http://hdl.handle.net/10150/635548 Fri, 06 Mar 2026 02:10:59 GMT 2026-03-06T02:10:59Z http://hdl.handle.net/10150/650520 Journal of Range Management, Volume 43, Number 1 (January 1990) Complete digitized issue. Mon, 01 Jan 1990 00:00:00 GMT http://hdl.handle.net/10150/650520 1990-01-01T00:00:00Z http://hdl.handle.net/10150/644931 Soil moisture patterns below mounds of harvester ants Laundré, J. W. Harvester ants are a major component of western rangeland. Little is known about ants' role in soil water dynamics. Annual patterns of soil moisture under mounds of the harvester ant (Pogonomyrmex owyheei, Cole) were studied in southeastern Idaho. Soil moisture at 20-cm intervals to a depth of 100 cm was estimated monthly with a neutron probe. Between 60 and 100 cm, higher levels of moisture were found below mounds than in control areas. The amount of water added to the soil during spring recharge was greater in control areas at 20 cm but greater under ant mounds at depths below 60 cm. Under ant mounds, approximately 1.3 cm more water was added to the soil between 60 and 100 cm. Mon, 01 Jan 1990 00:00:00 GMT http://hdl.handle.net/10150/644931 1990-01-01T00:00:00Z http://hdl.handle.net/10150/644923 Seedbed ecology of winterfat: effects of mother-plant transpiration, wind stress, and nutrition on seedling vigor Booth, D. T. The upward movement of absorbed salts within a plant is influenced by the transpiration stream. This study tested the hypothesis that transpiration by winterfat mother plants affects seedling vigor. Mature plants, growing in a greenhouse, were exposed to forced air and measurements were made on water loss from the plants, concentrations of Ca++, Mg++, Na+, and K+ in the diaspores, and on offspring growth parameters. The diaspores produced by the plants were germinated and grown under 2 identical temperature regimes, except that 1 regime included 1 hour of dark-period freezing stress. The forced-air treatment had no detectable effect on mother plants, including no significant (P less than or equal to 0.05) effect on water loss or on cation concentrations in the diaspore. However, it did significantly decrease offspring vigor. Analysis of the total test-plant population revealed significant, linear relationships between water loss and: diaspore yield, Ca++ and K+ concentrations in the diaspore, seedling dry weight, and seedling hypocotyl length. Linear relationships between seedling variables and covariables provided evidence that Ca++, K+ and Na+ influence seedling weight, moisture, and hypocotyl length. It is concluded that mother-plant transpiration, windstress, and nutrition affect offspring vigor. Mon, 01 Jan 1990 00:00:00 GMT http://hdl.handle.net/10150/644923 1990-01-01T00:00:00Z http://hdl.handle.net/10150/644917 Responses of endophyte-bearing and endophyte-free varieties of Lolium perenne L. to fungicide treatment and simulated herbivory Boerner, R. E. J.; Scherzer, A. J.; Sturgis, B. G. The effects of the presence of fungal endophytes, treatment with a systemic fungicide, and simulated herbivory on growth and biomass allocation were investigated in 2 varieties of perennial ryegrass (Lolium perenne): 'Repell', an endophyte-bearing variety, and 'Pennfine', a low-endophyte variety. In the absence of herbivory or fungicide there were no significant differences in the growth or pattern of biomass allocation between varieties. Treatment with the systemic fungicide benomyl reduced growth of both varieties by approximately 50% and reduced root growth more than shoot growth; fungicide effects were similar in the 2 varieties. Simulated herbivory reduced root growth more in endophyte-bearing Repell plants than in endophyte-free Pennfine plants, and root:shoot ratios of Repell plants were significantly lower than those of Pennfine plants following either moderate or severe herbivory. Statistically significant interactions between fungicide treatment and simulated herbivory were frequent in Repell plants but absent in Pennfine plants, suggesting that the fungicide had both direct phytotoxic effects and indirect effects mediated through the loss of endophytes by the Repell plants. While the proximate cost to seedlings bearing endophyte seemed small, the presence of the endophytes altered the allocation pattern of biomass following herbivory in such a way as to increase the probability of mortality. Mon, 01 Jan 1990 00:00:00 GMT http://hdl.handle.net/10150/644917 1990-01-01T00:00:00Z