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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The plant phenology monitoring design for The National Ecological Observatory Network

Elmendorf, Sarah C., Jones, Katherine D., Cook, Benjamin I., Diez, Jeffrey M., Enquist, Carolyn A. F., Hufft, Rebecca A., Jones, Matthew O., Mazer, Susan J., Miller-Rushing, Abraham J., Moore, David J. P., Schwartz, Mark D., Weltzin, Jake F. 04 1900 (has links)
Phenology is an integrative science that comprises the study of recurring biological activities or events. In an era of rapidly changing climate, the relationship between the timing of those events and environmental cues such as temperature, snowmelt, water availability, or day length are of particular interest. This article provides an overview of the observer-based plant phenology sampling conducted by the U.S. National Ecological Observatory Network (NEON), the resulting data, and the rationale behind the design. Trained technicians will conduct regular in situ observations of plant phenology at all terrestrial NEON sites for the 30-yr life of the observatory. Standardized and coordinated data across the network of sites can be used to quantify the direction and magnitude of the relationships between phenology and environmental forcings, as well as the degree to which these relationships vary among sites, among species, among phenophases, and through time. Vegetation at NEON sites will also be monitored with tower-based cameras, satellite remote sensing, and annual high-resolution airborne remote sensing. Ground-based measurements can be used to calibrate and improve satellite-derived phenometrics. NEON's phenology monitoring design is complementary to existing phenology research efforts and citizen science initiatives throughout the world and will produce interoperable data. By collocating plant phenology observations with a suite of additional meteorological, biophysical, and ecological measurements (e.g., climate, carbon flux, plant productivity, population dynamics of consumers) at 47 terrestrial sites, the NEON design will enable continental-scale inference about the status, trends, causes, and ecological consequences of phenological change.
2

Design for ground beetle abundance and diversity sampling within the National Ecological Observatory Network

Hoekman, David, LeVan, Katherine E., Ball, George E., Browne, Robert A., Davidson, Robert L., Erwin, Terry L., Knisley, C. Barry, LaBonte, James R., Lundgren, Jonathan, Maddison, David R., Moore, Wendy, Niemelae, Jari, Ober, Karen A., Pearson, David L., Spence, John R., Will, Kipling, Work, Timothy 04 1900 (has links)
The National Ecological Observatory Network (NEON) will monitor ground beetle populations across a network of broadly distributed sites because beetles are prevalent in food webs, are sensitive to abiotic factors, and have an established role as indicator species of habitat and climatic shifts. We describe the design of ground beetle population sampling in the context of NEON's long-term, continentalscale monitoring program, emphasizing the sampling design, priorities, and collection methods. Freely available NEON ground beetle data and associated field and laboratory samples will increase scientific understanding of how biological communities are responding to land-use and climate change.
3

Survey and Analysis of Local Forestry-Related Ordinances in the Northeast, Mid-West, and Western United States

Johnson, William F. 07 April 2003 (has links)
In the United States, federal, state, and local forest policies affect many aspects of the forest industry. Regulations from all levels dictate how resource professionals manage the forest resources of the country. This study examines state and local regulatory relationships with a primary focus on local regulations in the Northeast, Mid-West, and western regions of the United States. A total of 388 local forestry ordinances were identified among the 35 states of the Northeast, Mid-West, and western regions of the United States. The Northeast contains the majority of local forest ordinances with 351. These ordinances are distributed among 8 states and many small local government types. The Mid-West currently embraces fewer local forest regulations with 16 ordinances across 4 states. In the West, 21 local forestry ordinances were found of which most are fostered by comprehensive forest practice acts. The primary objective of most local regulations in all regions is to regulate timber harvesting to some degree. The scope of the remaining local regulations; however, varied by region. The presence of local regulations has existed for over 30 years, and there are indications that they will have an even greater impact on forest management in the future. In addition, local regulations are steadily becoming more comprehensive in scope, which makes it difficult to determine their impacts. The cumulative impact of local regulation rests not only in the number of ordinances, but also in the area they govern, stringency of provisions, local resource conditions, and degree of enforcement. / Master of Science
4

Climate change is advancing spring onset across the U.S. national park system

Monahan, William B., Rosemartin, Alyssa, Gerst, Katharine L., Fisichelli, Nicholas A., Ault, Toby, Schwartz, Mark D., Gross, John E., Weltzin, Jake F. 10 1900 (has links)
Many U.S. national parks are already at the extreme warm end of their historical temperature distributions. With rapidly warming conditions, park resource management will be enhanced by information on seasonality of climate that supports adjustments in the timing of activities such as treating invasive species, operating visitor facilities, and scheduling climate-related events (e.g., flower festivals and fall leaf-viewing). Seasonal changes in vegetation, such as pollen, seed, and fruit production, are important drivers of ecological processes in parks, and phenology has thus been identified as a key indicator for park monitoring. Phenology is also one of the most proximate biological responses to climate change. Here, we use estimates of start of spring based on climatically modeled dates of first leaf and first bloom derived from indicator plant species to evaluate the recent timing of spring onset (past 10-30 yr) in each U.S. natural resource park relative to its historical range of variability across the past 112 yr (1901-2012). Of the 276 high latitude to subtropical parks examined, spring is advancing in approximately three-quarters of parks (76%), and 53% of parks are experiencing "extreme" early springs that exceed 95% of historical conditions. Our results demonstrate how changes in climate seasonality are important for understanding ecological responses to climate change, and further how spatial variability in effects of climate change necessitates different approaches to management. We discuss how our results inform climate change adaptation challenges and opportunities facing parks, with implications for other protected areas, by exploring consequences for resource management and planning.

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