Reading Project Noxious Weed Risk Assessment Hat Creek Ranger District Lassen National Forest April 3, 2013

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1 Reading Project Noxious Weed Risk Assessment Hat Creek Ranger District Lassen National Forest April 3, 2013 Prepared By: /s/ Tim Kellison Date: Tim Kellison Assistant Forest Botanist Reviewed By: /s/ Allison L. Sanger Date: Allison L. Sanger Forest Botanist Introduction When a ground-disturbing action or activity is proposed, a Noxious Weed Risk Assessment (NWRA) determines the risk of introducing or spreading noxious weeds associated with the proposed action. This Risk Assessment is a guide for evaluating risks and explains the components, variations and risks (high, moderate, and low), which make up this risk assessment. Non-Proposed Action Dependent Factors 1) Inventory: The Reading Project is located within the Summit (MA #10) and Lost Creek (MA #17) Management Areas in the Lassen National Forest Land and Resources Management Plan (LRMP 1992) and encompasses approximately 11,071 acres. The Reading Project treatment area is approximately 4,278 acres of the total project area. The area has been surveyed in the past for various projects (Table 1) noxious weed surveys were done in conjunction with rare plant surveys for these projects. Table 1: Past Surveys Conducted in the Reading Project Area Project Survey Year Badger Project 2009, 2011 & 2012 Badger Insect Salvage 1993 Bunchgrass Salvage 1994 Lost Creek M.A North Face Salvage 1994 PCT Relocation 1989 South Bunch 1998, 2002, 2003 & 2005 Westside Salvage

2 2) Known Noxious Weeds: The California Department of Food and Agriculture s noxious weed list ( divides noxious weeds into categories A, B, and C. A-listed weeds are those for which eradication or containment is required at the state or county level. For B-listed weeds, eradication or containment is at the discretion of the County Agricultural Commissioner. C-listed weeds require eradication or containment only when found in a nursery or at the discretion of the County Agricultural Commissioner. One C-listed species, Bull thistle (Cirsium vulgare), has been observed at disturbed sites within the project area. No other noxious weed species are known from the project area; however, there is one Klamathweed (Hypericum perforatum) occurrence just outside the project boundary and along the main haul route for project activities occurring in the vicinity of West Prospect Peak. In addition, several noxious weeds are known to occur along highway 44, approximately two and a half air-miles north of the project area. Bull thistle (Cirsium vulgare): Scattered across the project area, in small numbers, at disturbed sites such as old landings and skid trails. None of these observations have been officially mapped or documented. 3) Habitat Vulnerability: The Reading Project is situated along the northern border of Lassen Volcanic National Park (LVNP) and extends north across Badger Mountain and West Prospect Peak on the Hat Creek Ranger District of the Lassen National Forest (LNF). The geomorphology within the project area is dominated by Badger Mountain and West Prospect Peak, both with moderately steep slopes and some areas with gentle slopes along the lower portions of these mountains. There are two canyons with steep walls and moderate vegetative cover, one of which has extensive lava fields throughout. Elevations range from 5,300 feet in the northern portion of the projcet area to over 8,100 feet at West Prospect Peak, near the eastern edge of the project boundary. The vegetation is mostly composed of very dense mixed conifer forest with some areas dominated by yellow pine forest. Several plantations are located within the project area as well. Much of the habitat within these plantations has been substantially altered by the construction of windrows and the undesirable proliferation of shrubs such as manzanita. Riparian habitat occurs along Hat Creek and to a lesser extent within Rail Canyon. Extensive shrub fields and sparsely vegetated lava fields occur along the southwestern flank of Badger Mountain. The most common conifers include white fir, Jeffrey and ponderosa pine, with a smaller component of sugar pine, Douglas fir, incense cedar and red fir. In some areas dense thickets of lodgepole pine can be found. The understory vegetation components include greenleaf manzanita, bush chinquapin, whitethorn, gooseberry, snowberry, herbs, grasses and sedges. Of the 11,071 acres of LNF lands that were affected by the Reading Fire, approximately 7,900 acres burned under moderate to high intensity. The disturbed soils, removal of surface vegetation and duff, and reduction in overstory cover in these areas renders this habitat vulnerable to noxious weed establishment and proliferation. The project area has also experienced ground disturbance over time from routine road construction and maintenance activities, logging operations, plantation creation, prescribed fire and 2

3 previous wildland fires. Overall, due to the considerable reduction in canopy cover, understory vegetation and duff, as well as past disturbance in the project area, there is a high risk for weed invasion from current habitat vulnerability. 4) Non-Project-Dependent Vectors: Vehicle traffic and road maintenance equipment are the most important non-project-dependent vectors of noxious weeds in the project area. There are several Forest Service (FS) roads in and around the project area, including FS road 32N12 which connects Highway 44 to the West Prospect Peak Fire Lookout. There are many known weed sites along the highway which may be carried into the burned area. In addition, there is extensive recreational Off Highway Vehicle (OHV) use near the project area, especially around Potato Butte. These OHV users have been observed on roads within the project area and evidence of disturbance from these types of vehicles has been reported off road, even on the Pacific Crest Trail (PCT), a designated hiking trail. Vehicles may translocate weed seeds and propagules in mud that affixes to tires, and thus function as vectors for noxious weed spread. Routine road maintenance activities may also contribute to weed spread as heavy equipment brings in off-forest weed seeds and/or propagules. Wildlife can serve as non-project vectors, posing a small additional risk for the spread of noxious weeds. Presently, no livestock grazing is taking place within the project area. Overall, there is currently a moderate vulnerability from non-project dependant vectors, mainly due to the proximity of Highway 44, the vehicle traffic on FS roads and the recreational use of OHVs in and around the project area. Proposed Action-Dependent Factors 5) Habitat Alteration Expected as a Result of Project: The Reading Project would remove fire-affected trees on approximately 2,508 acres of natural stands and 1,053 acres plantations. Surface fuel loads created during harvest would be treated using either mechanical piling or hand piling; most of these piles would be burned. Danger tree removal would occur on approximately 542 acres along forest system roads and native conifers would be planted on approximately 4,273 acres to expedite reforestation within the burned area. Site preparation for reforestation would be completed through harvest and surface fuel treatments. No soil preparation, such as soil ripping, would be conducted outside of windrowed plantations. In addition, snag research plots would be established on approximately 75 acres and would include a range of treatments designed to create snag retention levels from zero to 100 percent of the existing basal area. Up to two miles of temporary roads would be constructed to facilitate project activities; these roads would be decommissioned after use. These project activities are expected to slightly increase current habitat vulnerability, given that much of the tree canopy was already lost in the Reading Fire. The proposed action would alter the existing habitat by removing standing dead trees that provide some remaining shade, and by disturbing the soil further through temporary road construction and mechanical timber harvest activities. Site preparation for reforestation would create patches of disturbed soils as biomass is harvested in preparation for replanting with native conifers. 3

4 Overall, the potential risk of noxious weed invasion from project-related habitat alteration appears to be moderate, due to shade reduction and soil disturbance which would augment the level of habitat alteration that has already occurred from the Reading Fire. 6) Increased Vectors as a Result of Project Implementation: The Reading Project has the potential to increase the risk of noxious weed invasion by creating new vectors for weed spread or increasing the probability that existing vectors would bring weeds into the project area. System roads within the project area would receive increased traffic from project-related activities and the use of mechanical ground-based equipment may serve as vectors for weed spread as weed seeds or propagules affix to mud on vehicle tires and equipment. Though there are few known noxious weed occurrences located along roads within the project area, several weeds are known to occur along Highway 44 and FS roads that may be used to access the project area that are at risk of spreading further. Approximately 0.25 miles of existing unauthorized routes would be upgraded to forest transportation standards and added as National Forest System roads. The addition of these roads to the forest transportation system would provide new avenues for noxious weed invasion into the project area. In addition, two miles of temporary roads would be constructed for project implementation; however, these roads would be decommissioned after use, reducing the risk for the establishment of noxious weeds within the project area. Overall, the movement of mechanical equipment through the project area during salvage harvest and reforestation activities combined with the addition of unauthorized routes to the forest road system poses a moderate potential risk of transporting weed seeds and propagules. 7) Integrated Design Features: The following Design Integrated Features (IDFs) implemented as part of the proposed action would greatly reduce the risk factors described in this document. a. All off-road equipment would be weed-free prior to entering the Forest. Staging of equipment would be done in weed free areas. b. New small infestations identified during project implementation would be evaluated and treated according to the species present and project constraints and avoided by project activities. If larger infestations were identified after implementation, they would be isolated and avoided by equipment, or equipment used would be washed after leaving the infested area and before entering an uninfested area. c. Post project monitoring for implementation and effectiveness of weed treatments and control of new infestations would be conducted as soon as possible, and for a period of multiple years after completion of the project. d. If project implementation calls for mulches or fill, they would be certified weed-free. e. Any seed mixes used for revegetation of disturbed sites will consist of locally adapted native plant materials to the extent practicable. 4

5 8) Anticipated Weed Response to Proposed Action: Currently there is one low priority noxious weed within the Reading Project area. Existing conditions within the project area are largely defined by the effects of wildfire, which removed canopy cover, understory vegetation and duff, resulting in a high risk for noxious weed invasion related to habitat vulnerability. There is a moderate risk due to non-project vectors, project level habitat alteration and increased vectors as a result of project implementation. Integrated Design Features such as equipment cleaning, treatment of new infestations and post-project monitoring would ensure that weed spread within the project area is minimized. Overall, with incorporation of Integrated Design Features as part of the Proposed Action, there is a low to moderate potential for weed spread with the implementation of the Reading Project (Table 2). Table 2: Summary of the Reading Project Risk Assessment Non-proposed action-dependent factors Inventory Known noxious weeds Habitat vulnerability Non-project-dependent vectors Adequate Currently one C-listed species present (bull thistle). Prevention high priority; control low priority. High current vulnerability Moderate current vulnerability Proposed action-dependent factors Habitat alteration expected as a result of project Increased vectors as a result of project implementation Integrated Design Features Anticipated Weed Response to the Proposed Action Moderate risk Moderate risk Reduced risk Low to moderate potential for weed spread 9) Costs: Noxious weeds can greatly reduce the value of public lands through negative impacts to timber production, grazing, wildlife habitat and recreational opportunities. Furthermore, noxious weed control is expensive and time-consuming. Prevention and control of small infestations can minimize these impacts and reduce long-term expenditures. Noxious weed surveys, control of small infestations and post-project monitoring are all vital to reducing overall impacts and costs from noxious weeds. 5