Academic literature on the topic 'Quiet encroachment'

Plant communities of the Jornada Basin are characteristic of the northern Chihuahuan Desert both in structure and dynamics. Although a number of plant communities can be differentiated, five major vegetation types are often distinguished that differ in plant species cover and composition, as well as other factors, such as animal populations, soil properties, and elevation. These five types are black grama (Bouteloua eriopoda) grasslands, playa grasslands, tarbush (Flourensia cernua) shrublands, creosotebush (Larrea tridentata) shrublands, and mesquite (Prosopis grandulosa) shrublands. Similar to many other parts of the Chihuahuan Desert, these plant communities have experienced major shifts in vegetation composition over the past 50–150 years (York and Dick-Peddie 1969). The most dramatic changes in vegetation and associated ecosystem processes have occurred as a result of a shift in life form due to woody plant encroachment into perennial grasslands (Grover and Musick 1990; Bahre and Shelton 1993). This encroachment of shrubs has occurred in many arid and semiarid regions of the world, including the Western United States, northern Mexico, southern Africa, South America, New Zealand, and Australia (McPherson 1997; Scholes and Archer 1997). A number of drivers have been implicated in these grass–shrub dynamics, including various combinations of livestock grazing, small animal activity, drought, changes in fire regime, and changes in climate (Humphrey 1958; Archer 1989; Allred 1996; Reynolds et al. 1997; Van Auken 2000). The causes of shrub invasion are quite variable and often poorly understood, although the consequences consistently lead to the process of desertification (Schlesinger et al. 1990). This chapter describes the characteristics of each vegetation type and the documented changes in each type at the Jornada Basin. We then discuss the key drivers influencing these dynamics. Vegetation in the Chihuahuan Desert region has been classified as desert-grassland transition (Shreve 1917), desert savanna (Shantz and Zon 1924), desert plains grasslands (Clements 1920), desert shrub grassland (Darrow 1944), and shrubsteppe (Kuchler 1964). Desert grassland is often used as a general descriptive name for the area (McClaran 1995), although landscapes at the Jornada and throughout the northern Chihuahuan Desert often consist of a mosaic of desert grasslands, Chihuahuan Desert shrublands, and plains-mesa sand scrub (Dick-Peddie 1993).

The importance of World War I as a watershed in twentieth-century American history has long been recognized, and recent studies agree that that interpretation applies to higher education and to American Catholic history. Not surprisingly, it also applies to the development of Catholic higher education. The war did not in itself revolutionize that activity, but by reinforcing and accelerating tendencies already at work it closed the door on one epoch and set the stage for another. The decisive difference between the two eras was that the war settled in favor of the modernizing reformers the debate over the organizational issues discussed in Chapter 2. This came about because efforts to rationalize Catholic higher education were swept along in what David M. Kennedy has called “the great war-forced march toward a better articulated structuring of American life.” Coming after two decades of industrial consolidation and in the midst of a craze for “efficiency,” wartime mobilization brought the movement for planning and control to an unprecedented level of intensity. “Czars” were appointed, or national commissions established, to supervise industrial production, agriculture and food distribution, fuel supplies, labor, the railroads, and shipping. Mobilization of opinion was entrusted to the Committee on Public Information, which reached into every corner of the land, including the schools. This was all carried on at a high pitch of patriotism; the same emotion, along with the felt need to keep pace with ongoing changes, led to the creation of many voluntary agencies of coordination, such as the American Council on Education and the National Research Council, to mention two quite important for higher education. By far the most important result of this impulse among American Catholics was formation in 1917 of the National Catholic War Council and its transformation after the war into a permanent organization called the National Catholic Welfare Conference (both of which used the initials NCWC). Scholars have only recently begun to unravel the complexities of this story, but their work makes clear that, precisely because the NCWC represented so important a step toward centralization, its formation aroused fierce opposition from Catholics fearful of encroachments on their own freedom of action.

Summary Late in the life of the Steam Assisted Gravity Drainage (SAGD) process, it has become common practice to drill a single, horizontal infill well (called a “Wedge Well™” by some) in the oil bank located between two mature SAGD well pairs to produce the bitumen that has been heated and mobilized but is unable to be effectively drained by gravity given the largely lateral location relative to that of the SAGD producers. Since this oil bank is surrounded by the large, depleted steam chamber created by the existing well pairs, it requires little heat to mobilize bitumen. One of the challenge