|Effects of intraspecific competition on growth and photosynthesis of Atriplex prostrata|
Wang, L.-W.; Showalter, A.M.; Ungar, I.A. (2005). Effects of intraspecific competition on growth and photosynthesis of Atriplex prostrata. Aquat. Bot. 83(3): 187-192
In: Aquatic Botany. Elsevier Science: Tokyo; Oxford; New York; London; Amsterdam. ISSN 0304-3770, more
Competition; Density; Growth; Halophytes; Inhibitors; Intraspecific relationships; Photosynthesis; Atriplex prostata
|Authors|| || Top |
- Wang, L.-W.
- Showalter, A.M.
- Ungar, I.A.
We investigated the effect of intraspecific competition on growth parameters and photosynthesis of the salt marsh species Atriplex prostrata Boucher in order to distinguish the effects of density-dependent growth inhibition from salt stress. High plant density caused a reduction of 30% in height, 82% in stem dry mass, 80% in leaf dry mass, and 95% in root dry mass. High density also induced a pronounced 72% reduction in leaf area, 29% decrease in length of mature internodes and 50% decline in net photosynthetic rate. The alteration of net photosynthesis paralleled growth inhibition, decreasing from 7.6 ± 0.9 μmol CO2 m−2 s−1 at low density to 3.5 ± 0.4 μmol CO2 m−2 s−1 at high density, indicating growth inhibition caused by intraspecific competition is mainly due to a decline in net photosynthesis rate. Plants grown at high density also exhibited a reduction in stomatal conductance from 0.7 ± 0.1 mol H2O m−2 s−1 at low density to 0.3 ± 0.1 mol H2O m−2 s−1 at high density and a reduction in transpiration rate from 6.0 ± 0.3 mmol H2O m−2 s−1 at low density to 4.3 ± 0.3 mmol H2O m−2 s−1 at high density. Biomass production was inhibited by an increase in plant density, which reduced the rate of photosynthesis, stomatal conductance and leaf area of plants.