Barry Logan

Professor of Biology and Chair of Biology Department

Teaching this semester

BIOL 2210/ENVS 2223. Plant Ecophysiology

Examines the functional attributes of plants and the manner in which they vary across the plant kingdom by the processes of evolution and acclimation. Topics of focus include photosynthesis and protection again high-light stress, the acquisition and distribution of water and mineral nutrients, and environmental and hormonal control of development. Special topics discussed may include plant parasitism, carnivory, the origins and present state of agriculture, plant responses to global climate change, plant life in extreme environments, and the impacts of local land-use history on plant communities. Contemporary research instrumentation is used in weekly laboratories, some conducted in the field, to enable first-hand exploration of phenomena discussed in lecture.

Professor Logan arrived at Bowdoin from the University of Colorado - Boulder in 1998 and has since had various roles at the College. In addition to being a professor, he has served as the Director of the Biochemistry program, Associate Dean for Academic Affairs, and assumed the role of Biology Department Chair in 2017. He is a plant physiological ecologist examining plant responses to environmental stress, with particular interest in photosynthesis and physiological mechanisms that protect leaves from excess light damage. He studies host-parasite interactions, acclimation to winter in evergreens, and global climate change.


  • B.A., Biology, Cornell University
  • Ph.D., EPO Biology, University of Colorado; Boulder

PDF Curriculum Vitae

Research Interests

The ecophysiology of eastern dwarf mistletoe infection - Eastern dwarf mistletoe, a diminutive parasitic plant, can fell a mature white spruce in a matter of years. Curiously, a closely related host growing in the same forest stands, red spruce, tolerates infection and even succeeds in killing the parasite. Students, collaborators and I seek to determine the causal chain of events leading to white spruce mortaility and contrast it against the mechanism of red spruce tolerance, drawing upon observations at scales from gene expression and hormone metabolism through whole–tree growth and stand dynamics. The host-parasite interactions we study are shaped by 19th century removal of red spruce/fir-dominated forests to create pastureland that was subsequently abandoned and recolonized by white spruce. We conduct this work at several sites along the Maine coast, including Monhegan Island.

The relationship between remotely sensed and leaf-level chlorophyll fluorescence emission - Chlorophyll, the green pigment in leaves responsible for absorbing light that powers photosynthesis, exhibits the unusual feature of re-emitting a small fraction of the light it absorbs (so-called fluorescence). Physiologists examining individual leaves have measured fluorescence for decades and have developed methods of using the strength of fluorescence emission to probe the inner workings of photosynthesis and leaf responses to environmental stress. Only recently, instruments capable of measuring chlorophyll fluorescence have been mounted on aircraft and satellites, allowing for remote sensing of whole landscapes. We partner with collaborators at Boston University and the University of Utah to understand how remotely sensed chlorophyll fluorescence might deepen our understanding of forests and their response to, for example, global climate change. [Some of this work is supported by a grant from the National Institute of Standards and Technology.]   

The photoprotective role of anthocyanins - Anthocyanins, pigments responsible for the color of many red and purple plant organs (e.g., maple leaves in autumn) often accumulate in the upper layers of photosynthetic tissues during exposure to environmental stress and during juvenile and senescent stages of development. Using a combination of model systems (e.g., red- and green-leafed varieties of Coleus) and native plants (e.g., elderberry fruit-bearing stalks [peduncles]), students, collaborators at Victoria University of Wellington and I examine the hypothesis that anthocyanins screen light that would otherwise harm photosynthetic cells below.

Jaret Reblin, Laboratory Instructor in Biology, is a close collaborator on many aspects of these and other projects. 

Publications (last five years)

(* Bowdoin undergraduate):

Gould KS, Jay-Allemand, C, Logan BA, Baissac Y, Bidel LPR (2018) When are foliar anthocyanins useful to plants? Re-evaluation of the photoprotective hypothesis using Arabidopsis thaliana. Environmental and Experimental Botany in press 

Cooney LJ, Logan BA, Walsh* MJL, Nnatabeugo* NB, Reblin JS, Gould KS (2018) Photoprotection from anthocyanins and thermal energy dissipation in senescing red and green Sambucus canadensis peduncles. Environmental and Experimental Botany in press

Harris* JP, Logan BA (2018) Seasonal acclimatization of thallus proline contents of Mastocarpus stellatus and Chondrus crispus: Intertidal Rhodophytes that differ in freezing tolerance. Journal of Phycology 54: 419-422

Bowling DR, Logan BA, Hufkens K, Aubrecht DM, Richardson AD, Burns SP, Blanken PD, Eiriksson D Limitations to winter and spring photosynthesis of a Rocky Mountain subalpine forest. Agricultural and Forest Meteorology 252: 241-255

Magney TS, Logan BA, Reblin JS, Boelman NT, Eitel JUH, Greaves HE, Griffin KL, Prager CM, Vierling LA (2017) Xanthophyll cycle and photosynthetic activity in two prominent Arctic shrub species. Arctic, Antarctic, and Alpine Research 49: 277-289

de Villier* JA, Reblin JS, Logan BA (2017) Needle properties of host white spruce (Picea glauca [Moench] Voss) experiencing eastern dwarf mistletoe (Arceuthobium pusillum Peck) infections of differing severity. Botany 95: 295-305

Boelman NT, Magney TS, Logan BA, Griffin KL, Eitel JUH, Greaves H, Prager CM, Vierling LA (2016) Spectral determination of concentrations of functionally diverse pigments in increasingly complex arctic tundra canopies. Oecologia 182: 85-97

Magney TS, Eitel JUH, Griffin KL, Boelman NT, Greaves HE, Prager CM, Logan BA, Zheng G, Ma L, Fortin EA, Oliver RY, Vierling LA (2016) LiDAR canopy radiation model reveals patterns of photosynthetic partitioning in an Arctic shrub. Agricultural and Forest Meteorology 221: 78-93

Logan BA, Stafstrom* WC, Walsh* MJL, Reblin JS, Gould KS (2015) Examining the photoprotection hypothesis for adaxial foliar anthocyanin accumulation by revisiting comparisons of green- and red-leafed varieties of coleus (Solenostemon scutellarioides). Photosynthesis Research 124: 267-274

Reblin JS, Logan BA (2015) Impacts of eastern dwarf mistletoe on the stem hydraulics of red spruce and white spruce, two host species with different drought tolerances and responses to infection. Trees – Structure and Function 29: 475-486 Lewis JD, Phillips NG, Logan BA, Smith RA, Aranjuelo I, Clarke S, Offord CA, Frith A, Barbour M, Huxman T, Tissue DT(2015) Rising temperature may negate the stimulatory effect of rising CO2 on growth and physiology of Wollemi pine (Wollemia nobilis). Functional Plant Biology 42: 836-850

Cooney LJ, Schaefer HM, Logan BA, Cox B, Gould KS (2015) Functional significance of anthocyanins in peduncles of Sambucus nigra. Environmental and Experimental Botany 119: 18-26 Medeiros JS, Begaye A, Hanson DT, Logan B, Pockman WT (2015) Photoprotective response to chilling differs among high and low latitude Larrea divaricata grown in a common garden. Journal of Arid Environments 120: 51-54

Logan BA, Demmig-Adams B, Adams III, WW, Bilger W (2014) Context, quantification, and measurement guide for non-photochemical quenching of chlorophyll fluorescence. In: Non-Photochemical Fluorescence Quenching and Energy Dissipation in Plants, Algae, and Cyanobacteria (Demmig-Adams B, Garab G, Adams WW III, Govindjee eds). Advances in Photosynthesis and Respiration, Volume 40. Springer, Dordrecht, 187-201

Magney TS, Eusden* SA, Eitel JUH, Logan BA, Jiang J, Vierling LA (2014) Assessing leaf photoprotective mechanisms using terrestrial LiDAR: towards mapping canopy photosynthetic performance in three dimensions. New Phytologist 201: 344-356

Student Research (since 2014)

logan with students

Bowdoin undergraduates are involved in nearly all aspects of my research. Many complete year-long independent projects for graduation with honors in Biology or Biochemistry. Others pursue lab or field research full-time in the summer with the support of fellowships (see the Biology Department and Student Fellowships and Research websites for more information). From my lab to date, 25 Bowdoin students have co-authored publications in peer-reviewed scientific journals (five of those students were first authors).

Student Research in Professor Logan's Lab (since 2014)
(* denotes Honors in Biology or Biochemistry)

Hanna Baldecchi*, 2017/2018 The impact of eastern dwarf mistletoe on red spruce vs. white spruce tree vigor. 

Sophia Lopez*, 2017/2018 Shifts in needle pigments as a photoprotective mechanism during winter downregulation of photosynthetic activity in subalpine coniferous trees

Trevor Kenkel, 2016/2018 Photosynthetic responses of aquaponics-grown leafy crops to measurement conditions.

Nora Hefner, 2016 Photosynthetic responses of different accessions of Brachypodium sylvaticum exposed to water stress.

Benjamin West*, 2015/2016 Examining functional roles for anthocyanins in plant leaves.

Sara Hamilton, 2015 Photosynthetic responses of different accessions of Brachypodium sylvaticum.

Michael Walsh*, 2013/2014 Functional implications of the reddening of the fruit-bearing stalks (peduncles) of elderberry (Sambucus sp.).

John de Villier*, 2013/2014 Progressive effects of eastern dwarf mistletoe (Arceuthobium pusillum) parasitism on white spruce (Picea glauca) physiology (co-advised with Jaret Reblin).

Course Syllabi

Biology 2210 (ES 2223): Plant Ecophysiology

Biology (ES) 3280: Plant Responses to the Environment 2018