Raymond J. Pool

Bio: Raymond J. Pool is an academic researcher from University of Nebraska–Lincoln. The author has contributed to research in topics: Vegetation (pathology) & Metabolic water. The author has an hindex of 6, co-authored 12 publications receiving 139 citations.

Report on the Dune-Areas of New Zealand, their Geology, Botany and Reclamation

Abstract: In the subject index no titles are given, but references are given to the year and author, so that the corresponding title can be easily found in the chronological catalogue. It is obvious that a scientific bibliography like this serves a very useful purpose to the student and investigator, especially when it is well arranged and possesses a high degree of completeness, as is the case here. With Sommerville's book at his command the worker in the field of non-Euclidean or n-dimensional geometry is unusually well equipped for referring quickly to the literature of his subject.

Plant Water Relations

Abstract: INTRODUCTION P ERHAPS no subject in plant physiology has been discussed at greater length than the problem of the rise of water in trees. The literature of this subject has been increasing since the appearance of Stephen Hales's Vegetable Staticks in I727. It is now enormous. Some phases of the earlier scientific discussions have filtered out into the realm of popular knowledge, and intelligent people everywhere are now at least aware of the existence of a peculiarly interesting problem in this connection. The ascent of sap constitutes a subject of perennial interest o many minds that are not specially devoted to plant physiology or even to any branch of natural science. The more fruitful contributions toward an appreciation of this very fundamental natural process are, however, of recent date, for what now seems to be the basic clue to the mechanics of the rise of water in trees did not get adequately presented until the appearance of Dixon's publication in I909. Study in this field has gone on with renewed vigor since that time, and the general principles involved in the \"transpiration stream\" appear now to be fairly well worked out. But these recent results have not yet reached the intelligent public; indeed, they are only beginning to be presented in school and college text books of botany, and their implications are but vaguely envisaged by many professional workers in plant physiology. Popular science and school and college science must generally lag very much behind research, but in this case the lag is remarkably great. The physical explanation of the rise of water in trees now leads far beyond this movement itself, to problems of the entrance of water into the plant body on the one hand, and, on the other hand, to those of water retention within the plant and of water loss. Tall trees furnish an obvious example of certain apparently somewhat uncanny phases of plant water relations, but forms of low stature generally present he same problems. From a less philosophical point of view the subject of plant water relations is of interest o all who have to do with living plants, which implies almost everybody. I may mention agriculture as the great, fundamental human occupation and then proceed to note how important water is in crop production. As the earth is constituted, water and temperature-the water supply and the heat supply-are the main limiting conditions that demark vegetational and agricultural regions. Water conditions of crop plants are readily amenable to artificial modification. Recent advance in our knowledge of how plants need water and why some forms need more to produce a crop than others has led to great improvement in irrigation and drainage. Also, attacks of fungus and insect parasites on cultivated plants are found to be related in many cases to the moisture conditions of air and soil. In the following pages I aim to present a

Species distribution and community organization in a Nebraska Sandhills mixed prairie as influenced by plant/soil-water relationships.

Abstract: Plant and soil water relationships in a typical nebraska Sandhills prairie were examined to 1) explain the observed distribution patterns of several dominant grasses along a topographic gradient, and 2) show how spatial and temporal variations in soil moisture are critical to community organization on a sandy substrate. An experimental transect encompassing the major community and soil types along a steep, west-facing vegetated dune was established. Maximum available water was shown to be significantly higher in the fine textured surface soils of the lowland sites than the coarse textured sands of the dune sites. Seasonal (1979) patterns of available soil moisture of the sampling sites on the transect showed that in the upper elevation dune sands, moisture was available in the entire profile with surface depletions not occurring until mid to late summer. In contrast, moisture in the surface 60–80 cm in the fine textured lowland soils was exhausted by early to mid-summer with the entire profile nearly dry by late summer. Deep-rooted, C4 species, Andropogon hallii and Calamovilfa longifolia which are common on upper, coarser sandy soils showed significantly greater water stress on fine textured soils than on dune sands. C3, shallowrooted species, Agropyron smithii, Stipa comata, and Koeleria cristata always experienced lower mid-day and predawn leaf water potentials than the C4 species. The C3 species, with the exception of Koeleria are most abundant on finer textured soils that provide substantial moisture during their peak activity in the spring. It appears that the C4 species show more conservative water use patterns than the C3 species as significantly lower leaf conductances in the C4's were measured when soil water was abundant. The C3 species appear to be opportunistic with available water and rapidly deplete surface soil moisture as a result of high transpiration rates. These data suggest that the temporal and spatial distribution of available water along this gradient controls species distribution according to rooting morphology, photosynthetic physiology, and water deficits, incurred by transpirational losses. Competitive interactions between species that utilize soil moisture differently may be an important factor in community organization.

Big sagebrush: A sea fragmented into lakes, ponds, and puddles

Abstract: _____________________________________ Welch, Bruce L. 2005. Big sagebrush: A sea fragmented into lakes, ponds, and puddles. Gen. Tech Rep. RMRS-GTR-144. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 210 p. Pioneers traveling along the Oregon Trail from western Nebraska, through Wyoming and southern Idaho and into eastern Oregon, referred to their travel as an 800 mile journey through a sea of sagebrush, mainly big sagebrush (Artemisia tridentata). Today approximately 50 percent of the sagebrush sea has given way to agriculture, cities and towns, and other human developments. What remains is further fragmented by range management practices, creeping expansion of woodlands, alien weed species, and the historic view that big sagebrush is a worthless plant. Two ideas are promoted in this report: (1) big sagebrush is a nursing mother to a host of organisms that range from microscopic fungi to large mammals, and (2) many range management practices applied to big sagebrush ecosystems are not science based.