ISSN:
1573-5036
Keywords:
biomass partitioning
;
clonal variation
;
N-availability
;
Populus tremuloides
;
root longevity
;
soil warming
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Trembling aspen (Populus tremuloides Michx.) is the most widely distributed tree species in North America making it important to terrestrial carbon and nutrient cycles. Due to anthropogenic climate change high latitude temperatures are expected to increase, making it necessary to assess the feedback between above- and below-ground carbon pools to increased temperature at sites of both high and low N-availability. We grew four clones of aspen at two levels of soil temperature and two levels of soil N-availability for 98 days and quantified photosynthesis, growth, biomass allocation, and root length production and mortality. High soil temperature increased rates of photosynthesis (65%), resulting in greater whole-plant growth (37%) through increases in roots, stems, and foliage; however these increases generally occurred only in soil of high N-availability. Root:shoot biomass allocation varied between clones but was unaffected by the soil temperature or N-availability treatments. Root length production and mortality increased at elevated soil temperature, but this response was modified by soil N-availability. At high soil temperature, soil N-availability had little effect on root dynamics, while at low soil temperature, high soil N-availability increased both the production and mortality (turnover) of roots. We conclude that trembling aspen has the potential for substantially greater growth and root turnover under conditions of warmer soil at sites of both high and low N-availability, but that allometric patterns of growth are under strong genetic, rather than environmental control.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004560311563
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