Wolf Management
CiteSpace
To find the pivotal article around the wolf controversy, we made a general search in the Web of Knowledge. We marked all the search results and saved the records, including the citations, to a file so we could upload them into CiteSpace. We had 202 results from the Web of Knowledge that was uploaded to CiteSpace. CiteSpace is an application that visualizes and analyzes trends and patterns in scientific literature. Once this information is imported into CiteSpace there are large purple circles that indicate the articles that are pivotal within the search on the Web of Knowledge. As the circles get smaller and not colored they are less pivotal but still are a part of the controversy. From this pivotal article, it links to the articles that have cited or referenced it directly or indirectly; it also shows the clusters that are citing the article.
Pivotal Article Surround the Gray Wolf
The article, Moose Browsing and Soil Fertility in the Boreal Forests of Isle Royale National Park by J. Pastor and B. Dewey, is a pivotal article surrounding the controversy of the reintroduction of the gray wolf into Yellowstone National Park. They discuss that selection on hardwoods by moose with the avoidance of conifers alters community composition and structure, which in turn can affect nutrient cycles and productivity. There results show that the moose affects the ecosystem by addressing both the quantity and quality of litter returning to the soil, and hence N mineralization and net primary productivity, by browsing on hardwoods. This will increase the productivity of the shrub, conifer, due to the opening of the canopy since moose prevent the in-growth of browsed seedling and saplings to the tree stratum. “This positive and degenerative feedback can continue until all of the net primary production is concentrated in unbrowsed spruce and moose consumption exceeds browse production” (Pastor and Dewey 1993). At this point, the moose population will collapse because of food limitation.
The sub-topics or clusters that have used this article are the moose-forest-soil ecosystem and the gray wolf restoration. This article has been influential to the moose-forest-soil ecosystem because it has identified the possible impacts that ungulate species, such as moose, have on the dynamics of the ecosystem. It is important to note that without the predator-prey interaction of the gray wolf in the Yellowstone National Park that its ecosystem could be very vulnerable to the over browsing of hardwoods. This is where the article is related to the gray wolf restoration efforts in Yellowstone National Park. This cluster has been influenced by Pastor and Dewey’s article because it shows the importance the gray wolf has to the balance of an ecosystem. It was important to reintroduce the wolf back into Yellowstone National Park to reduce the moose and elk populations which would reduce the over browsing of hardwoods and therefore increase the growth of seedling and saplings.
The sub-topics or clusters that have used this article are the moose-forest-soil ecosystem and the gray wolf restoration. This article has been influential to the moose-forest-soil ecosystem because it has identified the possible impacts that ungulate species, such as moose, have on the dynamics of the ecosystem. It is important to note that without the predator-prey interaction of the gray wolf in the Yellowstone National Park that its ecosystem could be very vulnerable to the over browsing of hardwoods. This is where the article is related to the gray wolf restoration efforts in Yellowstone National Park. This cluster has been influenced by Pastor and Dewey’s article because it shows the importance the gray wolf has to the balance of an ecosystem. It was important to reintroduce the wolf back into Yellowstone National Park to reduce the moose and elk populations which would reduce the over browsing of hardwoods and therefore increase the growth of seedling and saplings.
| moosebrowsingandsoilfertilityintheborealforestofisleroyalenationalpark.pdf |
Related Clusters
Two research clusters that can be found related to this article, and the controversy over the wolf's endangered status in general, are clusters revolving around the moose-forest-soil ecosystem, and gray wolf restoration. Both of these are important to consider because the gray wolf population has direct effects on the moose-forest-soil ecosystem that must be considered in its restoration, and ultimately its conservation. One of the articles in the moose-forest-soil ecosystem cluster, for example, by S.J. McNaughton, discusses grass-ungulate species relationships in general in the Serengeti and how ungulate species affect plant growth and productivity. In this study, a permanent enclosure was built in the chosen study area where plant biomass and above-ground net productivity was calculated, as well as grazing intensity. Results indicated that overgrazing in the Serengeti had actually resulted in compensatory growth responses from the plants, improving their competitive fitness; however, this was not without cost, and in the long run, their absolute fitness may be impaired. In another study by John Bryant and Peggy Kuropat , plant palatability and its influence on herbivore/ungulate species foraging patterns was looked at, as they attempted to determine whether subarctic herbivores preferred to seek out plants with high nutritional value and high energy, or avoid plants with high concentrations of secondary compounds that may be harmful to them. Their results indicated that the herbivores prefer avoiding plants with potentially harmful secondary compounds, and do not select their forage based on nutritional content.
Both of these articles from this cluster studied the relationship between ungulate species and the plants/grass they feed on, and how this relationship impacts the ecosystem as a whole. This has immediate applications to the controversy over the wolf, because if it is shown that the ungulate species are overgrazing, causing severe damage to the ecosystem, then their numbers must be regulated; and since wolf prey on these ungulate species, it provides a good reason to keep them under protection so that they can keep their numbers under control. Likewise, it provides a good foundation for gray wolf restoration efforts, particularly in areas where overgrazing has become an issue. They are an important part of the ecosystems in which they reside, and are suffering from not only hunting, but also habitat loss. A study in certain localities in North America, conducted by Niles Lehman, et al. also reveals that male gray wolves, unable to find female wolf mates, have begun pairing off with female coyotes instead, threatening their genetic integrity. This shows that wolf populations are still low and in need of protection, evidenced by the fact that some male wolves are unable to find mates; and not only that, but that situation will worsen, if the insidious effects of hybridization with coyotes is allowed to continue. Both of these clusters then, the "moose-forest-soil ecosystem" and "gray wolf restoration" can be used in support of the "pro-wolf" side of the controversy.
| moose_forest_soil1.pdf |
| moose_forest_soil2.pdf |
| gray_wolf_restore1.pdf |
