Composite Training Unit Exercises and Joint Task ... - Govsupport.us

COMPTUEX/JTFEX EA/OEA Final Chapter 3Coastal salt marsh—0.1%Both the flora and fauna of the island have been radically altered by human activities. Although the lastremaining non-native feral ungulates (goats [Capra hircus], sheep [Ovis aries], pigs [Sus scrofa], muledeer [Odocoileus hemionus], and cattle [Bos taurus]) introduced at various times to the island in the late1800s and early 1900s, were removed from the island in 1993. Their presence has significantly impactedthe native vegetation and topsoil (U.S. Navy, 2005). These impacts have also affected the remainingwildlife species present on the island. There are 272 species of native plants, 245 bird species, sixmammal species, and two reptile species known to occur on the island. In addition, there are 124 plantspecies, three bird species, and eight mammal species that have been introduced to the island (U.S. Navy,2006).There are no perennial streams on SCI. Intermittent streams are present during the rainy season as watermoves through the numerous steep canyons before reaching the ocean. The rainy season is generallyfrom November to April, with the annual precipitation averaging approximately 7 in (18 cm). Persistentsurface water falls into two categories: naturally held water in canyons and artificially held water inconstructed impoundments. Natural water is held through the dry period of the year in bedrock plungepools located in the deeper portions of the island’s major canyons.Other than salt marsh, aquatic and wetland habitats on SCI are very limited. They include man-madeimpoundments with associated marsh vegetation and natural aquatic and wetland habitats associated withintermittent streams, especially on the east side of the island where perennial seeps may exist (U.S. Navy,2000).SCI supports 11 Federally-listed endangered or threatened plant and wildlife species, most of which arealso State-listed:Birdso California brown pelican (Pelecanus occidentalis californicus)—endangeredo San Clemente loggerhead shrike (Lanius ludovicianus mearnsi)—endangeredo San Clemente sage sparrow (Amphispiza belli clementeae)—threatenedo Western snowy plover (Charadrius alexandrinus nivosus)—threatenedReptileso Island night lizard (Xantusia riversiana)—threatenedPlantso San Clemente Island broom (Lotus dendroideus var. traskiae)—endangeredo San Clemente Island bush-mallow (Malacothamnus clementinus)—endangeredo San Clemente Island Indian paintbrush (Castilleja grisea)—endangeredo San Clemente Island larkspur (Delphinium variegatum ssp. kinkiense)—endangeredo San Clemente Island woodland star (Lithophragma maximum)—endangeredo Santa Cruz Island rock cress (Sibara filifolia)—endangeredOther State-listed island species include the San Clemente Island fox (Urocyon littoralis), Xantus’smurrelet (Synthliboramphus hypoleucus), Santa Catalina bedstraw (Genus Galium), and San ClementeIsland silver hosakia (Lotus argophyllus var. adsurgens). Many of the island’s sensitive species are onlyknown to occur on SCI or the other Channel Islands (U.S. Navy, 2006).February 2007 3-66