In striking contrast to conventional measures, our open-ended analysis uncovere...
We investigated gender bias in letters of recommendation as a possible cause of the under-represe... more We investigated gender bias in letters of recommendation as a possible cause of the under-representation of women in Experimental Particle Physics (EPP), where about 15% of faculty are female—well below the 60% level in psychology and sociology. We analyzed 2206 letters in EPP and these two social sciences using standard lexical measures as well as two new measures: author status and an open-ended search for gendered language. In contrast to former studies, women were not depicted as more communal, less agentic, or less standout. Lexical measures revealed few gender differences in either discipline. The open-ended analysis revealed disparities favoring women in social science and men in EPP. However, female EPP candidates were characterized as “brilliant” in nearly three times as many letters as were men.
In this paper, we estimate the effect of primary school teachers' gender biases on boys' and girl... more In this paper, we estimate the effect of primary school teachers' gender biases on boys' and girls' academic achievements during middle and high school and on the choice of advanced level courses in math and sciences during high school. For identification, we rely on the random assignments of teachers and students to classes in primary schools. Our results suggest that teachers' biases favoring boys have an asymmetric effect by gender-positive effect on boys' achievements and negative effect on girls'. Such gender biases also impact students' enrollment in advanced level math courses in high schoolboys positively and girls negatively. These results suggest that teachers' biased behavior at early stage of schooling have long run implications for occupational choices and earnings at adulthood, because enrollment in advanced courses in math and science in high school is a prerequisite for post-secondary schooling in engineering, computer science and so on. This impact is heterogeneous, being larger for children from families where the father is more educated than the mother and larger on girls from low socioeconomic background.
Omnipresent calls for more women in university administration presume women will prioritize using... more Omnipresent calls for more women in university administration presume women will prioritize using resources and power to increase female representation, especially in STEM fields where women are most underrepresented. However, empirical evidence is lacking for systematic differences in female vs. male administratorsŠ attitudes. Do female administrators agree on which strategies are best, and do men see things differently? We explored United States college and university administratorsŠ opinions regarding strategies, policies, and structural changes in their organizations designed to increase women professorsŠ representation and retention in STEM fields. A comprehensive review of past research yielded a database of potentially-effective, recommended policies. A survey based on these policies was sent to provosts, deans, associate deans, and department chairs of STEM fields at 96 public and private research universities across the U.S. These administrators were asked to rate the qu...
Audits of tenure-track hiring reveal faculty prefer to hire female applicants over males. However... more Audits of tenure-track hiring reveal faculty prefer to hire female applicants over males. However, audit data do not control for applicant quality, allowing some to argue women are hired at higher rates because they are more qualified. To test this, Williams and Ceci (2015) conducted an experiment demonstrating a preference for hiring women over identically-qualified men. While their findings are consistent with audits, they raise the specter that faculty may prefer women over even more-qualified men, a claim made recently. We evaluated this claim in the present study: 158 faculty ranked two men and one woman for a tenure-track-assistant professorship, and 94 faculty ranked two women and one man. In the former condition, the female applicant was slightly weaker than her two male competitors, although still strong; in the other condition the male applicant was slightly weaker than his two female competitors, although still strong. Faculty of both genders and in all fields preferred t...
Psychological science in the public interest : a journal of the American Psychological Society, 2014
Much has been written in the past two decades about women in academic science careers, but this l... more Much has been written in the past two decades about women in academic science careers, but this literature is contradictory. Many analyses have revealed a level playing field, with men and women faring equally, whereas other analyses have suggested numerous areas in which the playing field is not level. The only widely-agreed-upon conclusion is that women are underrepresented in college majors, graduate school programs, and the professoriate in those fields that are the most mathematically intensive, such as geoscience, engineering, economics, mathematics/computer science, and the physical sciences. In other scientific fields (psychology, life science, social science), women are found in much higher percentages. In this monograph, we undertake extensive life-course analyses comparing the trajectories of women and men in math-intensive fields with those of their counterparts in non-math-intensive fields in which women are close to parity with or even exceed the number of men. We begi...
A single factor goes a long way in explaining the dearth of women in math-intensive fields. How c... more A single factor goes a long way in explaining the dearth of women in math-intensive fields. How can we address it? Wendy M. Williams [professor] and Department of Human Development at Cornell University, where she founded and directs the Cornell Institute for Women in Science, a research-outreach center focusing on empirical analysis of women's scientific careers. Stephen J. Ceci [Helen Carr Chaired Professor] Developmental Psychology at Cornell. I have frequently been questioned, especially by women, of how I could reconcile family life with a scientific career. Well, it has not been easy.-Marie Curie, two-time Nobel Prize winner and mother of a daughter, Irène Joliot-Curie, who also won the Nobel Prize Jennifer was an extremely talented undergraduate, majoring in mathematics and engineering. Her grades and test scores were nearly perfect; her professors saw a bright future for her as an engineering professor and encouraged her to pursue a doctorate. In graduate school, she continued to excel, accumulating high-quality publications, fellowships and awards. She landed a premier postdoctoral position and was headed for a first-tier professorship. But she never applied for a tenure-track academic job. As a 33-year-old postdoc, she could not imagine waiting to have children until after tenure at age 40, nor could she imagine how she would juggle caring for a young family with the omnipresent demands of an assistant professorship. The harried lives of the two tenured mothers in her department convinced her that such a path was not for her. Jennifer made the choice to have a family and teach mathematics part-time at a local community college. Although it's not hard to find evidence of women professors' many successes in the academy, scenarios like Jennifer's are all too common. Women hold a substantial portion of professorships in the humanities and liberal arts, and they are well represented in the social sciences and some fields of natural science, such as biology. Overall, women make up 33 percent of faculty at doctoral-level institutions. They receive many teaching and service awards and do as well as men in winning grants. But women are in short supply in mathintensive fields, such as chemistry, physics, mathematics, engineering and computer science. For example, in the top 100 U.S. universities in 2007, women full professors in these fields numbered only 4.4 to 12.3 percent, and women were only 16 to 27 percent of assistant professors (see Figure 2). What is going on here? Why are women who are talented and dedicated enough to graduate from college with degrees in mathematics not progressing through graduate school and ultimately earning full professorships? Where are these women going, and why do they leave their chosen field?
Nilanjana Dasgupta's (this issue) stereotype inoculation model (SIM) helps explain why what feels... more Nilanjana Dasgupta's (this issue) stereotype inoculation model (SIM) helps explain why what feels like a free choice to pursue one life path over another "is often constrained by subtle cues in achievement environments that signal who naturally belongs there and is most likely to succeed and who else is a dubious fit" (p. 231). She posits that seeing others like themselves in successful roles inoculates women against negative stereotypes that impede their success and persistence in specific achievement contexts.
Despite impressive employment gains in many fields of science, women remain underrepresented in f... more Despite impressive employment gains in many fields of science, women remain underrepresented in fields requiring intensive use of mathematics. Here we discuss three potential explanations for women’s underrepresentation: (a) male–female mathematical and spatial ability gaps, (b) sex discrimination, and (c) sex differences in career preferences and lifestyle choices. Synthesizing findings from psychology, endocrinology, sociology, economics, and education leads to the conclusion that, among a combination of interrelated factors, preferences and choices—both freely made and constrained—are the most significant cause of women’s underrepresentation.
The behavioral sciences have come under attack for writings and speech that affront sensitivities... more The behavioral sciences have come under attack for writings and speech that affront sensitivities. At such times, academic freedom and tenure are invoked to forestall efforts to censure and terminate jobs. We review the history and controversy surrounding academic freedom and tenure, and explore their meaning across different fields, at different institutions, and at different ranks. In a multifactoral experimental survey, 1,004 randomly selected faculty members from top-ranked institutions were asked how colleagues would typically respond when confronted with dilemmas concerning teaching, research, and wrong-doing. Full professors were perceived as being more likely to insist on having the academic freedom to teach unpopular courses, research controversial topics, and whistle-blow wrong-doing than were lower-ranked professors (even associate professors with tenure). Everyone thought that others were more likely to exercise academic freedom than they themselves were, and that promot...
This research is based in far north-west Queensland at Boodjamulla National Park, a dryland savan... more This research is based in far north-west Queensland at Boodjamulla National Park, a dryland savannah dominated by Eucalyptus and Melaleuca woodlands and floodplains. The interspaces between the perennial tussock grasses are dominated by cyanobacterial soil crusts. The wet season is governed by monsoonal troughs and in the dry season there is often no rain at all. This two-year project has focused on; establishing the diversity of the different crust ecosystems, net carbon uptake annually, and seasonal eco-physiological function. Crust communities can be divided into three main types: flood plain crusts dominated by Scytonema, Simploca and Nostoc, with abundant liverworts and some areas of moss; dry savannah and elevated crusts dominated by Scytonema and Stigonema with lichens and liverworts and; rock crusts dominated by cyanobacteria and cyanolichens. CO2 exchange is measured with an automated cuvette system that records the CO2 difference over three minutes on a thirty-minute cycle...
(ITE), Natural Environment Research Council (NERC), under contract to the Department of the Envir... more (ITE), Natural Environment Research Council (NERC), under contract to the Department of the Environment (DOE) as WE/NERC contract DGR/483/23. ITE is grateful to DOE and their Review Committee for support throughout, and to DOE for permission to publish the contract report in this form. Errata-p9 line 11 from end, delete 'centuries', insert 'century'. p35 ling3 from end, spelling-'pastures'. p54 line 16, should read I. .. cold and moderately wet. .. I. p58 line 11 from end, delete 'and', insert 'but'. p15 line 22, delete 'were'. insert 'was'.-p85 line 17 from end, should read I. .. as moderately cold and. .. '. p130 line 7 , delete 'occupies', insert 'occupy' 136 line 16, delete 'intensive', insert utensive'. I line 3, delete 'or', insert 'of'.
Restoration of soils post-mining requires key solutions to complex issues through which the distu... more Restoration of soils post-mining requires key solutions to complex issues through which the disturbance of topsoil incorporating soil microbial communities can result in a modification to ecosystem function. This research was in collaboration with Iluka Resources at the Jacinth-Ambrosia (J-A) mineral sand mine located in a semi-arid chenopod shrubland in southern Australia. At J-A, assemblages of microorganisms and microflora inhabit at least half of the soil surfaces and are collectively known as biocrusts. This research encompassed a polyphasic approach to soil microbial community profiling focused on "biobanking" viable cyanobacteria in topsoil stockpiles to facilitate rehabilitation. We found that cyanobacterial communities were compositionally diverse topsoil microbiomes. There was no significant difference in cyanobacterial community structure across soil types. As hypothesised, cyanobacteria were central to soil microprocesses, strongly supported by species richness and diversity. Cyanobacteria were a significant component of all three successional stages with 21 species identified from 10 sites. Known nitrogen-fixing cyanobacteria Symploca, Scytonema, Porphyrosiphon, Brasilonema, Nostoc, and Gloeocapsa comprised more than 50 % of the species richness at each site and 61 % of the total community richness. In the first study of its kind, we have described the response of cyanobacteria to topsoil stockpiling at various depths and ages. Cyanobacteria are moderately resilient to stockpiling at depth and over time, with average species richness greatest in the top 10 cm of the stockpiles of all ages and more viable within the first 6 weeks, indicating potential for biocrust re-establishment. In general, the resilience of cyanobacteria to burial in topsoil stockpiles in both the short and long term was significant; however, in an arid environment recolonisation and community diversity could be impeded by drought. Biocrust re-establishment during mine rehabilitation relies on the role of cyanobacteria as a means of early soil stabilisation. At J-A mine operations do not threaten the survival of any of the organisms we studied. Increased cyanobacterial biomass is likely to be a good indicator and reliable metric for the re-establishment of soil microprocesses.
The Boodjamulla National Park research station is situated in the northwestern Queensland dry sav... more The Boodjamulla National Park research station is situated in the northwestern Queensland dry savannah, where the climate is dominated by summer monsoons and virtually dry winters. Under shrub canopies and in between the tussock grasses cyanobacterial crusts almost entirely cover the flood plain soil surfaces. Seasonality drives N fixation, and in the savannah this has a large impact on both plant and soil function. Many cyanobacteria fix dinitrogen that is liberated into the soil in both inorganic and organic N forms. We examined cyanobacterial species richness and bioavailable N spanning 7 months of a typical wet season. Over the wet season cyanobacterial richness ranged from 6 to 19 species. N-fixing Scytonema accounted for seasonal averages between 51 and 93 % of the biocrust. Cyanobacterial richness was highly correlated with N fixation and bioavailable N in 0-1 cm. Key N-fixing species such as Nostoc, Symploca and Gloeocapsa significantly enriched soil N although Nostoc was the most influential. Total seasonal N fixation by cyanobacteria demonstrated the variability in productivity according to the number of wet days as well as the follow-on days where the soil retained adequate moisture. Based on total active days per month we estimated that N soil enrichment via cyanobacteria would be ∼ 5.2 kg ha −1 annually which is comparable to global averages. This is a substantial contribution to the nutrient-deficient savannah soils that are almost entirely reliant on the wet season for microbial turnover of organic matter. Such well-defined seasonal trends and synchronisation in cyanobacterial species richness, N fixation, bioavailable N and C fixation (Büdel et al., 2018) provide important contributions to multifunctional microprocesses and soil fertility.
Boodjamulla National Park research station is situated in north-west Queensland in the dry savann... more Boodjamulla National Park research station is situated in north-west Queensland in the dry savannah where the climate is dominated by summer monsoons and virtually dry winters. Cyanobacterial crusts almost entirely cover the flood plain soil surfaces in between the tussock grasses. Cyanobacteria fix dinitrogen that is liberated into the soil in both inorganic and organic N forms. Seasonality drives N-fixation and in the savannah, this has a large impact on both plant and soil function. In this research project, we examined the cyanobacterial species richness and bioavailable N spanning the seven months of a typical wet season. We hypothesised that cyanobacterial richness and bioavailable N would peak at the time of the heaviest rains and gradually decline in the latter stages of the wet season. We also anticipated that the abundance of N-fixing cyanobacteria would be correlated to N-fixation and N-enrichment of the surface soils. Over the wet season cyanobacterial richness ranged fr...
Proceedings of the National Academy of Sciences of the United States of America, Jan 13, 2015
National randomized experiments and validation studies were conducted on 873 tenure-track faculty... more National randomized experiments and validation studies were conducted on 873 tenure-track faculty (439 male, 434 female) from biology, engineering, economics, and psychology at 371 universities/colleges from 50 US states and the District of Columbia. In the main experiment, 363 faculty members evaluated narrative summaries describing hypothetical female and male applicants for tenure-track assistant professorships who shared the same lifestyle (e.g., single without children, married with children). Applicants' profiles were systematically varied to disguise identically rated scholarship; profiles were counterbalanced by gender across faculty to enable between-faculty comparisons of hiring preferences for identically qualified women versus men. Results revealed a 2:1 preference for women by faculty of both genders across both math-intensive and non-math-intensive fields, with the single exception of male economists, who showed no gender preference. Results were replicated using w...
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Linguistic analysis of 2,206 letters of recommendation compared gender bias in two disciplines di... more Linguistic analysis of 2,206 letters of recommendation compared gender bias in two disciplines differing in women’s representation: experimental particle physics (EPP, <15% female) and social science (>60% female). Standard lexical measures (e.g., “communal,” “agentic,” and “standout”) did not show bias against women in either discipline. On the contrary, in letters about women, female physicists used more positive-affect words, while male physicists used fewer negative-affect words as well as more references to hard work/effort. Neither discipline showed gender differences in the rank of letter writers, but social scientists wrote longer letters about women and wrote more often for candidates of their own gender. However, standard lexical measures assess only overt expressions of bias and may miss more subtle gendered language. We therefore developed a novel, open-ended measure of gendered usages. In striking contrast to conventional measures, our open-ended analysis uncovere...
We investigated gender bias in letters of recommendation as a possible cause of the under-represe... more We investigated gender bias in letters of recommendation as a possible cause of the under-representation of women in Experimental Particle Physics (EPP), where about 15% of faculty are female—well below the 60% level in psychology and sociology. We analyzed 2206 letters in EPP and these two social sciences using standard lexical measures as well as two new measures: author status and an open-ended search for gendered language. In contrast to former studies, women were not depicted as more communal, less agentic, or less standout. Lexical measures revealed few gender differences in either discipline. The open-ended analysis revealed disparities favoring women in social science and men in EPP. However, female EPP candidates were characterized as “brilliant” in nearly three times as many letters as were men.
In this paper, we estimate the effect of primary school teachers' gender biases on boys' and girl... more In this paper, we estimate the effect of primary school teachers' gender biases on boys' and girls' academic achievements during middle and high school and on the choice of advanced level courses in math and sciences during high school. For identification, we rely on the random assignments of teachers and students to classes in primary schools. Our results suggest that teachers' biases favoring boys have an asymmetric effect by gender-positive effect on boys' achievements and negative effect on girls'. Such gender biases also impact students' enrollment in advanced level math courses in high schoolboys positively and girls negatively. These results suggest that teachers' biased behavior at early stage of schooling have long run implications for occupational choices and earnings at adulthood, because enrollment in advanced courses in math and science in high school is a prerequisite for post-secondary schooling in engineering, computer science and so on. This impact is heterogeneous, being larger for children from families where the father is more educated than the mother and larger on girls from low socioeconomic background.
Omnipresent calls for more women in university administration presume women will prioritize using... more Omnipresent calls for more women in university administration presume women will prioritize using resources and power to increase female representation, especially in STEM fields where women are most underrepresented. However, empirical evidence is lacking for systematic differences in female vs. male administratorsŠ attitudes. Do female administrators agree on which strategies are best, and do men see things differently? We explored United States college and university administratorsŠ opinions regarding strategies, policies, and structural changes in their organizations designed to increase women professorsŠ representation and retention in STEM fields. A comprehensive review of past research yielded a database of potentially-effective, recommended policies. A survey based on these policies was sent to provosts, deans, associate deans, and department chairs of STEM fields at 96 public and private research universities across the U.S. These administrators were asked to rate the qu...
Audits of tenure-track hiring reveal faculty prefer to hire female applicants over males. However... more Audits of tenure-track hiring reveal faculty prefer to hire female applicants over males. However, audit data do not control for applicant quality, allowing some to argue women are hired at higher rates because they are more qualified. To test this, Williams and Ceci (2015) conducted an experiment demonstrating a preference for hiring women over identically-qualified men. While their findings are consistent with audits, they raise the specter that faculty may prefer women over even more-qualified men, a claim made recently. We evaluated this claim in the present study: 158 faculty ranked two men and one woman for a tenure-track-assistant professorship, and 94 faculty ranked two women and one man. In the former condition, the female applicant was slightly weaker than her two male competitors, although still strong; in the other condition the male applicant was slightly weaker than his two female competitors, although still strong. Faculty of both genders and in all fields preferred t...
Psychological science in the public interest : a journal of the American Psychological Society, 2014
Much has been written in the past two decades about women in academic science careers, but this l... more Much has been written in the past two decades about women in academic science careers, but this literature is contradictory. Many analyses have revealed a level playing field, with men and women faring equally, whereas other analyses have suggested numerous areas in which the playing field is not level. The only widely-agreed-upon conclusion is that women are underrepresented in college majors, graduate school programs, and the professoriate in those fields that are the most mathematically intensive, such as geoscience, engineering, economics, mathematics/computer science, and the physical sciences. In other scientific fields (psychology, life science, social science), women are found in much higher percentages. In this monograph, we undertake extensive life-course analyses comparing the trajectories of women and men in math-intensive fields with those of their counterparts in non-math-intensive fields in which women are close to parity with or even exceed the number of men. We begi...
A single factor goes a long way in explaining the dearth of women in math-intensive fields. How c... more A single factor goes a long way in explaining the dearth of women in math-intensive fields. How can we address it? Wendy M. Williams [professor] and Department of Human Development at Cornell University, where she founded and directs the Cornell Institute for Women in Science, a research-outreach center focusing on empirical analysis of women's scientific careers. Stephen J. Ceci [Helen Carr Chaired Professor] Developmental Psychology at Cornell. I have frequently been questioned, especially by women, of how I could reconcile family life with a scientific career. Well, it has not been easy.-Marie Curie, two-time Nobel Prize winner and mother of a daughter, Irène Joliot-Curie, who also won the Nobel Prize Jennifer was an extremely talented undergraduate, majoring in mathematics and engineering. Her grades and test scores were nearly perfect; her professors saw a bright future for her as an engineering professor and encouraged her to pursue a doctorate. In graduate school, she continued to excel, accumulating high-quality publications, fellowships and awards. She landed a premier postdoctoral position and was headed for a first-tier professorship. But she never applied for a tenure-track academic job. As a 33-year-old postdoc, she could not imagine waiting to have children until after tenure at age 40, nor could she imagine how she would juggle caring for a young family with the omnipresent demands of an assistant professorship. The harried lives of the two tenured mothers in her department convinced her that such a path was not for her. Jennifer made the choice to have a family and teach mathematics part-time at a local community college. Although it's not hard to find evidence of women professors' many successes in the academy, scenarios like Jennifer's are all too common. Women hold a substantial portion of professorships in the humanities and liberal arts, and they are well represented in the social sciences and some fields of natural science, such as biology. Overall, women make up 33 percent of faculty at doctoral-level institutions. They receive many teaching and service awards and do as well as men in winning grants. But women are in short supply in mathintensive fields, such as chemistry, physics, mathematics, engineering and computer science. For example, in the top 100 U.S. universities in 2007, women full professors in these fields numbered only 4.4 to 12.3 percent, and women were only 16 to 27 percent of assistant professors (see Figure 2). What is going on here? Why are women who are talented and dedicated enough to graduate from college with degrees in mathematics not progressing through graduate school and ultimately earning full professorships? Where are these women going, and why do they leave their chosen field?
Nilanjana Dasgupta's (this issue) stereotype inoculation model (SIM) helps explain why what feels... more Nilanjana Dasgupta's (this issue) stereotype inoculation model (SIM) helps explain why what feels like a free choice to pursue one life path over another "is often constrained by subtle cues in achievement environments that signal who naturally belongs there and is most likely to succeed and who else is a dubious fit" (p. 231). She posits that seeing others like themselves in successful roles inoculates women against negative stereotypes that impede their success and persistence in specific achievement contexts.
Despite impressive employment gains in many fields of science, women remain underrepresented in f... more Despite impressive employment gains in many fields of science, women remain underrepresented in fields requiring intensive use of mathematics. Here we discuss three potential explanations for women’s underrepresentation: (a) male–female mathematical and spatial ability gaps, (b) sex discrimination, and (c) sex differences in career preferences and lifestyle choices. Synthesizing findings from psychology, endocrinology, sociology, economics, and education leads to the conclusion that, among a combination of interrelated factors, preferences and choices—both freely made and constrained—are the most significant cause of women’s underrepresentation.
The behavioral sciences have come under attack for writings and speech that affront sensitivities... more The behavioral sciences have come under attack for writings and speech that affront sensitivities. At such times, academic freedom and tenure are invoked to forestall efforts to censure and terminate jobs. We review the history and controversy surrounding academic freedom and tenure, and explore their meaning across different fields, at different institutions, and at different ranks. In a multifactoral experimental survey, 1,004 randomly selected faculty members from top-ranked institutions were asked how colleagues would typically respond when confronted with dilemmas concerning teaching, research, and wrong-doing. Full professors were perceived as being more likely to insist on having the academic freedom to teach unpopular courses, research controversial topics, and whistle-blow wrong-doing than were lower-ranked professors (even associate professors with tenure). Everyone thought that others were more likely to exercise academic freedom than they themselves were, and that promot...
This research is based in far north-west Queensland at Boodjamulla National Park, a dryland savan... more This research is based in far north-west Queensland at Boodjamulla National Park, a dryland savannah dominated by Eucalyptus and Melaleuca woodlands and floodplains. The interspaces between the perennial tussock grasses are dominated by cyanobacterial soil crusts. The wet season is governed by monsoonal troughs and in the dry season there is often no rain at all. This two-year project has focused on; establishing the diversity of the different crust ecosystems, net carbon uptake annually, and seasonal eco-physiological function. Crust communities can be divided into three main types: flood plain crusts dominated by Scytonema, Simploca and Nostoc, with abundant liverworts and some areas of moss; dry savannah and elevated crusts dominated by Scytonema and Stigonema with lichens and liverworts and; rock crusts dominated by cyanobacteria and cyanolichens. CO2 exchange is measured with an automated cuvette system that records the CO2 difference over three minutes on a thirty-minute cycle...
(ITE), Natural Environment Research Council (NERC), under contract to the Department of the Envir... more (ITE), Natural Environment Research Council (NERC), under contract to the Department of the Environment (DOE) as WE/NERC contract DGR/483/23. ITE is grateful to DOE and their Review Committee for support throughout, and to DOE for permission to publish the contract report in this form. Errata-p9 line 11 from end, delete 'centuries', insert 'century'. p35 ling3 from end, spelling-'pastures'. p54 line 16, should read I. .. cold and moderately wet. .. I. p58 line 11 from end, delete 'and', insert 'but'. p15 line 22, delete 'were'. insert 'was'.-p85 line 17 from end, should read I. .. as moderately cold and. .. '. p130 line 7 , delete 'occupies', insert 'occupy' 136 line 16, delete 'intensive', insert utensive'. I line 3, delete 'or', insert 'of'.
Restoration of soils post-mining requires key solutions to complex issues through which the distu... more Restoration of soils post-mining requires key solutions to complex issues through which the disturbance of topsoil incorporating soil microbial communities can result in a modification to ecosystem function. This research was in collaboration with Iluka Resources at the Jacinth-Ambrosia (J-A) mineral sand mine located in a semi-arid chenopod shrubland in southern Australia. At J-A, assemblages of microorganisms and microflora inhabit at least half of the soil surfaces and are collectively known as biocrusts. This research encompassed a polyphasic approach to soil microbial community profiling focused on "biobanking" viable cyanobacteria in topsoil stockpiles to facilitate rehabilitation. We found that cyanobacterial communities were compositionally diverse topsoil microbiomes. There was no significant difference in cyanobacterial community structure across soil types. As hypothesised, cyanobacteria were central to soil microprocesses, strongly supported by species richness and diversity. Cyanobacteria were a significant component of all three successional stages with 21 species identified from 10 sites. Known nitrogen-fixing cyanobacteria Symploca, Scytonema, Porphyrosiphon, Brasilonema, Nostoc, and Gloeocapsa comprised more than 50 % of the species richness at each site and 61 % of the total community richness. In the first study of its kind, we have described the response of cyanobacteria to topsoil stockpiling at various depths and ages. Cyanobacteria are moderately resilient to stockpiling at depth and over time, with average species richness greatest in the top 10 cm of the stockpiles of all ages and more viable within the first 6 weeks, indicating potential for biocrust re-establishment. In general, the resilience of cyanobacteria to burial in topsoil stockpiles in both the short and long term was significant; however, in an arid environment recolonisation and community diversity could be impeded by drought. Biocrust re-establishment during mine rehabilitation relies on the role of cyanobacteria as a means of early soil stabilisation. At J-A mine operations do not threaten the survival of any of the organisms we studied. Increased cyanobacterial biomass is likely to be a good indicator and reliable metric for the re-establishment of soil microprocesses.
The Boodjamulla National Park research station is situated in the northwestern Queensland dry sav... more The Boodjamulla National Park research station is situated in the northwestern Queensland dry savannah, where the climate is dominated by summer monsoons and virtually dry winters. Under shrub canopies and in between the tussock grasses cyanobacterial crusts almost entirely cover the flood plain soil surfaces. Seasonality drives N fixation, and in the savannah this has a large impact on both plant and soil function. Many cyanobacteria fix dinitrogen that is liberated into the soil in both inorganic and organic N forms. We examined cyanobacterial species richness and bioavailable N spanning 7 months of a typical wet season. Over the wet season cyanobacterial richness ranged from 6 to 19 species. N-fixing Scytonema accounted for seasonal averages between 51 and 93 % of the biocrust. Cyanobacterial richness was highly correlated with N fixation and bioavailable N in 0-1 cm. Key N-fixing species such as Nostoc, Symploca and Gloeocapsa significantly enriched soil N although Nostoc was the most influential. Total seasonal N fixation by cyanobacteria demonstrated the variability in productivity according to the number of wet days as well as the follow-on days where the soil retained adequate moisture. Based on total active days per month we estimated that N soil enrichment via cyanobacteria would be ∼ 5.2 kg ha −1 annually which is comparable to global averages. This is a substantial contribution to the nutrient-deficient savannah soils that are almost entirely reliant on the wet season for microbial turnover of organic matter. Such well-defined seasonal trends and synchronisation in cyanobacterial species richness, N fixation, bioavailable N and C fixation (Büdel et al., 2018) provide important contributions to multifunctional microprocesses and soil fertility.
Boodjamulla National Park research station is situated in north-west Queensland in the dry savann... more Boodjamulla National Park research station is situated in north-west Queensland in the dry savannah where the climate is dominated by summer monsoons and virtually dry winters. Cyanobacterial crusts almost entirely cover the flood plain soil surfaces in between the tussock grasses. Cyanobacteria fix dinitrogen that is liberated into the soil in both inorganic and organic N forms. Seasonality drives N-fixation and in the savannah, this has a large impact on both plant and soil function. In this research project, we examined the cyanobacterial species richness and bioavailable N spanning the seven months of a typical wet season. We hypothesised that cyanobacterial richness and bioavailable N would peak at the time of the heaviest rains and gradually decline in the latter stages of the wet season. We also anticipated that the abundance of N-fixing cyanobacteria would be correlated to N-fixation and N-enrichment of the surface soils. Over the wet season cyanobacterial richness ranged fr...
Proceedings of the National Academy of Sciences of the United States of America, Jan 13, 2015
National randomized experiments and validation studies were conducted on 873 tenure-track faculty... more National randomized experiments and validation studies were conducted on 873 tenure-track faculty (439 male, 434 female) from biology, engineering, economics, and psychology at 371 universities/colleges from 50 US states and the District of Columbia. In the main experiment, 363 faculty members evaluated narrative summaries describing hypothetical female and male applicants for tenure-track assistant professorships who shared the same lifestyle (e.g., single without children, married with children). Applicants' profiles were systematically varied to disguise identically rated scholarship; profiles were counterbalanced by gender across faculty to enable between-faculty comparisons of hiring preferences for identically qualified women versus men. Results revealed a 2:1 preference for women by faculty of both genders across both math-intensive and non-math-intensive fields, with the single exception of male economists, who showed no gender preference. Results were replicated using w...
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Papers by Wendy Williams