David Dale

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landscape sensitivity Unlike people, all landscapes are not created equal. The fascinating variety of landforms that seduces many geomorphologists to their calling also gives rise to a tremendous range in landscape response to natural and anthropogenic change. Landscape sensitivity may be considered to measure the degree to which a landscape will respond to a unit change in geomorphological forcing. Landscape sensitivity therefore characterizes the intrinsic susceptibility of a landscape to geomorphological change. Such susceptibility is a function of the nature of the change and the nature, distribution, and juxtaposition of spatially variable landscape characteristics, such as soils, topography, and bedrock lithology and structure.

Variability in the intrinsic sensitivity of a landscape to different geomorphological processes, and the importance of being able to relate specific processes to specific places, is readily illustrated through the example of shallow landsliding. Common sense suggests that steep slopes are more prone to landsliding than gentle slopes. Other factors that influence the potential for shallow landsliding are drainage area (which influences how wet a site is), soil strength properties (i.e. cohesion and friction angle), and the effective cohesion provided by the root strength of vegetation. The sensitivity of a landscape to loss of root strength (such as follows a timber harvest) varies greatly according to topographic position and soil properties. Steep, convergent topography with cohesionless soils is the most sensitive location, whereas low-gradient, divergent topography with highly cohesive soils is least sensitive. Hence, the overall sensitivity of a landscape to changes in processes that influence shallow landsliding will depend upon the specific topography and soils present in the landscape.

Similarly, the juxtaposition of elements within a landscape can strongly influence landscape sensitivity to particular processes. Consider further the example of shallow landsliding discussed above. The net downstream impact of a change in land use that accelerates landsliding, and thereby increases the sediment supply in the headwaters of a drainage basin, can depend upon the nature of the channel system between the input and the site of interest. A channel system with abundant sediment-storage elements distributed along its length may rapidly damp out the effects of a pulsed increase in sediment supply. In contrast, a channel system with little buffering capacity for storage of sediment will rapidly deliver increased sediment loads to downstream environments. Landscape sensitivity must be evaluated in relation to particular processes operating in the context of a particular landscape.

Landscape sensitivity also varies with different types of external forcing on landscape processes. The sensitivity of a landscape may be very different for changes in climate, the nature of the ground surface (e.g. changes in impervious area or in soil properties), or in boundary conditions (resulting, for example, from dam construction or the removal of flow obstructions, such as large logs from streams). Again, the sensitivity of the landscape will vary according to the influence of the change on hydrogeomorphological processes that govern the erosion, transport, and deposition of sediment. Landscapes are perhaps most sensitive to changes in those processes that dominate their morphology and dynamics.

A key aspect of landscape sensitivity is resistance to change, or the ability of a landscape to resist or absorb impulses of change. Landscape resilience can differ over different timescales and for systems that encompass different spatial scales. Gradual change and the accumulated effects of individually small changes in landscape processes can eventually cause a large landscape response. Or a landscape could be very sensitive to minor changes, but the response might also be minor. In contrast, catastrophic changes can result in rapid pulses of dramatic change, even in relatively insensitive landscapes. Moreover, a system could be very sensitive to large changes, but also quite resilient and recover quickly from even catastrophic disturbance. Finally, the scale of the system can influence its sensitivity to change. Small systems, for example, may equilibrate rapidly with changes in hydrogeomorphological forcing, and hence be quite sensitive to anthropogenic change. Conversely, large systems may respond slowly and the landscape response may integrate environmental changes over longer time periods.

Although landscape sensitivity is difficult to quantify because of the huge range of possible processes and intrinsic variability in landscape attributes, the concept is important for understanding natural landscape dynamics and for planning and evaluating land use. Humans have long recognized the disruptive effects of natural disturbance (albeit under the guise of natural disasters), but our cultures have not been very good at recognizing the sensitivity of the landscape to our actions. This has had unfortunate consequences, for failure to gauge landscape sensitivity to forest clearing and agricultural practices contributed to the decline of many once-great civilizations.

In the context of watershed management, landscape sensitivity reflects the intrinsic capability and capacity of a landscape to sustain a given land use. Hence, landscape sensitivity is a function of what is done where on a landscape. Although land use has traditionally been determined primarily on the basis of land ownership and short-term economic interests, the recent formalization of methodologies for conducting watershed analysis provides a framework for holistically examining how a landscape functions as a system and thereby how better to match human actions to the ability of a landscape to endure or sustain particular actions. Landscape sensitivity is not something that can be measured precisely and accurately, but the concept is useful in examining the interaction of humans and their environment.

David R. Montgomery

Bibliography

Carter, V. G. and and Dale, T. (1974) Topsoil and civilization. University of Oklahoma Press, Norman.
Goudie, A. (1986) The human impact on the natural environment. MIT Press, Cambridge, Mass.
Marsh, G. P. (1864) Man and nature; or physical geography as modified by human action. Charles Scribner, New York.
Thomas. D. S. G. and and Allison, R. J. (1993) Landscape sensitivity. John Wiley and Sons, Chichester.
Turner, B. L., II, Clark, W. C., Kates, R. W., Richards, J. F., Mathews, J. T., and Meyer, W. B. (eds) (1990) The Earth as transformed by human action. Cambridge University Press.

Boy Scouts v. Dale, 530 U.S. 640 (2000), argued 26 Apr. 2000, decided 28 June 2000 by vote of 5 to 4; Rehnquist for the Court, Stevens and Souter in dissent.

In 1990, Boy Scouts of America (BSA) revoked the membership of Assistant Scoutmaster and Eagle Scout James Dale, charging that Dale failed to meet BSA's standards, which “forbid membership to homosexuals.” Dale, assisted by Lambda Legal, filed suit in the New Jersey courts.

In Roberts v. United States Jaycees (1984) and Rotary International v. Rotary Club of Duarte (1987), the Supreme Court has recognized a “right to associate for the purpose of engaging in those activities protected by the First Amendment … as an indispensable means of preserving other individual liberties” (Roberts, p. 618). This freedom of expressive association implied the right to be able to control political, religious, or cultural messages attributed to a group.

In this manner, freedom of association may come into tension with the goal of nondiscrimination. Freedom of expressive association case law attempts to balance these competing claims—the right of a group to control its message versus the right of individual or potential group members to be treated without prejudice. The Court's precedents hold that compelling state interests, unrelated to the suppression of ideas, may justify some infringement upon freedom of association, provided the state does so by the least restrictive means.

In Dale, the Court held, 5 to 4, that the forced inclusion of homosexuals as BSA members would significantly alter Boy Scouts' message, impairing its First Amendment right of “protected association.” The majority accepted BSA's assertion that it is a private association that “teaches that homosexual conduct is not morally straight.” Relying on Hurley v. Irish‐American GLB Group (1995), BSA could not to be compelled to send a message it did not want to send. The Court also noted that expansive definitions of the term “public accommodation” in state statutes increasingly threaten First Amendment values.

Justice John Paul Stevens asserted in dissent that Dale's mere membership could not be construed as BSA's own speech, unless one concludes that “homosexuals are simply so different from the rest of society that their presence alone … should be singled out for special First Amendment treatment” (p. 696).

Boy Scouts is also about the progress and status of the gay civil rights movement. The Court had held in Bowers v. Hardwick (1986) that the right of privacy should not be extended to acts of adult consensual homosexual sodomy performed at home, a position it overturned in Lawrence v. Texas (2003). The Court in Lawrence appeared to be responding to, or sharing, the public's growing sentiments of limited tolerance.

Bibliography

Erin Ackerman and and Joel B. Grossman , Competing Constitutional Claims: Boy Scouts of America v. James Dale, in Creating Constitutional Change: Clashes over Power and Liberty in the Supreme Court, edited by Gregg D. Ivers and Kevin T. McGuire (2004).
David McGowan , Making Sense of Dale, Constitutional Commentary 18 (Spring 2001): 121–175.

Erin Ackerman

David Dale 1739–1806, Scottish cotton manufacturer and philanthropist. In 1785 he built New Lanark, a cotton mill and model community that provided his employees with good housing and schools. He was succeeded at New Lanark by his son-in-law, Robert Owen , who later made the community world famous. Dale withdrew in 1770 from the Church of Scotland, founding the Old Independents, or Dalites, whom he served as minister.