May 1997
To formulate IPM practices that made sense for the refuges, the Contractor team and the principal participants needed to have an understanding of the current conditions on the refuges -- what animals inhabited leased lands and surrounding lands, what crops are being grown, how pests are currently controlled, and many other aspects of current natural and human systems. Therefore, this section has four parts. The first addresses the current land- and water-based habitat conditions on the Tule Lake and Lower Klamath leased lands, or lands affected by practices on the leased lands. The second part discusses the current agricultural and pest management practices on the leased lands. The third addresses agricultural economic conditions on the leased lands, and the fourth, provides a brief economic analysis of IPM.
The following information in this section is taken primarily from the "Habitat Management Plan Lower Klamath National Wildlife Refuge" (U.S. Fish and Wildlife Service 1994), "A Brief Vegetation Study of Selected Areas in Lower Klamath National Wildlife Refuge" (Pederson and Pederson 1981), and from personal conversations with Service staff, Dr. David Mauser and Jim Hainline, between June and October 1996.
There are seven habitat types on Lower Klamath NWR. The habitats on Lower Klamath are managed to emulate historic habitats that occupied the Lower Klamath Lake ecosystem. Habitats range from open water areas dominated by submersed vegetation to upland habitats. For further discussion of species and habitats at risk, and fish, wildlife, and plant pest species, see Appendix A and Appendix B, respectively.
Seasonally Flooded Wetlands This habitat type was likely a significant proportion of the original Lower Klamath Lake system and is critical to meeting the migratory waterfowl management goals of the Refuge. In addition, this habitat provides brood areas for early nesting waterfowl species such as mallards (Mauser et al. 1994) and pintails.
Management of seasonally flooded wetlands requires flooding during early fall to early winter (Sept-Nov) and dewatering in late spring to early summer by gradually lowering the water level either by draining and/or by evaporation. This water management develops a productive wetland habitat that can be optimally used by migratory waterfowl and other wildlife.
The protracted drawdown of water during the growing season yields a complex mosaic of vegetative communities. Plant diversity is enhanced by uneven bottom contours exposed by a declining plane of water. As these "patches" of the bottom are dewatered, they warm, allowing germination of various plant species. Since these "patches " dry at different times, a specific plant association develops on each and results in a "patchwork" of differing plant associations in the unit.
An important plant association within seasonal wetlands is the red goosefoot community. Red goosefoot produces large numbers of seeds, an important food source of fall migrating mallards, pintails (Pederson and Pederson 1983), and other dabbling ducks. The invertebrate populations that develop after flooding are sought by many species of migrating waterfowl (Pederson and Pederson 1983), shorebirds (Helmers 1992), and other marsh birds during the spring migration and the breeding season. In addition, aquatic invertebrates are used by young waterfowl (Sugden 1973) and other wetland wildlife species.
Smartweed is another important plant produced by seasonal flooding. This plant is found in association with other plant species or in rather extensive single-species stands. During the fall, it is readily used by migrating waterfowl for food and cover. Smartweed, as with other seasonally flooded wetland plants, provides good substrate and cover for aquatic invertebrates.
Over time (3 to 4 years), red goosefoot and smartweed are replaced by alkali bulrush. Although this plant may be associated with other plants, it often forms large single-species patches. The plant is a prolific producer of seeds; however, these seeds are not a significant food source for waterfowl (Pederson and Pederson 1983) or other wildlife. On the positive side, the plant's structure provides excellent cover for migrating and breeding waterfowl. Other species such as red-wing and yellow-headed blackbirds, sora and Virginia rails, and sandhill cranes make considerable use of alkali bulrush for nesting and brood rearing.
Permanently Flooded Wetlands This habitat emulates the permanently flooded emergent wetlands that typified much of historic Lower Klamath Lake. Permanent wetlands are crucial to meeting the refuge goals of waterfowl production and habitat for fall and spring migrant waterfowl. In addition, permanently flooded wetlands meet the habitat needs of several federal- or state-designated sensitive wildlife species (see Table 2). These wetland units are characterized by year-round flooding and contain two major plant communities. The emergent community is composed of hardstem bulrush and cattail with minor inclusions of river bulrush. The emergent vegetation provides nesting substrate for many species of waterfowl, wading birds, and passerine birds, and acts as cover for resting waterfowl during periods of inclement weather.
The submersed plant community is dominated by sago pondweed with lesser amounts of baby pondweed and coontail. This community is found in open water zones where water depths range from 6 inches to 3 feet.
Sago pondweed is a major food source to migrating canvasbacks that feed almost exclusively on sago tubers during their 3-month stay in the fall. Other species of waterfowl such as the redhead, American widgeon, lesser scaup, mallard, American coot, and tundra swan consume the vegetative parts and seeds of this as well as other submersed plants. The submersed plant community supports a diverse and productive invertebrate (primarily insects, worms, and snails) community. These are sought by many species of migratory waterfowl and other marsh birds. During the summer months, invertebrates are a high-protein food for breeding and molting waterfowl, grebes, and most ducklings. Breeding eared and western grebes, as well as coots, use vegetative parts of submersed plants to construct their nests.
Colonial nesting species such as white pelicans, double-crested cormorants, and great blue herons use permanent wetland units for nesting. These units provide the security and remoteness required for nesting, and an abundant supply of fish, the primary food item for these birds. The western pond turtle, a federal sensitive species (see Table 2), is frequently sighted in Unit 2, a permanently flooded wetland (see Figure 2 (60K)).
An additional use of permanently flooded wetlands is by molting waterfowl (July-September). Because these birds are flightless during this period, food, water, and cover must be in close proximity. Large, permanently flooded marshes on Lower Klamath are used heavily for this purpose. Ducks have been documented to travel over 300 miles from their nesting areas to these marshes to molt.
Seasonally Flooded Uplands Seasonally flooded uplands were an integral part of the historic system. Periods of high stream flow and/or lake levels periodically inundated upland sites. This habitat type is crucial to meeting refuge goals pertaining to spring migrant waterfowl.
Seasonally flooded uplands are differentiated from seasonally flooded marshes by the length of the flooded period and the plant communities that result. Unlike the seasonally flooded marshes, these units are flooded for 3 to 4 weeks during the growing season and usually remain dry until late in the year (Dec-Jan). Because most seasonally flooded uplands are located at an elevation that makes water delivery difficult, many are dependent on runoff from the local watershed.
Management of seasonally flooded uplands involves flooding in early to late winter. No additional water is added in the spring and water from this habitat evaporates by late April. The uneven drainage of the unit gives a mosaic or patchwork of different plant communities. The habitat produced provides important spring habitat for migrating waterfowl, shorebirds, and sandhill cranes as well as breeding habitat for certain waterfowl, shorebirds, passerine birds, pronghorn antelope and mule deer (Appendix C).
To enhance habitat for spring migrant waterfowl, late-fall grazing occurs in several flooded upland units, principally Sheepy West and Units 5a. This grazing reduces cured vegetation that allows spring regrowth to be exposed and used as green browse by waterfowl. During the spring, 20 to 30 percent of the waterfowl use on Lower Klamath NWR occurs in the seasonally flooded upland units (particularly Sheepy West and unit 5a, less than 10 percent of the total refuge). During the remainder of the year, these units support fewer numbers of wildlife, but support some species seldom found on the remainder of the refuge.
The following description of vegetative communities in seasonally flooded uplands is taken from Brown (1986):
"The low grass-forb community is composed of species such as foxtail barley..., rabbitfoot grass ..., Nevada bluegrass ..., whitetop [i.e., hoary cress] ..., and paintbrush ... It acts as a source of seeds and provides substrate for aquatic invertebrates, critical to many ducks and shorebirds during the spring migration. During late spring and summer, seasonally flooded uplands provide nesting sites for ducks, ground-nesting passerine birds, raptors such as northern harriers ... and short-eared owls ..., and shorebirds such as long-billed curlews... and willets... Canada geese... and sandhill cranes use this community for brood rearing.
The foxtail barley-whitetop community is another component of seasonally flooded uplands. It provides essentially the same wildlife benefits as the low grass-forb community, but because of differences in the annual water regime or livestock grazing rates, a less diverse vegetative composition develops.
A third plant community includes the tall forb community which includes stinging nettle .., yarrow..., fireweed, flixweed ..., and Great Basin wildrye... This community provides the thickest cover for wildlife and is used as nesting cover by ducks and pheasants ... and as a fawning area by pronghorn antelope."
Open Submersed This habitat typifies areas of the original lake, dominated by submersed plants. Open submersed habitats are needed to meet refuge goals pertaining to migration habitat for diving ducks and swans, and waterfowl production. These deep-flooded units support dense beds of sago pondweed. During fall and spring, large concentrations of swans, widgeon, coots and diving ducks are commonly seen in these areas (Appendix C). When dewatered in the spring, these units are heavily used by migrating shorebirds.
Grain Fields Barley, and to a lesser extent, oats, help meet the fall nutritional requirements of migratory waterfowl. The refuge crop is also intended to attract early migrating waterfowl away from privately grown crops in the Basin. Barley is the predominant crop grown on Lower Klamath, planted by cooperative farmers or the refuge staff. In the case of a cooperative farming agreement, seed, cultivation, and weed control are provided in return for 66 percent of the harvest. The remainder is left standing for wildlife. If the field is farmed by refuge staff, the entire crop is left standing for wildlife. Reclamation leases are on a cash basis, thus the entire field is harvested with waste grain left after harvest as a food source for wildlife.
When barley fields are dry in the fall, they are used primarily by dabbling ducks and geese. Beginning in the late fall to early winter, fields are pre-irrigated in preparation for spring planting. At this time they receive heavy use by waterfowl, especially dabbling ducks, geese, and swans. Flooding also forces rodents from their burrows making them available to a variety of raptors and wading birds. When water is removed from the fields in the spring, large concentrations of shorebirds use these fields.
Irrigated Pasture/Hay This habitat type provides crucial feeding areas for spring migrant geese. Under provisions of the Kuchel Act, Reclamation leases 1,940 acres of the Straits Unit for pasture and hay. The Service authorizes haying on an additional 200 acres on the west side of Unit 2. During the spring waterfowl migration, these areas are heavily used by white-fronted, cackling, and Ross's geese. Long-billed curlews and willets use these areas for nesting in late spring and white-faced ibis use pasture/hay areas extensively when under summer irrigation. Bald eagles forage for rodents as these fields are flooded in winter.
Uplands Upland areas are located in Unit 14, and in topographically elevated areas in wetland units. These areas typically do not flood during the winter and, because of the terrestrial nature of the flora and fauna, add significantly to the plant and wildlife diversity of the refuge. This habitat type is crucial to meeting the needs of several species of federal category and state sensitive species (see Table 2).
Return to the IPM Plan Table of Contents or continue on to b. Habitat Description for Tule Lake
