Grant A. Harris

Root phenology as a factor of competition among grass seedlings.

Highlight: Roots of plants express phenology significant to competitive relationships, as do aerial parts. The following developmental stages of root phenology are proposed: (1) germination, (2) initial root growth, (3) rapid extension of root-soil contact, (4) dormancy, and (5) death. Examples of root phenological development in seedlings of three grass species are given to demonstrate effects on competition.

Variability within and among populations of four grass species

The importance of morphological variation for evolutionary and phylogenetic stud- ies is well recognized. This paper concentrates on morphological differences within and among population samples of several species of grasses to interpret potential for further differentiation. Analysis of gross morphology, a traditional tool of systematics, is coupled with numerical taxonomy to identify kinds of morphological differentiation among populations of species of four steppe grasses: Bromus japonicus, B. tectorum, Poa secunda, Pseudoregneria spicata. Floral and vegetative vari- ation in Poa secunda is consistent with apomictic differentiation. Floral characteristics in this species were responsible for more phenotypic divergence between populations (71%) than within popu- lations (35%), while vegetative traits were responsible for 29% of total variance between populations and 65% within populations. Inbreeding in the two Bromus species is not associated with any notable morphological differentiation between populations. Bromus tectorum appears to retain mor- phological uniformity throughout the area sampled. Character states for Pseudoregneria spicata ex- hibit varying degrees of plasticity depending on the population. This comparative study, concerned with differences and similarities in amounts and kinds of variation of morphological traits, repre- sents a first attempt to assess how morphological variation can be examined to detect the potential for some kinds of speciational events.

Population dynamics of seeded species on northeast Washington semiarid sites, 1948-1983.

Fifty-one graminoid and 10 forb taxa commonly used in range seedings were planted at 3 semiarid northeast Washington sites, spring and fall seasons, in monospecific stands, on 5.5 m by 1.3 m plots, 1948 to 1951. Population dynamics and clipped yields were observed at irregular intervals from 1952 to 1983. Ten graminoid, but no forb, taxa are recommended for range seeding. Grass species differ markedly in fitness for the sites, as demonstrated in success of passing through the environmental sieve, recruiting posterity, and long-term survival. Species interactions were site specific, demonstrating characteristic and complex demographic schedules at each site. Hard fescue was the most aggressive competitor, progressively replacing many of the others at all sites. Crested wheatgrass taxa provided the highest yields. Species mixtures which developed were unstable in the long term (30 years), and are not recommended in seeding practice. Authors are professor emeritus, Dep. Forestry and Range Management, Washington State University, Pullman, 99164-6410; former research assistaqt, Washington S&;,.Jniversity, presently research assistant professor, Utah State Unwersity, Logan Manuscript accepted 4 June 1985. Exotic graminoid species have been introduced onto semiarid sites in the western United States over the past century to restore valuable perennial forage plants where climax species have been removed. Eventual ecological adjustment of these extrinsic populations into the habitats which they have been introduced is frequently in doubt, because accurate long-term records have rarely been kept. Consequently, information necessary for selection of proper species to be used in future seeding activities is inadequate. More than 30 years of records are now available for 3 sites in northeast Washington. The primary objective of these trials was to bracket the environments with exotic forage taxa having differing site requirements, as a means of selecting the highest producing, longest lived, and most competitive for each location. Sixty-one species and varieties (or cultivars), were included. Although modern concepts of population ecology were not included in the original design, results provide a rare, if less than ideal, perception of population dynamics. Plant population ecology terms and concepts of Silverton (1982) are followed in this discussion. It is our purpose to report here both species fitness and demographic trends. 46 JOURNAL OF RANGE MANAGEMENT 39(l), January 1966 Table 1. Site characteristics at three Northeast Washington species adaptation nurseries.

Changing philosophies of rangeland management in the United States.

Ranchers and professional range managers have sometimes thought that they make major decisions controlling rangeland use. During certain periods of our history this may be true, particularly on private lands. But grazing use on public lands is more or less rigidly controlled by government, which is responsible and responsive to appropriate legislative bodies. And in our democracy, legislative representatives are likely to be strongly influenced by expressed public sentiments. At times, the whole system pays little attention to problems of rangeland use, but at other times the attention of an aroused public is focused directly on these problems. Because we are currently enjoying such attention, it seems timely to examine the changing philosophies of rangeland management and the forces which bring about these changes. Rangeland constitutes almost half of the total surface area of the United States and is by far the greatest single land use category. Even though rangelands are generally at the bottom of the scale in productive capacity, they are so extensive in area that they cannot avoid public attention for long. During recurring periods of public conservation enthusiasm (typified by the current “ecology” binge, the creation of the alphabet soup federal agencies of the mid-nineteen-thirties, and the conservation furor at the turn of the last century), major legislation is written to preserve natural resources, including ranges. Restrictive legislation usually provides for the establishment of a bureau in government to enforce provisions of the act. Then the policy becomes somewhat self-sustaining and very difficult to change without support from a powerful political group.

Economics of Selected Alternative Calving Dates.

Highlight Shifting calving dates from present early spring to fall or late spring dates offers an opportunity fo increase income fo range-based cattle operations in north central or norfheastern Washington. Lower death losses and beffer marketing opportunities more than offsei higher winter feed costs. Fall calves also make more efficient use of abundant spring ranges in ihis region, and dry cows make more uniform use of mountain summer ranges.

Natural Vegetation of Oregon and Washington

Revised edition of the authors Vegetation of Oregon and Washington, originally published by the U.S. Forest Service in 1973. Reprinted with new bibliographic supplement by the OSU Press in 1988.