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Geology topics

D.M. Graber

Publications and source records attributed to D.M. Graber.

6 recordsLinked to original sources
USGS2011

Proactive conservation management of an island-endemic bird species in the face of global change

Biodiversity conservation in an era of global change and scarce funding benefits from approaches that simultaneously solve multiple problems. Here, we discuss conservation management of the island scrub-jay ( Aphelocoma insularis ), the only island-endemic passerine species in the continental United States, which is currently restricted to 250-square-kilometer Santa Cruz Island, California. Although the species is not listed as threatened by state or federal agencies, its viability is nonetheless threatened on multiple fronts. We discuss management actions that could reduce extinction risk, including vaccination, captive propagation, biosecurity measures, and establishing a second free-living population on a neighboring island. Establishing a second population on Santa Rosa Island may have the added benefit of accelerating the restoration and enhancing the resilience of that island's currently highly degraded ecosystem. The proactive management framework for island scrub-jays presented here illustrates how strategies for species protection, ecosystem restoration, and adaptation to and mitigation of climate change can converge into an integrated solution.

California↗
USGS2002

Alien plant species threat assessment and management prioritization for Sequoia-Kings Canyon and Yosemite National Parks

Executive Summary This document reports the results of alien species surveys at Sequoia-Kings Canyon and Yosemite national parks. It includes the findings of a comprehensive literature review of the biology and ecology of all alien plant species found during these surveys and the ranking of those species for prioritizing management and control programs. Surveys primarily targeted areas of human disturbance, such as campgrounds, corrals, developments, roads, trails and pastures. Alien species richness was compared across elevational gradients within the parks. To compare and contrast species composition among sites, an exploratory cluster analysis of the sites included in the speciesrichness- by-elevation figures was conducted using ordination techniques. All alien species discovered during the directed surveys were grouped into one of four management priority categories based on their attributes, potential impacts, and geographical extent. Category 1 species are aliens that are currently restricted to a relatively small number of sites in each park and have either been shown to greatly affect native vegetation or have a high probability of causing serious impacts. Category 2 species are restricted to a relatively small number of sites and are ones that generally have a lesser effect on native vegetation. Category 3 species are broadly distributed in the parks, are apparently increasing their ranges within the parks, and are those that have been shown to have a great impact on native vegetation. Category 4 species are those that were detected by the surveys but not assigned to one of the three ranked categories and are considered low priority.

Open-File Report↗
USGS1997

Management of Sequoiadendron giganteum and Sequoia sempervirens forests in the reserves of California - Considerations of ecology and conservation

Giant sequoia ( Sequoiadendron giganteum ), also known as “Bigtree” and “Sierra Redwood,” is entirely restricted to the Sierra Nevada mountain range in the State of California, while coast redwood ( Sequoia sempervirens ) is restricted to coastal northern California, extending northward slightly into the State of Oregon. Both charismatic species, members of the family Taxodiaceae, have served as important cultural icons in America, and both have played important roles in the history of nature conservation. The two species share important ecological similarities as well as significant differences; these ecological factors have become increasingly important in effecting their conservation, and in developing successful strategies for the long-term sustainable management of the forest communities in which they occur. The bulk of giant sequoia groves occur in reserves protected from logging, while only a small proportion of coast redwoods are similarly protected. For most of its history in the 20th century, conservation has been concerned with protecting uncut “old-growth” forest stands of giant trees. While this remains of great concern to the public, scientists and reserve managers have, in recent decades, extended their interest to what is known as “ecosystem management,” which includes all aspects of the natural ecosystems in which coast redwoods and giant sequoias occur. For the first time, attempts are presently beginning--in those areas outside the national parks, state parks, and other reserves, to reconcile some levels of timber harvest with the long-term sustainable preservation of the character and biodiversity of giant sequoia and redwood forests.

California↗
USGS1986

Natural fire management in national parks

An evolving understanding of ecological processes, together with ambiguities in National Park Service policy, have led to multiple interpretations of the role of management in our large natural area National Parks. National Park Service management policies must be dynamic and responsive to changes in scientific knowledge and societal values. We propose that the principal aim of NPS resource management in natural areas is the unimpeded interaction of native ecosystem processes and structural elements. The case of the changing role of natural fire management is used as an example in developing this rationale.

Environmental Management↗