PARENT SESSION
Poster Session #64: Long Term Ecological Research.
Friday, August 9. Presentation from 8:00 AM to 9:30 AM. Exhibit Hall B & C, TCC
35
Dynamics of juniper, pinyon and oak mast production in woodland ecosystems of central New Mexico.
ZLOTIN, ROMAN*,1, 1 Indiana University, Bloomington, IN
ABSTRACT- The study of mast production (MP) was carried out at Sevilleta LTER Site in 1997-2001. Three permanent 1-ha plots were under study in juniper savanna (JS), oak-juniper savanna (OJS), and oak-pinyon-juniper woodland (OPJW). The following questions were addressed: (a) What are environmental factors determining spatial heterogeneity of MP and horizontal structure of woodland ecosystems? (b) What are meteorological conditions determining annual dynamics of Juniper monosperma, Pinus edulis, and Quercus turbinella? (c) Which of these three species are most productive? Spatial structure of woodland ecosystems depends on spatial heterogeneity of soil water capacity and available soil moisture. Consequently, in better conditions (OPJW) total coverage of tree canopy is higher, less trees died during the 1950s drought, higher percentage of female juniper trees (60-65%) or female strobils in pinyon, and higher rate of recruitments (20-30%) of total number of trees has been observed. Total productivity of berries, nuts, and acorns is also higher in OJPW. Annual dynamics of MP is correlated with weather conditions in spring: high moisture, lower air temperature, and weaker wind defined higher juniper berry production. Pinyon and oak had opposite preference: dry and hot spring favors high production of pinyon cones, sound nuts in cones, and acorns. The critical factor is also success of pollination: the higher tree density, the higher production of nuts and acorns. Peaks of MP have a periodicity of 3-5 years and perhaps correspond to the El Nino cycles. Juniper is able to produce up to 600 kg/ha (dry weight) of berries, maximum biomass of pinyon nuts is 250 kg/ha, and acorns - 150 kg/ha.
KEY WORDS: Mast Production, One-seed Juniper, Pinyon, Oak