Aerial parts of the caespitose type of bluebunch wheatgrass (Agropyron spicatum) have been shown to direct rainwater and to concentrate it in the soil immediately beneath individual plants. The degree to which water collects beneath the bunches appeared to be related to the size of the canopy. It is possible that the rapid decline of bluebunch wheatgrass under heavy grazing is related to soil moisture redistribution caused by the removal of its aerial parts.

The mesquite twig girdler (Oncideres rhodosticta Bates) was found to inflict considerable damage to mesquite in Texas and may prove to be a valuable biological control agent for this noxious species. Preliminary observations in infested areas indicated that about 90 percent of the mesquite trees had been attacked by the girdler and that about 40 percent of all branches from 0.5 to 2.0 cm in diameter had been girdled.

A study of the maximum air temperature near the soil surface at 11 grassland locations was made during the summer of 1968 using a simple maximum temperature indicator. Maximum temperatures within the first centimeter above the soil were found to exceed 144 F on a number of these locations. Although the range of indicators was not large enough to include the extremes at all locations, a seasonal pattern was identifiable. Large local differences in near-surface temperatures were frequently observed.

Very heavy grazing of fescue grassland range at Stavely, Alberta, compared to light grazing, changed the color of the Ah horizon from black to dark brown and the pH from 5.7 to 6.2, reduced the percent organic matter, reduced percent total P but increased NaHCO3-soluble P, and increased soil temperature but decreased percent soil moisture. Trends indicated that soil of the very heavily grazed field was being transformed to a soil characteristic of a drier microclimate.

Exposure of alkali sacaton seeds to light for a few seconds after imbibition delayed germination 24 hr, exposure for 9 to 13 hr delayed germination 28 hr, exposure for more than 13 hr delayed germination 72 hr, and continuous exposure reduced germination 40%.

Broad, shallow intermediate pits have proved to be longer lasting than conventional pits on semidesert range in the 6- to 8-inch summer rainfall zone in southern Arizona. Rainfall penetration averaged twice as deep in the pits as on adjacent flats. Herbage production of buffelgrass averaged 2 1/2 times as high, over a 4-year period, on the intermediate pits as on conventional pits, and five times as much as on similar adjacent untreated range.

As ecological concepts become incorporated into the training and background information of professional land managers, they also become incorporated into land management policies. Recent developments in ecology, such as nutrient cycling studies and computer simulation of complex processes, have a favorable climate for acceptance. Possible applications should be carefully studied by land managers.

Soil temperature at the 18-inch depth was the most important factor affecting response of honey mesquite to 2,4,5-T application. Temperatures at this depth in the high 60's F or low 70's F resulted in no mesquite kills with the best results obtained if temperatures were over 80 F. Phenological development was essentially as important with plants having mature leaves and seed pods being easiest to kill. Trees with small and blooming spikes and those without flowers or pods were hardest to kill with 2,4,5-T. Other variables usually considered important, such as soil moisture, were important only in combination with other variables. Mesquite trees growing on upland and sandy sites are apparently more susceptible to 2,4,5-T largely because the soil is usually several degrees F warmer than bottomland and clay sites.

Effects of rootplowing, with or without seeding, on forage production and composition of native grasses were determined on a deep upland range site. Percent composition of stoloniferous species, particularly buffalograss, was reduced initially and after 6 growing seasons by the rootplowing treatments. Frequency counts indicated a reduction of Texas wintergrass on rootplowed plots (seeded and nonseeded) compared to an undisturbed, native check area. This reduction the first growing season was attributed to the competitive effect of sorghum almum introduced in the seeding mixture. Unsuccessful establishment of other seeded grasses (sideoats grama and switchgrass) appeared to be related to poor seedbed preparation, competition from sorghum almum plants, and below normal rainfall immediately after seeding. Rootplowing decreased grass production. After 6 growing seasons, significantly less forage per acre was produced on rootplowed-seeded plots than on nonrootplowed plots. Differences in forage production were related to plant composition and density. /// El estudio fué empezado en el año de 1964 en el rancho experimental de Texas en el Municipio de Throckmorton; el diseño incluyó testigo; y se pasó arado para desenraizar sin la siembra y se pasó arado para desenraizar con la siembra. Después de 6 años los dos tratamientos disminuyeron la producción de forraje y composición de zacates deseables. El zacate sorghum almum (Sorghum almum) apareció en la siembra. El arado desenraizador controló el mezquite (Prosopis glandulosa var. glandulosa).

Burning increases the production and cattle preference of weeping lovegrass. A winter burn increased spring and summer herbage yields of weeping lovegrass 14% and utilization 53%. Burning increased crude protein from 3.6% on untreated lovegrass to 7.6% on unfertilized burned plots. It increased crude protein content from 5% on unburned fertilized plots to 10.5% on burned fertilized plots. Forty-four pounds per acre nitrogen fertilization increased crude protein but had little effect on forage production and utilization. /// Weeping lovegrass (Eragrostis curvula (Schrad.) Nees) tiene buena adaptación a varios climas y suelos, especialmente suelos arenosos. Este zacate tiene menor palatabilidad. Este estudio se llevó a cabo en la granja experimental de Texas Tech cerca de Amarillo, Texas, E.U.A., se demostró que puede aumentar la palatabilidad del zacate con quema. La quema durante invierno aumentó la producción de forraje en un 14%, la intensidad de pastoreo en un 53%, y el contenido de proteína en un 3.4%. La fertilización de nitrógene a 44 Kgs/Ha. aumentó el contenido de proteína pero no influyó en la producción de forraje ni en la palatabilidad del zacate.