ANIMALS

with little change occurring over time. Spring and seep communities are characterized by cattails, sedges, seeds, rushes, and cresses.

2.7.5 Rare, Threatened, and Endangered Plants

As provided by the Endangered Species Act of 1973, the U.S. Fish and Wildlife Service published in the Federal Register (40 FR 127:27828-27924, 1975; 41 FR 117: 24524-24572, 1976) lists of more than 1,700 species of vascular plants proposed for endangered or threatened status.

Endangered plants are those species that are in danger of extinction throughout all or a significant portion of their range. Threatened plant species are those that presently are not endangered but are likely to become so within the forseeable future throughout all all or a significant portion of their range. Botanical surveys for endangered, threatened, and rare plants were conducted on the Medford District in 1978. As a result of this survey, six proposed endangered or threatened plants are listed as having been observed on BLM lands within the JKS YUS. These plants species are shown on Table 2-4.

A State Provisional List of Rare, Threatened, and Endangered Plants in Oregon has been complied by members of the Oregon Rare and Endangered Plant Species Task Force. This list contains all the species which have been proposed for endangered or threatened status plus many additional species on which the Task Force is gathering information to help determine the present status of these species.

Some 20 species of plants included on the State Provisional List have been observed on BLM land in the JKS YUs and are listed in Table 2-5.

2.8 ANIMALS

2.8.1 Terrestrial Vertebrates

Animal distribution, diversity, and abundance is dependent on various factors; of primary importance is vegetation. Each vegetational zone described in Section 2.7 contains a variety of plant communities which may be in different successional or seral stages. It is these differences in communities and the variety of animals found in the

successional stages that account for planning area.

It should not be inferred that each animal species is found only in one particular successional stage of a given community or zone, as community structure and physical environmental features may be similar enough between

to allow considerable species overlap, especially in animal populations with wide habitat tolerances. However, in some cases a very close relationship to a particular stage or zone does exist.

Proposed Endangered or Threatened Plant Species Observed in the JKSYUS

A Botanical Field Inventory, BLM Medford, District, 1978.

Source: A Botanical Field Inventory, BLM - Medford District, 1978.

ANIMALS

Successional stages are dynamic. They are always progressing toward their climax form and, during this progression, their faunal components are also changing. A climax white fir forest, for instance, supports a very different animal association than it did in its early successional stage several hundred years before. Progress toward climax can be curtailed at any point by outside influences either natural or artificial. For instance, fire or logging may set back succession, and those animal species associated with the stage will be replaced with those adapted to exist in the early successional stages.

Modifying or removing one particular stage, e.g. old growth, has a profound effect on those individuals and species occurring there. It is recognized that these effects do not stop with just those species, as the ecosystem as a whole is altered by the modification of one of its parts. Certain results may be harmful to some species and beneficial to others, but all are affected. There are 40 species of amphibians and reptiles, 217 species of birds, and 81 species of mammals that occur or probably occur in the planning area. A complete list is available on request from the Oregon State Office.

A list of terrestrial vertebrates that seemed most that seemed most likely to be affected either positively or negatively by the proposed action was developed. The list was limited to those species normally associated with the forest types that would be harvested. One result of this limitation was the exclusion of those species found in the planning area but not in the forest type that would be harvested; for instance, agricultural or chaparral lands. The list was prepared from many published sources (Browning 1975; Burt and Grossenheider 1964; Gabrielson and Jewett 1940; Ingles 1965; Maser et al. (in press); Meslow 1977; Peterson 1961; Robbins et al. 1966) as well as from BLM documents. To further reduce the number of species to those which were judged significant, seven criteria were established. These criteria of significance are:

Threatened, or endangered, or of special status.

Dependence on mature or old-growth timber for part of their life cycle.
Dependence on early seral stages for part of their life cycle.
Limited geographical range.

Recreation or commercial importance.

Limited adaptability.

Important prey species of the spotted owl.

Selections of species of limited adaptability were based on the work of Thomas et al. (1977), who established a vulnerability index based on the number of successional stages and plant communities used for feeding and reproduction. The fewer stages and communities used, the lower the index number. Those species with a low index number have narrower habitat requirements than those species with a higher number and are more vulnerable to habitat modification.

All known terrestrial vertebrate species inhabiting commercial timber lands were tested against the seven criteria. Those meeting one or more of these criteria appear in Table 2-6. The use of seral stages was adapted from Thomas