Chapter 5. Affected Environment This chapter provides a description of the affected environment in terms of the physical, biological, cultural, and socioeconomic environments. Section 5.1 provides a regional overview of the environment. Sections 5.2 through 5.6 provide more detailed descriptions of the covered refuges in the Klamath Basin National Wildlife Refuge Complex (Refuge Complex): Upper Klamath National Wildlife Refuge (Refuge), Bear Valley Refuge, Lower Klamath Refuge, Tule Lake Refuge, and Clear Lake Refuge. 5.1 Regional Overview 5.1.1 Physical Environment Geographic Setting The Refuge Complex is located in northeastern California and southern Oregon (see Figure 1.1) in the Upper Klamath Basin watershed. It is situated in a high desert transition zone between the southern Cascade Range and the northern Sierra Nevada Mountains. Much of the Upper Klamath Basin was part of ancient Lake Modoc, a pluvial lake formed during the Pleistocene that covered an area of 1,100 square miles (Benke and Cushing 2005). The remnant of Lake Modoc is now Upper Klamath Lake. The surrounding lands greatly reflect the former presence of the ancient lake, and wetlands and marshes are characteristic of the area (Benke and Cushing 2005). The Refuge Complex encompasses a wide range of habitats and topography. The average elevation is about 3,937 feet above sea level. Tule Lake Refuge and Lower Klamath Refuge are the largest and best-known refuges in the complex. Both units are situated mostly in northern California, immediately south of the Oregon state line. Upper Klamath Refuge is located in Oregon, immediately north and west of Klamath Falls. Bear Valley Refuge is also located in Oregon, 2 miles west of the town of Wordon. Clear Lake Refuge is located in northeastern California, approximately 10 miles east of Newell, California. Climate The Refuge Complex has a semi-arid climate with dry, hot summers and cold winters. Summer temperatures can occasionally reach 100 degrees Fahrenheit, but generally cool rapidly during the evening and nighttime hours. Nighttime temperatures can, and often do, dip below 32 degrees Fahrenheit during the summer months. January is the coldest month of the year, but frost can occur in every month. Strong winds are common, especially during winter months. Temperature and precipitation vary with elevation, slope, and aspect. Precipitation generally occurs during the winter and spring months, with the lower elevation refuges receiving approximately 7 to 11 inches of rainfall annually. Bear Valley Refuge can receive approximately 18 to 25 inches of rainfall annually. The surrounding higher elevations receive more precipitation, which enters the Upper Klamath Basin and the Klamath River through a series of rivers and creeks. However, the Upper Klamath Basin climate includes periodic drought cycles that generally follow a 10-year pattern. During the driest years, annual precipitation can be as low as 30% of average. 5-1 The primary season for lightning activity extends from mid-May through mid- September, with occasional activity as early as April and as late as November. From mid-June through August, lightning commonly occurs unaccompanied by precipitation. A climatic summary for the Refuge Complex region is provided in Table 5.1. Table 5.1. Regional Climatic Summary City Average Temperature Average Precipitation Precipitation (degrees Fahrenheit) (inches) Peak Months Maximum Minimum (July) (Jan) Klamath Falls, Oregon 85.1 21.1 13.72 November through January Merrill, Oregon 82.6 18.6 11.48 November through January Tulelake, California 84.6 20.1 10.92 November through January Source: Western Regional Climate Center 2008 Climate Change The Intergovernmental Panel on Climate Change (IPCC) has concluded that warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level (IPCC 2007). The U.S. Department of Interior (DOI) issued an order in January 2001 requiring its land management agencies to consider potential climate change impacts as part of long-range planning endeavors. Great Basin Ecoregion All five refuges are within the northern portion of the Great Basin Ecoregion (Point Reyes Bird Observatory [PRBO] 2011). In the Great Basin, regional climate models project mean annual temperature increases of 1.7 to 2.4 degrees Celsius by 2070. For the same time period the mean diurnal temperature range is projected to increase by 0.1 to 0.2 degrees Celsius based on two regional climate models presented in Stralberg et al. (2009). One of the greatest challenges in addressing climate change in California is that there are uncertainties associated with projections of future conditions, yet there is a need to make important long-term decisions to accommodate those potential changes (Dettinger 2005). Different global and regional climate models produce differences in the projected future climate conditions. Despite these uncertainties, there are some important generalizations for California: 1) uncertainties associated with future greenhouse-gas emissions are comparable with the differences among climate models, so that neither source of uncertainties should be neglected or underrepresented; 2) over the next 100 years, climate models currently project greater and more consistent changes in temperature than in precipitation; 3) projections of extremely wet futures for California are outliers among current projections; and 4) projections that are warmest tend to yield a moderately drier California, while the cooler projections yield a somewhat wetter future (PRBO 2011). Bell et al. (2004) also project an increase in temperature range for the ecoregion. The projected impacts of climate change on thermal conditions in the Great Basin will be warmer winter temperatures, earlier warming in the spring, later cooling in the fall, and increased summer temperatures (PRBO 2011). 5-2 Currently, there is more uncertainty about precipitation projections than for temperature projections in the Great Basin; however, the most recent investigations indicate a drier future relative to current conditions (PRBO 2011). Regional climate models project a decrease in mean annual rainfall of 32 to 85 millimeters by 2070 (PRBO 2011). On the basis of analyses of wildfire risks in California under four climatic change scenarios, Westerling and Bryant (2008) projected increases in the probability of large (more than 200 hectares) fires in the Great Basin by the end of the twenty-first century, more so under the drier, higher emissions scenario (also known as the Geophysical Fluid Dynamics Laboratory A2 scenario). Many climate change scenarios predict shifts in vegetation concurrent with changes in temperature and precipitation patterns. Of the three major vegetation groups in the Great Basin ecoregion, increases were projected to 2070 in the area of desert scrub (51% to 63%) and eastside pine/pinyon pine/juniper (45% to 38%), and the area of the third major vegetation type, sagebrush/bitterbrush/low sage, was projected to decrease by 56% to 41% (PRBO 2011). Although they do not provide summaries of ecoregional change, maps in Lenihan et al. (2008) show vegetation shifts in the Great Basin that include an increase in the area of conifer forest and grasslands and decreases in the area of shrublands by the 2070–2099 period. These shifts may be hastened by changes in fire regimes (frequency, severity, and extent and frequency). In the Great Basin, projected changes in climate are predicted to affect vegetation communities with potential serious consequences for wildlife (PRBO 2011). These changes will include projected increases in the amount of pine and juniper forest and desert scrub and grasslands, and a loss of sagebrush and other shrub habitats. Secondly, high temperature events will become more common, and may increase by as much as 2.7 degrees Celsius. Given the arid conditions throughout the Great Basin, this increase in temperature may increase heat and water stress for some wildlife. Lastly, snow-fed rivers and streams will have less water, especially during the spring and summer, which may reduce habitat for some wildlife associated with riparian areas. Klamath Basin Mayer and Naman (2011) studied how streamflow response to climate is influenced by geology and elevation. The overall objective of their study was to examine the streamflow response to these climatic trends, as mediated by geology and elevation. This section summarizes the conclusions of their study. The climate trends in the Klamath Basin area are similar to what has been described elsewhere for the Pacific Northwest (Beebee and Manga 2004; Mote 2003). Winter temperatures in the Klamath Basin area have increased by about 1 degree Celsius since 1945 throughout the region, resulting in large decreases in spring snowpack at elevations less than 1,800 meters (average decrease of 38%), similar to findings reported for the Pacific Northwest in general (Mote 2003). Winter precipitation trends since 1945 have been less consistent and more spatially variable than temperature trends in the region. Generally, winter precipitation has decreased in some areas of southern Oregon and increased in some areas of northern California. The relative declines in spring snow water equivalent at elevations less than 1,800 meters have been much greater than the relative declines in winter precipitation in the area over the same period (Mayer and Naman 2011). Geology