Gerald J. Gottfried

Ecology and management of oak and associated woodlands: Perspectives in the southwestern United States and northern Mexico

This symposium focused on technologies that bridge the gap between research and its application in the management of woodlands. Topic areas include: ecology and silvicutural practices; growth, yield, and utilization potentials; livestock and grazing practices; wildlife habitat and values; and hydrology and watershed management. The proceedings include titles and abstracts of all papers in Spanish, a bibliography, and a summary of research needs.

Diversity of Frankia Populations in Root Nodules of Geographically Isolated Arizona Alder Trees in Central Arizona (United States)

ABSTRACT The diversity of uncultured Frankia populations in root nodules of Alnus oblongifolia trees geographically isolated on mountaintops of central Arizona was analyzed by comparative sequence analyses of nifH gene fragments. Sequences were retrieved from Frankia populations in nodules of four trees from each of three mountaintops (n = 162) and their levels of diversity compared using spatial genetic clustering methods and single-nucleotide or 1, 3, or 5% sequence divergence thresholds. With the single-nucleotide threshold level, 45 different sequences with significant differences between the mountaintops were retrieved, with the southern site partitioning in a separate population from the two other sites. Some of these sequences were identical in nodules from different mountaintops and to those of strains isolated from around the world. A high level of diversity that resulted in the assignment of 14 clusters of sequences was also found on the 1% divergence level. Single-nucleotide and 1% divergence levels thus demonstrate microdiversity of frankiae in root nodules of A. oblongifolia trees and suggest a partitioning of diversity by site. At the 3 and 5% divergence levels, however, diversity was reduced to three clusters or one cluster, respectively, with no differentiation by mountaintop. Only at the 5% threshold level do all Frankia strains previously assigned to one genomic group cluster together.

Transpiration by dryland oaks: studies in the south-western United States and Northern Israel

Abstract Increased understanding of transpiration by dryland oaks in the woodlands of the south-western United States and northern Israel has been obtained from studies in the two countries. Transpiration was estimated in both studies by the heat pulse velocity (HPV) method in stands of Quercus emoryi , a drought-deciduous species growing in the south-western United States, and stands supporting Q. ithaburensis , a deciduous oak, and Q. calliprinos , an evergreen oak, in northern Israel. Estimates of daily transpiration rates by individual trees and annual transpiration amounts on a stand basis indicate that depending on the species and stand structure, 45–80% of the precipitation inputs to the stands sampled are represented by transpiration component of the respective hydrologic cycles.

Dryland forestry for sustainable development

Dryland forestry is concerned with the management of trees and shrubs for sustainable development of dryland regions of the world. Applications of dryland forestry include the production of wood for fuel, poles and posts, and building materials; fruit and nut production; fodder, browse, and forage production; modification of local microclimates for improved agricultural crop production; and protection of lands susceptible to water or wind erosion, etc. These applications are combined into land-use practices linked to peoples needs and social values. Dryland forestry, therefore, can be defined more broadly as the management and often establishment of trees and shrubs to improve the livelihood and quality of life for people in dryland regions.

Natural Regeneration in Encinal Woodlands of Southeastern Arizona

COCKRUM, E. L., AND S. P. CROSS. 1964. Time of bat activity over water holes. J. Mamm., 45:635636. COCKRUM, E. L., AND Y. PETRYSZYN. 1991. The long-nosed bat, Leptonycteris: an endangered species in the Southwest? Occas. Papers Mus., Texas Tech Univ., 142:1-32. COOK, J. A. 1986. The mammals of the Animas Mountains and adjacent areas, Hidalgo County, New Mexico. Occas. Papers Mus. Southwestern Biol., Univ. New Mexico, 4:1-45. DRUECKER, J. D. 1966. Distribution and ecology of the bats of southern Hidalgo County, New Mexico. Unpubl. M.S. thesis, Univ. New Mexico, Albuquerque. FINDLEY, J. S., A. H. HARRIS, D. E. WILSON, AND C. JONES. 1975. Mammals of New Mexico. The Univ. New Mexico Press, Albuquerque. HALL, E. R. 1981. The mammals of North America. John Wiley and Sons, New York, 1:1-600 + 90. HAYWARD, B., AND E. L. COCKRUM. 1971. The natural history of the western long-nosed bat Leptonycteris sanborni. W. New Mexico Univ., Res. Sci., 1:75-123. HOWELL, D. 1972. Physiological adaptations in the syndrome of chiropterophily with emphasis on the bat Leptonycteris Lydekker. Unpubl. Ph.D. dissert., Univ. Arizona, Tucson. SHULL, A. M. 1988. Endang red and threatened wildlife and plants; determination of endangered status for two long-nosed bats. Fed. Reg., 53(109): 38456-38460.

Snowpack-runoff relationships for mid-elevation snowpacks on the Workman Creek watersheds of Central Arizona

Snowpacks in the southwestern United States melt intermittently throughout the winter. At some mid-elevation locations, between 7,000 and 7,500 ft, snowpacks appear and disappear, depending on the distribution of storms during relatively dry winters. Some winter precipitation can occur as rain during warm storms and is not reflected in the snow course data. The USDA Natural Resources Conservation Service (NRCS) maintains a system of measuring stations to index snow conditions and predict snowmelt runoff. The three Workman Creek watersheds in the Sierra Ancha Experimental Forest north of Globe were instrumented in late 1938 to study the hydrology of southwestern mixed conifer forests and to determine changes in streamflow and sedimentation resulting from manipulating the forest cover. The watersheds were deactivated in 1983, but they were re-instrumented in June 2000 after the Coon Creek wildfire to measure fire effects on forest hydrology and sediment dynamics. The Rocky Mountain Research Station would like to use NRCS data from the Middle Fork of Workman Creek to reinforce its hydrologic data acquisition and interpretation efforts. Snow water equivalent data can be used to characterize past winter runoff volumes and peak mean daily runoff. Significant regressions were developed between the data sets with coefficients of determination values ranging from 0.40 to 0.77. The relationships defined by these regressions will allow researchers and managers to ascertain the impacts of fire on snowmelt-related hydrologic processes and to estimate winter flows for the years when the installations were closed. They also provide an insight into the snowpack runoff relationships for intermittent snowpacks that are common at intermediate elevations throughout Arizona.

Dynamics of a pinyon-juniper stand in northern Arizona: a half-century history

This paper adds to the limited knowledge of stand dynamics in pinyon-juniper woodlands by reporting on the changes in species composition, numbers of trees, arrangements of trees, and total height and volume in a stand from late 1938 to early 1991. This information should be helpful in managing pinyon-juniper woodlands to sustain their productivity and maintain their multiple-use values. The annual increase of 1.2 trees per acre does not reflect the massive invasion of trees suspected by many people.

Bird species and numbers of birds in oak savannas of the Southwestern Borderlands region including effects of burning

ABSTRACT Oak savannas of the Southwestern Borderlands region provide food, cover, and sites for nesting, roosting, and perching for a diversity of bird species. The results of a five-year (2003–2007) study of bird species, numbers of birds, and their diversities in the naturally occurring (unburned) oak savannas of the region are reported in this paper. Effects of cool-season and warm-season prescribed burning treatments and a wildfire on bird species and numbers of birds sighted on the same study area after these burning events are also presented. These effects were difficult to isolate, however, because of the large variability in the tallies of bird species and numbers of birds obtained throughout the study.

Growth and development in an old-growth Arizona mixed conifer stand following initial harvesting

Abstract An alternative analysis predicted that a treatment for southwestern mixed conifer forests that included patch clear-cut openings, group selection, and single-tree selection would benefit the greatest mix of resources from a previously unharvested watershed in eastern Arizona. The harvest reduced overall stand density from 45.8 to 30.2 m2 ha−1 and created 63 patch clear-cut and group selection openings. The objective was to evaluate if the prescribed silvicultural treatment would benefit the timber resources following an initial entry into an old-growth mixed conifer stand. The treatment maintained the preharvest uneven-aged structure and increased timber productivity. Diameter and basal area growth increased for most species. Periodic gross growth was essentially unchanged, at about 4.90 m2 ha−1, but the same volume was being added to fewer trees. The stand, icluding most openings, was generally well stocked with new natural and advance regeneration. The Thomas Creek treatment should be considered for similar old-growth stands where harvesting is prescribed or for dense, partially harvested stands. Growth data can be used in simulation models.

Fire effects on tree overstories in the oak savannas of the Southwestern Borderlands Region

Effects of cool-season and warm-season prescribed burning treatments and a wildfire on tree overstories in oak savannas on the Cascabel Watersheds of the Southwestern Borderlands Region are reported in this paper. Information on the initial survival, levels of crown damage, species compositions and densities, annual growth rates, and basal sprouting following these burning events is presented. Impact of the fires on spatial distributions of trees in the overstories is also described. These events were all of low fire severities. As a consequence, effects of the prescribed burning treatments and the wildfire on tree overstories of the watersheds were similar and, therefore, the data sets were pooled. Effects of these fires on the tree overstories were mostly minor and often insignificant in terms of management implications.