Abstract Detail

Ecophysiology

Da Ros, Letitia [1], Soolanayakanahally, Raju [2], Guy, Robert [3], Mansfield, Shawn [4].

Phosphorus Storage and Reabsorption in Riparian Tree Species: Environmental Applications of Canadian Poplar and Willow.

Phosphorus is a contaminant of concern in agricultural systems as increased concentrations in surface water runoff have led to escalating incidents of eutrophication. Two decades of reducing phosphorus through improved land management have yielded few results in terms of algal bloom prevention and enhancing water quality in freshwater catchments, a fact attributable to the lack of reduction in terrestrial losses of sediment and dissolved phosphorus. A potential solution involves planting buffer strips of high biomass producing tree species along riparian zones to stabilize river banks, preventing sedimentary addition of phosphorus, while minimizing seasonal soluble phosphorus inputs from water runoff via vegetative filtering and growth.
In Canada, trees belonging to the family Salicaceae such as willows and poplars inhabit a diverse geographical range that stretches across the continent. As a consequence of this significant distribution, attributes related to biomass production such as growth traits and cell wall characteristics are highly variable among genotypes, allowing poplar and willow to be used for a wide range of environmental applications. This includes their use in agroforestry to prevent soil erosion, reclaim marginal lands and act as vegetative filters that prevent environmental contaminants from entering surface water runoff. Understanding nutrient allocation and storage in Canadian cultivars thereby becomes imperative in assessing their long-term potential as biological tools for mitigating the downstream effects of phosphorus enriched soils. Preliminary results suggest that increased exposure of up to six times the required amounts of phosphorus has no effect on the biomass accrual of Canadian poplar or willow hybrid varieties. Subsequent elemental analysis of xylem, root and leaf tissue using ICP-AES, found that leaves were the primary location of phosphorus storage for the majority of hybrids. Hybrid poplar also exhibited increased foliar phosphorus concentrations with increasing exposure to phosphorus. Moreover, during senescence, poplar leaves contained between 20-44% more phosphorus per unit of dry weight while willow leaves contained 35-66% less than pre-senescent leaf tissue. Should higher reabsorption rates be achievable in the phosphorus accumulating poplar hybrid, phytoremediation of phosphorus heavy soils could be attained by coppicing existing stands and then turning the material into value added products.

1 - University of British Columbia, Wood Science, 2424 Main Mall, Vancouver, BC, V6T1Z4, Canada
2 - Agriculture and Agri-Food Canada, Agroforestry Development Centre, No.2 Government Rd., Indian Head, SK, S0G 2K0, Canada
3 - University of British Columbia, Forest and Conservation Sciences, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada
4 - University of British Columbia, Wood Science, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada

Keywords:
Nutrient accumulation
senescence
Salicaceae
phytoremediation
phosphorus
Nutrient reabsorption.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PEP012
Abstract ID:1241
Candidate for Awards:Physiological Section Best poster presentation,CSPB President's Award for Best Student Presentation