BOTANY TECHNICAL SPECIALIST’S REPORT BURNED AREA EMERGENCY REHABILITATION for STATION FIRE Resource: Botany Fire Name: Station Fire – National Forest System Lands Month/Year: 09/2009 Author Name: Janet Nickerman, Joanna Clines, Jan Beyers with assistance from Kerry Myers, Tommy Stoughton and Krissy Day. Author Duty Station: Angeles, Sierra National Forest, PSW Research Station and the San Bernardino National Forest. Thickleaf yerba santa resprouting after a fire. (photo by Stoughton) I. SUMMARY The Station Fire started on August 26, 2009 and burned 161,188 acres. It is the largest fire in the recorded history of Los Angeles County. Until now, the largest fire was 75,000 acres. There are approximately 37 cities that surround the fire perimeter. The fire area is extremely steep, inaccessible and it supports some important and unique habitats. There is occupied and potential habitat for one federal endangered plant species and eleven Forest Service Sensitive plant species. Thirty seven plant communities were burned or impacted by suppression activities. Some of these habitats and species are at risk to further losses. For example, disturbances/degradation from post­fire impacts of sediment and ash delivery will result in loss of water quality, scouring of riparian systems and loss of wildlife habitat at natural springs and spring developments due to sediment delivery and erosion. In addition, vegetation community Page 1 of 24 recovery is at risk for delayed recovery due to invasive species and illegal Off Highway Vehicle (OHV) activity. Summary of Initial Concerns o Invasive species spread (see Specialist Report for Noxious Weeds and Non­native invasive plant species). o Illegal Off Highway Vehicle traffic ie, Impacts to habitat/vegetation as a result of loss of barriers and off­road vehicle incursions o Disturbance associated with increased need for road maintenance to prepare for winter storms o Increased dispersed recreation use due to loss of native vegetative barriers Vegetation Recovery: • All plant communities are subject to delayed recovery due to illegal OHV activity and invasive species infestations • Desert scrub and high intensity burns in coniferous plant communities are the most vulnerable to delayed recovery. Federal Endangered and Forest Sensitive Plant Species Habitat and Occurrences Federal Endangered Species: • Lower Big Tujunga Canyon (slender horned spineflower) Forest Service Sensitive Plant Species: • Mill Creek ­ (San Gabriel manzanita) • Pacifico Campground (Short joint beavertail) • On Big Tujunga Canyon Road (California satintail) • Mt Gleason Area (Mt Gleason paintbrush and Palmer’s mariposa lily) • On Santa Clara Divide Road (San Gabriel Mountain Sunflower) • Upper Chilao/Horseflat Campground (San Gabriel Mountain Sunflower, Chickweed Starry Puncturebract, Southern skullcap, Transverse Range phacelia, San Gabriel Linanthus, Alkali Mariposa Lily and Palmer’s mariposa lily) • Westfork of the San Gabriel River (Falls Canyon Research Natural Area) II. RESOURCE CONDITION ASSESSMENT/ VALUES AT RISK A. Fire Summary The Station Fire burned over 161,188 acres of the Angeles National Forest. The fire burned through chaparral and other fire­adapted plant communities that are generally expected to recover naturally, provided that invasive plants are not able to establish at the expense of the native plants and provided that illegal OHV recreation is prevented. About 11% of the area burned at a high severity, 62% at moderate severity, and 16% burned at low severity. About 11% of the area within the burn area consists of unburned islands or patches. Dominant vegetation types in the burned area consist primarily of chaparral communities, including lower montane mixed chaparral, ceanothus chaparral, scrub oak chaparral, chamise chaparral, upper montane mixed chaparral, desert transition chaparral, and soft scrub mixed Page 2 of 24 chaparral. The vegetation in the lower elevation portions of the fire is dense, tall (15­20’ tall) ceanothus, chamise, scrub oak, and manzanita shrubs with live oaks. Some canyons support bigcone Douglas fir trees, canyon live oak, interior mixed hardwood, and coast live oak vegetation. Upper elevations support ponderosa/Jeffrey pine, and mixed conifer vegetation. Planted ornamental conifers are scattered throughout. Stream corridors contain riparian mixed hardwood, white alder, willow, mule fat, cottonwood, and California sycamore vegetation types. Some portions of the fire area have not experienced any significant large fire activity in the past forty years. By acreage, montane mixed chaparral, ceanothus mixed chaparral, and scrub oak chaparral were most abundant (Table 1). Table 1. Station fire burned vegetation types. Vegetation Type Acres Vegetation Type Acres Bigcone Douglas­Fir 14,324.0 Buckwheat 906.1 Birchleaf Mountain Mixed Conifer 2,099.3 Mahogany 3,021.4 Ceanothus Mixed Ponderosa/Jeffrey Pine 3,956.1 Chaparral 17,310.3 Singleleaf Pinyon Pine 301.7 Chamise 2,620.7 Non­Native/Ornamental Conifer 89.7 Montane Mixed Chaparral 67,338.1 Ornamental Hardwood/Conifer 27.0 Manzanita Chaparral 1,666.6 Black Oak 10.8 Rabbitbrush 67.5 California Bay 164.6 Scrub Oak 14,344.0 Soft Scrub Mixed Canyon Live Oak 11,779.8 Chaparral 3,971.9 Coast Live Oak 808.7 Sumac Shrub 1,782.1 Coastal Mixed Hardwood 320.2 Tucker / Muller Scrub Oak 97.3 Interior Mixed Hardwood 1,516.2 Basin Sagebrush 373.9 Montane Mixed Hardwood 109.0 California Juniper (shrub) 104.8 Baccharis (Riparian) 30.1 Desert Mixed Shrub 46.7 Great Basin Chaparral California Sycamore 122.7 Transition 4,028.4 Fremont Cottonwood 117.3 Semi­Desert Chaparral 1,020.1 Riparian Mixed Hardwood 576.9 Annual grasses and forbs 291.2 White Alder 295.0 Willow (Shrub) 216.3 Barren 664.75 Riversidean Alluvial Scrub 69.6 Urban 995.42 California Sagebrush 690.6 Water 148.47 A. Values at Risk – Plant Communities: The majority of the vegetation within the fire area consists of various types of chaparral and other shrubland communities within their normal burn rotation interval. Large portions of these areas had not burned for 30+ years. All plant communities are subject to delayed recovery due to Page 3 of 24 illegal OHV activity and invasive species infestations. Desert scrub and moderate to high intensity burns in coniferous plant communities are the most vulnerable to delayed recovery. Desert communities typically get less rainfall which delays recovery and high intensity burns in coniferous forest have a high mortality rate and fewer trees are likely to recover. Additionally, fewer conifer seeds will survive in the seed bank. Illegal OHV activity is a threat to national forest land. Erosion, user conflicts, spread of invasive species, damage to cultural sites, disturbance to wildlife, destruction of wildlife habitat, and risks to public safety can result from unauthorized OHV use. For example, if dirt bikes drive cross country (not following existing trails), they will run over plants, small mammals and reptiles, compact the soil of recovering areas and encourage other riders for follow newly formed illegal trails. In these newly impacted areas, native vegetation either won’t grow or will be stunted. Highly disturbed areas favor the establishment of invasive species and limit native vegetation recovery. The Angeles National Forest (ANF) covers 70% of the open space in Los Angeles County with a population of over 11 million. This large population base results in very high legal and illegal use of Off Highway Vehicle (OHV) areas on the forest. OHV riders on the ANF may be similar to riders in other parts of the county but the difference is the large number of people who live and recreate in LA County. The challenge for the ANF is managing the high number of non­conforming riders, OHV users that illegally gain access onto the forest from driving around a locked gate or closed signs. This type of user causes conflict with non­motorized users and damage to natural and cultural resources. Due to increasing population and developments that border the forest, it is becoming increasing difficult to patrol illegal OHV. After the Marek Fire, the ANF posted 200 carsonite signs and 15 wooden trails during winter and spring 2009. All signs were all removed from 1 to 24 hours after installation. In addition, fences, rock barriers and vegetative screening were installed to control illegal OHV. All measures were ineffective and uncontrolled OHV continues in many areas. The only successful measure was gate closure in areas with steep side walls immediately adjacent to the gates. In this case, riding around the gate was not possible. Several invasive species that are known to impact California native plant communities are present (cheatgrass, soft chess, wild oats, black mustard, rip gut brome). All these species are easily transported by vehicles. The spread of noxious weeds and other non­native invasive plant species is a threat to native plant communities in and adjacent to the Station Fire area. The spread of Spanish broom, arundo, tree of heaven and non­native annual grasses are of the greatest concern as 1) there are large infestations of these species present, 2) they have the potential to expand quickly, 3) are hard to control, 4) they have the ability to quickly overcome and degrade native habitats, 5) fire and ground disturbing activities are known to promote the establishment of these species (Fire Effects Information System 2003, Bossard et. al 2002). Tamarisk, yellow star thistle and spotted knapweed are noxious weeds not presently known within the burned area but have the potential Page 4 of 24 to invade after fire. These invasive species are of concern because they degrade all habitats and native species. Arundo resprouting three weeks after burning (photo Nickerman) B. Values At Risk – Plants Federal Endangered: Slender horned spineflower (Dodecahema leptoceras) Slender horned spineflower is a federal listed endangered species. Slender­ horned spineflower is a small, spreading annual in the buckwheat family (Polygonaceae), with stems reaching 3­15 cm across. This annual has a basal rosette of leaves, from which rise dense flowering stalks.