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Tree-ring widths from 1576 white spruce trees growing at 78 treelines distributed across 19 research sites along a longitudinal gradient in the Brooks Range of northern Alaska. The general purpose of the sampling was to examine west-east variation in white spruce growth responses to changes in climate. Trees were sampled at both high ("alpine") and low elevation treelines ("arctic"). Increment cores were collected in August and September of 2022 as low as possible on each tree (~25 centimeter height). Trees indicated with an "f" were treated with NPK (nitrogen, phosphorus, potassium) fertilizer in June of 2019 and June of 2021.
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White spruce (Picea glauca) seedling heights and ages from treelines across Alaska's Brooks Range, 2021
We destructively sampled up to 15 white spruce (Picea glauca) seedlings (<140 centimeters tall) from 2 study treelines (1 upper elevation, Alpine, and 1 lower elevation, Arctic) at 16 sites across Alaska's Brooks Range in August-September 2021. We harvested 3 seedlings each in 5 height classes (0-10, 10-30, 30-60, 60-100, 100-140cm). Height (cm) was measured in the field before harvest as vertical distance from ground to tallest living tissue. The target of harvest was the root-shoot boundary, where above ground stem interfaces with roots. The earliest years of a seedling should be located in the wood of this section. For very small seedlings we harvested whole seedlings. In the laboratory we cut ~1cm thick "cookies" of the harvest root-shoot section, progressively sanded until cells were visible under the microscope and then counted rings back to the pith. For small seedlings, we counted bud scars along the stem. We used the earliest date obtained from these counts as the germination date (the innermost year, or In.year in the data csv). The general purpose of the sampling was to examine west-east variation in white spruce growth and reproduction responses to changes in climatic gradients and ongoing climate change.
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- PAR ID:
- 10469807
- Publisher / Repository:
- NSF Arctic Data Center
- Date Published:
- Subject(s) / Keyword(s):
- White spruce Picea glauca seedling tree rings height-age relationships age-height relationships treeline Arctic treeline
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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