1. Soil (and DWM) sampling on 2014 Tanana Pilot Inventory
R. Pattison (PNW FIA), H. Andersen (PNW FIA) ,A. Gray (PNW FIA), Kristen Manies (USGS),
FIA (IM and DC staff)
Jamie Hollingsworth – UAF
State of Alaska Division of Forestry
(Doug Hanson)
Tetlin NWR
Mike Amacher (USFS)

2. Field plots:
Tanana Valley State Forest: ~ 72 forested plots
Tetlin NWR: ~27 forested plots
Total: ~99 forested plots

3. Protocols- All plots are sampled for soils
subplot/plot – forested only
subplots/plot – forest & non-forested
Borderline plots?

4. Makita protocol-
(Nadler and Wein 1998)

5. Makita protocol-

7. Measurements and collections
2014 collected 1-4” of mineral
2016 collected 4” of mineral
Crews go to 40” to try to get to
mineral soil

8. Measurements and collections
2014
2016

9. Soil C totals
Soils were % of total ecosystem
C (tree, DWM and soil)
White spruce/TVSF soils = 47%,
black spruce /TNWR soils = 84%
56,728 (+ 4,224) thousand tons of soil C on the TVSF and TNWR

10. Soil C totals organic layer contained 65 -81% of soil C
mineral soil (1”) contained % of soil C,
Litter and live moss contained % of soil C

11. Soil C per acre
Highest soil C values in black spruce forests lowest in aspen
38% of black spruce plots on TVSF did not sample entire organic layer

12. Missing layer
In 2014 only included a layer if the layer beneath it was in the core.
E.g., in order to capture all of the organic layer the core needed to have mineral soil
In 2016 – considering ways to model out missing layers- e.g., based values of a portion of a layer (bulk density and %C) and thickness values in the literature.

13. Organic layer composition
organic layer contained % of
total soil C
Dead moss : % of organic layer
Root dominated duff-
found on all forest types
9% % of organic layer
upper humified duff layer was not
present on balsam poplar forests but accounted for 17 to 35% of the other
forest types

14. Values are similar to other studies
2014 pilot - organic layer C 12 – 28 tons acre-1
Hollingsworth et al. (2008) black spruce forests tons acre-1
Kane and Vogel (2009) 17 to 33 tons acre-1
Ping et al organic layer contained tons acre-1
(52 sites in interior Alaska dominated by black spruce across a range of topographic positions from well drained to poorly drained, sampled soils down to 39”

15. Thaw depths Thaw depths taken at 4 points near soil sampling location
Sampled to 39” (1m), recorded what is at the bottom (frozen soil, rock, not reached)
Thaw depths were deepest in the balsam poplar and aspen forest types and shallowest in black spruce forests.

16. Thaw depth and date
Frozen soils (above mineral ) were encountered throughout the
growing season, not just early on.

17. Results
Of the 99 field plots – soil samples were collected on 78 plots.
Frozen soils within 1 m
Black spruce - 47 of the 49 plots.
Depth of the frozen soils was cm.
White spruce - 9 of the 14 plots.
Depth of the frozen soils was cm
Paper birch - 22 of the 25 plots.
Depth of the frozen soils was cm.
Maybe highlight that if you cant get to mineral soil because of frozen soils you may have issues with knowing how much deeper the mineral soil is, or being able to know the extent of the organic layer. Note that we are moving to collecting in 4” units, if you can get 4” collect it.

18. DWM Coarse woody debris > 3” diameter, > 6” in length
Fine woody debris < 3” in diameter
Litter and duff depth taken at the end of each transect -

19. Future directions
Refine insights based on veg and ground cover, community composition and soil C
Develop linkages with remotely sensed data-
Integrate soil data with fire studies
e.g., Alonzo et al. (in review) examined ground layer burning on Kenai using lidar data as validated by FIA DWM litter and duff data.
Maybe highlight that if you cant get to mineral soil because of frozen soils you may have issues with knowing how much deeper the mineral soil is, or being able to know the extent of the organic layer. Note that we are moving to collecting in 4” units, if you can get 4” collect it.