Title: The older plant gets the sun: Age-related changes in Miscanthus × giganteus phenology

Abstract

Abstract Age‐related changes are usually overlooked in perennial grass research; when they are considered it is usually as a change in plant size (e.g., biomass). Whether other physiological or developmental aspects change as stands age, and how those aspects may impact long‐term stand dynamics, remains unclear. Conventional experimental designs study a single stand over multiple growing seasons and thereby confound age‐related changes with growing season conditions. Here we used a staggered‐start experimental design with three repeated planting years over two growing seasons to isolate growing season effects. We studied changes in Miscanthus × giganteus phenology during its yield‐building stage (first 3 years) and estimated age, growing season and nitrogen (N) effects on development using nonlinear regression parameters. Stand age clearly changed plant growth; faster developmental rates were usually seen in 1‐year‐old stands (young), but because 2‐ and 3‐year‐old stands (mature) emerged 3 months earlier than newly planted stands they produced 30% more stems with 30%–60% more leaves. Nitrogen fertilization modulated some age‐related phenological changes. Fertilized 2‐year‐old stands reached similar stem densities as unfertilized 3‐year‐old stands and had fewer number of senesced leaves like 1‐year‐old stands. In addition, N fertilization had no effect on young M. × giganteus , but extended mature stands’ growing season more thanmore » 2 weeks by hastening emergence and delaying senescence. It also delayed flowering regardless of stand age. Our results suggest that, along with changes in size, M. × giganteus stands showed shifts in developmental strategies: young stands emerged later and developed faster, while mature stands grew for longer but more slowly. In temperate regions, where hard frost events are likely to interrupt development in late autumn, rapid early development is critical to plant survival. Nonlinear regression parameter differences proved effective in identifying phenological shifts.« less

Authors:

Tejera, Mauricio D.  ^[1];

• Search DOE PAGES for author "Tejera, Mauricio D."
• Search DOE PAGES for ORCID "0000-0003-1698-0501"

Miguez, Fernando E.  ^[1];

• Search DOE PAGES for author "Miguez, Fernando E."
• Search DOE PAGES for ORCID "0000-0002-4627-8329"

Heaton, Emily A.  ^[1]

• Search DOE PAGES for author "Heaton, Emily A."
• Search DOE PAGES for ORCID "0000-0003-4521-7273"

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+ Show Author Affiliations

1. Department of Agronomy Iowa State University Ames IA USA

Publication Date:

Mon Aug 31 00:00:00 EDT 2020

Research Org.:

USDOE Bioenergy Research Centers (BRC) (United States). Center for Advanced Bioenergy and Bioproducts Innovation (CABBI)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER); USDA; National Institute of Food and Agriculture (NIFA); Leopold Center for Sustainable Agriculture; Iowa Energy Center

OSTI Identifier:

1665922

Alternate Identifier(s):

OSTI ID: 1666380; OSTI ID: 1786906

Grant/Contract Number:  

SC0018420; 1008969; DE SC0018420

Resource Type:

Published Article

Journal Name:

Global Change Biology. Bioenergy

Additional Journal Information:

Journal Name: Global Change Biology. Bioenergy Journal Volume: 13 Journal Issue: 1; Journal ID: ISSN 1757-1693

Publisher:

Wiley

Country of Publication:

United Kingdom

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES; aging; bioenergy; competitor-stress tolerance-ruderal (CSR) theory; growth dilution; morphological development; nitrogen dilution; nonlinear models; perennial grass; staggered-start design