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Publications

Explore WARC's science publications.

Filter Total Items: 3380

The Interface Between Theory and Data in Structural Equation Models

Structural equation modeling (SEM) holds the promise of providing natural scientists the capacity to evaluate complex multivariate hypotheses about ecological systems. Building on its predecessors, path analysis and factor analysis, SEM allows for the incorporation of both observed and unobserved (latent) variables into theoretically based probabilistic models. In this paper we discuss the interfa
Authors
James B. Grace, Kenneth A. Bollen

Back to the basics: Lake Tahoe, California /Nevada: Geography and mathematics

Back to the Basics: Lake Tahoe, California/Nevada* continues the Wetland Education Through Maps and Aerial Photography (WETMAAP) Program of exercises on teaching foundational map reading and spatial differentiation skills. It is the third published exercise from the Back to the Basics series developed by the WETMAAP Program. The current exercise modified is from the Lake Tahoe Back to the Basics w
Authors
Lawrence R. Handley, Catherine M. Lockwood, Nathan Handley

Vanishing before our eyes

No abstract available
Authors
Wylie C. Barrow, William R. Fontenot, Madeline H. Barrow, Richard A. DeMay, David Muth

Evaluation of eelgrass beds mapping using a high-resolution airborne multispectral scanner

Eelgrass (Zostera marina) can provide vital ecological functions in stabilizing sediments, influencing current dynamics, and contributing significant amounts of biomass to numerous food webs in coastal ecosystems. Mapping eelgrass beds is important for coastal water and nearshore estuarine monitoring, management, and planning. This study demonstrated the possible use of high spatial (approximately
Authors
H. Su, D. Karna, E. Fraim, M. Fitzgerald, J. S. Myers, R. Dominguez, B. Coffland, Lawrence R. Handley, T. Mace

A multivariate model of plant species richness in forested systems: Old-growth montane forests with a long history of fire

Recently, efforts to develop multivariate models of plant species richness have been extended to include systems where trees play important roles as overstory elements mediating the influences of environment and disturbance on understory richness. We used structural equation modeling to examine the relationship of understory vascular plant species richness to understory abundance, forest structure
Authors
D.C. Laughlin, J.B. Grace

Assessment of gamete quality for the eastern oyster (Crassostrea virginica) by use of fluorescent dyes

Evaluation of sperm motility is the single most widely used parameter to determine semen quality in mammals and aquatic species. While a good indicator for fresh sperm viability, post-thaw motility is not always effective at predicting fertilizing ability. Techniques using fluorescent dyes can assess functionality of mammalian sperm, but have not been widely applied in aquatic organisms. The easte
Authors
C. G. Paniagua-Chavez, J. Jenkins, M. Segovia, T.R. Tiersch

Responses of neotropical mangrove seedlings grown in monoculture and mixed culture under treatments of hydroperiod and salinity

We investigated the combined effects of salinity and hydroperiod on seedlings of Rhizophora mangle and Laguncularia racemosa grown under experimental conditions of monoculture and mixed culture by using a simulated tidal system. The objective was to test hypotheses relative to species interactions to either tidal or permanent flooding at salinities of 10 or 40 g/l. Four-month-old seedlings were ex
Authors
P. Cardona-Olarte, R.R. Twilley, K. W. Krauss, V. Rivera-Monroy

Genetic structure of natural and restored shoalgrass Halodule wrightii populations in the NW Gulf of Mexico

The decline of seagrass communities worldwide has sparked an urgent need for effective restoration strategies, which require a working knowledge of population genetic structure. Halodule wrighti is a common seagrass of the Caribbean region that is being restored to areas of the Gulf of Mexico, yet little is known of its population genetics. This study provides an assessment of individual, clonal a
Authors
S.E. Travis, P. Sheridan

Deep-water antipatharians: Proxies of environmental change

Deep-water (307-697 m) antipatharian (black coral) specimens were collected from the southeastern continental slope of the United States and the north-central Gulf of Mexico. The sclerochronology of the specimens indicates that skeletal growth takes place by formation of concentric coeval layers. We used 210Pb to estimate radial growth rate of two specimens, and to establish that they were several
Authors
B. Williams, Michael J. Risk, Steve W. Ross, K. J. Sulak

Seed dispersal in fens

Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and reducing genetic exchange. Species in fragmented wetlands may have lower reproductive success, which can
Authors
B. Middleton, R. Van Diggelen, K. Jensen

New geographic records of Hamlets, Hypoplectrus spp. (Serranidae), in the Caribbean Sea

The exact number of species of hamlets, Hypoplectrus spp., in the Caribbean is controversial and the geographic distributions of these species/forms are poorly documented. We report Curaçao, Netherlands Antilles, as a new locality for the Barred Hamlet, H. puella (Cuvier), and Shy Hamlet, H. guttavarius (Poey); and St. John and St. Thomas, U.S. Virgin Islands, for the Tan Hamlet, Hypoplectrus sp.
Authors
Ernest H. Williams, Lucy Bunkley-Williams, Caroline S. Rogers, Robert Fenner

Red mangrove (Rhizophora mangle) reproduction and seedling colonization after Hurricane Charley: Comparisons of Charlotte Harbor and Tampa Bay

Reproductive aspects of life history are known to be important in recovery following disturbance in many plant species although this has not been well studied in mangroves. Hurricane Charley devastated large areas of mangroves in Charlotte Harbor, Florida, in August 2004. We surveyed 6 forests in Charlotte Harbor (2002, 2003, and 2005) and 16 in Tampa Bay, Florida (2001, 2002, 2003, and 2005) for
Authors
C.E. Proffitt, E.C. Milbrandt, S.E. Travis
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