Nonstructural carbohydrate and element pools in globemallow (Sphaeralcea): defoliation effects and seasonal trends

Pendery, Bruce M. and Rumbaugh, Melvin D. and Mayland, H.F. and Harrison, Philip A. (1994) Nonstructural carbohydrate and element pools in globemallow (Sphaeralcea): defoliation effects and seasonal trends. Great Basin Naturalist. 53(4):332-340.

PDF 832.pdf Download (499kB)

Abstract

Globemallows (Sphaeralcea spp.) are arid land forbs suitable for seeding with crested wheatgrass
(Agropyron cristatum [L.] Gaertner). However, little is known about the quantitative role of total nonstructural carbohydrates
(TNC) in relation to globemallow tolerance of grazing, or about seasonal dynamics of mineral elements. The
objectives of this study were to compare TNC and element pools (concentration x biomass) in the roots, crowns, and
shoots of clipped versus unclipped S. munroana (Dougl.) Spach. Seedlings of S. munroana were transplanted to a northern
Utah field site in 1985. Interplanted crested wheatgrass provided a uniform competitive background. One-half of
the globemallows were clipped to 5 cm on 10 May 1986 when stems were elongating and root and crown TNC pools
were low. The remaining globemallows were not clipped. Root, crown, and shoot pools of TNC and elements (N, P, K,
Ca, and Mg) were determined on 1 May, 20 May, 7 June, 11 July, 22 September, and 5 November 1986, and 29 May
1987. Defoliation did not affect shoot weights during a 1-year period. Experiment-long TNC and element pools also
were not affected by clipping. Results indicate that S. munroana shoot recovery from a single spring grazing during a 1-year period would not be impaired by low root and crown TNC pools, and that TNC stored in the roots and crowns
would account for only 7% of the regrowth produced. Furthermore, TNC and element pools of roots and crowns were
generally constant from May to September but increased from September to November. TNC and element pools in
shoots increased from May to September and then generally declined by November. TNC pools of roots and crowns
declined during winter.

Item Type:	Article
NWISRL Publication Number:	0832
Subjects:	Mass Import - unclassified
Depositing User:	Dan Stieneke
Date Deposited:	20 Nov 2010 21:53
Last Modified:	29 Nov 2016 18:59
Item ID:	614
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/614