Campus Units

Agronomy

Document Type

Article

Publication Version

Published Version

Publication Date

2016

Journal or Book Title

Global Change Biology: Bioenergy

Volume

8

First Page

818

Last Page

825

DOI

10.1111/gcbb.12291

Abstract

The production of perennial cellulosic feedstocks for bioenergy presents the potential to diversify regional economies and the national energy supply, while also serving as climate ‘regulators’ due to a number of biogeochemical and biogeophysical differences relative to row crops. Numerous observational and model-based approaches have investigated biogeochemical trade-offs, such as increased carbon sequestration and increased water use, associated with growing cellulosic feedstocks. A less understood aspect is the biogeophysical changes associated with the difference in albedo (a), which could alter the local energy balance and cause local to regional cooling several times larger than that associated with offsetting carbon. Here, we established paired fields of Miscanthus 9 giganteus (miscanthus) and Panicum virgatum (switchgrass), two of the leading perennial cellulosic feedstock candidates, and traditional annual row crops in the highly productive ‘Corn-belt’. Our results show that miscanthus did and switchgrass did not have an overall higher a than current row crops, but a strong seasonal pattern existed. Both perennials had consistently higher growing season a than row crops and winter a did not differ. The lack of observed differences in winter a, however, masked an interaction between snow cover and species differences, with the perennial species, compared with the row crops, having a higher a when snow was absent and a much lower a when snow was present. Overall, these changes resulted in an average net reduction in annual absorbed energy of about 5 W m -2 for switchgrass and about 8 W m -2 for miscanthus relative to annual crops. Therefore, the conversion from annual row to perennial crops alters the radiative balance of the surface via changes in a and could lead to regional cooling.

Comments

This is an article from Global Change Biology: Bioenergy 8 (2015): 818, doi:10.1111/gcbb.12291. Posted with permission.

Rights

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Copyright Owner

The Authors

Language

en

File Format

application/pdf

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