Scholarly Work - Ecology
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Item Exotic Grass Invasion Increases Forage Productivity and Reduces Diversity of a High Altitude Mesic Grassland(Montana State University, 2021-02) Weaver, T; Bao, SMesic temperate rangeland, e.g. from the North American mixed grass prairie, Rocky Mountain grasslands and southern hemisphere continents is being invaded by the exotic rhizomatous grasses, Poa pratensis and Bromus inermis. To project the effects of their invasion on one grassland, we compared community properties in- and outside of clones invading a level environmentally homogeneous meadow representative of our high altitude fescue grasslands. Yields increased from native vegetation dominated by Festuca idahoenis (Feid, x= 96 gm/m2) through exotic vegetation dominated by Poa (x= 158 gm/m2) to Brome (x= 258 gm/m2) with little difference in forage quality (protein content). Some, e.g. a grazier, might therefore view the change as beneficial. Measurement of community composition in the three communities showed a considerable impoverishment of the native fescue (Feid) community by exotic invasion, an impoverishment understated by measured reduction in species richness [i.e. from Feid (16-12 species per 1.13m2) through Poa (11) to Brome (4 ); species evenness (Simpson) [i.e. from 88-84 to 81 to 42 ]; and life-form evenness (%forb) [i.e, Feid (42-34%) through Poa (23%) to Brome (5%). The impoverishment probably resulted first, from competitive exclusion of natives by lack of soil resources captured by exotics (whose entry surely demonstrated a superior capacity to acquire water and nutrients) and second, for natives associated with taller Brome, from a reduction of ground-level light, a deficiency confirmed by etiolation of the natives. Conservationists will surely decry the losses. Due to the inexorable rhizomatous spread of Poa and Brome and the resultant impossibility of controlling them, we deduce that managers should accept the foresee-able [vegetation] type-conversion and develop methods for managing/using the new vegetation- - a resigned reaction paralleling the response necessary for other anthropogenic factors: urbanization, N-supplementation, pollution and climate change. We expect parallel responses in other mesic grasslands. Sampling and statistics completed 2014- 20l5. 1st draft reviewed 2016.Item Distribution of Exotic Plants in the N. Rocky Mountains by Environmental Type and Disturbance Condition(Montana State Univeristy, 1989-06) Weaver, T.; Gustafson, D.; Lichthardt, J.; Woods, B.This report lists seventy-three exotic species found in a systematic sampling of major environmental zones of the Rocky Mountains between the Canadian border and central Wyoming. For each exotic it states the regional distribution, the environmental types (HTs) it occupies (% constancy), the disturbance conditions (DCs) it occupies (% constancy), and its dominance (in terms of% frequency and% cover) in each cell of the HT x DC matrix. Park managers need to develop policy with respect to legally noxious weeds, forage grasses (eg Phleum pratense, Poa pratensis, Bromus inermis, and Dactylis glomerata), and forage legumes (eg Melilotus and Trifolium spp).Item PLANTS ESTABLISHING IN ROCKY MOUNTAIN ENVIRONMENTS-- a manual for choosing native species for revegetation(Montana State University, 1995) Weaver, T.; Gustafson, D; Lichthardt, JSpecies which have established naturally on a disturbed site in a given environment-- climate and disturbance level (defined below)-- are good candidates for revegetation plantings in that environment. On this basis we recommend native plants (grasses, forbs, and shrubs) for revegetation plantings, if they occur on at least half of the sites sampled in the environmental type and cover at least 1% of the ground there. We also list exotic plants establishing on once disturbed roadside sites; if these plants do not invade native vegetation they might, under some circumstances, be used for revegetation The environmental types considered include dry grasslands (BOGR/STCO and AGSP/BOGR), moist grasslands (FESC/FEID and FEID/AGCA) sagebrush (ARAR/FEID and ARTRVAS/FEID) , warm dry forests (PSME/ SYAL and PSME/PHMA), warm moist forests (POTR/CARU, THPL/OPHO, TSHE/CLUN, ABLA/CLUN), cool forests (ABLA/XETE, ABLA/ARCO, and ABLA/VACC), mountain meadows (FEID/AGCA, listed above) and alpine (DESC/CARX) . In each environment plant performance is contrasted across five disturbance types: continually disturbed types (roadshoulders and the adjacent ditch slope), once disturbed sites (roadcuts with organic matter removed and cleared right-of-way without organic matter removal), and undisturbed late seral sites.Item Greater Yellowstone climate assessment: past, present, and future climate change in greater Yellowstone watersheds(Montana State University, Institute on Ecosystems, 2021-06) Hostetler, Steven; Whitlock, Cathy; Shuman, Bryan; Liefert, David; Drimal, Charles Wolf; Bischke, ScottThe Greater Yellowstone Area (GYA) is one of the last remaining large and nearly intact temperate ecosystems on Earth (Reese 1984; NPSa undated). GYA was originally defined in the 1970s as the Greater Yellowstone Ecosystem, which encompassed the minimum range of the grizzly bear (Schullery 1992). The boundary was enlarged through time and now includes about 22 million acres (8.9 million ha) in northwestern Wyoming, south central Montana, and eastern Idaho. Two national parks, five national forests, three wildlife refuges, 20 counties, and state and private lands lie within the GYA boundary. GYA also includes the Wind River Indian Reservation, but the region is the historical home to several Tribal Nations. Federal lands managed by the US Forest Service, the National Park Service, the Bureau of Land Management, and the US Fish and Wildlife Service amount to about 64% (15.5 million acres [6.27 million ha] or 24,200 square miles [62,700 km2]) of the land within the GYA. The federal lands and their associated wildlife, geologic wonders, and recreational opportunities are considered the GYA’s most valuable economic asset. GYA, and especially the national parks, have long been a place for important scientific discoveries, an inspiration for creativity, and an important national and international stage for fundamental discussions about the interactions of humans and nature (e.g., Keiter and Boyce 1991; Pritchard 1999; Schullery 2004; Quammen 2016). Yellowstone National Park, established in 1872 as the world’s first national park, is the heart of the GYA. Grand Teton National Park, created in 1929 and expanded to its present size in 1950, is located south of Yellowstone National Park1 and is dominated by the rugged Teton Range rising from the valley of Jackson Hole. The Gallatin-Custer, Shoshone, Bridger-Teton, Caribou-Targhee, and Beaverhead-Deerlodge national forests encircle the two national parks and include the highest mountain ranges in the region. The National Elk Refuge, Red Rock Lakes National Wildlife Refuge, and Grays Lake National Wildlife Refuge also lie within GYA.Item Evaluating Irrigation Efficiency: Toward a Sustainable Water Future for Montana(The Montana University System Water Center, 2020-11) Lonsdale, Whitney R.; Cross, Wyatt F.; Dalby, Charles E.; Meloy, Sara E.; Schwend, Ann C.Water is our most valuable natural resource, and is used to support the demands of industry, agriculture, hydroelectric power generation, and municipalities. Water also sustains Montana’s booming recreation and tourism economy and maintains the diverse freshwater ecosystems that provide natural goods and services and promote human well-being. As our population continues to grow, and the collective demand for water increases, it is imperative that we carefully assess how our water is used, as well as how changes in water distribution, management, and governance are likely to influence its availability in the future. This is especially important in the context of a changing climate.Item CLIMATE CHANGE AND HUMAN HEALTH IN MONTANA: A Special Report of the Montana Climate Assessment(Montana Institute on Ecosystems, 2020-12) Adams, Alexandra K.; Byron, Robert; Maxwell, Bruce D.; Higgins, Susan; Eggers, Margaret; Byron, Lori; Whitlock, CathyThe purpose of this assessment is to a) present understandable, science-based, Montana-specific information about the impacts of climate change on the health of Montanans; and b) describe how our healthcare providers, state leaders, communities, and individuals can best prepare for and reduce those impacts in the coming decades. This assessment draws from, and is an extension to, the 2017 Montana Climate Assessment (MCA1) (Whitlock et al. 2017), which provides the first detailed analysis of expected impacts to Montana’s water, forests, and agriculture from climate change. MCA explains historical, current, and prospective climate trends for the state based on the best-available science. The 2017 Montana Climate Assessment did not address the impact of climate change on the health of Montanans. This special report of the MCA fills that important knowledge gap; it represents a collaboration between climate scientists and Montana’s healthcare community and is intended to help Montanans minimize the impacts of climate on their health.Item 2017 Montana Climate Assessment: Stakeholder driven, science informed(Montana Institute on Ecosystems, 2017-09) Whitlock, Cathy; Cross, Wyatt F.; Maxwell, Bruce D.; Silverman, Nick; Wade, Alisa A.The Montana Climate Assessment (MCA) is an effort to synthesize, evaluate, and share credible and relevant scientific information about climate change in Montana with the citizens of the State. The motivation for the MCA arose from citizens and organizations in Montana who have expressed interest in receiving timely and pertinent information about climate change, including information about historical variability, past trends, and projections of future impacts as they relate to topics of economic concern.This first assessment reports on climate trends and their consequences for three of Montana’s vital sectors: water, forests, and agriculture. We consider the MCA to be a sustained effort. We plan to regularly incorporate new scientific information, cover other topics important to the people of Montana, and address the needs of the state.