Elevated CO2 and O3 Effects on Fine-Root Life Span in Ponderosa Pine

We used minirhizotrons to assess the effects of elevated CO2, N, and season on the life-span of ponderosa pine (Pinus ponderosa Dougl. ex Laws.) fine roots. CO2 levels were ambient air (A), ambient air + 175 µmol·mol-1 (A + 175) and ambient air + 350 µmol·mol-1 (A + 350). N treatments were 0, 100, and 200 kg N·ha-1 per year (N0, N100, and N200, respectively). Fine root survival was strongly influenced by season and seemed to be most strongly linked to soil temperature. Roots born in the fall and winter had longer median root life-span (MRLs) than those born during the spring and summer. Elevated CO2 increased root life-span, but N fertilization decreased it. Under A, MRL was 74 ± 12 days (mean ± SE) and was significantly different from the MRL for the A + 350 treatment (102 ± 14 days). MRL under A + 175 averaged 92 ± 10 days. MRL was 116 ± 13 days for the N0 treatment and was significantly greater than MRL for the N100 (70 ± 10 days) and N200 (62 ± 14 days) treatments. Assuming that longer lived fine roots continue their resource acquisition functions, then elevated CO2 may have the effect of extending the resource acquisition period. In contrast, fine roots in N-rich environments have shorter life-spans than fine roots in N-poor environments.

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Intrinsic and Extrinsic Controls of Fine Root Life Span

Critical Reviews in Plant Sciences ◽

10.1080/07352689.2012.734742 ◽

2012 ◽

Vol 32 (3) ◽

pp. 151-161 ◽

Cited By ~ 66

Author(s):

Han Y. H. Chen ◽

Brian W. Brassard

Keyword(s):

Life Span ◽

Fine Root ◽

Root Life Span

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Explaining Variation in Fine Root Life Span

Progress in Botany ◽

10.1007/978-3-540-36832-8_17 ◽

2007 ◽

pp. 382-398 ◽

Cited By ~ 15

Author(s):

Michael S. Peek

Keyword(s):

Life Span ◽

Fine Root ◽

Root Life Span

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Effects of root diameter, branch order, soil depth and season of birth on fine root life span in five temperate tree species

European Journal of Forest Research ◽

10.1007/s10342-017-1068-x ◽

2017 ◽

Vol 136 (4) ◽

pp. 727-738 ◽

Cited By ~ 5

Author(s):

Jiacun Gu ◽

Yan Wang ◽

Timothy J. Fahey ◽

Zhengquan Wang

Keyword(s):

Life Span ◽

Tree Species ◽

Fine Root ◽

Soil Depth ◽

Root Diameter ◽

Season Of Birth ◽

Branch Order ◽

Root Life Span

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Effects of elevated CO2 and O3 on soil respiration under ponderosa pine

Soil Biology and Biochemistry ◽

10.1016/j.soilbio.2005.12.003 ◽

2006 ◽

Vol 38 (7) ◽

pp. 1764-1778 ◽

Cited By ~ 17

Author(s):

David T. Tingey ◽

Mark G. Johnson ◽

E. Henry Lee ◽

Claudia Wise ◽

Ronald Waschmann ◽

...

Keyword(s):

Soil Respiration ◽

Elevated Co2 ◽

Ponderosa Pine ◽

Elevated Co2 And O3

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(324) Irrigation Effects on Fine Root Dynamics in Peach (Prunus persica)

HortScience ◽

10.21273/hortsci.40.4.1038d ◽

2005 ◽

Vol 40 (4) ◽

pp. 1038D-1038

Author(s):

Christina Wells ◽

Desmond Layne

Keyword(s):

Soil Temperature ◽

Life Span ◽

Root Length ◽

Fine Roots ◽

Fine Root ◽

Root Dynamics ◽

Fine Root Dynamics ◽

Tree Phenology ◽

Peach Trees ◽

Root Life Span

We are using a minirhizotron camera system to observe fine root dynamics beneath irrigated and nonirrigated peach trees. Our long term goals are: 1) to relate the timing of fine root production to tree phenology, soil water content, and soil temperature; and 2) to determine how fine root architecture and demography differ between trees with and without supplemental irrigation. In early 2002, minirhizotrons were constructed and installed beneath each of 72 open-center, 4-year-old `Redglobe' peach trees at the Musser Fruit Research Farm near Clemson University. Beginning in May 2002, videotaped images from each minirhizotron were collected at 2-week intervals; notes on tree phenology were also recorded biweekly. Videotapes were digitized in the lab, and information on root length, diameter, appearance and longevity was extracted from the images. Soil temperature and volumetric water content were measured in the orchard throughout the growing season. In the 2 years following minirhizotron installation, irrigated trees allocated a significantly greater percentage of their fine root length to the upper soil layers and exhibited less root branching than nonirrigated trees. Fine roots produced by irrigated trees lived significantly longer: irrigated trees had a median root life span of 165 days, while nonirrigated trees had a median root life span of only 115 days (P< 0.001; proportional hazards regression). Fine roots from irrigated trees remained in the physiologically active “white” state for an average of 10 days longer than roots from nonirrigated trees (P< 0.001). Data from 2002–03 indicate that the trees produce new root flushes at least three times during the year, with a significant flush occurring immediately after harvest.

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