ISSN:
1432-1939
Keywords:
Genotypic tradeoff
;
Plant height
;
Relative growth rate
;
Serengeti
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract We determined the relationship between plant height and whole-plant relative growth rate (g g-1 day-1) for ten genotypes of Sporobolus kentrophyllus collected from an intensively grazed site on the Serengeti Plains, Tanzania. Plants were grown for 7 weeks in a greenhouse in Syracuse, N.Y., and harvested weekly. Plants that received simulated bovine urine showed a negative relationship between plant height and growth rate, suggesting a genetic tradeoff between competitive ability if ungrazed (height) and ability to recover from grazing (growth rate). There was no height-growth rate relationship under nitrogen addition rates similar to field mineralization rates. In addition, faster-growing, shorter plants tended to have relatively higher above-ground growth rates than slower-growing, taller plants. These results suggest that natural selection has maintained a gradient of morphologies within this species ranging from short, rapidly growing genotypes adapted to intense grazing conditions to tall, slow-growing, grazer-susceptible genotypes that are superior light competitors in absence of herbivory.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00329793
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