Band Dendrometer, Inventory, and Litterfall DataA.D. McGuire, R.W. Ruess, J.S. Clein, J.Yarie

Ecological Question•What is the sensitivity of AGNPP to climate variability and change at the BNZ LTER? Spatial Scale Questions•Do responses of individual trees scale to the stand?•Do all age cohorts respond similarly to climate variability?•Do floodplain and upland stands respond to climate variability in different ways, and are there differences within landscapes in the spatial variability (among reps) of response?•Are there any detectable shifts in allometry in response to climate? (litterfall vs wood responses?) Temporal Scale Questions•What successional stages are most sensitive to climate? Is this a function of species, successional stage (site factors), or both?

Scope of Core Data

• Band dendrometer data - annually from 1989/1990 to present

• Inventory data - 1989, 1993, 1997, 2000, and 2004; next collection scheduled for summer 2008

• Litterfall data- fall and spring, 1986 to present

Design and Status of Core Data

• All these data are collected by the site management team (Jamie Hollingsworth and Brian Charlton) on a set schedule:

• Band dendrometer data - bands are checked each year, about 10 trees from each species in each site are banded

• Inventory data - DBH is measured ~every 4 years on ALL trees in each plot

• Litterfall data - trays collected once in fall??• All data collected at FP1s, 2s, 3s, 4s, 5s, UP1s, 2s, 3s

Core Data Availability• Band dendrometer data - these data had been

available as change in diameter, but were pulled last year after closer inspection identified a number of problems. These data have been re-qc’ed and are almost ready to be put back into the data catalog

• Inventory data – these data have never been available online, but are almost ready, we just need to get all the metadata ready

• Litterfall data - these data includes litter, wood, and pellets, and have been available on the data catalog from 1985-2006 (2006 data were collected in 2007)

Contributions to network wide data bases

• Band dendrometer and inventory data - these data are currently being used to estimate aboveground stand-level NPP. When this is done, NPP time series will be made available to TRENDS.

• We contributed our first iteration of NPP to a preliminary synthesis that is being conducted by Alan Knapp

• Litterfall data - are ready for TRENDS

Core data analysis with respect to:

• Climate variability - we have our first estimates of aboveground white spruce NPP for FP4A and UP3A. We have compared temporal variability of these estimates to temporal variability in air temperature and precipitation.

• We are working on completing analyses for other sites and stages to answer the questioned outlined in the first slide

• Successional dynamics - we are looking at estimates for total biomass in the different sites

• We think it is most likely to pick up succession dynamics in the younger stands (not climate sensitivity)

White spruce aboveground NPP

class0 class1 class2 class3 class4 class5 class6

UP3A

1992 1994 1996 1998 2000 2002 2004 2006

# tr

ee

s/h

a

020406080

100120140160180200

FP4A

1992 1994 1996 1998 2000 2002 2004 2006

# tr

ee

s/h

a

0

20

40

60

80

100

120

140

Inventory Data Band Dendrometer Data NPP Data by size class

NPP Data for each Site

UP3A

1992 1994 1996 1998 2000 2002 2004 2006 2008

NP

P (

kg C

/ha

/yr)

0

100

200

300

400

500

600

700

FP4A

1992 1994 1996 1998 2000 2002 2004 2006 2008

NP

P (

kg C

/ha

/yr)

0

100

200

300

400

500FP4A

1992 1994 1996 1998 2000 2002 2004 2006 2008Wh

ite s

pru

ce N

PP

(kg

C/tr

ee

/yr)

0

2

4

6

8

UP3A

1992 1994 1996 1998 2000 2002 2004 2006 2008Wh

ite s

pru

ce N

PP

(kg

C/tr

ee

/yr)

0

2

4

6

8

10

1992 1994 1996 1998 2000 2002 2004 2006 2008

NP

P (

kg C

/ha

/yr)

0

200

400

600

800

1000

1200

1400

1600

FP4AUP3A

Leaf Litterfall by Site

B-birch As-aspen WS-white spruce W-willowBP-balsam poplar A-alderBS-black spruce

Year

1985 1990 1995 2000 2005 2010

Leaf

litt

erfa

ll (g

C m

-2 y

r-1)

0

100

200

300

400

500B/As- 1AWS/B- 2AWS- 3AW- 1ABP/A- 2ABP/WS- 3AWS- 4ABS- 5ABS- 5C

r = 0.197p <0.0001n= 412

Black symbols-upland sitesRed symbols-floodplain sites

Climate compared to NPP

June prec (cm, LTER1)

0 20 40 60 80 100ab

oveg

roun

d N

PP

(kg

C/h

a)

200

400

600

800

1000

1200

1400

1600FP4A r² = 0.0UP3A r² = 0.34

June tair (oC, LTER1)

13 14 15 16 17 18 19 20

ab

ove

gro

un

d N

PP

(kg

C/h

a)

200

400

600

800

1000

1200

1400

1600

FP4AUP3A

FP4A r² = 0.14UP3A r² = 0.25

Future analysis of data

• Over the next couple years, we should have aboveground NPP estimates for each stand. This will include estimates for aboveground biomass by vegetation type and size classes.

• Analyze the responsiveness of NPP to climate.• Analyze how NPP changes with stand development and

how NPP changes across successional sequences.• Determine what accounts for variations in stand-level

NPP at the landscape level.

Recommendations • Band dendrometer data-

• There needs to be better representation of size classes of the trees being measuring, i.e., use of the inventory data to document population dynamics.

• Are the bands working?• Evaluate methods for tracking interannual changes in tree diameter

consistently and accurately over a long time period to determine the best method for future monitoring

• Identify which stands will help us answer our questions and are the best candidates for continued monitoring in the next phase of the LTER.

Other opportunities

• We would like to get a more complete biogeochemical budget for some sites

• We make lots of assumptions when we do try to put together a budget for these sites

• It would be useful to collect more site specific information, i.e. leaf chemistry, soil carbon, and root production