Ecological Dynamics on Yellowstone's Northern Range (2002) / Chapter Skim
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5 Conclusions and Recommendations
5 Conclusions and Recommendations
Pages 120-137
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From page 120... ...
Thus, we probably cannot ever manage Yellowstone National Park (YNP) to maintain some agreed-upon stable condition, if that were to become a management objective.
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From page 121... ...
Research outside the park, however, does not support the hypothesis that a new state has become established (Kay ~ 9901. To evaluate whether the northern range is approaching a threshold, beyond which willow and aspen communities will be unable to reestablish themselves, we must have some idea of the range of natural variation (Landres et al.
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From page 122... ...
For wildlife managers, a desirable state usually is defined by a consistent harvest of the target species, stable vegetation communities, and a small Toss of the target animals to severe weather. Restoration ecologists, on the other hand, try to achieve desired ecosystem dynamics by reducing or eliminating human perturbations and restoring natural ecosystem processes and the ecosystem components that drive these processes.
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From page 123... ...
to an emphasis on rates and variation. Ecological processes include production of crowd-pleasing cohorts of elk and bison calves in spring, but they also include the interrelationships between all species, including competition, predation, winter starvation, and changes in vegetation communities.
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From page 124... ...
should explain the importance of ecosystem processes, trophic level relationships among species, primary production, and nutrient cycling. Although emphasis on biodiversity is certainly justified, the role of the area's landscape, climate, and history in maintaining the biodiversity of the area and its dynamic nature should be explained.
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From page 125... ...
A large spatial extent is also important to preserve key ecosystem processes in the face of disturbances that recur over periods of centuries and affect areas of tens to thousands of square kilometers. The large fires that burned much of YNP in 1988 are the most obvious example of such a phenomenon; other examples include the eruption of Mount St.
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From page 126... ...
Elk populations have been subjected to annual harvest outside YNP ever since its establishment, and late-season hunting was initiated in 1968. Thus, the condition of the animals and the winter range is likely to have been better since ~ 968 than if the population size had been regulated solely by natural factors, includingcompetition for forage and starvation.
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From page 127... ...
a severe winter that causes starvation, and (~) a vigorous predator population that can keep the elk population from rapidly recovering.
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From page 128... ...
UNDERSTANDING THE CONSEQUENCES OF ALTERNATIVE MANAGEMENT APPROACHES Resource managers at YNP use natural regulation as the management approach for the biota of the northern range for scientific reasons and to meet public expectations. In any natural resource management context, the selection of an approach is inevitably in part a value judgment.
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From page 129... ...
Adaptive management requires clearly defined goals, and it is predicated on use of a scientifically sound, comprehensive, integrated research program and {ong-term monitoring to determine the successes and/or consequences of management decisions. The following text explores the scientific lessons that might be learned from various management approaches, including natural regulation.
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From page 130... ...
However, this management approach also might confound our ability to understand the effects of wolf reintroduction, and the key disadvantage of the approach is that hunting success cannot be assured because elk might remain within the park, even during severe weather. Improve Opportunities for Increased Out-Migration Because lower elevation winter range outside the park has been greatly reduced, YNP resource managers could work with other state and federal agencies and land owners adjacent to the park to add more lands at lower elevations for winter use by ungulates.
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From page 131... ...
Natural Regulation YNP resource managers consider the northern range to be in acceptable condition and the role and numbers of ungulates and other wildlife appropriate for a national park, and the best available scientific evidence does not indicate that ungulate populations are irreversibly damaging the northern range (Chapter 41. In addition, several significant changes have been made in the northern range in recent years, including the reintroduction of wolves and expansion of the winter range outside the park; the long-term influence of these changes cannot yet be determined.
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From page 132... ...
One is that enough elk migrated out of the park in severe winters to greatly reduce browsing pressure on aspen. The other is that wolves, be
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From page 133... ...
The summer range does not seem to be limiting to the ungulate populations. Densities are relatively low on the summer range because the animals are spread out over larger areas than during winter-range use.
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From page 134... ...
Because of development on the park's borders, ungulates do not have free access to areas outside YNP that they formerly used during times of environmentally imposed stress. Because ungulate populations are influenced by activities both inside and outside the park, the conclusions in this report should not be interpreted as either vindication or criticism of YNP's natural regulation policy.
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From page 135... ...
· The NPS educational and outreach program can play an important role in fostering public understanding of the complex and dynamic nature of ungu{ate ecology in the GYE, which is an essential adjunct to effective management of northern Yellowstone ungulates. Therefore, we encourage the NPS to increase its focus on entire ecosystem relationships, processes, and dynamics of the GYE, especially emphasizing the importance of primary production and trophic-leve!
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From page 136... ...
The study should evaluate the likely consequences of a full range of potential management options, from doing nothing to actively controllingpredators and providing artificial winter feed. · Periodic surveillance for pathogens (including brucellosis)
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From page 137... ...
Human-induced climate change is expected to be yet another long-term influence on the ecosystem. Reconciling the laudable goals of preserving ecosystem processes and associated ecosystem components with human interests and influences on wildIands will be a growing challenge in the future, not only in the GYE.
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