16 research outputs found
Beyond Trust Species: The Conservation Potential of the National Wildlife Refuge System in the Wake of Climate Change
Over the last two decades, the U.S. Fish and Wildlife Service (“FWS”) has come to define its conservation mission in the context of species protection. The concept of “trust species” is now a common focal point for the myriad responsibilities of the FWS. This has become problematic for one of the major programs of the agency: management of the world’s largest biodiversity conservation network, the national wildlife refuge system (“NWRS”). A major legislative overhaul of the NWRS charter and the imperatives of climate change adaptation have weakened the concept as a reliable touchstone for NWRS management and expansion. The FWS should build on its culture and history to respond to new challenges that the conservation network cannot meet with the “trust species” concept alone. While management to benefit specific species offers a simple measure of accomplishment, as a policy tool it creates more problems than it solves. Adherence to the “trust species” theme limits full engagement with, and abdicates the FWS’ leadership role in, contemporary conservation challenges and science. This article makes the case for alternative measures of NWRS conservation success that move beyond just counting populations.
We begin in Part I by tracing the rise of the trust concept to prominence as the dominant FWS conservation theme. We illustrate how the idea works in practice with three examples. In Part II we proceed to analyze what the “trust species” theme offers for conservation objectives and what problems it presents for the NWRS. We conclude that, on balance, its strengths do not justify its predominance. In particular, the trust concept has four problems. First, it fails to capture the full, systemic statutory mandate, and thus neglects an important part of Congress’ instructions. Second, it invites confusion with real federal trust duties pertaining to natural resources damages and relations with Indian tribes. Third, it risks conflation with state public trust doctrines, and therefore blurs the distinction between the FWS’ functions and the state role in wildlife management. Fourth, it narrows the FWS’ conservation vision to only a few elements of the broader ecological concerns animating landscape-level nature protection. Part III shows how climate change, ecosystem management, and land acquisition would be better addressed through a broader approach. We conclude with some suggestions for alternatives to the reductive “trust species” focus. Ecological integrity offers a more accurate theme for the NWRS goals, a more robust tool for adapting to climate change, and a concept that the scientific literature recognizes and quantifies
Beyond Trust Species: The Conservation Potential of the National Wildlife Refuge System in the Wake of Climate Change
Factors Affecting Attwater\u27s Prairie-Chicken Decline on the Attwater Prairie Chicken
We examined the association between changes in the number of Attwater\u27s prairie- chicken (Tympanuchus cupido attwateri) on the Attwater Prairie Chicken National Wildlife Refuge from 1972 to 1993 and changes in refuge management practices (burning and grazing). We also examined the relationship of prairie-chicken population increases and decreases on the refuge to rainfall and off-refuge prairie-chicken populations. Burning within the prairie-chicken\u27s core habitat on the refuge and variability in grassland structure were directly correlated (P\u3c 0.05) with increases and declines in prairie-chicken populations. Refuge population increases and declines were inversely correlated (P\u3c 0.1) with average April rainfall/event, May absolute departure from long-term average rainfall, May number of rainfall events, annual absolute departure of rainfall from the long-term average, and the annual number of rainfall events. Refuge population increases and declines were directly correlated (P \u3c 0.1) with off-refuge populations, although the off- refuge population decline began 4 years earlier than on-refuge
Structure–property relationships of cellulose nanofibril hydro- and aerogels and their building blocks
ISSN:2040-3364ISSN:2040-337
Nanostructural Properties and Twist Periodicity of Cellulose Nanofibrils with Variable Charge Density
Cellulose
nanofibrils (CNFs) are a renewable and facile to produce
nanomaterial that recently gained a lot of attention in soft material
research. The nanostructural properties of the fibrils largely determine
their self-organizing functionalities, and the ability to tune the
CNF nanostructure through control of the processing parameters is
therefore crucial for developing new applications. In this study,
we systematically altered the CNF production parameters (i.e., variation
in cellulose source, chemical, and mechanical treatment) to observe
their impact on the nanostructural properties of the resulting fibrils.
Atomic force microscopy (AFM) allowed detailed topological examination
of individual CNFs to elucidate fibril properties such as contour
length, kink distribution and the right-handed twist periodicity of
individual fibrils. Statistical analysis revealed a large dependency
of the fibril properties on the industrial treatment of the cellulose
source material. Our results furthermore confirm that the average
charge density of the fibrils regulates both contour length and twist
periodicity and, thus, has a very strong impact on the final morphology
of CNFs. These results provide a route to tune the detailed nanostructure
of CNFs with potential impact on the self-organization of these biological
colloids and their optimal use in new nanomaterials
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Climate Change Adaptation for the US National Wildlife Refuge System
Since its establishment in 1903, the National Wildlife Refuge System (NWRS) has grown to 635 units and 37 Wetland Management Districts in the United States and its territories. These units provide the seasonal habitats necessary for migratory waterfowl and other species to complete their annual life cycles. Habitat conversion and fragmentation, invasive species, pollution, and competition for water have stressed refuges for decades, but the interaction of climate change with these stressors presents the most recent, pervasive, and complex conservation challenge to the NWRS. Geographic isolation and small unit size compound the challenges of climate change, but a combined emphasis on species that refuges were established to conserve and on maintaining biological integrity, diversity, and environmental health provides the NWRS with substantial latitude to respond. Individual symptoms of climate change can be addressed at the refuge level, but the strategic response requires system-wide planning. A dynamic vision of the NWRS in a changing climate, an explicit national strategic plan to implement that vision, and an assessment of representation, redundancy, size, and total number of units in relation to conservation targets are the first steps toward adaptation. This adaptation must begin immediately and be built on more closely integrated research and management. Rigorous projections of possible futures are required to facilitate adaptation to change. Furthermore, the effective conservation footprint of the NWRS must be increased through land acquisition, creative partnerships, and educational programs in order for the NWRS to meet its legal mandate to maintain the biological integrity, diversity, and environmental health of the system and the species and ecosystems that it supports