# ****************************************************************
# ** Please acknowledge the contributors and the International  **
# ** Multiproxy Paleofire Database when using these data.       **
# ****************************************************************
#
# Site name: Archuleta Mesa Plot D2
# Investigators: Peter M. Brown and Rosalind Wu
#
# Dating Method  : Crossdated
# Collectors     : Peter M. Brown, Rosalind Wu
# Species name   : Pinus ponderosa
# Common name    : Ponderosa pine
# Country        : United States
# State          : Colorado
# National Forest: San Juan National Forest
# Ranger district: Pagosa
# UTM easting    : 0299384 (NAD83, 13)
# UTM northing   : 4114979 (NAD83, 13)
# Elevation      : 2190 m
# Slope          : 7 deg
# Aspect         : 253 deg
# Sample Storage Location: Rocky Mountain Tree-Ring Research, Inc., 
# Ft. Collins, CO
#
# Fire scar data from this site are available in FHX2 format at:
# ftp://ftp.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/northamerica/usach022.fhx
# along with associated metadata at:
# ftp://ftp.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/northamerica/usach022.txt
#
# Methods: See Brown and Wu 2005. Increment cores were removed from 10 cm
# height above ground level on living trees and cross sections were cut 
# from logs and snags such that one surface was 10 cm above the estimated 
# root-shoot boundary. Sampled cores were no more than a field estimated
# 10 yr from pith to minimize pith offset when assessing pith date. On 
# increment cores and cross sections that did not include pith but inside
# ring curvature was visible, pith dates were estimated using overlaid 
# concentric circles of varying diameters that take into account both 
# average inside ring widths and an estimated distance to pith. Pith dates 
# at 10 cm height were corrected to germination dates by subtracting
# 5 yr, the average time we estimated for seedlings to grow from germination 
# to 10 cm height (P. M. Brown, unpublished data).
#
# Reference: P.M. Brown & R. Wu. 2005. Climate and disturbance forcing of
# episodic tree recruitment in a southwestern ponderosa pine landscape.
# Ecology 86:3030-3038.
#
# Abstract:  Strong but relatively short (annual to decadal length) climate 
# change can have broad-scale and long-lasting effects on forest communities. 
# Climate impacts forests through direct effects on tree demography (mortality 
# and overstory recruitment) and indirect effects on disturbance regimes. 
# Here, we compare multicentury chronologies of tree recruitment from a 
# 307-ha ponderosa pine forest in southwestern Colorado to reconstructions
# of fire years, hydroclimate, and the El Nino-Southern Oscillation (ENSO).
# Few trees predate a regional multiyear megadrought centered in the 1580s. A
# prolonged pluvial in the early 1600s resulted in a pulse of tree recruitment
# that corresponds to recruitment seen over much of the Southwest. Other cohorts
# in the early 1700s and mid-1800s established during multidecadal fire-
# quiescent periods. These periods correspond to shifts in ENSO that apparently
# resulted in dampening of interannual wet/dry oscillations responsible for
# fuel buildup and drying. Fires, mediated by stochastic climate variation,
# acted as a density independent regulation on tree populations since
# establishment was not limited by overstory tree density, but rather by
# fire-caused mortality of seedlings and saplings during periods of more
# frequent fires. Even-aged cohorts in ponderosa pine forests likely have
# little if anything to do with episodic mortality caused by more severe
# fires, but rather relate mainly to episodic recruitment opportunities.
# Fire cessation after Euro-American settlement in the late 1800s resulted
# in an increase in tree density and changes in forest composition, which
# are major factors that have contributed to recent severe wildfires in other
# Southwestern forests. Our results document clear linkages between synoptic
# climate forcing, fires, and recruitment episodes, and highlight the
# importance of regional historical processes on contemporary forest
# composition and structure.
#
	1	Tree ID
	2	Year
	3	Feature
PPD21,1740,pith
PPD21,2002,bark
PPD22,1788,earliest ring
PPD22,1789,fire scar undetermined
PPD22,2002,bark
PPD23,1732,pith
PPD23,2002,bark
PPD24,1648,pith
PPD24,2002,bark
PPD25,1720,pith
PPD25,2002,bark
PPD27,1920,pith
PPD27,2002,bark
PPD28,1740,pith
PPD28,2002,bark
PPD29,1750,pith
PPD29,2002,bark
PPD210,1750,pith
PPD210,2002,bark
PPD212,1720,pith
PPD212,2002,bark
PPD213,1721,pith
PPD213,1945,bark
PPD214,1571,pith
PPD214,1834,last ring
PPD215,1577,pith
PPD215,1927,last ring
PPD216,1755,pith
PPD216,2002,bark
PPD218,1744,pith
PPD218,2002,bark
PPD220,1748,pith
PPD220,2002,bark
PPD221,1719,pith
PPD221,1960,bark
PPD222,1735,pith
PPD222,2002,bark
PPD223,1722,pith
PPD223,2002,bark
PPD224,1720,pith
PPD224,2002,bark
PPD225,1748,pith
PPD225,2002,bark
PPD226,1613,pith
PPD226,1970,bark
PPD227,1916,pith
PPD227,2002,bark
PPD228,1743,pith
PPD228,2002,bark
PPD229,1641,pith
PPD229,1760,last ring
PPD230,1748,pith
PPD230,2002,bark