
Research Focus
I am currently the vegetation scientist on site at Hubbard Brook Experimental Forest (HBEF) working as a team with Tim Fahey (Cornell University) and John Battles (UC Berkeley). Our charge is to quantify the plant community’s response to the press of chronic perturbations (e.g., warming climate, air pollution, invasive pest and diseases) and the pulse of catastrophic disturbances (e.g., ice storms, floods, windstorms); and to anticipate the consequences of these responses on the structure and function of the forest.
Since 2003, my main research focus has been at HBEF and the NSF-funded Long-term Ecosystem (LTER) project. In 2011, I took over supervision of the vegetation measurements so vital to making accurate biomass estimates and for understanding the trajectory of the Northern Forest. A defining aspect of the research at HBEF is the long-term nature, the quantity, and the quality of the data. As the field supervisor, I ensure the continuity of this record by training the undergraduate field crews and monitoring their work. I have spent summers working in the woods side-by-side with the undergraduates. The connection with the forest and the students helps me to recognize the incipient changes in ecology and to appreciate the mind-set of today’s young adults. In short, I improve as an ecologist and mentor.
My observations of the plant community at HBEF have raised several pressing questions. My role as an LTER project scientist gives me the means to answer them. For example, I am leading our efforts:
1) To address the “black box” of forest ecology – Can we predict the future forest from current seed production and seedling survival?
2) To track the influx and survival of climate migrants, white pine and red oak, into the northern hardwood forest – Are these potential climate immigrants responding to the documented increase in season length?
3) To implement baseline seedling plots with environmental measurs in eastern hemlock and white ash dominated locations and monitor for the presence of incipient invasive pests, hemlock woolly adelgid and emerald ash borer, respectively – Will the inevitable opening up of the canopy through the impacts of these pests speed immigration of red oak and white pine into the northern hardwood forest?
4) To explore the demography, ecology and taxonomy of the round-leaved orchid population – How is our newly delineated hybrid influencing the population demography of the two parent taxa?
5) To quantify the extent of beech bark disease (BBD) in the valley – Is the severity of BBD predictable by landscape variables?
Additional Links
Awards and Honors
- 2016 Tuckerman Award for best paper published on lichens in The Bryologist in 2015 (2016) American Bryological and Lichenological Society
Selected Publications
Journal Publications
- Cleavitt, N. L., Battles, J. J., Johnson, C. E., & Fahey, T. J. (2018). Long-term decline of sugar maple following forest harvest, Hubbard Brook Experimental Forest, NH. Canadian Journal of Forest Research. 48:23-31.
- Cleavitt, N. L., Battles, J. J., Fahey, T. J., & Blum, J. (2014). Determinants of survival over seven years for a natural cohort of sugar maple seedlings in a northern hardwood forest. Canadian Journal of Forest Research. 44:1112-1121.
- Cleavitt, N. L., Ewing, H. A., Weathers, K. C., & Lindsey, A. M. (2011). Acidic atmospheric deposition interacts with tree type and impacts the cryptogamic epiphytes in Acadia National Park, Maine, USA. The Bryologist. 114:570-582.
- Cleavitt, N. L., Fahey, T. J., & Battles, J. J. (2011). Regeneration ecology of sugar maple (Acer saccharum Marsh.): seedling survival in relation to nutrition, site factors and damage by insects and pathogens. Canadian Journal of Forest Research. 41:235-244.
- Cleavitt, N. L., Dibble Alison, C., & Werier David, A. (2009). Importance of forest matrix to epiphytic macrolichens and bryophytes of Acadia National Park, Maine. The Bryologist. 112:467-487.