Abstract This paper considers the potential for co-evolutionary interactions between plant secondary compounds and browsing mammals in a relatively simple system. It first briefly presents several theoretical ideas on plant-animal co-evolution and then present the evidence on interactions between mammalian browsers and woody plants in boreal regions that may bear on the co-evolutionary questions.
Paper Outline:
Introduction
Theoretical Co-evolution
Browsers and Food Plants in the Boreal Forest
Variation in Secondary Compounds and Browsing Resistance
Estimating Plant Fitness
The Herbivores: Hares, Moose, and Voles
Conclusion
From the Paper "The evidence for the effects of secondary compounds on fitness has not been measured directly for boreal mammals. However, the evidence presented above suggests that they may be important. Both the fine-scale selectivity of browsers among similar plants and plant parts that vary in their levels of secondary compounds (Bryant et al. 1991a,b, Bryant et al. 1992) and the potentially severe effects of these chemicals on the herbivores' nutritional status (Iason and Palo 1991) suggest that the ability to avoid or detoxify secondary compounds is a result of selection."
Abstract This paper presents a discussion about the effects of global warming on the Northern Boreal Forest. The author takes us on a tour of the forest itself and the effects that the global warming process has on the forest as well as what the future impact will be.
Abstract The paper discusses a study undertaken as a collaborative effort by three different authors, that attempts to use the theory of gap dynamics to resolve the inconsistencies between the general belief that aspen stands are generally younger and uniform in age, versus available qualitative estimates that are consistent with much older forests. The paper examines how their conclusions and results raise a number of poignant issues, including environmental sustainability and CO2 emissions.
From the Paper "The long term success of any forest management program is dependent upon how accurate the data is. The trembling aspen (populus tremuloides) is an example of a tree commonly found in western boreal forests and is the main focus of this research paper. This study, undertaken as a collaborative effort by three different authors, attempts to use the theory of gap dynamics to resolve the inconsistencies between the general belief that aspen stands are generally younger and uniform in age, versus available qualitative estimates that are consistent with much older forests. The authors consistently argue that parts of Northern Alberta's boreal mixed wood forests are older than is generally thought, and is therefore being incorrectly managed."
Abstract This paper reviews and answers two questions. The first of these deals with carbon sequestration and whether or not Canada should use its boreal forests in pursuit of this aim. The second question discusses how a forest manager can best utilize her available budget to re-seed the areas falling under her jurisdiction. After some thought, the paper argues that a mix of aerial re-seeding and natural regeneration is the best way to go.
From the Paper "Question 4: Whether or not the Boreal forest region of Canada should be used to sequester Carbon that Canadians emit into the Atmosphere. A: For one thing, the boreal forest region comprises 58 percent of Canada's landmass ("About Canada's Boreal", sec.2). That leaves only 42 percent of the rest of the country. Therefore, it seems logical to infer that whatever carbon dioxide the rest of the country can produce, the boreal region can effectively store it. Moreover, trees obviously store carbon as part of their own process of respiration, so this would policy of carbon sequestration would not impose an undue burden upon valuable wildlife (at least tree "wildlife" anyway)."
Abstract The Arctic National Wildlife Refuge is the most promising onshore area for oil exploration and one of the wildest areas remaining in the United States. Therefore, the conflict between the need to develop energy resources and the desire to preserve wild areas has led to the prolonged debate over the merits of programs to lease the region for oil exploration and development. According to the paper, drilling in the Arctic National Wildlife Refuge would cause environmental costs that include some elements that are essentially certain, as well as elements that are uncertain, such as the unpredictable effects on the number and health of certain important species. The paper concludes that development is environmentally damaging no matter the cautions, because it alters the wild state of the region forever.
From the Paper "When Alaska entered the Union in 1958, Congress transferred an exceptionally large amount of land to the new state, and at the same time, the Department of the Interior used its authority to administratively reserve land for federal use, resulting to decades of controversy and disputes (Grover). Since 1957, the United States Department of the Interior has exercised primary administrative authority over most of the land comprising modern-day ANWR Grover). This fact has meant that a great deal to people who care about the Refuge (Grover). Federal management has produced a land that is valued as much for its unique wilderness character as it is prized for its suspected mineral wealth, and in particular, it has precluded significant petroleum exploration and development of the Refuge (Grover)."
Abstract This paper discusses the factors that regulate the population size of the lynx canadensis, the Canadian lynx that is common to boreal forests in nearly all of Canada, Alaska and the northern contiguous United States. It specifically looks at environmental, predation, competition and food availability factors. The paper includes graphs in its explanations.
From the Paper "When the hare population begins to increase, the Lynx population follows the trend, as there is more prey available to feed on. Once the point where there are more hares being killed than are being born is reached, the prey population begins to fall. Due to the decreasing food supply, the Lynx population begins to suffer and declines as well. This is crucial in understanding why the lynx species does not grow out of control or suffer extinction (King & Schaffer 2001). During the low cycle of the hare population, the Lynx switches to hunting red squirrels; this shows the adaptive capabilities of the lynx that prevent the species from going completely extinct. However, as the hare population begins to rebound, the Lynx return to the hare as its primary source of prey and the cycle begins again (O'Donoghue et. al. 1998). The Lynx shows clear functional responses to changes in the densities of hares. Kill rates of the lynx varied from 0.3 to 1.2 hares per day, with the highest kill rate being one year after the peak in hare density (King & Schaffer 2001). This cyclic concept is illustrated in Figure 2."
