Publication details
Shoot heterogeneity in trees: Consequences of Patchy N availability and vascular transport
| Authors | |
|---|---|
| Year of publication | 2009 |
| Type | Article in Periodical |
| Magazine / Source | Nova Acta Leopoldina Neue Folge |
| MU Faculty or unit | |
| Citation | |
| Field | Botany |
| Keywords | sectorial xylem anatomy;patchy N availability;shoot heterogeneity |
| Description | We examined responses of two gymnosperms, Picea abies and Thuja occidentalis, to two nitrogen treatments, homogenous and patchy. We quantified whether the distribution and abundance of newly assimilated N would be more heterogeneous when the nitrogen supply was patchy. Plants were grown in split root treatment and supplied with N only to one separated root. After 3 months of cultivation we quantified 15N content in the current year needles for each branch. We found that patchy N supply lead to significant increase in heterogeneity of N distribution within shoot of both species. Within the patchy treatment, the coefficient of variation in relative 15N was greater for lower branches than for upper branches indicating that the distribution of 15N was less variable toward the top of the plant. We discuss several mechanisms that may contribute to more homogeneous N distribution in upper branches of the shoot. We conclude that seasonal N recycling of N within plant did not result in homogeneous distribution of newly assimilated N when N supply is patchy. |
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