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Growth and dry matter partitioning in loblolly and ponderosa pine seedlings in response to carbon and nitrogen availability
Author(s) -
GRIFFIN KEVIN L.,
WINNER WILLIAM E.,
STRAIN BOYD R.
Publication year - 1995
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1995.tb03022.x
Subject(s) - dry matter , nitrogen , loblolly pine , biomass (ecology) , biomass partitioning , nutrient , growing season , shoot , carbon fibers , agronomy , botany , woody plant , pinus <genus> , biology , horticulture , chemistry , ecology , materials science , organic chemistry , composite number , composite material
summary We grew loblolly pine ( Pinus taeda L.) and ponderosa pine ( Pinus ponderosa Dougl. ex Laws.) seedlings in a factorial experiment with two CO 2 partial pressures (35 and 70 Pa) and two nitrogen treatments (1‐0 and 3–5 mM NH 4 + ) for one growing season in a ‘common garden’ experiment designed to examine the extent that dry matter and nitrogen accumulation and partitioning are environmentally controlled. Ponderosa pine seedlings grown in 35 Pa CO 2 and 3.5 mM NH 4 + showed symptoms of nitrogen toxicity, characterized by greatly reduced growth, and moderately reduced total plant N. With the exception of this treatment combination, there were no significant differences between species in total plant dry matter or total plant nitrogen, suggesting that responses of growth to environmental conditions were stronger than heritable responses. There were however large differences in dry matter and N partitioning between the two species. Increases in leaf mass were largest in loblolly pine, whilst ponderosa pine tended to have higher root: shoot (R:S) ratios. R:S ratio of loblolly increased in response to C availability and decreased in response to N availability, whilst R: S ratio of ponderosa pine was much less responsive to resource availability. Total plant N varied with N supply, and N partitioning was related to plant growth and carbon partitioning. Carbon and N were interactive, such that an increase in the accumulation of either resource was always accompanied by an increase in the other. Over several seasons the different patterns of resource acquisition and biomass allocation that we observed in a uniform environment could potentially result in different growth rates at most resource levels. In the first season, contrary to our expectations, heritable differences in growth rate did not appear.