Chapter 4, Affected Environment, Draft Comprehensive Conservation Plan
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4 Affected Environment USFWS Sunrise over a Wells County wetland. The nine wetland management districts manage The prairies of North Dakota have become an thousands of noncontiguous tracts of federal land ecological treasure of biological importance for totaling 1,125,084 acres. These lands include 1,208 waterfowl and other migratory birds. The prairie WPAs, 37 WDAs, and tens of thousands of conservation potholes of North Dakota and South Dakota support easements. a wide diversity of wildlife, but they are most famous for their role in waterfowl production. Although the This chapter describes the physical environment and Prairie Pothole Region occupies only 10% of North biological resources of these district lands. In addition, America’s waterfowl-breeding range, it produces the affected environment includes the fire and grazing approximately 50% of the continent’s waterfowl history, cultural resources, visitor services, socioeconomic population. environment, and operations of the districts. Complexes of wetlands scattered throughout the wetland management districts attract breeding duck 4.1 Physical Environment pairs. While semipermanent and permanent wetlands The districts are primarily east and north of the provide brood-rearing habitat and migratory stopover Missouri River, from the Canadian border south to the habitat, respectively, it is the smaller temporary and state line of South Dakota. Because districts cover seasonal wetlands that draw breeding duck pairs to such a large geographic area, the physical environment the North Dakota prairies and other parts of the and biological resources are described in terms of Prairie Pothole Region. physiographic region (or level 3 and level 4 ecoregions) (Bryce et al. 1996) in which each district is located. GLOBAL WARMING Five physiographic regions occur in the nine-district area: Red River Valley, Glaciated Plains, Turtle The DOI issued an order in January 2001 requiring Mountains, Missouri Coteau, and Coteau Slope federal agencies under its direction that have land (see figure 6, map of physiographic regions). These management responsibilities to consider potential physiographic regions correspond closely to the level 3 climate change effects as part of long-range planning ecoregions described below with the exception of endeavors. the Turtle Mountains, which is described as a level 4 ecoregion. 38 Draft CCP and EA, North Dakota Wetland Management Districts Figure 6. Map of the physiographic regions in the nine districts, North Dakota. Chapter 4 — Affected Environment 39 The U.S. Department of Energy’s report, “Carbon The highest temperature ever recorded in North Sequestration Research and Development,” concluded Dakota was 121°F at Steele on July 6, 1936, and the that ecosystem protection is important to carbon lowest temperature measured was –60°F at Parshall sequestration and may reduce or prevent loss of carbon on February 15, 1936. Temperatures of 100°F or higher currently stored in the terrestrial biosphere. The occur nearly every year somewhere in North Dakota. report defines carbon sequestration as “the capture Chances of this occurring are greatest in the south- and secure storage of carbon that would otherwise be central area where, in about 85% of the years, maximum emitted to or remain in the atmosphere.” temperature will equal or exceed 100°F. These temperatures of 100°F or more last only for a day or The increase of carbon dioxide (CO2) within the earth’s two. In the northeast, temperatures reach 100°F or atmosphere has been linked to the gradual rise in higher in only 3 years out of 10 (Jensen, no date). surface temperature commonly referred to as “global warming.” In relation to comprehensive conservation Annual precipitation ranges from less than 13 inches planning for Refuge System units, carbon sequestration in the northwest to more than 20 inches in parts of the constitutes the primary climate-related effect considered Red River Valley and southeast. The lines of equal during planning. precipitation, although subject to some meandering, are oriented north–south; as a generalization, Vegetated land is a tremendous factor in carbon precipitation increases about 1 inch for every 50 miles sequestration. Large, naturally occurring communities of eastward movement. of plants and animals that occupy major habitats— grasslands, forests, wetlands, tundra, and desert— There are two areas where the general increase of are effective both in preventing carbon emission and precipitation in an easterly direction does not apply: in acting as biological “scrubbers” of atmospheric CO2. Q One area is located in the southwest where the One Service activity in particular—prescribed burning annual precipitation of more than 16 inches is higher than the surrounding area. This area —releases CO2 directly to the atmosphere from the biomass consumed during combustion yet results in no of higher precipitation is largely a result of net loss of carbon because new vegetation quickly topographic uplift. germinates and sprouts to replace the burned-up Q The other area is in the north-central section of biomass. This vegetation sequesters an approximately the state, where the annual precipitation of less equal amount of carbon as was lost to the air (Dai et al. than 16 inches is lower than surrounding areas. 2006). Several other effects of climate change may need This area is caused primarily by air moving consideration in the future: downhill from all but a southerly direction, Q Habitat available in lakes and streams for cold- which works against the precipitation process water fish such as trout and salmon could be (Jensen, no date). reduced. Annual snowfall in North Dakota ranges from less Q Forests may change, with some plant species than 26 inches in parts of Mountrail and McLean shifting their range northward or dying out and counties (west-central portion of the state) to about other trees moving in to take their place. 38 inches in a belt extending diagonally across the state northeast–southwest (Jensen, no date). Q Ducks and other waterfowl could lose breeding habitat because of stronger and more frequent droughts. PHYSIOGRAPHY, GEOGRAPHY, AND SOILS Q Changes in the timing of migration and nesting This section describes the districts’ ecoregions and could put some birds out of synchronization with soils. the life cycles of their prey. EEccooregions CLIMATE Four level 3 ecoregions cover the nine districts (see figure 7): Lake Agassiz Basin, Northern Glaciated The normal average annual temperature in North Plains, Northwestern Glaciated Plains, and Dakota ranges from 37°F in the northeast to 43°F Northwestern Great Plains. The differences in along the southern border. January is the coldest ecosystem properties and functions in the level 3 month with average temperatures ranging from 2°F ecoregions are distinguished by the patterns of biotic in the northeast to 17°F in the southwest. July is the and abiotic phenomena: vegetation, climate, soils, land warmest month with temperatures averaging 67°F use, wildlife use, and hydrology. Local biotic and abiotic in the northeast to 73°F in parts of the south. The factors have further refined the ecoregions. Each range of normal average monthly temperatures level 3 ecoregion is subdivided into several level 4 between the coldest and warmest months is 54°F in ecoregions; level 4 ecoregions are the finest level in the southwest and 65°F in the northeast. These large the hierarchy (Bryce et al. 1996). Table 3 displays the annual ranges attest to the continental nature of level 3 ecoregions in which each district occurs. North Dakota’s climate (Jensen, no date). 40 Draft CCP and EA, North Dakota Wetland Management Districts Figure 7. Map of the level 4 ecoregions in the nine districts, North Dakota. Chapter 4 — Affected Environment 41 Table 3. Ecoregions in the Nine Districts, North Dakota. Wetland Management District Level 3 Ecoregion Northern Glaciated Plains Arrowwood Ecoregion 46 Northwestern Glaciated Plains Ecoregion 42 Northwestern Great Plains Audubon Ecoregion 43 Northern Glaciated Plains Ecoregion 46 Northwestern Glaciated Plains Ecoregion 42 Chase Lake Northern Glaciated Plains Ecoregion 46 Northwestern Glaciated Plains Ecoregion 42 Northwestern Great Plains Crosby Ecoregion 43 USFWS Northern Glaciated Plains North Dakota’s prairie is a haven of unique species. Ecoregion 46 NORTHWESTERN GLACIATED PLAINS ECOREGION 42 (LEVEL 3) Northern Glaciated Plains Portions of Audubon, Chase Lake, Crosby, Kulm, and Devils Lake Ecoregion 46 Lostwood wetland management districts occur within Lake Agassiz Basin Ecoregion 48 this ecoregion. Northern Glaciated Plains J. Clark Salyer The Northwestern Glaciated Plains ecoregion marks Ecoregion 46 the westernmost extent of continental glaciation. Northwestern Glaciated Plains The youthful morainal (ridges of rock debris at the Ecoregion 42 margins of glaciers) landscape has significant surface Kulm irregularity and high concentrations of wetlands. Northern Glaciated Plains The rise in elevation along the eastern boundary Ecoregion 46 defines the beginning of the Great Plains. Land use is transitional between the intensive dryland farming Northwestern Glaciated Plains in Drift Plains ecoregion 46i (below) to the east and Ecoregion 42 the predominance of cattle ranching and farming to Northwestern Great Plains the west in Northwestern Great Plains ecoregion 43 Lostwood Ecoregion 43 (described below). Missouri Coteau Ecoregion 42a (Level 4) Northern Glaciated Plains Ecoregion 46 Like closely spaced ocean