Hansen 1 Hans Hansen ES 600 Conaway, Hitch Capstone Paper Draft 13 April 2015 Climate Vulnerability Assessment: Wild Rice Introduction Wild rice, known as Manoomin by the Ojibwe of northern Wisconsin, is a cultural artifact and a foundational commodity for the Ojibwe s heritage and subsistence. Although wild rice has proliferated across the Lake Superior basin for thousands of years, and specifically throughout the Bad River Watershed, a changing climate threatens the permanence of wild rice in the region. Wild rice s long maturation period heightens its vulnerability and its sensitivity to a change in environment, especially rapid changes to the water level. The anticipated wetter winters and warmer summers over the next century may contribute to a shift in species and the disappearance of wild rice in northern Wisconsin and on the Bad River Watershed. Wild rice requires a specific environment as part of a wetland ecosystem. Because wetlands act as the interface between terrestrial and aquatic ecosystems, they are sensitive to changes in air temperature, regional precipitation, runoff, [and] snow cover caused by climate change (Huff and Thomas, 2014, p. 49). Moreover, wild rice only proliferates in water ranging from 1-3 feet in depth with low turbidity and located on northwest portions of lakes and rivers. This specific environment limits the ability of wild rice to flourish on many portions of lakes and
Hansen 2 rivers and increases the vulnerability of the species to withstand increasing winter and summer temperatures and greater precipitation due to climate change. Vulnerability of Coastal Landscapes Coastal ecosystems are extremely vulnerable with increased temperatures and changes in precipitation. In certain areas, a changing climate could progress coastal wetlands toward terrestrial ecosystems. Water levels of Lake Superior have been highly variable between 1860 and 2006 with a severe decline in lake levels between 1997 and 2000 (Cruce, 2011, p. 8). Water levels of northern Wisconsin lakes have fluctuated over the last century with a recent decline to the lowest levels in the 70-year record (Betz, 2011, p. 16). Although relatively slow change in coastal ecosystems enables adaptation and the introduction of new wildlife species, sudden, rapid change in climate could have catastrophic effects as few wetland organisms would be able to adapt (Huff and Thomas, 2014, p. 50). Huff and Thomas (2014) state that it is possible for coastal wetlands to expand initially with decreased lake levels since more of Lake Superior s coastline will be exposed, allowing the expansion of wetland communities. However, a prolonged decrease in water levels or any sporadic change would have negative consequences for a variety of plant and animal habitats, including wild rice (p. 47, 50). Warming Temperatures Increasing temperatures have implications for wild rice abundance as they contribute to greater evaporation of lakes and rivers and influence a shift in species, including the introduction of invasive species. Average air temperatures in Wisconsin increased by 1.0 degree Celsius and minimum average air temperatures increased by 1.6 degrees Celsius between 1895 and 2005,
Hansen 3 increasing the amount of evapotranspiration, the total evaporation and plant transpiration, on the watershed (Huff and Thomas, 2014, p. 13). Coupled with greater precipitation, higher average air temperatures contribute to an increase in oscillation of water levels throughout the Bad River Watershed and directly impact wild rice habitats. Winter Temperatures Winter temperatures have increased in northern Wisconsin as reflected in the ice cover on Lake Superior, which has significantly decreased in recent years. Between 1998 and 2001, average ice cover was 27 percent compared to 68 percent from 1963-2001. Additionally, ice cover on Lake Superior has decreased by 11 percent from 1906 to 2006 (Huff and Thomas, 2014, p. 36). Specific to Bayfield County, the location of the Kakagon Slough and many other wild rice beds, ice cover has decreased by 3 days per decade over the past 150 years. Warmer winter temperatures impact wild rice during its dormancy period, which typically occurs during winter months when wild rice beds are frozen. Wild rice seeds germinate in the spring when warming water and low oxygen conditions stimulate germination. Shorter winters induced by warming temperatures will ultimately alter the lifespan of wild rice by shortening the dormancy period, inducing germination earlier in the spring, and increasing the period of time at which wild rice is susceptible to natural and human threats (Wild Rice). Summer Temperatures Warmer temperatures may contribute to a shift in species as northern habitats acquire the climates of southern locations. Increased temperatures will exceed the thermal tolerance of certain species. Many species will in turn migrate to appropriate climates while certain species
Hansen 4 with poor mobility may experience extinction. In some situations, invasive species will migrate northward and interfere with the abundance of existing species. Elder Ojibwe ricer John Denomie mentioned loosestrife (Lythrum) and pickerel weed (Pontederia) as especially threatening to wild rice populations on the Bad River Watershed: They hurt our rice because it chokes off the roots. It gets so abundant that it even comes up in the water (Denomie, personal communication, 2015). Therefore, warming summer temperatures are already causing a shift in species and the introduction of invasive plants to wild rice populations in the Bad River Watershed. Snow Cover Precipitation has increased throughout the Midwest by approximately 10 percent over the past century and there is consensus that precipitation will continue to increase during winter months throughout the 21 st century (WICCI, 2011, p. 168). The impact of greater snow cover is not observable in the winter as much as it is in the spring when the snow melts and increases the fluctuations of water levels in lakes and rivers. These fluctuations occur as wild rice exits its dormancy period and germinates in the spring. If water levels are not conducive to the germination of the seed, the rice will remain dormant for up to five years. Therefore, water level fluctuations in the spring may increase the number of dormant seeds and a decreased abundance of wild rice. Wisconsin s rivers and streams have also historically been affected by fluctuations in precipitation. From 1950 to 2006, the U.S. Geological Survey observed an increase of 10 to 15 percent in statewide precipitation. Correspondingly, the annual flows observed in Wisconsin s rivers increased by 14 percent over the same 57-year span. Future predictions of greater snowfall
Hansen 5 in the winter and spring will likely contribute to greater runoff events resulting in soil erosion, channel erosion, [and] increases in sediment and nutrient transport (Betz, 2011, p. vi). Thus, the river habitats on which wild rice proliferates will experience a change in water composition and potentially a decrease in habitat due to the erosion of riverbeds associated with greater springtime runoff. Major Flood Events Sporadic changes in water level have significant implications for wild rice abundance, especially during the floating leaf stage of development when the wild rice is extremely vulnerable to change. Annual fluctuations in water are necessary but sporadic changes may destroy entire rice beds as wild rice depends on environmental stability to proliferate. However, major flooding events impact rice beds differently on rivers and lakes. Relatively open systems such as rivers and flowages appear to vary less in rice abundance than relatively closed lake systems (David, 2010, p. 1). This may be due to the short period of a surge in a river or the consistency in the available nutrients. Nevertheless, major flood events change the composition of the nutrient loads and the turbidity of rivers while increasing the erosion of riverbeds on which wild rice grows. Water levels vary on an annual basis as reflected in John Denomie stating that 2014 s water levels were higher than [he had] ever seen them before, [while] some years, they re just real low (Butler & Denomie, personal communications, 2015). However, with greater precipitation and the predicted increase in sporadic weather, major flooding events are anticipated to increase, threatening the ability of wild rice abundance on rivers and lakes.
Hansen 6 Correlation between Climate Variables and Impacts on Wild Rice Case Study To demonstrate the correlation between snow cover, winter temperature, summer temperature and the amount of wild rice harvested, harvest and climate data was collected for Bayfield County during the years 2001-2002 and 2003-2004. 2001-2002 experienced a warm winter with the average temperature in January 2002 being 21.4 degrees and February 2002 being 24.9 degrees. The summer was also warmer with an average temperature of 71.3 degrees in July (Western Regional Climate Center). 2002 experienced large amounts of snowfall with 119.9 inches. The following fall, only 40 pounds of wild rice were harvested on the Kakagon Slough (David, 2006, p. 1). In comparison, 2003-2004 was a cold year with the average January temperature being 7.47 degrees. The summer was normally warm with an average July temperature of 59.48 degrees. Snowfall for Bayfield County was also low as it only snowed 102.1 inches (Western Regional Climate Center). The 2004 harvest of wild rice on the Kakagon Slough was one of the largest during the last decade as 100 pounds of wild rice were collected (David, 2006, p. 2). The data collected is limited by the number of people harvesting rice on the Kakagon Slough during any given year and the lack of harvest data available during all years of the past decade. However, it is apparent that the year with greater snowfall and greater average winter and summer temperatures experienced lower harvest yields than the year with a cooler winter, an average summer, and low snowfall. Therefore, increased temperature and increased snowfall has implications for the amount of wild rice collected. Intervention Changing climates have potentially disastrous consequences for wild rice on the Bad River Watershed including a reduction in abundance and the shift of wild rice species out of the
Hansen 7 watershed. Jason Carlson (personal communications, 2015) recommends integrating tradition and technology into refurbishment efforts with education as the foundation to restoration. A clear understanding of the environmental requisites of wild rice may be obtained through scientific inquiry while Traditional Ecological Knowledge may be used to gather information on traditionally harvested rice beds. Moreover, acknowledging the human threats to wild rice populations, including recreational features and infrastructure projects, would limit the human impact on wild rice. Comprehensive knowledge of water quality, water depth, and nutrient demands would lessen the damage to existing rice populations, better predict future impairments to wild rice, and inform wetland restoration efforts. Educational campaigns targeted at various groups would also transfer knowledge and lessen potential damage to wild rice beds. Jason Carlson (personal communications, 2015) mentioned rice camps for youth to connect people to culture and land through resources. The camps transfer traditional techniques of planning, harvesting, and processing the rice to increase appreciation of the culture surrounding the grain. Outreach campaigns targeted at landowners may also help with creating a greater understanding of the impacts of land use on the rice and limiting the potential damage to wild rice beds. Thus, educating various populations should be foundational to protecting wild rice populations. Conclusion Wild rice, known as Manoomin by the Ojibwe of northern Wisconsin, is a cultural artifact and a foundational commodity for the Ojibwe s heritage and subsistence. However, environmental change resulting from changing climates has impacted wild rice abundance over the past century and is predicted to continue to decrease the proliferation of wild rice. Increasing
Hansen 8 annual temperature contributes to shifting species, the introduction of non-native, invasive species, and the potential extinction of certain plant varieties. Moreover, shorter winters affect the dormancy period of wild rice, ultimately altering the life cycle of the plant. Greater precipitation is predicted to cause a change in environment with increased runoff and a change in the composition of water, thus impacting wild rice during its germination period. Climate change will also increase the vulnerability of coastal ecosystems on which wild rice abundance relies. Wild rice abundance has been greatly impacted over the past century by a changing climate and the predicted increase in annual temperatures and precipitation have significant implications for wild rice populations on the Bad River Watershed.
Hansen 9 References Betz, C. R., Asplund, T., Hurley, J. (2011). Water resource working group report. Wisconsin Initiative on Climate Change Impacts. v-16. Butler, H. & Denomie, J. (2015). Personal Communication Carlson, J. (2015). Personal Communication Cruce, T., & Yurkovich, E. (2011). Adapting to climate change: A planning guide for state coastal managers. Silver Spring, MD: NOAA Office of Ocean and Coastal Resource Management. 8-12. David, P. (2006). Wild Rice (Manoomin) Abundance and Harvest in Northern Wisconsin in 2006. Great Lakes Indian Fish & Wildlife Commission. 2. David, P. (2010). Wild Rice (Manoomin) Abundance and Harvest in Northern Wisconsin in 2001. Great Lakes Indian Fish & Wildlife Commission. 1. Huff, A. and Thomas, A. (2014). Lake Superior Climate Change Impacts and Adaptation. Prepared for the Lake Superior Lakewide Action and Management Plan Superior Work Group. Available at http://www.epa.gov/glnpo/lakesuperior/index.html. 1-13. Wild Rice. Great Lakes Indian Fish and Wildlife Commission. Retrieved from: http://www.glifwc.org/publications/pdf/wildrice_brochure.pdf Wisconsin s Changing Climate: Impacts and Adaptation (2011). Wisconsin Initiative on Climate Change Impacts. Nelson Institute for Environmental Studies, University of Wisconsin Madison and the Wisconsin Department of Natural Resources.