Search

Strip-mining for coal and other mineral resources in the southwestern United States has produced problems in reclamation entirely different from those encountered in regions of higher or more effective precipitation. It was the intent of this study to look at the essentially random assortment of environmental factors left after the mining process and to determine qualitatively, as well as quantitatively, which of those factors are more likely to lead to the successful germination and establishment of invading plant species. A second objective was to determine what changes in the spoil material are occurring as a result of plant establishment. Major factors affecting initial invasion and establishment of plant species were found to include topography, slope exposure, degree of surface compaction, and the presence of large rocks on and below the spoil surface. Ecological reactions of established plants include reduced spoil surface temperature extremes, the trapping of wind-blown seed and sand, litter accumulation, and a change in the concentrations of some salts beneath the plant. Sodium ion concentration beneath established four-wing saltbush (Atriplex canescens) increased as a function of depth and distance from the plant while those of potassium decreased. A number of recommendations to improve mine reclamation success are made based on the results of this study.

This study was begun in the summer of 1975 at site 29SJ627, In Marcia's Rincon, Chaco Canyon, New Mexico. Dates of the occupation of the site were from ca. 800 A.D. to 1050 A.D. The primary purposes of the study were to identify pollen; investigate factors affecting variability, including temporal, functional, and spatial factors; investigate sampling techniques to obtain adequate representation of variability; comparison of pollen and flotation samples. A total of 83 samples were processed and 34 taxa were identified. Within site 29SJ627 a block of rooms was chosen for extensive sampling. Within the rooms a grid system was developed for sampling different levels. All features in the rooms were sampled. Results indicate that storage and preparation of agricultural and wild food products occurred in the site. A strict delineation between habitation and storage rooms was not made. The pollen of mesic plants (Typha sp or Sparganium sp.) was recovered. These plants are not known to grow in Chaco Canyon today. Variability within a room is extremely high. A composite pinch sample from many locations in a room would probably express this variability. Pollen and flotation samples produce complementary data. Pollen contamination of exposed surfaces was shown to occur within 12 hours or less.

Fourwing saltbush [Atriplex canescens (Pursh) Nutt.] seedlings were subjected to water stress treatments and temperature-photoperiod regulation to determine if these treatments might induce greater hardiness to subsequent drought stress. Seedlings ages 2, 4, and 8 weeks after emergence were allowed to wilt before rewatering or kept at minimum soil moisture stress. Seedlings aged 2 weeks after emergence were subjected to four regimes of hot and cold temperatures and long and short photoperiods in growth chambers. Treatments were applied for four weeks. Height, fresh weight and dry weight of shoots, and dry weight of roots were reduced by water stress and cold temperature treatments, and root to shoot ratios were increased by these treatments. No significant changes in leaf osmotic potential, xylem pressure potential, or transpiration rates per unit leaf area were observed for any treatment. Reduction in transpiration rates on a whole plant basis did occur for water stress treated 4- and 8-week-old plants and cold temperature-short photoperiod treatment plants. While drought survival response was not significantly different for any treatment, soil water potential at LD50 was lower for 2-week-old plants than for 4- and 8-week-old plants and was lowest in cold temperature-short photoperiod treatment plants. Overall, fourwing saltbush seedlings change most significantly in morphological features rather than in physiological responses. It is suggested that although survival in this species may be improved by water stress and/or cold temperature-short photoperiod treatments beginning on 2-week-old plants, this species is already genetically adapted to water stress as a drought avoider.

The Datil Mountains of west-central New Mexico were selected for a floristic inventory and analysis because of the lack of previous study in this section of the state. The location of the study area in relationship to the Basin and Range, Southern Rocky Mountain, and Colorado Plateau physiographic provinces was a major factor in determining the initial need for floristic work in the Datil Mountain area. An annotated checklist of the vascular flora of the study area was compiled. For those 590 collected taxa, available information was compiled which could serve as a useful tool for land management in this region of New Mexico. An appendix of the mammals and birds noted within the study area during the three years of field collection is supplied to serve as an aid in the ecological assessment of the study area. The study area was divided into two sections according to geologic parent material. A sandstone parent material section comprised the northern third of the study area and a volcanic parent material section formed the southern two thirds. Initial observations indicated that these two sections consisted of relatively distinct floristic elements. A distributional analysis was performed on the taxa in each section according to their natural categorization into geographic units and by their presence in the neighboring political entities of Texas, Colorado, Arizona, and Mexico. The degree of relationship was determined by index of similarity and chi-square tests. Test results indicate that the two sections are ecotonal in nature, but the flora of the volcanic section maintains a greater affinity for the Rocky Mountain province and that of the sandstone section has a greater affinity for members of the Madro-Tertiary Geoflora.

Because the area has been highly disturbed, the streams within Jemez Creek watershed often carry excessive loads of sediment. During recession of high water, sand and silt are deposited upon the Aufwuchs and Pantosteus plebeius ingest this inorganic material with their food, Had the original problem been to study food habits, it would have been desir­able to work in some less disturbed area.

The writer has attempted to determine what species occur on Mount Taylor. This information should reveal any deviations from the expected floristic pattern as well as general distributional trends. If deviations are detected, the writer will attempt to explain them in the general discussion. Most of the answers and conclusions are of a speculative nature because of insufficient meteorologic information and comparative data from other regions.

The basidiomycete flora of the Sandia Mountains has never really been investigated before. At best this survey can serve only as a rather spotty general sketch of fungi in the area. But at least it is a beginning, and one which is not slanted just at the pathological aspects. It is my hope that such information as has been uncovered will help in future ecological and taxonomic investigations of the fungi of these mountains.

The invasion of a high elevation burn (3500 m) by Engelmann spruce (Picea engelmannii Parry) was investigated on the Santa Fe National Forest in north-central New Mexico. Population analyses and a field germination test of spruce seeds under various treatments were performed. The resistance of soil moisture blocks and soil temperatures were measured. The fire which occurred in 1886 eliminated a climax spruce-fir forest and resulted in a subalpine grassland at elevations above the zone where aspen (Populus tremuloides Michx.) has invaded. The estimated crown coverage of trees in the grassland is less than 5%. Engelmann spruce comprises 92.5% of the trees in sampling plots, while limber pine (Pinus flexilis James) and corkbark fir (Abies lasiocarpa var. arizonica (Merriam) Lemm.) comprise 4.1% and 3.4%, respectively. The density of trees in all size classes is 7.3 trees/100 m2. The size class distribution of spruce shows a marked J-shape which is assumed to be an indication of an increasing rate of establishment. More rapid invasion seems to occur on north aspects. Establishment was found to be a non-random process, following a clumped distribution; however, no site factor was found to be correlated with tree density. The diameter growth rate of Engelmann spruce was determined to be 0.77 cm/year. The growth rate for spruce greater than 10 cm in diameter was found to be neither increasing or decreasing with age. The deviations in an age distribution of spruce were positively correlated with June plus July precipitation during this years of establishment. The treatments had significant effects on the germination and seedling survival of Engelmann spruce. Black plastic mulch increased germination; however, it also increased seedling mortality. Pine bark mulch treatment and greenhouse (polyethylene enclosure) treatment decreased germination, while the disturbed treatment did not appear to affect germination or mortality. The amount and distribu

In this study, the number of viable mold spores trapped by a power-assisted sampling device was counted to determine the number of spores per cubic foot of air. Mold colonies were then sub-cultured and identified to genus. Meteorological data for the times of sampling and for the entire year were furnished by the Environmental Sciences Service Administration. It was determined that certain spore types did show a seasonal variation, with different types predominating at different times of the year. Certain local climatic conditions prevailing at the time of sampling tended to select for the predominance of a particular type of spore, for example, Penicillium after precipitation and Rhizopus with windstorms. The numbers of different spores trapped are shown as numbers per cubic foot of air at the sampling time.

Chlorophyll concentration and reflectance of bark samples of Populus tremuloides Michx. growing at various elevations in the Sangre de Cristo mountain range of New Mexico indicate the appearance of greener barked trees at higher elevations is due to the reflectance characteristics of a bloom of dead periderm cells and not to increased chlorophyll concentrations. Chlorophyll concentration in aspen bark were, in fact, inversely correlated (p=.001) with altitude. The higher concentration of chlorophyll at lower elevations is effectively masked by a white bloom which is also characteristic of exposed site trees. At higher elevations the bloom is yellow-brown and more translucent thus allowing the chlorophyll layers beneath to show through. Therefore, trees at higher elevations appear greener even though they have lower corticular chlorophyll concentrations. The ecological significance of attitudinal variations in chlorophyll concentrations and reflectance of aspen bark is discussed.

The geographic variation of the pocket gopher Thomomys bottae in the Rio Grande Valley of New Mexico and Conejos County, Colorado were studied. The pocket gophers were collected and prepared as standard museum skins and skulls. Various dimensions of the pocket gophers are measured, treated statistically, and plotted as Dice squares. Four groups of geographically related and like-sized animals were noted. These groups could be associated with four previously described subspecies of T. bottae. It was possible to observe a correlation between the mean size of each sample of gophers and the soil type in which they were found. The hypothesis that sexual dimorphism in size is most apparent in deep friable soils was not substantiated. On the basis of color alone the samples could be placed in the same groups derived by using size alone. Pelage color could be related in a general way to the color of the soil inhabited by these animals. This correlation was not exact.