Canadian Forest Service Publications

Salix species variation in leaf gas exchange, sodium, and nutrient parameters at three levels of salinity. 2017. Major, J.E.; Mosseler, A.; Malcolm, J.W. Canadian Journal of Forest Research 47: 1045–1055

Year: 2017

Available from: Atlantic Forestry Centre

Catalog ID: 39579

Language: English

CFS Availability: PDF (download)

Available from the Journal's Web site.
DOI: 10.1139/cjfr-2017-0028

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Abstract

Leaf gas exchange, Na+, and nutrient parameters were quantified under control (CTL), medium (MST), and high (HST) saline treatments for Salix discolor Muhl. (DIS), Salix eriocephala Michx. (ERI), and Salix interior Rowlee (INT). Net photosynthesis (Pn) increased from CTL to MST for all species but remained unchanged between MST and HST for surviving INT plants in HST. Salix interior had greater water-use efficiency (WUE) than DIS and ERI. Under CTL, INT had 13× the leaf Na+ concentration of DIS and ERI, but INT Na+ only increased by 17% across each saline treatment, whereas DIS and ERI leaf Na+ increased 6.0× from CTL to MST. Salix discolor and ERI had greater cation to Na+ ratios than INT; however, INT ratios were stable across saline treatments, whereas the DIS and ERI ratios dropped precipitously. Across species and treatments, Pn had a significant positive relationship to total aboveground dry mass, supporting the sink regulation of Pn theory. Also, Pn showed a significant positive relationship to WUE and leaf N and to leaf Na+, which probably reflects greater energy expenditure required to mitigate the higher levels of Na+. The saline tolerance of INT may be due to natural selection pressure in the arid regions of the southwestern United States, where it is believed to have its evolutionary origins.

Plain Language Summary

Leaf gas exchange, sodium, and nutrient parameters were quantified under control (CTL), medium (MST), and high (HST) saline treatments for Salix discolor (DIS), S. eriocephala (ERI), and S. interior (INT). Net photosynthesis increased from CTL to MST for all species but remained unchanged between MST and HST for surviving INT plants in HST. Salix interior had greater water-use efficiency (WUE) than DIS and ERI. Under CTL, INT had 13x the leaf sodium concentration of DIS and ERI, but INT sodium only increased by 17% across each saline treatment, whereas DIS and ERI leaf sodium increased 6.0x from CTL to MST. Across species and treatments, photosynthesis had a significant positive relationship to total aboveground dry mass. Also, photosynthesis showed a significant positive relationship to WUE and leaf nitrogen and to leaf sodium, which probably reflects greater energy expenditure required to mitigate the higher levels of sodium. The saline tolerance of INT may be due to natural selection pressure in the arid regions of the southwest USA, where it is believed to have its evolutionary origins.

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