Juniperus Scopulorum Sarg Research Articles

Growth of Forbs, Shrubs, and Trees on Bentonite Mine Spoil under Greenhouse Conditions

Revegetation on raw bentonite spoil with or without treatments is often more practical than replacing topsoil in areas where it is scarce or nonexistent. The effect of raw bentonite spoil treated with ponderosa pine sawdust on plant survival and growth was compared to other treatments including perlite, gypsum, straw, vermiculite, and no treatment. Plants tested were the droughtand salt-resistant species of fourwing saltbush (A triplex canescens (Pursh) Nutt.), rubber rabbitbrush (Chrysothamnus nauseousus (Pallo) Britt.), big sagebrush (Artemisia tridentata tridentata Nutt.), common winterfat (Ceratoides lanata (Pursh) Moq.), Rocky Mountain juniper (Juniperus scopulorum Sarg.), Russian olive (Elaegnusangustifolia L.), common yarrow (AchilleamUlifolium L.), and desert globemallow (Sphaeralcea ambigua Gray). Desert globemallow, fourwing saltbush, and rubber rabbitbrush had substantial growth and survival on sawdust, perlite, and vermiculite treated spoil. The growth promoting effect of sawdust is particularly promising; it is readily available and cost is minimal. Bentonite, a cream to greenish-gray colored clay consisting of the mineral montmorillonite (Gries 1974), occurs in much of the northern Great Plains as widespread beds interstratified with the dark gray marine shales. Bentonite mine spoil is commonly described as shales containing sodium montmorillonite. When wet, the bentonite spoil swells, and infiltration, permeability, and aeration approach zero. Excessive salt concentrations increase the osmotic potential of the spoil solution to a level that can be toxic to plants. Because of these problems, revegetation of bentonite mine spoil in arid and semiarid regions of the northern Great Plains, is extremely difficult (Bjugstad 1979). Several factors can be employed to improve revegetation efforts: (1) improving the physical and chemical conditions of the spoils, (2) covering bentonite spoils with topsoil and more favorable overburden, (3) using the most salt adaptable plants (Shannon 1979), (4) developing new genetic strains of salt adaptable plants for the future (Epstein et al. 1980), or (5) utilizing drip irrigation systems, but this may be expensive. Replacing the original topsoil to bentonite spoil has improved plant survival somewhat (Bjugstad 1979, Dollhopf et al. 1980, Dollhopf and Bauman 1981). However, much of the bentonite land has only shallow surface soil-less than 15 cm. In many places it is not practical to restore the original soil to bentonite-mined lands. This study was initiated to determine, based on greenhouse trials, the plant species most adaptive to spoil conditions and spoil amendments conducive to plant growth and establishment without topsoil.

Baseline sulphur and fluoride concentrations in indigenous plants common in the northern Great plains

Pre-industrial baseline concentrations of fluoride and sulphur content of 17 plant species indigenous to the Northern Great Plains coal fields are described. Values for both fluoride and sulphur approximate a log-normal distribution. Baseline sulphur values for eastern North America and fluoride baselines are higher than those observed in this study and should not be considered representative of vegetation from the Northern Great Plains. Concentrations of fluoride and sulphur in plant tissues from a moderately polluted Great Plains site provide upper limit values describing the potential increase under PSD Class II increments. Juniperus scopulorum Sarg. could serve as a long-term regional biomonitor for sulphur and fluoride pollution.

Analysis of conifer leaf free amino acids by gas-liquid chromatography

Free amino acids from the leaves of ten North American conifer species have been analysed by packed-column gas-liquid chromatography as their N(O,S)-heptafluorobutyryl isobutyl esters. The species examined were Balsam fir [ Abies balsamea (L.) Mill], douglas fir [ Pseudotsuga menzeisii (Mirb.) Franco], western hemlock [ Tsuga heterophylla (Raf.) Sarg.], Rocky mountain juniper ( Juniperus scopulorum Sarg.), western juniper ( Juniperus occidentalis, Hook), lodgepole pine ( Pinus contorta Dougl. var. latifolia Engelm.), ponderosa pine ( Pinus ponderosa Laws.), black spruce [ Picea mariana (Mill.) BSP], colorado spruce ( Picea pungens Engelm.), and white spruce [ Picea glauca (Moench) (Voss)]. All the proteic amino acids and some biologically important non-proteic amino acids were readily assayed. Gas chromatography-mass spectrometry was used to confirm the identity of the proteic amino acids and the homogeneity of the corresponding peaks. Ten unidentified components were partially characterised by their mass spectra.

Seasonal variation of sexual differences in the volatile oil of Juniperus scopulorum

Very few differences between male and female trees were found in the volatile oil composition of Juniperus scopulorum Sarg. Differences were more apparent when the compounds were calculated as percent of total oil than as weight per g dry matter. Almost all of the sexual differences occurred in the growing season (March–May). Essentially no differences were observed during the rest of the year. The observed differences were very small and should not affect the choice of plant material used in revegetating efforts (when browse potential is important). These differences should not affect chemosystematic studies, particularly if sampling is done during the period of the year when the plants are dormant.

Seasonal Variation in the Volatile Terpenoids of Juniperus scopulorum (Cupressaceae)

Fifteen trees in a natural population of Juniperus scopulorum Sarg. were sampled at 4-week intervals throughout a year and the terpenoid constituents were extracted from the foliage. Several environmental variables were measured. Correlations with changes in volatile oil composition (computed as both relative percentages and as weights) were examined. Significant seasonal variations were discovered in both the relative percentage and weight data. These seasonal changes in the volatile oil composition were correlated with linear growth, temperature, yield of volatile oil, and dry weight of foliage. Seasonal variation in the terpenoids computed on a weight basis was found to be greater than the seasonal variation of the terpenoids computed as relative percents of the total oil. Evidence is presented which indicates that there is no stable period to sample on a weight basis, but sampling in the late fall and winter periods minimizes variation in the relative percentage data. The use of relative percentage data is thus encouraged for chemosystematic studies.

SEASONAL VARIATION IN THE VOLATILE TERPENOIDS OF JUNIPERUS SCOPULORUM (CUPRESSACEAE)

Fifteen trees in a natural population of Juniperus scopulorum Sarg. were sampled at 4‐week intervals throughout a year and the terpenoid constituents were extracted from the foliage. Several environmental variables were measured. Correlations with changes in volatile oil composition (computed as both relative percentages and as weights) were examined. Significant seasonal variations were discovered in both the relative percentage and weight data. These seasonal changes in the volatile oil composition were correlated with linear growth, temperature, yield of volatile oil, and dry weight of foliage. Seasonal variation in the terpenoids computed on a weight basis was found to be greater than the seasonal variation of the terpenoids computed as relative percents of the total oil. Evidence is presented which indicates that there is no stable period to sample on a weight basis, but sampling in the late fall and winter periods minimizes variation in the relative percentage data. The use of relative percentage data is thus encouraged for chemosystematic studies.

Characterization of the Forest Floor in Stands along a Moisture Gradient in Southern New Mexico

AbstractForest floor properties of stands along a moisture gradient from dry, represented by a piñon‐juniper stand (Pinus edulis Engelm—Juniperus scopulorum Sarg.), to wet, represented by a white fir stand (Abies concolor [Gordon & Glend.] Lindl.), were studied. Dry weights and amounts of nutrients were directly related to the moisture gradient. For example, dry weights of the forest floor increased from 9.4 to 80.8 metric tons/ha from the dry to the wet end of the moisture gradient, respectively. Nutrient concentrations were not related to the moisture gradient with the exception of K. In the more mesic stands sufficient water appears to have been present to allow substantial leaching of K from the forest floor.