The Jasper Ridge elevated CO{sub 2} experiment: Root acid phosphatase activity in Bromus hordeaceus and Avena barbata remains unchanged under elevated [CO{sub 2}]
- Univ. of California, Berkeley, CA (United States)
- Stanford Univ., CA (United States)
Root acid phosphatase activity increases phosphate available to plants by cleaving phosphate esters in soil organic matter. Because of increased plant growth potential under elevated [CO{sub 2}], we hypothesized that high [CO{sub 2}]-grown plants might exhibit higher phosphatase activity than low [CO{sub 2}]-grown plants. We assayed phosphatase activity in two species grown on two substrates (Bromus on serpentine soil and Bromus and Avena on sandstone soil) under high and low [CO{sub 2}] and under several nutrient treatments. Phosphatase activity was expressed per gram fresh weight of roots. Phosphatase activity of Bromus roots (on sandstone) was first assayed in treatments where only P and K, or only N, were added to soil. Bromus roots in this case showed strong induction of phosphatase activity when N only had been added to soil, indicating that Bromus regulated its phosphatase activity in response to phosphate availability. Both Bromus and Avena growing in sandstone, and Bromus growing in serpentine, showed enhanced phosphatase activity at high nutrient (N, P, and K) levels over that at low nutrient levels, but no differences between phosphatase activity were apparent between [CO{sub 2}] treatments. The increased phosphatase activity at high N, P, and K may indicate enhanced {open_quotes}growth demand{close_quotes} (reflected in higher biomass) in both Avena and Bromus. In contrast, though Bromus {open_quotes}growth demand{close_quotes} (biomass) increased under high [CO{sub 2}] on sandstone, phosphatase activity did not increase.
- OSTI ID:
- 95760
- Report Number(s):
- CONF-9507129--
- Journal Information:
- Bulletin of the Ecological Society of America, Journal Name: Bulletin of the Ecological Society of America Journal Issue: 2 Vol. 76; ISSN BECLAG; ISSN 0012-9623
- Country of Publication:
- United States
- Language:
- English
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