Archive | November, 2015

National Greater Sage-Grouse Planning Strategy: Livestock Grazing and Invasive Species

The National Greater Sage-Grouse Planning Strategy is a commendable effort to improve management of more than 60 million acres of the Sagebrush Sea, a little known landscape that is vitally important to fish and wildlife, recreation, western communities and sustainable economic development. The federal government released Records of Decision for 14 of 15 final sage-grouse plans prepared under the Planning Strategy in September 2015. While no conservation strategy is perfect, given the level of management discretion and deference in the final plans, interpretation and implementation of the plans will be particularly important to their success or failure to conserve and recover sage-grouse and their habitat.

Defenders of Wildlife closely monitored development of key sage-grouse conservation measures throughout the planning process. A number of issues remain unresolved in the Records of Decision (ROD) and approved resource management plan amendments (ARMPA). In this series of blog posts, Defenders will respectfully offer recommendations to address certain deficiencies in the final plans to improve conservation of sage-grouse and hundreds of other species that depend on sagebrush steppe. Although the Bureau of Land Management (BLM) and the U.S. Forest Service were both involved in the Planning Strategy, our analyses and recommendations will focus on the BLM, which manages the majority of sage-grouse habitat on federal lands.

MANAGEMENT ISSUE: the BLM’s Records of Decision and approved resource management plan amendments fail to provide direction for managing livestock grazing to avoid contributing to the spread of invasive annual grasses (primarily cheatgrass) in sage-grouse habitat.

RECOMMENDATIONS

   1. Manage livestock grazing to help restore, maintain and improve habitat resiliency against cheatgrass incursion in sage-grouse habitat.

    2. Use livestock to control cheatgrass only in limited circumstances.

   3. Adopt a universal desired habitat condition of less than 5 percent cheatgrass cover within 4 miles of all occupied or pending sage grouse leks.

 

Cheatgrass dominating sagebrush steppe in Idaho.

THREAT: Annual grasses, especially cheatgrass (Bromus tectorum), are a significant threat to sage-grouse and their habitat (US FWS 2010; Miller et al. 2011; Connelly et al. 2011). The BLM has expressed concern about the spread of cheatgrass on sagebrush steppe for nearly two decades (e.g., Pellant 1996). Cheatgrass is now the dominant species on 100 million acres (158,000 square miles) in the Intermountain West (Rosentreter 1994: 170, citing Mack 1981) and is a primary driver of huge, unnatural fires in sagebrush steppe (Miller et al. 2011). The conversion of sagebrush habitat to exotic annual grasslands is by one account “massive” (Allen 2003). Scientists have reported a strong correlation between livestock grazing and cheatgrass incursion (Reisner et al. 2013; Reisner et al. 2015).

EFFECT:  Reisner et al. (2013) found that, even after controlling for other factors that may contribute to the spread of cheatgrass, there is a strong correlation between grazing effects and cheatgrass incursion. Cattle grazing increases cheatgrass dominance in sagebrush steppe by decreasing bunchgrass abundance, altering and limiting bunchgrass composition, increasing gaps between perennial plants, and trampling biological soil crusts (Reisner et al. 2013; Knick et al. 2003).

A massive burn in Idaho driven by the occurrence cheatgrass in sagebrush steppe.

A massive burn in Idaho driven by the occurrence cheatgrass in sagebrush steppe.

Livestock grazing is also ineffective for controlling cheatgrass, even at the highest grazing intensities (Reisner et al 2013; Hempy-Mayer and Pyke 2008). As the BLM stated in the draft Idaho/southwestern Montana sage-grouse plan (draft Idaho/SW Montana: 3-64 – 3-65), “[i]ntensive livestock grazing is often suggested for controlling cheatgrass competition. Although targeted grazing may have some applications for fuels management, it is not effective in reducing cheatgrass competition…. During the short time when cheatgrass is highly palatable in the spring, a sufficient number of livestock cannot be concentrated on a small enough area to reduce the cheatgrass seed significantly or reduce cheatgrass seed lying on the soil surface. In addition, this type of grazing can be detrimental to remaining perennial grasses, opening the site up for further cheatgrass expansion in the future.”

DRAFT RESOURCE MANAGEMENT PLANS/SUB-REGIONAL ENVIRONMENTAL IMPACT STATEMENTS: All of the draft plans recognized that invasive plants, including cheatgrass, are an important management issue in sagebrush steppe. Most of them specifically identified cheatgrass as a threat to wildlife, including sage-grouse and other sagebrush-dependent species such as pronghorn (draft Bighorn Basin: 3-96) and sage thrasher (draft Bighorn Basin 3-109). Many of the draft plans also acknowledged that livestock grazing and “excessive grazing” can spread invasive plants (e.g., draft Buffalo: 306; draft Bighorn Basin: 4-146; draft Billings-Pompey’s Pillar: 3-88; draft Miles City: 3-77; draft South Dakota: 361; draft Oregon: 4-89). The draft Nevada/northeastern California plan observed that “[l]ivestock grazing is one of the vectors to introduce and or increase the spread of invasive weeds” and that “[m]ultiple factors can influence an area’s susceptibility to cheatgrass invasion, including livestock grazing, perennial grass cover and biological soil crusts”(draft Nevada: ch. 4, 54, citing Reisner et al. 2013).

MANAGEMENT DIRECTION: The Secretary of the Interior issued Order 3336, “Rangeland Fire Prevention, Management and Restoration,” which included direction to “reduce the likelihood, size, and severity of rangeland fires by addressing the spread of cheatgrass and other invasive, non-native species” (SO 3336: 2).

MANAGEMENT PRESCRIPTIONS: Reisner et al (2013), cited in every one of the BLM planning documents, provided clear, science-based prescriptions for managing grazing to avoid contributing the spread of cheatgrass:

“If the goal is to conserve and restore resistance of [big sagebrush] systems, managers should consider maintaining or restoring:

(i) high bunchgrass cover and structure characterized by spatially dispersed bunchgrasses and small gaps between them;
(ii) a diverse assemblage of bunchgrass species to maximize competitive interactions with B. tectorum in time and space; and
(iii) biological soil crusts to limit B. tectorum establishment. Passive restoration by reducing cumulative cattle grazing may be one of the most effective means of achieving these three goals” (Reisner et al. 2013: 1).

Additional research found that cheatgrass and clasping pepperweed (Lepidium perfoliatum, a non-native mustard) out-compete native grasses where vegetative communities are stressed by higher surface temperatures, limited moisture and grazing pressure (i.e., south facing slopes) (Reisner et al. 2015). The U.S. Geological Survey recommends adjusting and even suspending livestock grazing as part of a passive restoration program to maintain and reestablish resilient sagebrush steppe (Pyke et al. 2015).

PROPOSED FINAL RESOURCE MANAGEMENT PLANS/SUB-REGIONAL ENVIRONMENTAL IMPACT STATEMENTS: None of the proposed final sage-grouse plans prescribed grazing management to avoid contributing to cheatgrass invasion, although the Nevada/northeastern California plan included an action to monitor and manage grazing practices to “prevent the establishment of invasive species” (Nevada: 2-30, Action VEG-ISM 1).

While lacking in measures to prevent the spread of cheatgrass, all but two of the proposed plans claim that grazing can reduce fire fuels (i.e., cheatgrass) in sagebrush steppe. Federal land managers could misinterpret such general statements as direction for using livestock as a “tool” for controlling cheatgrass, contrary to evidence. The Humboldt-Toiyabe National Forest is preparing to issue a Record of Decision on the Bi-state Distinct Population Segment Forest Plan Amendment/Final Environmental Impact Statement that includes model language for using livestock as a tool to reduce fire risk from cheatgrass:

Grazing may be used to target removal of cheatgrass or other vegetation hindering [sage-grouse conservation] objectives where monocultures occur to reduce risk of fire and achieve or move toward desired habitat conditions. Sheep, goats, or cattle may be used as long as the animals are intensely managed and removed when incidental utilization of desirable species reaches 25%.

A cattle trail serves as a vector for cheatgrass to invade burned sagebrush habitat in Idaho.

A cattle trail serves as a vector for cheatgrass to invade burned sagebrush habitat in Idaho.

PROTEST RESOLUTION: The BLM issued reports for each responding to administrative protests submitted on the proposed final sage-grouse plans. The agency commonly responded “[t]he BLM has adequately analyzed and disclosed the effects of livestock grazing on native plant communities and invasive species, including cheatgrass” (e.g., Oregon protest resolution: 55; Nevada/NE California protest resolution: 131; Idaho/SW Montana protest resolution: 82). Calls to limit grazing to certain seasons and limit the loss of native perennials were met with promises to perform “site-specific analysis” during implementation (e.g., Northwest Colorado protest resolution: 24-25).

RECORDS OF DECISION: the BLM’s Records of Decision for both the Great Basin and Rocky Mountain regions defer to the underlying approved resource management plan amendments to implement grazing prescriptions in sage-grouse habitat. “Improper livestock grazing” is undefined yet identified as a negative impact on landscape conditions (RM ROD: 1-8; GB ROD: 1-7) and as a hindrance to achieving the habitat objective of maintaining or restoring healthy native perennial grasses (RM ROD: 1-26; GB ROD: 1-24–1-25).

APPROVED RESOURCE MANAGEMENT PLAN AMENDMENTS: While continuing to acknowledge the threat of cheatgrass to sage-grouse, none of the final plans specifically prescribe grazing management to avoid contributing to the spread of cheatgrass in grouse habitat. In fact, the plans defer again to existing rangeland health standards and guidelines for their particular region (e.g., Utah ARMPA: 1-14). These outdated and vague guidelines do not include direction for controlling grazing to avoid the spread of cheatgrass (indeed, if they did, they might have helped to prevent grazing from spreading the invader across sage-grouse range over the last 15 years). All of the final plans would accept a form of “targeted grazing” as a method to contain cheatgrass, a management method that has questionable effects (see above) (some plans do require the BLM to consult with ecologists to strategize use before implementation (e.g., Northwest Colorado ARMPA: 2-9, MD FIRE-12)).

Interestingly, two of the approved management plans adopted a quantitative habitat objective for cheatgrass cover in essential sage-grouse habitat. The Oregon ARMPA includes a habitat objective of less than 5 percent cheatgrass cover within 4 miles of all occupied or pending sage-grouse leks (Oregon ARMPA: 2-10, Obj Veg 3). The Nevada and Northeastern California ARMPA adopted a desired condition of less than 5 percent cheatgrass cover in nesting habitat from April 1 to June 30 (Nevada/NE California ARMPA: 2-4, Table 2-2). None of the other approved plans have a quantitative habitat objective or desired condition for cheatgrass cover.

Mark Salvo is Senior Director for Landscape Conservation at Defenders of Wildlife.

Jamison Shabanowitz is a Renewable Energy and Wildlife Fellow at Defenders of Wildlife.

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