INTEGRATED PEST MANAGEMENT PLAN
Maxwell National Wildlife Refuge
Colfax County, New Mexico
Written and Revised in 2002 by
Daniel R. Dinkler, Invasive Species Biologist
Dr. Elaine Snyder-Conn, National Pest Management Coordinator
Approvals and Concurrence
Maxwell National Wildlife Refuge:
Southwest Regional Office:
National Wildlife Refuge System
Refuge Supervisor, Arizona & New Mexico:
Invasive Species and IPM Coordinator:
Regional Contaminants Coordinator
National Pest Management Coordinator:
INTEGRATED PEST MANAGEMENT PLAN
Maxwell National Wildlife Refuge
Colfax County, New Mexico
The following is a comprehensive Integrated Pest Management (IPM) Plan for controlling or eliminating key weed and insect pests affecting Maxwell National Wildlife Refuge trust resources and to meet our compliance needs with State and Federal noxious and invasive species laws. This plan is developed under the authority of the Federal Plant Protection Act of 2000, the Federal Noxious Weed Act of 1974, Executive Order 13112, the Refuge Administration Act of 1965, the Refuge Improvement Act of 1997, and the New Mexico Noxious Weed Management Act of 1998, and is in following with the requirements of the Refuge Manual for the National Wildlife Refuge System (7 RM 14). This plan is also intended to address recent Director's priorities to control invasive species in the refuge system's "Fulfilling the Promise" document and related work group efforts.
Invasive and noxious weeds at Maxwell Refuge have already reduced wildlife habitat and biodiversity and are infesting neighboring lands. Not only are these invasive plants problematic on the refuge and across refuge boundaries, but when a cooperative farmer exports products off the refuge, such as alfalfa hay, and that hay contains invasive weeds, that hay can infest other off-refuge sites, providing a botanical version of “typhoid Mary”. Such transport can also occur by wind or water
, or by seed transport on farm or other equipment or the thousands of visitor vehicles traveling on and off the refuge. Obviously, these are not the kind of contributions to the ecosystem expected from our national wildlife refuges.
Maxwell Refuge recognizes the special importance of immediate and long-term attention to its invasive weeds based on the “3:1 principle” that for each year
a treatment is delayed, it will take an additional three years
to achieve the same level of control. That numeric value of “times three” applies to the increased labor and other costs, as well as to the volume of herbicides needed, if effective treatments are delayed. Thus, treatment costs can increase geometrically by delaying an effective control program . With this IPM Plan, Maxwell Refuge aims to demonstrate land stewardship in controlling invasive plants and other pests, while striving toward the goal of restoring native habitats and fauna, thereby re-establishing the health of the refuge ecosystem. The Director’s Priority for invasive species also elevates the control of invasive species on all units of the refuge system to a high priority.
By definition, a weed is an unwanted plant, wherever it occurs. On Maxwell Refuge, insect and weed pests are common in and around farm fields. Numerous exotic plant species considered noxious or invasive in New Mexico are well established on Maxwell Refuge
, competing with native plants for sunlight, water and nutrients, and jeopardizing the ability of the refuge to provide habitat for migratory birds, which is the primary purpose of the refuge. While many weeds establish by pioneering on disturbed sites, and are eventually followed in succession by native species, Maxwell Refuge also hosts a variety of more insidious, exotic, noxious plants termed “invasive
.” Such invasive plants are not only effective at pioneering disturbed sites, but they also proliferate to the exclusion of native plants, interrupting the natural process of plant succession and permanently dominating the vegetative communities in the absence of natural biocontrols from their original source locations. Once established, invasive species can have a dramatic, negative impact on ecosystems. Millions of acres of the western landscape have rapidly been taken over by single invasive species, with yellow starthistle and leafy spurge providing two of the worst examples.
In the plan, we present IPM treatments selected to control pests according to the refuge’s various site and soil types, with attention to resource needs. Both pesticide and non-pesticide control methods are considered
, specific to each pest species, as are mapping, monitoring and prevention methods. Previous experiences in controlling pests are also described, so that only methods that are likely to be effective in the future are used. If there are sensitive resources present at some of the sites, such as rare or listed species or other species of concern, limiting treatment options, these resources and their locations are discussed and low-risk treatment options are selected to protect the sensitive species or sites. For example, if an infestation is adjacent to a perennial water source and a herbicide treatment would likely contaminate that water, then that treatment option would be inappropriate at that site. Similarly, a broad-spectrum herbicide would be inappropriate unless it was used as a spot treatment only on the pest in question and precautions are identified to reduce drift, leaching, and runoff to sensitive areas nearby. In many cases, more than one invasive weed species is present on a site. In these instances, treatments are designed to treat the highest priority invasive plant species. This plan recognizes that pest control
, and particularly invasive species control, will require a multi-year commitment, with follow up monitoring, assessment of the successes and failures of treatments, and development of new approaches when proposed methods fail.
Maxwell National Wildlife Refuge is situated in northeastern New Mexico near the western edge of the historical shortgrass prairie and just east of the Sangre de Christo Mountains (Figure 1) very near the historic Santa Fe Trail. Situated in the watershed of the nearby Canadian River, Maxwell Refuge falls into the Arkansas-Red River Ecosystem and is administered through the U.S. Fish & Wildlife Service’s (Service) Southwestern Regional Office located in Albuquerque, New Mexico. The Refuge encompasses 2,792 acres of habitat acquired in fee title. Located in the highlands with elevations in the range of 6,100 feet, the topography includes areas that are almost flat interspersed with gently rolling, low hills, creating some sinks and playas, the largest of which have been converted to irrigation reservoirs that are owned and managed by the Vermejo Conservancy District.
Refuge History -
Land acquisition for Maxwell NWR was initiated in 1966. Historically, lands that today comprise the refuge supported shortgrass prairie. Grassland plant communities included associations dominated by blue gramma (Bouteloua gracilis
), and alkali sacaton (Sporobolus airoides
), with buffalograss (Buchloe dactyloides
), western wheatgrass (Pascopyrum smithii
), fourwing saltbush (Atriplex canescens
), alkali muhly (Muhlenbergia asperifolia
), and inland saltgrass (Distichlis spicata
) also common. The development of the first irrigation system in the area, which diverted water from the Vermejo River
, dates to the late 1880's. Scattered ranches with farming operations sprouted up and livestock grazing increased with the availability of water for stock tanks and the irrigation of crops. Along with introducing cattle and numerous weeds, settlement of the area frequently included planting Siberian elm (Ulmus pumila
, a.k.a. Chinese or Russian elm) to provide shelter belts around areas of habitation. Limited farming continues on the refuge, but livestock grazing was terminated in the late 1960's as lands were acquired.
Farming and grazing activities, along with the development of the irrigation system infrastructure, have altered most of the habitat on the refuge.
Refuge habitats include former pasture (referred to as range in this document), farm fields (both in use and abandoned), playa lakes and surrounding alkali flats, irrigation reservoirs and associated wetlands, and several wooded thickets associated with former home sites.
In 2000, 371 acres were under cultivation, with the majority of those acres farmed under cooperative agreement with two local farmers. The remaining acres were farmed directly by the refuge. Crops grown include alfalfa, which provides a significant amount of green browse for migratory birds during the migration and wintering seasons, and “hot foods”, or grain crops, that sustain birds and other wildlife in the cold of winter; typically barley, wheat or corn grown by the refuge or under cooperative farming agreements. In excess of 500 acres of previously-farmed and now-abandoned farm land await restoration to native prairie. Most the remainder of the refuge’s 2,792 acres have been altered by historical grazing, but never broken out and farmed, largely due to their location on inferior, saline soils. These grazed areas would also benefit from restoration, but the abandoned farm fields are better candidates for restoration due to their location on better soils and having better access and, in some cases, irrigation capability.
Three irrigation reservoirs, identified as Lakes 12, 13 and 14, are located within the refuge, predate establishment of the refuge, and are considered permanent reservoirs. These reservoirs, and the surrounding land, are owned and managed by the Vermejo Conservancy District (District), with the District managing the water levels. Lake 13 is a very popular angling site for stocked trout and catfish, attracting thousands of vehicle-based visitors annually. Numerous irrigation ditches, either owned by the District, or operated by the District as rights-of-way
, cris-cross the refuge, feeding the reservoirs and delivering water to area farmers. With the development of these reservoirs substantially more water currently exists on the refuge landscape today than was there historically. The reservoirs hold water all year, although water levels (and shorelines) vary with precipitation and irrigation demands.
With hundreds of acres of dammed-up standing water in the reservoirs, the water table in the vicinity of the dams is affected, creating moist soil conditions below the dams in some localized sites. The proliferation of irrigation ditches, both for inflow to supply the reservoirs and for delivery to area farms, creates seasonal open water areas and about 70 acres of cattail wetland and another 43 acres of rush/sedge wetland. These open water and wetland sites are sensitive areas which are important considerations when planning for the application of herbicides to the refuge landscape. The refuge has management agreements for about 900 acres of District-owned lands surrounding Lakes 12 and 14, bringing the total area managed by the refuge to about 3,700 acres.
Other sensitive areas that are largely seasonal in nature are water delivery canals and ditches that bring water into and out of the reservoirs, and seeps that develop below dams due to the hydraulic pressure exerted by standing water behind the dams.
Also, heavy rains can create temporary standing water in low lying, poorly drained sites for short durations.
Several unpaved roads provide vehicle access around and through the refuge, primarily on section and half-section lines. The roads themselves, and disturbed sites next to the roads, provide important weed habitat and transportation corridors. Most roads are gravel Colfax County right-of-ways passing through, or along, Refuge borders. State Highway 505, a paved asphalt road
, runs along the Refuge’s southern boundary. The refuge owns and manages two miles of unpaved road, and manages the public access roads at Lakes 13 and 14 under agreement with the District. Road composition affects the likelihood of vehicles and equipment picking up and transporting seeds in mud, aiding in the distribution of invasives. The identity of each road’s managing agency will be important in coordinating weed management activities, such as the timing of mowing.
- Soils on Maxwell NWR are deep silty clay loams derived from the Cretaceous shale and deposited by alluvial and eolian processes. The more lowland soils fall into the Vermejo soil series and the upland sites are represented by soils from the Swastika Series. The silty clay loams of the Vermejo Series are easily erodible and often high in salts. The silty loams and silty clay loams of the Swastika Series are also high in salts, but somewhat less erodible in comparison to the Vermejo Series. Both soil series are relatively low in organic matter and high in salts and pH (i.e., they are alkaline). Low lying sinks and the margin of playas are characterized by the presence white alkali and are virtually barren of vegetation.
Most of the farm fields and range sites are dominated by soils with high clay content, such as the Swastika-Colmor clay loam. These soils typically do not drain well due to their high clay content, and translocation of pesticides through the soil profile into the water table could be expected to be minimal. The rolling topography offers gentle slopes, with runoff minimal in combination with scant amounts of moisture normally received in any precipitation event. There are no geological outcrops that provide sandy or gravely substrate anywhere on the refuge. Additional detail on soils and their location are available from the Colfax County Soil Survey and in the refuge files.
Due in part to elevation, the climate is dry and cool, with a short growing season of only about 120 days. Precipitation is typical of the Southwest, averaging about 14.5 inches. Precipitation events can be quite variable, with summer showers not uncommon, depending on how well developed the summer “monsoon” season is. As with any thunderstorm activity, rainfall amounts can vary drastically over a short distance within the refuge. Included in the annual precipitation total is snow melt
, with snowfall averaging about 17.5 inches, providing about two inches of water when melted.
Paste Map Here. If possible, include some of the field locations.
High winds are not uncommon, especially during storms and in spring, and particularly in March and April. Late spring and summer mornings often begin with calm or light winds, typically changing to a southerly breeze as the day warms. Southerly winds that easily exceed the limits for boom spraying frequently prevail in the afternoon.
Sensitive Refuge Sites and Species - Sensitive areas on the refuge include the following:
the permanent water found in irrigation reservoirs 12, 13 and 14.
seasonal water flowing in irrigation delivery and inflow ditches.
moist seeps, dam faces & roadside ditches, when standing surface water is present.
susceptible crops, such as alfalfa and the clover mix used for rest/rotation.
the two black-tailed prairie dog towns (candidate species - see map)
range sites with dense nesting cover during the nesting season.
public use areas (primarily the dam at Lake 13) and roads.
a 80-acre Research Natural Area in the southwestern corner sited around the playa lake located adjacent to State Highway 505 (no special prohibition on controlling invasives).
A Section 7 Consultation covering black-tailed prairie dog towns was prepared and approved in 2001. Since there are no invasive infestations in or adjacent to either town, no conflicts with herbicide treatments are expected, and any insecticide application (for grasshoppers) will use a one quarter mile buffer from either town.
Two native thistle species, wavyleaf or silver thistle (Cirsium undulatum
) and yellowspine (Cirsium ochrocentrum
) occur on the refuge. Wavyleaf thistle is a common, widely distributed perennial with leaves grossly similar to musk thistle in appearance in early growth stages; yellowspine is a uncommon biennial or short-lived perennial with a very limited distribution on the refuge.
Drinking and Irrigation Water -
Historically, there were domestic ground water wells on the refuge. However, the refuge currently gets its domestic water from the City of Maxwell and irrigation water from the District, either from Stubblefield reservoir or Laguna Madre. There are currently no wells pumping groundwater from anywhere on the refuge.
Surrounding Land Uses -
The major industry and source of income in Colfax County is agriculture based, with cattle ranching predominating. Ecotourism is also an important and growing segment of the economy. Much of the open rangeland in the area is grazed, and growing alfalfa for hay to feed cattle and horses is an important component of the local agribusiness. To the extent that invasive species become established on rangeland and in fields and take over the landscape, the ability of that range and field crops to support livestock operations can be stressed beyond the already thin margin of economic viability that most operations run on in the arid New Mexico highland plains. Because of the short growing season, any form of competition from an infestation can adversely affect economic viability.
TABLE 1. BROADLEAF WEED SPECIES ON MAXWELL NWR
Priority invasive weed species are denoted by an asterisk (*). These invasive species are considered to present the greatest threats to the refuge environment.
Common Name (+) Scientific Name Synonym Comments/Locations
field bindweed (C) Convolvulus arvense
perennial morning glory prolific, perennial
yellow sweetclover Melilotus officinalis yellow clover prolific, winter annual
common cocklebur Xanthium strumarium common in fields, annual
spiny cocklebur Xanthium spinosum1 C6 (1 plant found), annual
*hoary cress (A) Cardaria draba whitetop B5, F1 and various, perennial
*Siberian elm (C) Ulmus pumila Russian elm scattered groves
curlycup gumweed2 Grindelia squarrosa rosinwood rangeland, biennial or perennial
scarlet gaura3 Gaura parviflori velvety gaura farm fields, biennial or annual
halogeton Halogeton glomeratus Scattered, disturbed sites, annual
horseweed3 Conyza canadensis rangeland, annual
*Russian knapweed (B) Centaurea repens several patches, perennial
kochia Kochia scoparia prolific, annual
prickly lettuce Lactuca serriola China or wild lettuce common, biennial or annual
locoweed (3 varieties) Oxytropis spp. crazyweed common in range sites, perennial, poisonous to ungulates
Venice mallow Hibiscus trionum rosemallow farm fields, annual
common mallow Malva neglecta buttonweed farm fields, annual, biennial or perennial
common mullein Verbascum thapsus various, biennial
*Russian olive (C) Elaeagnus angustifolia planted at refuge headquarters
common ragweed3 Ambrosia artemisiifolia prolific in fields, annual
*saltcedar (C) Tamarix ramosissima scattered sites
spiny sowthistle Sonchus asper Common, annual
broom snakeweed2 Gutierrezia sarothrae broomweed overgrazed sites, perennial
*bull thistle (B) Cirsium vulgare dams, ditches, biennial, deep tap
*Canada thistle (A) Cirsium arvense widespread, perennial and deep rooted
*musk thistle (B) Carduus nutans widespread, biennial or annual
Russian thistle Salsola iberica tumbleweed widespread, annual
yellowspine thistle 2 Cirsium ochrocentrum limited to stackyard behind headquarters
new in 2000. Exactly one spiny cocklebur plant was found in 2000 near the southwest corner of cooperatively farmed field C6.
a native plant but undesirable as forage and/or unpalatable or poisonous to livestock and possibly some wildlife
native to U.S. but proliferates in disturbed sites and grain crops. Horseweed is a nasal irritant to horses.
+ Class A, B, or C weed based on New Mexico Noxious Weed Management Act 1998 (see definitions Page 8).
Plant Pests -
The Refuge conducted an intensive field scouting program in 2000 and 2001 to identify nonnative species on the refuge and map their locations as a necessary first step in the development control strategies and this IPM Plan. Field scouting revealed numerous infestations on the refuge. In addition to prolific infestations of hoary cress and Canada, musk, and bull thistles on the refuge, scouting forays in 2000 during the bloom revealed numerous Russian knapweed infestations on and adjacent to the refuge
, especially along roadsides. Table 1 provides an extensive (but likely incomplete) list of exotic plants and other weeds established on Maxwell Refuge. Based on survey results and an assessment of threat and likelihood of effective control, the Refuge will focus control efforts on the following priority species: Russian knapweed; Canada, bull and musk thistles; hoary cress; Russian olive, saltcedar, and Siberian elm.
The selection of these priority invasive species was based on the rapid expansion capabilities of Russian knapweed, Canada, musk and bull thistles, and hoary cress in the refuge and their potential adverse impacts to farm and/or grasslands, including the toxic and allelopathic effects of many of these invasives (see following individual biology accounts). Also, Russian knapweed, Canada thistle, hoary cress, Siberian elm and saltcedar can form dense monospecific stands, suppressing crop yields and excluding native species. Prior to 2000, established saltcedar trees were uncommon
, but a large invasion of seedlings erupted following the flood of May 1999 but did not become visually evident until 2001. Saltcedar exudes salts that are phytotoxic, drastically lowering species diversity where it occurs. In addition
, saltcedar alters hydrology and has enormous water use as high as 200 gallons per tree each day, or more. As a result, there is less water and decreased biodiversity wherever saltcedar becomes established. There is typically a loss of both plant diversity and wildlife diversity as monospecific stands of saltcedar replace native species, a serious problem in riparian areas off the refuge and throughout the southwest. Russian olive and Siberian elm, like saltcedar, also present similar serious environmental threats.
In the New Mexico Noxious Weed Management Act of 1998, the New Mexico Department of Agriculture has identified offending invasive species in the State as either Class A, B or C
noxious weeds. Class A weeds occurring on the refuge include Canada thistle and hoary cress, while Russian knapweed and musk and bull thistles are identified as Class B weeds. Class C weeds found on the refuge include field bindweed, Siberian elm, saltcedar and Russian olive. Class A weeds are given the highest priority towards prevention and elimination in the state of New Mexico, and Class B, the second highest priority. We therefore plan to cooperate fully with the county and State in working to eliminate these weeds from the refuge
, although our strategies may sometimes differ, depending on the occurrence of sensitive plants and wildlife on the refuge.
Three important invasive species on Maxwell Refuge, not herein selected as priority species, are field bindweed, yellow sweet clover and kochia. Field bindweed could easily be included in the priority list if it were not for how well established and widespread it has become, making control with herbicide unrealistic and elimination virtually impossible. About the best manageable result that can be expected for bindweed is partial control or suppression in crop fields, although yet-untried biocontrols may hold some promise. Yellow clover, planted in refuge fields as part of the rest rotation cycle, has escaped and is also very well established in fields and range sites. Similarly, kochia is also very common in fields and ranges sites and would be extremely difficult to control.
Several other invasive species on the refuge would immediately become priority species and treated or uprooted immediately if identified, including yellow starthistle and leafy spurge. Leafy spurge is established in at least three sites in Colfax County, and seeds from yellow starthistle and numerous other invasive species infestations are just a few hours drive up Interstate 25 in Colorado and Wyoming, waiting to hitchhike a ride over Raton Pass to Maxwell, New Mexico. In addition, weed species such as common mullein and halogeton will be suppressed on an opportunistic basis, especially when co-located with other weeds.
Minor weeds with lower rates of spread were also not identified as priority weeds. Only a few individual yellowspine thistle plants were discovered in 2000 in the cooperative farmer’s stack yard behind headquarters, after flowering, perhaps demonstrating a late season growth habit. Russian thistle is a minor agricultural pest, preferring disturbed sites, and will be controlled incidentally to other farm weeds. Additionally, exactly one spiny cocklebur plant was discovered in 2000 near the southwest corner of cooperatively-farmed field C6. In addition to the above broadleaf “weeds”, there are also a variety of non-native grass species, including smooth brome (Bromus inermis) that are less well-known as to their identity, distribution and the degree of their threat potential. Continued scouting with additional training on grass identification will enable the refuge to study possible control needs for grass species.