Progress Report: Chiricahua fire-history gradient analysis and spruce-fir age structure; Cooperative Agreement #28-C4-858, Regional Dendroecology sub- project IV, parts 1 and 2.

Project Status

To meet the objectives of this project field trips were conducted during the summer of 1996. A total of 72 firehistory samples were collected in 12 sub-sites. Samples were collected along an elevation gradient and a range of aspects (Table 1).

Site ID	Elevation meters

Aspect

Site Name	Number of samples

Percent complete
BWF	2835	NE	Bear Wallow Flat	3	SP-100, D&A- 30
BGS	2880	W	Booger Spring	10	SP-100, D&A- 70
WCP	2700	S	W. of Cima Park	6	SP-100, D&A- 30
SCP	2926	S	S. of Cima Park	8	SP-100, D&A- 50
UWC	2680	N	Upper Ward Cyn.	4	SP-100, D&A- 75
ORO	2560	S	Op. Rocky Outcrop	5	SP-100, D&A- 40
UMC	2590	NW	Upper Mormon Cyn.	10	SP-100, D&A- 80
SDC	2500	S	Sandy Corner	5	SP-100, D&A- 40
MMC	2440	N	Mid Mormon Cyn.	6	SP-100, D&A- 50
SAB	2255	N	Steep and Burnt	3	SP-100, D&A- 100
MCS	2070	S	Mormon Cyn. Spring	7	SP-100, D&A- 10
LMC	2040	N	Lower Mormon Cyn.	5	SP-100, D&A- 60
total	total	summary
12	72	SP-100, D&A- 95

*SP = sample preparation, D&A = dating and analysis

Currently, all samples have been surfaced and prepared for analysis while approximately 50% have been cross-dated and the data entered in FHX2 format (FHX2 is a fire-history computer analysis program: Grissino-Mayer 1995).

Anticipated Schedule

Dating and analysis of samples is expected to be complete by 7/15/97. Subsequently, mean fire intervals and site atributes (aspect and elevation) will be used to generate a map layer representing potential fire regimes in the Chiricahua Mountains.

Additional field tasks remaining for this project include using a precise global positioning unit to record a sub-set of sample locations within sites in order to register site locations with pre- existing map data layers.

Spruce-fir age structure and fire history

A 400m age-structure transect was sampled on the north face of Flys Peak. 450 trees were cored for age determination and over 1200 seedlings were tallied. Fire-effects from the 1994 Rattlesnake Fire were also noted as they impacted the sampled area. Five fire-scarred trees were sampled in the vicinity of the transect to determine precise fire dates for fires affecting the transect area. Additionally, four aspen stands were cored to determine their establishment dates.

To date all samples have been prepared for analysis and fire-scarred specimens have been crossdated.

Site ID	Elev. (m)

Species

aspect

Site name	Number of samples

Status
Mos	2835	mixed	North	Mosca	460/1200	SP-100,D&A-100
FP2	2860	pine	NEast	Fly peak 2	5	SP-100,D&A-100
FP2	2800	aspen	North	Fly Peak 2	25	SP-100,D&A-0
WCU	2670	aspen	North	Ward Cyn Upper	15	SP-100,D&A-0

Anticipated Schedule