Malcolm Barnard

Mr. Malcolm Barnard

Department of Chemistry, University of Texas at Austin, Austin, Texas, USA
orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 August 2020 in Biogeochemistry
Verified
Journal Article
Closed access
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HPHans Paerl
Hans Paerl
NHNathan S. Hall
Nathan S. Hall
AHAlexandria G. Hounshell
Alexandria G. Hounshell
KRKaren L. Rossignol
Karen L. Rossignol
MBMalcolm Barnard
Malcolm Barnard
LHLawrence W. Harding
Lawrence W. Harding

9 January 2021 in Toxins
Verified
Journal Article
Open access
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MBMalcolm Barnard
Malcolm Barnard
JCJustin D. Chaffin
Justin D. Chaffin
HPHaley E. Plaas
Haley E. Plaas
GBGregory Boyer
Gregory Boyer
BWBofan Wei
Bofan Wei
HPHans Paerl
Hans Paerl
Cyanobacterial harmful algal bloom (CyanoHAB) proliferation is a global problem impacting ecosystem and human health. Western Lake Erie (WLE) typically endures two highly toxic CyanoHABs during summer: a Microcystis spp. bloom in Maumee Bay that extends throughout the western basin, and a Planktothrix spp. bloom in Sandusky Bay. Recently, the USA and Canada agreed to a 40% phosphorus (P) load reduction to lessen the severity of the WLE blooms. To investigate phosphorus and nitrogen (N) limitation of biomass and toxin production in WLE CyanoHABs, we conducted in situ nutrient addition and 40% dilution microcosm bioassays in June and August 2019. During the June Sandusky Bay bloom, biomass production as well as hepatotoxic microcystin and neurotoxic anatoxin production were N and P co-limited with microcystin production becoming nutrient deplete under 40% dilution. During August, the Maumee Bay bloom produced microcystin under nutrient repletion with slight induced P limitation under 40% dilution, and the Sandusky Bay bloom produced anatoxin under N limitation in both dilution treatments. The results demonstrate the importance of nutrient limitation effects on microcystin and anatoxin production. To properly combat cyanotoxin and cyanobacterial biomass production in WLE, both N and P reduction efforts should be implemented in its watershed.

4 April 2023 in Ecology
Verified
Journal Article
Open access
PDPeter Dunn
Peter Dunn
IAInsiyaa Ahmed
Insiyaa Ahmed
EAElise Armstrong
Elise Armstrong
NBNatasha Barlow
Natasha Barlow
MBMalcolm Barnard
Malcolm Barnard
LWLinda A. Whittingham
Linda A. Whittingham
Climate change models often assume similar responses to temperatures across the range of a species, but local adaptation or phenotypic plasticity can lead plants and animals to respond differently to temperature in different parts of their range. To date, there have been few tests of this assumption at the scale of continents, so it is unclear if this is a large‐scale problem. Here, we examined the assumption that insect taxa show similar responses to temperature at 96 sites in grassy habitats across North America. We sampled insects with Malaise traps during 2019–2021 (N = 1041 samples) and examined the biomass of insects in relation to temperature and time of season. Our samples mostly contained Diptera (33%), Lepidoptera (19%), Hymenoptera (18%), and Coleoptera (10%). We found strong regional differences in the phenology of insects and their response to temperature, even within the same taxonomic group, habitat type, and time of season. For example, the biomass of nematoceran flies increased across the season in the central part of the continent, but it only showed a small increase in the Northeast and a seasonal decline in the Southeast and West. At a smaller scale, insect biomass at different traps operating on the same days was correlated up to ~75 km apart. Large‐scale geographic and phenological variation in insect biomass and abundance has not been studied well, and it is a major source of controversy in previous analyses of insect declines that have aggregated studies from different locations and time periods. Our study illustrates that large‐scale predictions about changes in insect populations, and their causes, will need to incorporate regional and taxonomic differences in the response to temperature.

24 March 2022 in Earth and Space Science
Verified
Journal Article
Open access
DDDipankar Dwivedi
Dipankar Dwivedi
ASAndré Luís Diniz dos Santos
André Luís Diniz dos Santos
MBMalcolm Barnard
Malcolm Barnard
TCTheresa Crimmins
Theresa Crimmins
AMA. Malhotra
A. Malhotra
SWS. Weintraub‐Leff
S. Weintraub‐Leff
This article is composed of three independent commentaries about the state of Integrated, Coordinated, Open, Networked (ICON) principles in the American Geophysical Union Biogeosciences section, and discussion on the opportunities and challenges of adopting them. Each commentary focuses on a different topic: (a) Global collaboration, technology transfer, and application (Section 2), (b) Community engagement, community science, education, and stakeholder involvement (Section 3), and (c) Field, experimental, remote sensing, and real‐time data research and application (Section 4). We discuss needs and strategies for implementing ICON and outline short‐ and long‐term goals. The inclusion of global data and international community engagement are key to tackling grand challenges in biogeosciences. Although recent technological advances and growing open‐access information across the world have enabled global collaborations to some extent, several barriers, ranging from technical to organizational to cultural, have remained in advancing interoperability and tangible scientific progress in biogeosciences. Overcoming these hurdles is necessary to address pressing large‐scale research questions and applications in the biogeosciences, where ICON principles are essential. Here, we list several opportunities for ICON, including coordinated experimentation and field observations across global sites, that are ripe for implementation in biogeosciences as a means to scientific advancements and social progress.

1 September 2022 in Science of The Total Environment
Verified
Journal Article
Closed access
HPHaley E. Plaas
Haley E. Plaas
RPRyan W. Paerl
Ryan W. Paerl
KBKarsten Baumann
Karsten Baumann
CKColleen Karl
Colleen Karl
KPKimberly J. Popendorf
Kimberly J. Popendorf
HPHans W. Paerl
Hans W. Paerl