TITLE:
Interactive Effects of Elevated [CO2] and Soil Water Stress on Leaf Morphological and Anatomical Characteristic of Paper Birch Populations
AUTHORS:
Anjala Pyakurel, Jian R. Wang
KEYWORDS:
Carbon Dioxide Levels; Plasticity; Leaf Area; Stomatal Area; Stomatal Density; Pore Area and Guard Cell Width
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.5 No.5,
March
14,
2014
ABSTRACT: The leaf morphological and stomatal characteristics of
four paper birch (Betula papyrifera Marsh) populations, grown at four treatment conditions of carbon dioxide [CO2]
and soil water levels were investigated to determine whether future increases
in atmospheric [CO2] and water deficit affected the leaf
characteristics. The populations from Cussion Lake, Little Oliver, Skimikin and
Wayerton were grown for 12 weeks under ambient (360 ppm) and elevated (720 ppm) [CO2] at
both high and low water levels. The populations significantly differed in leaf
area and stomatal characteristics due to the interaction effects of [CO2],
water levels and population differences. Most leaf morphological
characteristics and stomatal density varied due to the effects of [CO2]
and/or populations, but not due to the effect of water levels. Although
elevated [CO2] alone barely affected stomatal area of the birch
populations, simultaneous elevated [CO2] at both water levels had
stimulated stomatal characteristics within and among the populations. Overall,
elevated [CO2] reduced leaf area and increased stomatal density; and
low water level resulted in smaller stomatal area, pore area and guard cell
width. However, the populations responded differently to an increase in [CO2]
and water levels. All populations showed plastic responses with respect to [CO2]
and water levels either by decreasing stomatal area under low water level or by
increasing stomatal density under elevated [CO2]. Hence, integration
between and within leaf characteristics had helped paper birch populations
maintain balance between [CO2] gain and water loss.