Food webs consist of a combination of bottom-up (resource-driven) and top-down (predator-driven) effects. The strength of these effects depends on the context in which they occur. I investigated food web (trophic) relationships between wolf (Canis lupus) predation, elk (Cervus elaphus) herbivory, aspen (Populus tremuloides Michaux) recruitment, and fire. The study...
Sustainable elk (Cervus canadensis) habitat management on U.S. Forest Service (USFS) lands involves a complex relationship between management practices and ecological processes. A relatively novel Rocky Mountain elk population (Cervus canadensis nelsoni) on the Plumas National Forest (PNF) in northeastern California became established in the early 2000s, but there is...
Like most ecological communities, aspen (Populus tremuloides) forests are influenced by a synergy of bottom-up (resources-driven) and top-down (predator-driven) processes. Since the 1920s, ecologists have observed the decline of many aspen communities throughout the Intermountain West. The extent and possible drivers of this decline are topics of much recent scientific...
Quaking aspen (Populus tremuloides) sustainability is a topic of intense interest in forest ecology.
Reports range from declines to persisting or increasing coverage in some areas. Moreover, there is little
agreement on ultimate factors driving changes. Low aspen recruitment has been attributed to climate
patterns, past management, herbivore increases, competitive...
This project examines the rulers of late medieval Castile, Enrique IV and Isabel I, and the controversies surrounding their reigns.
The paper begins with an examination of Isabel’s youth and education prior to her life at Enrique’s court. From there the troubles in Enrique’s reign are detailed beginning with discontented...
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Enrique’s first wife, Blanca. Daniel
Eisenberg surmises that Enrique petitioned for annulment from Blanca
This project examines the rulers of late medieval Castile, Enrique IV and Isabel I, and the controversies surrounding their reigns.
The paper begins with an examination of Isabel’s youth and education prior to her life at Enrique’s court. From there the troubles in Enrique’s reign are detailed beginning with discontented...
Full Text:
sought to annul their marriages. We know little about Enrique’s first wife, Blanca. Daniel Eisenberg
Beschta et al. (2013) synthesized the ecological effects 41 of climate change and ungulate
grazing on western public lands, grounding their recommendations in ecological considerations
and federal agency legal authority and obligations. Svejcar et al. (2014) suggest that Beschta et
al. (2013) neither “present a balanced synthesis of the scientific...
Aldo Leopold, perhaps best known for his revolutionary and poignant essays about nature, was also an eloquent advocate during the 1930s and 1940s
of the need to maintain wolves and other large carnivores in forest and range ecosystems.He indicated that their loss set the stage for ungulate irruptions
and ecosystem...
According to general top-down trophic theory, in the presence of carnivores, herbivore behavior and/or densities could change and result in an overall decrease in herbivory on plant communities. In this dissertation, I examined the potential relationship between gray wolf (Canis lupus) presence and absence on elk (Cervus elaphus) herbivory of...
Humans, in conjunction with natural top-down processes and through a sequence of cascading trophic interactions, may have contributed
to the Pleistocene megafaunal extinctions. The arrival of the first humans, as hunters and scavengers, through top-down forcing, could have
triggered a population collapse of large herbivores and their predators. We present...