Recipient Organization
UNIVERSITY OF MONTANA
COLLEGE OF FORESTRY AND CONSERVATION
MISSOULA,MT 59812
Performing Department
College of Forestry and Conservation
Non Technical Summary
Climate change in the Arctic and Boreal region is unfolding faster than anywhere else on Earth.Climate change is altering plants and forage for wildlife directly, and also indirectly through increased wildfires.Such changes are known to affect the abundance and distribution of herbivores. For caribou (Rangifer tarandus), an important cultural, socioeconomic, and ecological resource across Alaska, changing vegetation directly alters the composition, biomass or quality of available caribou forage. Caribou respond negatively to these vegetation changes as they require late-successional habitats. Most researchers think the range carrying capacity for caribou will therefore be reduced under climate change, leading to population declines.The Fortymile Caribou Herd (FMCH) of caribou in Alaska and the Yukon Territory, Canada is an important migratory herd of caribou, and perhaps the most important and accessible caribou herd for hunting by humans in Alaska.It is also unique insomuch that it has increased from about 52,000 in 2010 to upwards of 80,000 in 2017.Combined with the aforementioned concerns about climate-change induced threat of climate change, this growing caribou herd has prompted concerns by Federal and State natural resource management agencies about long-term risk of overgrazing of caribou ranges.If caribou are overgrazing their seasonal ranges, especially the slow-growing lichens that comprise the bulk of their winter foods, there is a real long-term risk of population collapse. This would also then reduce harvest (hunting) by Alaskans.Harvest management of the FMCH is very complex as this herd moves across two countries, and Federal law (ANILCA) that requires recreational and subsistence harvest to be separately managed by state and federal agencies. This complex management is reflected in a complex harvest management coalition structure that is comprised of dozens of natural resource management agencies and autonomous First Nation and Native Alaskan governments.Thus, in this complex Fortymile caribou herd system, an understanding of the risks of overgrazing by this growing caribou herd are needed to inform sustainable, long-term harvest management for both recreational and subsistence harvest.Our project will address both of these challenges.First, we will explore the Range health and management of the seasonal ranges of the important Fortymile caribou herd. We will test for evidence of overgrazing, range damage, and especially damage to slow-growing lichens to inform the biological question of whether caribou are at risk of overgrazing their seasonal ranges, managed by the BLM and NPS.Building on this biological/technical knowledge, then, we will conduct social science surveys of members of the Harvest Management Coalition to understand the adaptive capacity of this complex sociopolitical system to adapt to potential changes necessary to implement changes in harvest that are recommended by our biological/technical findings.This work will directly contribute to enhanced range management practices by the responsible federal agencies (BLM, NPS), and directly contribute to evidence-based changes in harvest management that provide critical recreational and subsistence hunting by native Alaskan's and recreational hunters.
Animal Health Component
100%
Research Effort Categories
Basic
0%
Applied
100%
Developmental
0%
Goals / Objectives
Climate change in the Arctic and Boreal region is unfolding faster than anywhere else on Earth, resulting in reduced Arctic sea ice, thawing of permafrost soils, decomposition of long-frozen organic matter, and alterations of ecosystem structure and function(Hinzman et al. 2005; Bhatt et al. 2010; Kasischke et al. 2010; IPCC 2014).Recent studies predict dramatic vegetation changes as shrub cover and tree line increase and advance northward(Walker et al. 2006; Zimov et al. 2006; Field et al. 2008; Myers-Smith et al. 2011).This increase in productivity results not only from warming temperatures, but lengthened growing seasons, increased precipitation and faster decomposition rates(van der Kolk et al. 2016; Yu et al. 2017).Furthermore, increasing frequency and severity of wildfires and droughts are causing abrupt and lasting changes to vegetation communities(Klein 1982; Fraser et al. 2014; Gustine et al. 2014).Ecological theory predicts that such profound changes in vegetation structure and function in the Arctic and Boreal regions would affect the abundance and distribution of herbivores in different ways(Post 2013).Some plant functional groups, like shrubs, are expanding their distribution in response to favorable conditions and outcompeting previously dominant functional groups(Myers-Smith et al. 2011; Fraser et al. 2014).For caribou, an important cultural, socioeconomic, and ecological resource across the circumpolar north(Hummel & Ray 2008), changing vegetation directly alters the composition, biomass or quality of available forages(Joly et al. 2007, Christie et al. 2015, Zamin et al. 2017, Mallory & Boyce 2018, Rickbeil et al. 2018).Caribou (Rangifer tarandus) respond negatively to these vegetation changes as they require late-successional habitats(Maier et al. 2005; Tape et al. 2016).Vegetation changes are thus expected to affect ecological carrying capacity (K) for large herbivores such as caribou across the Arctic.Kcan be defined as the equilibrium state between herbivore and plant populations(Caughley 1979; Fowler 1981; MacNab 1985; Caughley & Gunn 1993).For barrenground caribou (e.g.,R. taranadus granti), the increasing frequency of wildfires are burning more winter range taiga, killing old-growth forest bearing lichen, their major forage in winter(Joly et al. 2012; Gustine et al. 2014; Rickbeil et al. 2017; Russell 2018). Changes in biomass are increasing shrub cover on alpine tundra summer caribou ranges, but largely of unpalatable or lower quality forages(Turunen et al. 2009; Christie et al. 2015).Thus, most researchers thinkKwill be reduced for arctic caribou (Vors & Boyce 2009,Fauchald et al. 2017)Thus, there are concerns that some caribou populations may be approaching food-regulated carrying capacity(Caughley 1979; Boertje et al. 2012)and thus causing damage to their seasonal ranges.The Fortymile Caribou Herd (FMCH) of caribou in Alaska and the Yukon Territory, Canada is an important migratory herd of caribou, and unique insomuch that it has steadily increased in recent decades despite these changes in forage(Murie 1935; Valkenburg et al. 1994; McDonald & Cooley 2004).The FMCH is also amongst the most important and accessible caribou herds for Alaskan's due to its proximity to Fairbanks and a large human population. The FMCH population has increased from about 52,000 in 2010 to upwards of 80,000 in 2017.Thus, there is heightened concern for overgrazing by this important caribou herd especially because of concerns over climate change, and, because this caribou herd is growing. This is especially concerning for their primary winter food, lichen, which is slow growing, and responds to overgrazing over very long-time scales. With climate/fire changes to vegetation that are negatively affecting lichen cover itself, combined with concerns of overgrazing by this growing caribou herd, there are very real concerns that the population will cause long-term overgrazing damage to its seasonal ranges.Understanding socioeconomic system responses to climate change is recognized as a crucial step in adaptation(Smit & Wandel 2006; Moss et al. 2010).The sociopolitical management of FMCH for sustainable hunting is very complex. Management of the FMCH is made more complex by its transboundary nature ranging across east central Alaska and into the Yukon, across dozens of natural resource management agencies and autonomous First Nation and Native Alaskan governments(Boertje & Gardner 2000; Gronquist et al. 2005; HMC 2012).For example, the Bureau of Land Management (BLM, Steese Conservation Area) and National Park Service (NPS, Yukon Charley National Park Preserve) are responsible for administering management of the majority of this caribou herds seasonal ranges during winter and summer. Moreover, the Alaska National Interest Lands Conservation Act (ANILCA) of 1980 requires that Federal agencies separately administer both subsistence hunting on Federal lands in addition to State management of recreational wildlife harvest. Coordinating range and population management of this important herd across these jurisdictions is challenging. Harvest management is led by the Fortymile harvest management coalition (HMC), a management board comprised of state, federal agencies, representatives from Canada, and most importantly, members of all the communities within the FMCH range - including Native Alaskan's whose rights are enshrined in Land claim settlements. Over the last 25 years, this cooperative and multi-stakeholder approach has been a success story in accomplishing mutual goals of growing the herd.With > 80,000 caribou in the FMCH, however, there is now concern the herd may be reaching carrying capacity.And yet there is division within the coalition and resistance to increasing caribou harvest, which may ultimately threaten the future sustainability of this population. Compounding the uncertainty harvest is climate change, and its uncertain effects on caribou.Reconciling different harvest management strategies as caribou approach carrying capacity and start damaging range, especially under the future risk of climate change requires social science study of the socioecological harvest management system.Goals ObjectivesBased on the above introduction and background, we propose to address the following two research objectives, one focused on Biological processes, and the second on Sociological processes:What are the consequences of an increasing population of caribou on range management of this important caribou herd. Specifically, we will test predictions of overgrazing by caribou on range quality by testing for changes ina) diet and diet selection over time and space and,b) range management measures of plant biomass and quality.How will coupled human-natural ecosystems adapt caribou harvest management to account for population changes brought on by both an increasing population of caribou and a warming climate? We will address both adaptive capacity of the HMC to change both the a) recreational and b) subsistence hunting requirements of Federal and State management agencies in Alaska.
Project Methods
Study Area and SpeciesHistorically, the FMCH ranged from Fairbanks, AK to Lake Laberge, Yukon Territory, Canada(Murie 1935).From 1992 - 2008 the annual range increased to include central Yukon but caribou numbers remained low until in 2013, an expansion into the Yukon was documented.Although the population remained stable (~ 22,000 animals) in the early 1990's, the FMCH continued to be absent from much of its historic range and hunting in the Yukon and Alaska remained extremely low.Due to this, public dissatisfaction grew in response to established state and federal mandates, including harvest management plans(Gronquist et al. 2005).In 1993, a new grassroots coalition was initiated by the chief of the Dawson First Nation, and grew to include other Alaskan and Yukon territorial, state, and federal agencies, as well as Alaskan Native, Yukon First Nation, tourism, environmental and animal welfare groups.This "novel" approach to wildlife management has continued serving as a model for public participation(Boertje & Gardner 2000; Gronquist et al. 2005).Objective 1 - Characterizing Summer Range Diet and Forage Quality for CaribouFecal pellets- A critical prediction of density-dependent foraging is that at high densities, animals will select for lower-quality forage to reduce competition with conspecifics.We will conduct a time-series analysis using historical diet data fromMurie (1935, 1944)andSkoog (1956, 1968)with our current fecal pellet collection to assess how forage use has changed over time.We will use previously collected caribou fecal pellets in 2011 - 2018 to test for diet changes over time consistent with range degradation due to overgrazing. We will conduct fecal diet composition analysis at the Wildlife Habitat and Nutrition Lab at Washington State University (WSU). We will test for changes in the proportion of forage classes in the summer diet of FMCH over time using regression models.At high densities, we predict 1) elevated proportions of lichen in the diet of the FMCH and 2) a decrease in the proportion of higher-quality forage types (woody browse, graminoids and forbs) in the summer diet of the FMCH.GPS video camera collars- A critical prediction of density-dependent foraging is that as the density of caribou increase over space, animals will consume lower-quality forage to reduce competition.Using footage collected from ~30 GPS video camera collars that were deployed by Alaska Department of Fish and Wildlife Biologists (no University personnel were involved in animal capture or handling) , we will test predictions of individual and spatial variation in diets in a current time frame as collared caribou move throughout the summer range(Thompson et al. 2012; Newmaster et al. 2013).These collars will provide upwards of 500 hours of footage to compliment fecal diet information, but, critically, will be spatially georeferenced.Spatial variation allows us to test how animals are selecting forage in areas of high use as compared to areas of low use by caribou.Testing spatial variation in the diet is important because until now, there has been low power to detect changes over time with fecal pellet analyses.Changes in forage quality -One key prediction of overgrazing and range damage is that damage to plants increases from the repeated or excessive consumption by herbivores(Mysterud 2006).We predict 1) tannins will be higher in areas of repeated grazing and 2) the availability of high-quality forage will be lower in the center versus the extended portions of the summer range.We will test for spatial predictions of overgrazing on the availability of forages in summer using two different approaches.First, we will quantify the level of tannins in plant samples collected during previous field efforts by BLM and Alaska Fish and Game biologists. Second, we will test to see if there are differences in plant quality of caribou diet in high and low caribou density areas.Chemical nutrition analysis- To determine the chemical nutritional quality in forage, plant samples collected during the 2018 and 2019 field seasons will be prepared and sent to the Wildlife Habitat and Nutrition Lab at Washington State University for chemical nutritional analysis.We will quantify sequential fibers (% neutral detergent fiber [NDF], % acid detergent fiber [ADF], % acid detergent lignin [ADL];Van Soest 1982), micro minerals, and crucially here, tannin production in forage samples(Hanley et al. 1992).A key prediction of density dependence is that tannin concentrations will increase in areas of high caribou abundance.Objective 2 - How can we Adapt Twenty-Five Years of Cooperative Caribou Harvest Management for Success and Climate Change?The FMCH population provides a unique opportunity to examine social-ecological questions and how management of this herd may respond to overgrazing.The Harvest Management Coalition (HMC) was created to write harvest management plans for the FMCH and is comprised of representatives from a variety of local advisory committees, regional councils and Yukon Territory and First Nation government groups.Local advisory committees (i) are local groups that meet to discuss wildlife issues, (ii) provide a local forum for wildlife resource issues and (iii) provide recommendations to the Alaska Board of Game.Over the last 25 years, this cooperative and multi-stakeholder approach has been a success story in accomplishing mutual goals of growing the herd.The FMCH has grown to > 80,000 individuals and there is now concern the herd may be reaching carrying capacity.Some groups are concerned population declines will occur in the near future from the herd overshooting carrying capacity and thus, increased hunting quotas should be implemented to reduce caribou numbers and release overgrazing pressure across the herd's range.Alternatively, others believe management efforts should focus on the continued growth of the herd to achieve maximum range expansion into new ranges.Reconciling different management concerns in a new situation of abundant caribou may benefit from focused study of the socioecological management system.Here, we will test how management actions and decisions for the FMCH might adapt practices to account for population changes brought on by increasing caribou densities and climate?Objective 1 will give us a better understanding of where the FMCH population size in relation toKso that we might better inform decisions of density-dependent harvest.Here, in objective 2, we will focus on socio-ecological study of the Harvest management coalition itself to understand how harvest management actions can adapt to a growing caribou population as well as fire and climate change.?Social Science Interviews -We will first conduct three key informant interviews with those directly involved with FMCH research and management.Key informant interviews are those focused on a select group of individuals who can provide required insight, ideas and information on a certain subject.Two characteristics of qualitative key informant interviews are that 1) only a small number of informants are interviewed and 2) the unstructured and informal nature of these interviews gives them special relevance(Kumar 1989).Using information collected from three key informants, a social survey will be developed and sent/presented in person to 25 - 30 people involved with management of the FMCH.This group will include institutional representation from the Harvest Management Coalition, federal and state biologists, First Nations, Alaska natives and backcountry outfitters. Travel funding is requested to conduct the key informant interviews, to attend the next HWC meeting, and to administer the social science interviews amongst HWC members. Travel is anticipated to be completed by summer 2020.Travel is then requested for results of the social science survey to be reported back to the HWC in person in 2021.