Corallita (Antigonon leptopus) is a perennial vine, lauded as an ornamental for its vigorous growth, and plentiful (usually) pink flowers, and even its ability to smother unsightly landscapes. In the United States it thrives in horticultural zones 8 to 10, and also is successfully grown worldwide in tropical climates. When corallita is neglected, it can grow quickly over other vegetation, spreading beyond its area of introduction. Once established, it is difficult to eradicate because it produces many tuberous roots that can propagate vegetatively. Its fruits are buoyant, allowing for successful seed dispersal in water. The islands of Guam (South Pacific Ocean) and St. Eustatius (Caribbean Sea) represent two regions where corallita has become so pervasive that it threatens local diversity. In Florida, already it is classified as a Category II invasive. Our report reviews the literature and past studies of corallita, in addition to adding new taxonomic and distribution information from herbarium specimens to clarify the identity and geographic range. It is recommended that introductions of this plant by the horticultural industry in both tropical and temperate regions be closely monitored to prevent spread. On tropical island nations, we advise against any new introductions.

Nomenclature: Corallita; coral creeper; Mexican creeper; corallina, bellisima; Antigonon leptopus Hook. & Arn.

The success of Japanese stiltgrass as an invader may be due to its ability to respond to stochastic events (e.g., by sexual reproduction via chasmogamous [CH] flowers) and to maintain a beneficial genetic make-up (e.g., by self-fertilizing via cleistogamous [CL] flowers) when conditions are stable. This paper evaluates the importance of Japanese stiltgrass seed type (chasmogamous seeds, cleistogamous seeds, and seeds originating from forest-interior [F-I] plants) in terms of seed mass, viability, and germination across variable moisture regimes (three regions in West Virginia) and at two light levels (roadside and forest interior). Seeds from nine populations were sampled in three site types in 2005 and 2008 and stored at 5 C until testing in April 2009. Seeds were tested for viability using a dye test. Seeds were germinated under both constant and fluctuating day/night temperatures. Additional samples of CH and CL seeds collected in 2008 were tested for viability again in September 2010 for a measure of seed longevity. CL and F-I seeds were smaller in mass than CH seeds. Seeds from the drier sites were smaller in mass than seeds from the more mesic sites. CL seeds, followed by F-I seeds, were less viable than CH seeds in 2005 and 2008. CL and F-I seeds had lower germination rates than CH seeds for each site type in 2005, but germination rates of the seed types did not differ in 2008. Differences in seed longevity for 2008 seeds were lower for CL compared to CH seeds, but only in the drier sites. Japanese stiltgrass' longer-lived and larger CH seeds from the roadsides may ensure population survival over the long term. Younger CL and F-I seeds differ less from CH seeds in terms of germination than older seeds, which may help Japanese stiltgrass to maintain populations under relatively stable conditions in the short term.

Nomenclature: Japanese stiltgrass; Microstegium vimineum (Trin.) A. Camus.

Interpretive Summary: The differences in viability of the three seed types (CH, CL, and F-I) revealed in this study add support for focusing management efforts on Japanese stiltgrass populations in which CH seed production is highest, such as those along roadsides or in open areas exposed to higher light levels. The relative importance of the CH seeds suggests that Japanese stiltgrass has adapted to less-stable conditions (i.e., seeds that are a product of out-crossing are of more use than seeds that are product of self-fertilization). Nonetheless, Japanese stiltgrass produces large amounts of the less-viable CL seeds, which may enable it to maintain populations during stable conditions in the short term. Control treatments such as mowing (prior to flowering) stiltgrass populations in higher-light areas, such as roadsides, is a way to minimize CH seed output. Although any remaining upper CL flowers may transform into CH inflorescences, the amount of CH seeds produced should still be reduced. Treatment with herbicide of the roadside Japanese stiltgrass populations may better ensure that the forest interiors are not receiving a steady supply of CH seeds with comparatively high viability. The influence of regional moisture variation on Japanese stiltgrass seeds is less defined than the effects of light, but may be related to drought-induced seed dormancy of CH seeds. Seed longevity of both CL and F-I seeds is shorter in drier environments compared to seed longevity of CH seeds, which indicates that removal of Japanese stiltgrass populations that produce the most viable CH seeds may be even more effective in drier environments than in mesic environments. It is conceivable that after removing roadside populations of Japanese stiltgrass, small forest populations could eventually go extinct, especially under drier conditions.

Yellow starthistle represents one of the most spectacular examples of biological invasion in the western United States. However, the mechanisms leading to its success have not been clearly elucidated. Although its success has been attributed to superior competitive ability, few competition studies have been performed with yellow starthistle to test this assertion. Yellow starthistle and wild oat (a dominant component of California annual grasslands) were grown in monocultures and mixtures to assess the strength of competitive interactions between them. For either species, intraspecific competition exerted a greater influence over mean plant weight than did interspecific competition. A companion study revealed temporal separation in the phenology of these plants, explaining the weak role of interspecific competition. Additional measurements of growth and soil moisture dynamics in large 270-cm-tall by 50-cm-diam polyvinyl chloride columns also showed a lack of interspecific competition and confirmed that water use patterns differed between these species, indicating niche partitioning. Wild oat reduced soil moisture to 5% but only to a depth of approximately 150 cm. Yellow starthistle depleted soil moisture to less than 5% throughout the column to a depth of at least 270 cm. These patterns were present when wild oat and yellow starthistle were grown individually or together in the columns, indicating that yellow starthistle had a greater impact on soil moisture and to greater depths. Yellow starthistle's invasion of grasslands in California does not appear to be due to superior competitive ability, but may be due to its ability to access deeper soil moisture. These results support the empty niche hypothesis that implies that invasive species are successful in new habitats because they access resources not available to resident species.

Nomenclature: Yellow starthistle; Centaurea solstitialis L. CENSO; wild oat; Avena fatua L.

Interpretive Summary: Yellow starthistle has invaded California grasslands within the last 100 yr. The mechanism for this successful invasion is not known for certain, even though it would be useful in managing this troublesome weed. We grew yellow starthistle in competition experiments with wild oat. The results indicate that yellow starthistle is not a strong competitor in relation to wild oat. Soil water measurements indicate that yellow starthistle used water from deeper in the soil profile than wild oat, suggesting that these species avoid competition in this way. Results from this study support the “empty niche hypothesis,” which implies that yellow starthistle has successfully invaded California grasslands because there are unused resources, i.e., deep soil water, available to it in these systems. These results support the idea that controlling yellow starthistle without establishing a plant community that also utilizes this deep soil water will not provide a long-term solution to its invasion.

Little is known about the relationship between frequency of occurrence and the expected maximum distance a nonnative species might spread along a trail once introduced to an ecological system with high native species integrity. Understanding how colonization and invasive plant habitat degradation occur in largely intact ecosystems is challenging. Determining which nonnative species are most likely to spread might be possible, given a suite of environmental or trail conditions. Spread may be linked to a particular set of environmental conditions, or to type and level of trail use. A field study conducted on trails in Forest Service and State Park lands on the Kenai Peninsula, Alaska, was designed to determine frequency and spread distance of all nonnative vascular plant species per 100-m segments keyed to vegetation type, canopy cover class, aspect, trail use level, and trail use type. Although the maximum total number of nonnative species decreased with increased distances from trailheads, the average number of species remained nearly constant. Common dandelion, broadleaf plantain, and annual bluegrass exhibited consistent presence per canopy cover class or vegetation type. A nested subset analysis revealed a significant reduction in nonnative species presence beyond a 500-m distance from a trailhead and a moderately strong nestedness pattern. High-use trails exhibited the greatest numbers of nonnative species at the farthest distances from the trailhead and contained a greater number of less common nonnative species. Alaska and other northern biomes have relatively few widespread invasive problems, offering an opportunity to limit ecosystem degradation by invasion. Results suggest that control strategies might focus on high-use trails with open-canopy habitats to prevent spread.

Nomenclature: Common dandelion; Taraxacum officinale F.H. Wigg. ssp. officinale; broadleaf plantain; Plantago major L.; annual bluegrass; Poa annua L.

Interpretive Summary: Land managers are increasingly aware of potential negative effects of invasive species that currently exist at low concentrations with slow spread rates in most areas in Alaska. Fast-spreading exceptions have alerted managers to focusing management strategies on prevention and eradication to avoid wide-scale infestations. Identifying what species to focus control efforts on is important to managers with limited budgets or limited control options. This study measured invasive plant spread along trail systems on and near the Kenai Peninsula in south-central Alaska. Distribution of all nonnative plants along trail systems was assessed by quantifying frequency of occurrence by environmental predictors, including vegetation type, canopy cover class, trail use type, and trail use level. Results indicated that common trailhead species (dandelion, Taraxacum officinale; plantain, Plantago major; annual bluegrass, Poa annua) grow under the widest variety of trail conditions and have the greatest penetration along trails. All nonnative species grow best under open, low-density vegetation conditions (except open–wet conditions, such as wetlands); higher trail use level increases penetration distance. Managers aiming for prevention should focus efforts on removal of uncommon nonnative species found at any distance along trail systems. For eradication efforts, control should start at trailheads and concentrate on open-canopy, high-use areas.

Prairies are imperiled habitats, with remnants being generally small and often existing in isolation. Invasive plants have the potential to invade not just the edge of small remnants but also the interior because smaller remnants experience greater edge effects than do large, contiguous prairies. Additionally, invasive plants limit recruitment of native plants, which can arrest secondary succession. We proposed to assess techniques for restoration that included removing annual grasses and supplementing native species recruitment with seeding of native grass and forb species. We also assessed the effect of specific factors affecting recruitment: soil moisture and seed predation. Treatments included broadcast, spot, or no application of the herbicides imazapic and glyphosate and with or without seeding plus mulch. With treatments nested within each of three plant communities, ranging from annual- to perennial-dominated communities, in four blocks per community, plant characteristics (percentage of cover and plant density), soil moisture availability, and seed-predation losses were measured along a plant community gradient within one season at two locations. A combination of broadcast herbicide application and seeding with mulching was found to be more effective in reducing annual grasses and enhancing the establishment of native grass species in predominately annual and mixed communities (annuals and perennials). Spot herbicide application was effective in predominately perennial communities, whereas only seeding native species did not improve recruitment. Although seed predation reduced seedling recruitment, mulch provided seed protection and enhanced soil moisture retention. Plant community response to imposed treatments differed among communities, suggesting that a decision support tool would facilitate management decisions tailored for each plant community. The decision tool would be useful to ensure that appropriate treatments are applied and that specific factors affecting recruitment, such as seed predation and soil moisture, are addressed.

Nomenclature: Glyphosate; imazapic.

Interpretive Summary: Restoration of grasslands in the Pacific Northwest from annual, nonindigenous plant–dominated communities to native, perennial plant–dominated communities is impeded by loss of viable native perennial seed reserves and by competition from the nonindigenous annuals. Addressing those challenges within the framework of a decision mechanism that considers initial plant community composition would allow restoration strategies tailored to emphasize techniques appropriate to the challenges faced. Our study assessed techniques for restoration within Palouse Prairie that included removing annual grasses by broadcast and spot-herbicide applications and supplementing native species recruitment with seeding of native grass and forb species across a plant community gradient. We also assessed seed predation and soil moisture as specific factors affecting plant recruitment. The results showed that response to treatment differed for annual and perennial grasses and forbs among the plant communities. High seed predation, ranging from 40 and 85% was observed. Although seed predation was associated with the observed low recruitment of native perennial grasses, mulch seemed to provide seed protection and enhanced soil moisture retention. The results enabled us to develop a decision mechanism that suggests (1) predominately perennial plant communities do not benefit from added seed, but spot herbicide treatment can reduce annual grass cover; (2) broadcast herbicide applications are required in mixed plant communities, even when foliar cover of perennial grasses approaches 20%; and (3) predominately annual plant communities should be seeded along with the use of a broadcast herbicide application. Decision mechanisms focused on foliar cover and density of dominant plant sp

Preinvasion baseline data on entire communities are absent for most taxa in most places, and this limits our ability to connect long-term ecological changes to particular invasive species or invasion events. We obtained data on forest understory composition from 94 stands in the 1950s and again the 2000s. We recorded within-stand frequency of occurrence for garlic mustard, European buckthorn, and Bell's honeysuckle and identified changes in native plant species density in 20, 1-m² quadrats in invaded and noninvaded stands. All three invasive species were absent from all study sites 50 yr ago, yet at least one was present in 77.7% of the stands by the 2000s. All three species were present in 14.9% of the stands. Garlic mustard and European buckthorn were found at 47.9% of resurveyed sites, and Bell's honeysuckle was found in 40.4% of resurveyed sites. Native understory plant species density declined an average of 23.1% during the past 50 yr. Declines were not significantly different in stands with or without invasive plants. The absence of a measurable effect by invasive plant presence or frequency could be due to invasive plants being too few to have a measurable effect at the plot scale, species density being an insensitive response variable, time lags between invasions and effects, or regional factors like development pressure and fire suppression driving density declines in both invasives and native species.

Nomenclature: Bell's honeysuckle; Lonicera × bella Zabel (morrowii × tatarica); European buckthorn; Rhamnus cathartica L.; garlic mustard; Alliaria petiolata (Beib.) Cavara & Grande.

Interpretive Summary: Garlic mustard, European buckthorn, and Bell's honeysuckle are invasive plants of Eurasian origin that have established and spread in North America. All three species invade forests, but we know surprisingly little about how the richness or diversity of plant communities responds to that invasion. The absence of preinvasion plant community data from most stands contributes to our limited understanding. In this study, we acquired high-quality plant community data that was obtained in the 1950s from 94 forest stands in southern Wisconsin. None had garlic mustard, European buckthorn, or Bell's honeysuckle. We revisited those stands in the 2000s and replicated the survey methods. We were able to determine what fraction of the stands was invaded since the initial survey. Garlic mustard and European buckthorn were found in 48% of all stands, whereas Bell's honeysuckle was found at 40%. Across all sites, plant species richness at the plot scale declined 26%. Species richness declines did not differ between sites with and those without invasive plants, even when the frequency of the invasive plants was taken into account. The existence of baseline data from both invaded and uninvaded stands prevented us from incorrectly attributing species richness declines to invasive species effects. We caution readers against generalizing these findings beyond southern Wisconsin, and we do not claim that these invasive species have no effect on native plant communities because this was a correlative study. We instead argue that the combined effects of fire suppression and landscape fragmentation have contributed to declines in native species richness. Once established, however, garlic mustard, European buckthorn, and Bell's honeysuckle create conditions that facilitate their own persistence.

Wild chervil is an invasive biennial or short-lived perennial weed introduced into North America that negatively impacts forage production and degrades habitat for native plant species. A 2-yr study using prebloom mowing followed by combinations of herbicide, tillage, and grass seeding was conducted in the Pacific Northwest to identify an effective integrated weed management strategy for this species. By 2 mo after herbicide treatment (MAHT), wild chervil control with glyphosate ammonium sulfate (AMS) and clopyralid was 83 and 73%, respectively. Tillage with or without herbicide pretreatment resulted in 92 to 98% wild chervil control at 2 MAHT, whereas herbicide without tillage gave only 45% control across all treatments. Tillage with or without subsequent grass seeding reduced wild chervil density four-fold compared to herbicide alone at 9 MAHT. Herbicide tillage grass seeding resulted in similar wild chervil cover (1 to 5% cover) as herbicide tillage (1 to 6% cover) without subsequent grass seeding. Wild chervil biomass at 1 yr after herbicide treatment (YAHT) was reduced to 487 kg ha⁻¹ (439 lb ac⁻¹) with herbicide tillage compared to 4,256 kg ha⁻¹ for herbicide treatment alone. Herbicide tillage grass seeding increased grass dry weight at 1 YAHT from 201 kg ha⁻¹ for herbicide tillage to 1,575 kg ha⁻¹, compared to 351 kg ha⁻¹ in herbicide-only plots.

Nomenclature: Clopyralid; dicamba; glyphosate; triclopyr; 2,4-D; wild chervil; Anthriscus sylvestris (L.) Hoffmann.

Interpretive Summary: Wild chervil is an introduced biennial or short-lived perennial species found in the northeastern and midwestern states and adjacent Canada, as well as in middle Atlantic states and the Pacific Northwest. Control of this invasive plant is desirable, given its ability to reduce forage yield and quality, and to degrade native habitat. Mowing wild chervil prior to treatment with herbicides moderately increases control, but the impact of tillage on wild chervil control previously has not been examined. Because chemical or mechanical control of weeds in pastures and natural areas often results with injury to or elimination of nontarget plant species, revegetation of the site using well-adapted or native species generally must follow weed-control efforts. With these facts in mind, an integrated weed management strategy for wild chervil was developed that utilized prebloom mowing, herbicide application, and tillage, followed by seeding of well-adapted perennial grass species. An experiment was designed to test the effectiveness of this strategy, and two trials were conducted in the state of Washington from 2003 to 2005.

Tillage as used here provided 92 to 98% control of wild chervil at 2 mo after treatment, with or without a pretillage herbicide application. At 1 yr after treatment, wild chervil biomass was reduced nine-fold if plots were tilled after herbicide application, but seeding grass into tilled plots was necessary to increase grass biomass. In areas where tillage such as used here is not possible, glyphosate application should provide satisfactory control of wild chervil. Because wild chervil seed does not persist long in the field (often surviving only one winter), lasting control of this invasive weed species likely will result from a consistently-applied integrated control strategy such as presented here.

Quantification of interference with biological control agents can provide support for anecdotal claims of success or failure of agent establishment and efficacy. This study was initiated because of observed predation of cinnabar moth larvae by carpenter ants when releasing larvae for the control of tansy ragwort, an invasive plant in Montana. Biotic and abiotic factors were compared among three sites with historically variable moth population establishment. Two experiments were developed to (1) observe and document insect activity, predation, or disappearance on tansy ragwort stems either protected or accessible to ants; and (2) quantify the effects of ant exclusion on herbivory of tansy ragwort. Site comparisons indicated that ant colony density was highest at the driest of three sites, and, interestingly, no ant colonies were detected at the site with higher observed numbers of moth larvae and adults and lower densities of tansy ragwort. Available substrate (logs and stumps) for ant colonization did not differ between the three sites. In the ant exclusion experiments, a larger number of larvae were missing on plants accessible to ants (63%) compared with plants where ants were excluded (39%) after 36 h. Direct observation of predation of larvae by carpenter ants accounted for 9% of missing larvae on stems accessible to ants. Larvae were able to consume 81% of original flowers or buds on ant-excluded stems, compared with 18% consumption on ant-accessible stems, suggesting that ant predation could limit the efficacy of cinnabar moth larvae. These results provide one of many possible explanations for the anecdotal observations of large, persistent populations of cinnabar moths in moist areas. This work emphasizes the importance of post-release observation and monitoring to detect and, ideally, quantify factors to support anecdotal perceptions regarding the fate and subsequent efficacy of insect biological-control agents.

Nomenclature: Cinnabar moth; Tyria jacobaeae L.; carpenter ant; Camponotus spp.; tansy ragwort; Senecio jacobaea L.

Interpretive Summary: Biological control insects are often released into the environment and left unmonitored for long periods. As a result, the degree to which insects establish viable populations and the biotic and abiotic factors that affect establishment are often unknown. In this study, we show that carpenter ants could pose a threat to cinnabar moth larvae in forests in Montana. Preliminary data suggest that dry sites may foster higher numbers of carpenter ants colonies and that carpenter ants do attack and kill cinnabar moth larvae. When cinnabar moth larvae are being redistributed for biocontrol, dry sites with a higher probability of carpenter ant colonies should be avoided. Focusing efforts in areas with reduced probability of ant presence will lead to a decreased chance of larva predation, allowing for increased population growth at safer sites from which moth populations may acquire higher populations and then spread naturally to less-suitable sites with higher ant densities.

Yellow starthistle is the most widespread broadleaf invasive plant in the western United States, and it is particularly prevalent in California. Prior to the registration of aminopyralid in 2005, the standard for chemical control of yellow starthistle was the herbicide clopyralid. We report on a compilation of several independent trials comparing the efficacy of aminopyralid and clopyralid on yellow starthistle. Treatments were applied at several rates and timings at 11 locations in four states between 2001 and 2007. Treatments were made pre-emergence and postemergence at the seedling and rosette stages of yellow starthistle. Results showed that aminopyralid, even at the low rate of 18 g ae ha⁻¹, provided nearly complete control of yellow starthistle when treatments were made at the seedling stage. However, less consistent control (80 to 100%) resulted with applications made at the pre-emergence and rosette stages. At the seedling stage, aminopyralid is about four times more effective on yellow starthistle compared to clopyralid, based on the rate of acid equivalent. In the Central Valley of California, complete control was obtained at the lowest registered rate (53 g ae ha⁻¹) when applications were made from December through February. At two locations we also evaluated control of the poisonous native plant coast fiddleneck. Although clopyralid does not adequately control coast fiddleneck, aminopyralid provided almost complete control when applied in the winter growing season. Applications of aminopyralid at the rosette stage resulted in a two-fold increase in annual forage grass biomass the following year. These results indicate that aminopyralid is a valuable tool for land managers and can play an important role in integrated management strategies for yellow starthistle and coast fiddleneck.

Nomenclature: Aminopyralid; clopyralid; yellow starthistle; Centaurea solstitialis L.; coast fiddleneck; Amsinckia menziesii (Lehm.) A. Nels. & J. F. Macbr. var. intermedia (Fisch. & C. A. Mey.) Ganders.

Interpretive Summary: Yellow starthistle is one of the most invasive species of rangelands and natural areas in the western United States. Several control options have been developed including mowing, grazing, burning, biological control, and herbicides. Until 2005, the herbicide clopyralid was considered the most effective chemical option for yellow starthistle control. However, clopyralid does not provide effective control of coast fiddleneck, which often co-occurs with yellow starthistle in rangelands of California. Coast fiddleneck is toxic to livestock and often increases in cover following clopyralid treatment. Aminopyralid was registered for use in noncrop areas in 2005. In this study we compared the efficacy of aminopyralid and clopyralid for yellow starthistle and coast fiddleneck control at several rates and timings at 11 locations in four states during the time period ranging from 2001 to 2007. Our results indicate that aminopyralid requires about one-fourth the active ingredient compared to clopyralid to achieve similar control of yellow starthistle at the seedling stage. Unlike clopyralid, aminopyralid also provides excellent control of coast fiddleneck. Although pre-emergence applications and late-season applications (rosette stage) also control yellow starthistle, those timings were less consistent at lower rates and therefore required higher rates as per label instructions. Late-stage applications were more effective given higher rainfall. We did find that late-season application resulted in increased annual forage grass production the following year. In the Central Valley of California, the optimal timing of application was from December through February. In cooler climatic regions the optimal application timing window might be somewhat later. Our results indicate that aminopyralid is a very

We evaluated herbicide treatments for control of umbrella dracaena, locally invasive in central Florida. Biannual treatments of imazapyr (3.2 and 6.4 g ai L⁻¹), metsulfuron (0.08 and 0.16 g ai L⁻¹), and imazapyr (0.8 g ai L⁻¹) plus glyphosate (19.9 g ai L⁻¹) reduced cover to < 3% at 12 mo, but no treatment eliminated the plant. In contrast, a single treatment on individual potted plants in greenhouse trials was highly effective with ≥ 98% necrosis/chlorosis at 6 mo and no regrowth at 9 mo posttreatment for most treatments. Management of umbrella dracaena will require more than two herbicide treatments with imazapyr, metsulfuron, glyphosate, or a combination of these herbicides if eradication is to be achieved. Because it is currently problematic and localized in one specific area in about 40 ha, it should be a high management priority before it spreads throughout Florida and possibly other states.

Nomenclature: Umbrella dracaena; Dianella ensifolia (L.) DC. (Hemerocallidaceae) DNLEN; also known as cerulean flax lily.

Interpretive Summary: In this study, we evaluated chemical control of umbrella dracaena (Dianella ensifolia), which is currently problematic in a single state park in Florida but is spreading outside the park. We found that two biannual spot treatments with imazapyr (3.2 g ai L⁻¹) or metsulfuron (0.08 g ai L⁻¹) reduced D. ensifolia cover to 1 and 3%, respectively, at 12 mo under field trials, but no treatment eliminated the plant. Although our results indicate two herbicide treatments will reduce D. ensifolia cover by > 97%, additional follow-up treatments will be required for long-term control of this plant in the park and to eliminate its spread outside the park. Because D. ensifolia is primarily localized in one specific 40-ha area of a state park, funding should be earmarked to eradicate this plant before it continues to spread to other natural areas in Florida and possibly other states.

Rangeland health assessment provides qualitative information on ecosystem attributes. Successional management is a conceptual framework that allows managers to link information gathered in rangeland health assessment to ecological processes that need to be repaired to allow vegetation to change in a favorable direction. The objective of this paper is to detail how these two endeavors can be integrated to form a holistic vegetation management framework. The Rangeland Health Assessment procedures described by Pyke et al. (2002) and Pellant et al. (2005) currently are being adopted by land managers across the western United States. Seventeen standard indicators were selected to represent various ecological aspects of ecosystem health. Each of the indicators is rated from extreme to no (slight) departure from the Ecological Site Description and/or the Reference Area(s). Successional management identifies three general drivers of plant community change: site availability, species availability, and species performance, as well as specific ecological processes influencing these drivers. In this paper, we propose and provide examples of a method to link the information collected in rangeland health assessment to the successional management framework. Thus, this method not only allows managers to quantify a point-in-time indication of rangeland health but also allows managers to use this information to decide how various management options might influence vegetation trajectories. We argue that integrating the Rangeland Health Assessment with Successional Management enhances the usefulness of both systems and provides synergistic value to the decision-making process.

Interpretive Summary: Integrating the Rangeland Health Assessment with Successional Management enhances the usefulness of both systems and provides synergistic value to the decision-making process. Successional management provides a science-based management system based on the causes of vegetation dynamics. Rangeland Health Assessment provides a method for determining which causes of succession are most likely directing dynamics, and leads managers to those ecological processes most likely in need of repair. Thus, management can be tailored to specially address those causes and processes with the highest probability of directing vegetation on a favorable trajectory. Besides the clear economic advantage of lower management inputs associated with using the rangeland health assessment to identify which primary causes of succession are most likely directing dynamics, integrating Rangeland Health Assessment also has the advantage of avoiding unnecessary management inputs and has the additional advantage of minimizing unintended negative impacts on ecological processes.