Conifer Mortality Estimates Using Forest Inventory and Analysis’s Annual Inventory System Michael T. Thompson Forest Inventory and Analysis Interior West Region User Group Meeting April 13, 2010

FIA’s Annual Inventory Design  Federal legislation passed in 1998 dictated major changes to the FIA program.  Annual inventories in all states.  Annual inventory premise was a tradeoff between temporal currency and statistical reliability.  Panel – one of 5 to 10 interpenetrating groups.  The western regions are on a 10-year cycle where one panel of data represents 10 percent of all plots.

The Panel System  Hexagons of equal area are used to establish plot locations.  Each hexagon represents an area of about 6,000 acres.  The hexagons completely cover the conterminous 48 states. The Annual Inventory

Each year/panel is a spatially unbiased grid of plots that can provide a stand- alone inventory estimate. The stand-alone may be referred to a the independent panel design

Mortality Tree For inventories with no re-measurable previous inventory a mortality tree is defined as any standing dead tree 5.0- inches d.b.h./d.r.c. and larger that was alive within the past five years but has died. The attribute of interest for a mortality tree (volume, basal area, etc.) is usually expressed as an annual average over a five year interval. A general cause of death (i.e. insects) is assigned to all trees classified as mortality.

Can annual inventory mortality estimates enhance estimates from aerial detection surveys?

Average annual number of lodgepole pine mortality trees 5.0-inches and larger killed by insects in Colorado by mortality period,

Statistical Analysis Charts Display confidence intervals. Panel Effect Nonparametric test (Wilcoxon) Pr > Chi-Square <.0001 ANOVA Pr > F <.0001 Compare Individual Panels Test all combinations of individual panels against each other (Bonferroni multiple test correction factor ) (2004 – 2009)/( )*** significant at 0.05 level ( )/( )*** significant at 0.05 level (2004 – 2009)/( )*** significant at 0.05 level (2004 – 2009)/( )*** significant at 0.05 level (2004 – 2009)/( )*** significant at 0.05 level (2004 – 2009)/( )*** significant at 0.05 level (2003 – 2008)/( )*** significant at 0.05 level

Statistical Analysis – cont. Regression Analysis Label Parameter Standard Error t value Pr > |t| Intercept <.0001 Mortality period <.0001

Number of live lodgepole pine trees 5.0-inches d.b.h. and larger with evidence of bark beetle damage in Colorado by measurement year,

Number of live lodgepole pine trees >= 5.0-inches d.b.h. in Colorado by measurement year,

Number of live lodgepole pine trees in Colorado by diameter class, 2009

Number of live lodgepole pine trees >= 10.0-inches d.b.h. in Colorado by measurement year,

Average annual number of subalpine fir mortality trees 5.0-inches and larger in Colorado by mortality period,

Number of live subalpine fir trees >= 10.0-inches d.b.h. in Colorado by measurement year,

Average annual number of lodgepole pine mortality trees 5.0-inches and larger in Montana by mortality period,

Number of live lodgepole pine trees >= 10.0-inches d.b.h. in Montana by measurement year,

Average annual number of lodgepole pine mortality trees 5.0-inches and larger in Idaho by mortality period,

Remeasurement of Previously Established Plots Variable-radius Plots Montana

Relationship between initial conifer inventory, terminal conifer inventory, and conifer components of change on NFS forest land in Montana 1990’s2000’s

Relationship between initial conifer inventory, terminal conifer inventory, and conifer components of change on non-NFS forest land in Montana

Relationship between initial lodgepole pine inventory, terminal lodgepole pine inventory, and lodgepole pine components of change on NFS forest land in Montana

Relationship between initial whitebark pine inventory, terminal whitebark pine inventory, and whitebark pine components of change on NFS forest land in Montana

Conclusion  Lodgepole pine is experiencing extremely high levels of mortality in Colorado—primarily due to MPB epidemic.  Inventories of large-diameter lodgepole pines in Colorado are declining at an unusually rapid rate.  Initial results from annual inventories appear promising for evaluating trends in levels of tree mortality.  The power to detect significant events related to mortality and other parameters of interest will increase substantially with estimates derived from the remeasured (paired) plots that will eventually be available region-wide.