Title: Warming of alpine tundra enhances belowground production and shifts community towards resource acquisition traits

Abstract

Abstract Climate warming is expected to stimulate plant growth in high‐elevation and high‐latitude ecosystems, significantly increasing aboveground net primary production (ANPP). However, the effects of simultaneous changes in temperature, snowmelt timing, and summer water availability on total net primary production (NPP)—and elucidation of both above‐ and belowground responses—remain an important area in need of further study. In particular, measures of belowground net primary productivity (BNPP) are required to understand whether ANPP changes reflect changes in allocation or are indicative of a whole plant NPP response. Further, plant functional traits provide a key way to scale from the individual plant to the community level and provide insight into drivers of NPP responses to environmental change. We used infrared heaters to warm an alpine plant community at Niwot Ridge, Colorado, and applied supplemental water to compensate for soil water loss induced by warming. We measured ANPP, BNPP, and leaf and root functional traits across treatments after 5 yr of continuous warming. Community‐level ANPP and total NPP (ANPP + BNPP) did not respond to heating or watering, but BNPP increased in response to heating. Heating decreased community‐level leaf dry matter content and increased total root length, indicating a shift in strategy from resource conservation to acquisitionmore » in response to warming. Water use efficiency (WUE) decreased with heating, suggesting alleviation of moisture constraints that may have enabled the plant community to increase productivity. Heating may have decreased WUE by melting snow earlier and creating more days early in the growing season with adequate soil moisture, but stimulated dry mass investment in roots as soils dried down later in the growing season. Overall, this study highlights how ANPP and BNPP responses to climate change can diverge, and encourages a closer examination of belowground processes, especially in alpine systems, where the majority of NPP occurs belowground.« less

Authors:

Yang, Yan  ^[1];

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• Search DOE PAGES for ORCID "0000-0003-0858-7603"

Klein, Julia A.  ^[2];

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Winkler, Daniel E.  ^[3];

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Peng, Ahui  ^[4];

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Lazarus, Brynne E.  ^[5];

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Germino, Matthew J.  ^[5];

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Suding, Katharine N.  ^[6];

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• Search DOE PAGES for ORCID "0000-0002-5357-0176"

Smith, Jane G. ^[6]; Kueppers, Lara M.  ^[7]

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• Search DOE PAGES for ORCID "0000-0002-8134-3579"

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+ Show Author Affiliations

1. Institute of Mountain Hazards and Environment Chinese Academy of Sciences No. 9 Section 4, Renminnan Road Chengdu Sichuan 610041 China, Department of Ecosystem Science and Sustainability Colorado State University Campus Delivery 1476 Fort Collins Colorado 80523 USA
2. Department of Ecosystem Science and Sustainability Colorado State University Campus Delivery 1476 Fort Collins Colorado 80523 USA
3. Southwest Biological Science Center United States Geological Survey 2290 S West Resource Boulevard Moab Utah 84532 USA
4. Institute of Mountain Hazards and Environment Chinese Academy of Sciences No. 9 Section 4, Renminnan Road Chengdu Sichuan 610041 China
5. U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center 970 Lusk Street Boise Idaho 83706 USA
6. Institute of Arctic and Alpine Research University of Colorado Boulder Colorado 80309‐0450 USA
7. Energy and Resources Group University of California, Berkeley 310 Barrows Hall #3050 Berkeley California 94720 USA

Publication Date:

Tue Oct 20 00:00:00 EDT 2020

Research Org.:

Univ. of California, Merced, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC); National Natural Science Foundation of China (NSFC); National Science Foundation (NSF)

OSTI Identifier:

1678803

Alternate Identifier(s):

OSTI ID: 1786412; OSTI ID: 1849832

Grant/Contract Number:  

DE‐FG02‐07ER64457; FG02-07ER64457; 41271224; 4157120; DEB-1637686; DEB-141410

Resource Type:

Published Article

Journal Name:

Ecosphere

Additional Journal Information:

Journal Name: Ecosphere Journal Volume: 11 Journal Issue: 10; Journal ID: ISSN 2150-8925

Publisher:

Wiley Blackwell (John Wiley & Sons)

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; Environmental Sciences & Ecology; alpine tundra; belowground plant production; functional traits; Rocky Mountains; soil moisture; warming; water use efficiency