Field measurements and computer-based predictions suggest that the magnitudes of seasonal peak snowpack water equivalents are becoming less and the timing of these peaks is occurring earlier in the snowmelt-runoff season of the western United States. These changes in peak snowpack conditions have often been attributed to a warming of the regional climate. To determine if these changes are also occurring in Arizona, almost 75 years of water equivalent measurements on snow courses maintained by the U.S. Natural Resources Conservation Service and their cooperators have been analyzed in a preliminary study of possible effects of recent climatic change. The results of this analysis agree generally with the findings of other studies in the Western states.

Pollution and consistent exposure to nitrogen dioxide are known as factors in respiratory illnesses, such as pneumonia and emphysema.. Therefore, careful air monitoring of public areas is necessary. A convenient and cost-effective method uses passive diffusion tubes. These tubes, treated with Triethanolamine or TEA - a nitrogen dioxide absorbent, were placed in a non-smoking environment, The Meadows School in Las Vegas, for a control and smoking environments, which consisted of several small, neighborhood casino bars also in the Las Vegas area. After the tubes absorbed nitrogen dioxide from the designated environment for a week's time, they were analyzed and then tested spectrophotometrically. The results indicated that the non-smoking environments had a nitrogen dioxide concentration of approximately 0.004–0.011 ppm, semi-smoking areas (the dining area of the pubs) had a nitrogen dioxide concentration of 0.012–0.029 ppm and the most smoky areas (the bar area of the pubs) had a nitrogen dioxide concentration of 0.023–0.048 ppm. This assay suggests that the amount of nitrogen dioxide present is directly correlated with the concentration of cigarette smoke in a given area.

A number of perennial plant species can have different modes of reproduction, depending on environmental conditions. The objective of this paper is to review previously published literature regarding the benefits and costs of asexual (vegetative) and sexual reproduction in perennial plants, and to address which environmental conditions tend to favor each mode of reproduction in plants exhibiting both vegetative and sexual reproduction. Benefits of vegetative reproduction, through physiological integration among intraclonal ramets, may prolong the life in clones of individuals by spreading the risk of mortality over space. Costs of long-term integration may involve maintenance of connections and support of numerous daughter ramets at the expense of the parental clone. The depletion of genotypic variability within clonal populations through time makes them more susceptible to diseases, pathogens, and environmental stochasticity. However, benefits of sexual reproduction include genetic diversity, primarily through recombination, and ability to disperse into new areas. Genetic variation is responsible for the adaptation of populations to their environments. Phenotypes are the visible morphological appearance of genotypes interacting with the environment. Costs of sexual reproduction include construction of floral and reproductive structures. Seed germination and seedling growth are highly vulnerable to biotic and abiotic stresses. Some plant exhibit both types of reproduction, depending on the species and habitat conditions. Creosote bush (Larrea tridentata) and blackbrush (Coleogyne ramosissima) shrubs grow vegetatively on old, stable landscapes. Big sagebrush (Artemisia tridentata) shrubs grow vegetatively under favorable environmental conditions, and wild strawberry (Fragaria virginiana) plants grow on open habitats. On the contrary, these four plant species would show sexual reproduction when environmental conditions are unfavorable.

The Phoenix, Arizona metropolitan area is a top tourist destination with a climate that supports year-round outdoor and indoor activities even during periods of intense summer temperatures. This investigation provides an initial evaluation of the effects of the intense Southwest summer conditions on indoor versus outdoor shopping experiences as measured by human thermal comfort during afternoon and evening meteorological conditions. Both primary and secondary data were collected at four different shopping malls to calculate the heat index, discomfort index, and apparent temperature in addition to temperature, dew point, and relative humidity. Meteorological conditions account for more than 50% of the variance explained in the attendance of indoor malls during the afternoon, while attendance at outdoor malls was not significantly impacted by the weather. In the evening, the variance explained by meteorological conditions decreases to around 30% for the indoor mall locations, while 8% variance is explained at one of the outdoor malls. While attendance did increase in the evening at the outdoor locations and decreased at indoor locations, the choice of shopping location may have more to do with additional options after-hours, including dining and entertainment, at the outdoor locations. Although, human thermal comfort is a factor in recreational activities, specifically for shopping malls, a longer study period may be required, to determine decisions on shopping location and eating options.

Stream terraces of the Salt River form the interpretive backbone of Plio-Pleistocene landscape evolution of central Arizona, because they represent the base level of all tributary streams. This paper presents a new addition to T.L. Péwé' s Salt River Terrace sequence (in decreasing topographic position and age: Sawik, Mesa, Blue Point, and Lehi) that has been unrefined for the last 30 years. The existence of an older, higher terrace was predicted by research suggesting that the lower Salt River originated by lake overflow from an ancestral Pliocene lake in the Tonto Basin. Field reconnaissance, aerial photo interpretation, and sedimentological analysis revealed this terrace on the north side of the Salt River, named here the Stewart Mountain Terrace (SMT). Where exposed, the fluvial sediments of SMT overlay Tertiary basin fill unconformably. SMT sediments are characterized by ∼50 m thick fluvial gravels found more than 70 m above remnants of the Sawik Terrace. Although the gravels are distinctly Salt River in origin, Stewart Mountain gravels differ from the lower and younger Salt River Terraces. The clast sizes are much larger on average and host a significantly different lithology. Because of these differences the SMT has profound implications for the understanding of regional drainage reorganization after basin and range extension. The existence of this terrace and its distinct gravels are consistent with, but do not prove, a lake overflow mechanism for the initiation of through flowing drainage in the Salt River Valley.

With an increasing number of golf courses within Gold Canyon, Arizona, located at the foot of the Superstition Mountains, this study determines if characteristics of nocturnal katabatic flow, with respect to temperature, dew point, wind speed and direction, were altered due to a golf course. To answer this question, I devised a four transect plan in which four weather stations measured temperature and dew point at three levels (0.70 m, 1.25 m and 2.5 m), along with wind speed at two levels (1.25 m and 2.5 m), as well as wind direction at 2.5 m. I positioned two stations above the golf course, considered natural stations, and two stations below the golf course, considered to be anthropogenically influenced stations. I then collected data over a six-night period starting at 1700 MST on January 3 and ending at 0945 MST on January 9. A golf course community appears to significantly modify katabatic flow. Using Analysis of Variance, coupled with Tukey's comparison test, at the 95 percentile confidence interval, the mean temperature and dew point at 0.70 m, 1.25 m and 2.5 m were significantly different from the top of the course when compared to the bottom. Wind speeds at 1.25 m and 2.5 m were appreciably dissimilar. Locations below the golf course had considerably lower temperatures and higher dew points, with relation to proximity to the course. The most notable finding was directly down slope of the course where katabatic flow was found to be near non-existent, even when a strong katabatic flow event occurred just upslope of the golf course. This near elimination of katabatic flow is likely to be the result of cool/moist and, subsequently, dense air residing over the golf course due to the grass surface. As the katabatic flow moving off the nearby Superstition Mountains reached this cooler and more moist/dense air, it slowed as the density differences between the two air masses were lowered.

Multi-objective decision-making (MODM) is an appropriate approach for evaluating a forest management scenario involving multiple interests. Today's land managers must accommodate commercial as well as non-commercial objectives that may be expressed quantitatively and/or qualitatively, and respond to social, political, economic and cultural changes. The spatial and temporal characteristics of a forest ecosystem and the huge number of variables involved require the management of such a system in a spatiotemporal MODM framework. The particular MODM technique used in this paper is Compromise Programming. This technique is used to determine the most satisfactory management option, Compromise Programming uses a common management response indicator to solve a forest ecosystem management scenario in a fair and equitable manner.