ARS | Publication request: A FIELD TEST OF THE EFFECT OF CLIMATE CHANGE ON POA SANDBERGII

Submitted to: Ecological Society of America Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: February 15, 2000
Publication Date: N/A

Technical Abstract: The effect of climate change on Poa sandbergii was investigated in the field. Poa sandbergii is a small perennial bunchgrass common in the intermountain west. Cores of intact P. sandbergii and soils were transplanted between two elevations in 1994. At each site control cores of the population at the site were included in the study. The lower elevation (347 m) site represents a warmer (12.5 C average January maximum) and dryer (22.4 cm/y) climate while the upper elevation (884 m) site represents a cooler (8.0 degrees centigrade average January maximum) and wetter (27.2 cm/y) climate. Shoot biomass for the lower population at the lower site (3.30 g/m2) was significantly less than for the upper population at the lower site (7.23 g/m2). Shoot biomass for the lower population at the upper site (2.12 g/m2) was significantly less than for the upper population at the upper site (7.31 g/m2). Percent cover showed the same pattern as shoot biomass except that the lower population had significantly greater cover at the lower site (25.8 %) than at the upper site (11.7 %). Shoot nitrogen was measured on dry shoot material gathered at the end of the growing season. Reproductive effort (culms/m2) was zero for the lower population at the upper site while the other three population site combinations were indistinguishable. Abaxial stomatal density was significantly greater for the lower population at both sites than for the upper. There is no effect of climate change on P. sandbergii based on shoot biomass and percent cover under the conditions of the experiment. The loss of reproductive capacity in the lower populations at the upper site suggests that these populations are negatively affected by exposure to a cooler and wetter climate.