Ecology of Australian Alps Although her initial research activities focused on
coral fungi, she studied fungal and
nematode diseases of plants as well. As a student, attending field-trips with the McCoy Society for Field Investigation and Research In 1940, Carr was appointed the secretary of the committee to award the Isabella D. Marshall scholarship to enable a female student to live away from home in order to study at the
University of Melbourne. Marshall was the mistress of method of English in the School of Education at the University of Melbourne until her death in 1938. Marshalls friends raised £500 to fund the scholarship. From 1941 onward, Carr conducted extensive innovative ecology research in the
Australian alpine environment where extensive
over-grazing by cattle and sheep was causing
soil erosion and degradation of a delicate ecosystem. Permits to graze these high plains commenced in the late 1880s and the changes wrought by the hooved animals facilitated the arrival (in 1920s) of rabbits which caused further change. Additional motivation for the studies was prompted by the soil
siltation threat to the soon to be constructed
Kiewa Hydroelectric Scheme. Carr was the first research officer of the Soil Conservation Board and was responsible for establishing exclusion fencing on reference plots in
Bogong High Plains. Having excluded grazing from select high-plains plots (and not from adjacent plots), Carr and team members recorded changes in regrowth vegetation (both type and density) over decades. In the early years, Carr surveyed these plots via horseback on her own but over subsequent years with teams of participants (from department of botany, University of Melbourne), these plots have become the longest continuous series of ecological data-sites in Australia. In 2022 "Maisie's plots" were added to the Victorian Heritage Register.
Chronology of alpine ecology events The sequence of significant events in alpine ecology and Maisie Carr's role is detailed below: This has evolved into a teaching collection of 100-200 plant specimens from that region of north-east Victoria which is still in use for teaching and research field work purposes today. Much of this early taxonomy work was undertaken while she was employed at
University of Melbourne (beginning in 1949) in the Botany Department headed at the time by Prof. J. S. Turner. In addition to her research interests, she lectured on
plant taxonomy as well as ecology (to science and agricultural students) becoming a senior lecturer in that department three years later. Together with Professor John Stewart Turner she published academic reports of the results of the exclusion fencing experiments and more broadly the destructive impact of grazing on the ecology (of plant life as well as
soil degradation) of the Victorian alpine region. Carr's interest in the taxonomy of Australian plants (particularly the
Genus Eucalyptus) extended beyond the alpine species and this interest was fostered by her marriage (in 1955) to Denis John Carr, who was also an academic in the botany department at University of Melbourne. Their marriage was the start of decades of collaborative efforts studying
plant morphology and taxonomy. Their studies continued during academic appointments (of DJ Carr) in
Belfast (1960-1967) and later back in Australia (in
Canberra,
Australian National University from 1968) where Carr was a visiting fellow. Their academic contributions together resulted in dozens of articles, often in highly specialist publications. The couple was opposed to any splitting of the genus Eucalyptus into smaller groupings. They did, however, make significant contributions to descriptions of the morphology of eucalypts. Published phylogenetic analyses (based on DNA sequences and morphology) would later show that Eucalyptus was not a particularly uniform genus and that the classification needed to be revised. The current definitive electronic identification and information system covering 894 Australian eucalypts is EUCLID. ==Later life==