Lightscape Management.pdf

57 4.10 Lightscape Management

The Service will preserve, to the greatest extent possible, the natural lightscapes of parks, which are natural resources and values that exist in the absence of human-caused light.

The absence of light in areas such as caves and at the bottom of deep bodies of water influences biological processes and the evolution of species, such as the blind cave fi sh. The phosphorescence of waves on dark nights helps hatchling sea turtles orient to the ocean. The stars, planets, and earth’s moon that are visible during clear nights infl uence humans and many other species of animals, such as birds that navigate by the stars or prey animals that reduce their activities during moonlit nights.

Improper outdoor lighting can impede the view and visitor enjoyment of a natural dark night sky. Recognizing the roles that light and dark periods and darkness play in natural resource processes and the evolution of species, the Service will protect natural darkness and other components of the natural lightscape in parks. To prevent the loss of dark conditions and of natural night skies, the Service will minimize light that emanates from park facilities, and also seek the cooperation of park visitors, neighbors, and local government agencies to prevent or minimize the intrusion of artificial light into the night scene of the ecosystems of parks. The Service will not use artificial lighting in areas such as sea turtle nesting locations where the presence of the artificial lighting will disrupt a park’s dark-dependent natural resource components.

The Service will

+ restrict the use of artificial lighting in parks to those areas where security, basic human safety, and specifi c cultural resource requirements must be met;

+ use minimal-impact lighting techniques;

+ shield the use of artificial lighting where necessary to prevent the disruption of the night sky, natural cave processes, physiological processes of living organisms, and similar natural processes.

The decision about whether or not to install artifi cial lighting in particular circumstances is left to the discretion of the superintendent and is made through the planning process.

(See Cooperative Conservation Beyond Park Boundaries

1.6; Visitor Safety and Emergency Response 8.2.5, Facility

Planning and Design 9.1.1; Integration of Facilities into the

Park Environment 9.1.1.2; Energy Management 9.1.7)

4.11 Chemical Information and Odors

Natural chemicals and odors transmit information that is received by living organisms. Natural chemicals involved in the transmission of information are released by animals, plants, and geologic materials. Once released, these chemicals can be transmitted through air and water. Many animals can perceive these natural chemicals and modify their behaviors, such as mating, migration, feeding, predator avoidance, prey selection, and the establishment of social structures, as a response. Specific examples of relationships that involve natural chemical information and odors include, among others, + scent posts where one animal deposits one or more chemicals by rubbing, urination, defecation, or other means, and where other animals can detect the passage of the first animal because of the odor produced by a deposited chemical;

+ fl owers that produce odors that attract insects, birds, and other animals, with resulting cross-pollination of the fl owers and reproduction of the species as the outcome;

+ female insects that release chemicals (pheromones) that attract males, with fertilization of the female’s eggs and reproduction of the species as the outcome;

+ stressed trees that emit chemicals that some types of beetles use to find weakened trees, which they then successfully can colonize and use as habitat for reproducing themselves; and

+ geologic materials (soils or bedrock) that emit characteristic chemicals that fish can sense and use as guides to find the places in streams where they hatched and where they subsequently return to breed and deposit fertilized eggs, with reproduction of the species as the outcome.

The Service will preserve, to the greatest extent possible, the natural flow of natural chemical information and odors by preventing (1) the release of human-generated chemicals that can block the release, deposition, or perception of natural chemicals; and (2) human actions that disrupt or commingle the pathways through which natural chemicals are dispersed.

The Service acknowledges that some of its management activities may necessarily alter the natural flow of natural chemical information and odors. The Service may, for example, + introduce pesticides or pheromones into parks as part of an integrated pest management program;

+ construct and operate intensive development areas that eliminate animal scent stations and introduce unnatural chemicals;

+ change the vegetation and thereby change the kinds of natural plant chemicals released to the air;

+ move water from one drainage to another through water and sewer systems; or

+ provide for the use of exhaust-emitting motors in the air, on land, and on water.

Whenever the Service engages in activities that disrupt the natural flow of natural chemical information or odors, it will comply with all applicable laws, regulations, and policies and seek to minimize harm to the environment. In no case will the Service engage in an activity if it will impair park resources or values.

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