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261.
Payton Quinn Hostetter Nathan J. Evans Allen F. 《Environmental and Ecological Statistics》2019,26(2):107-125
Environmental and Ecological Statistics - Identifying where, when, and how many animals live and die over time is principal to understanding factors that influence population dynamics.... 相似文献
262.
Species-specific variation in cuttlebone δ13C and δ18O for three species of Mediterranean cuttlefish
Michael A. Dance Giambattista Bello Nathan B. Furey Jay R. Rooker 《Marine Biology》2014,161(2):489-494
Stable carbon (δ13C) and oxygen (δ18O) isotopes in cuttlebones of three species of Mediterranean cuttlefish (Sepia elegans, S. officinalis, and S. orbignyana) with different life histories were contrasted. Cuttlebone δ13C and δ18O were quantified at both the core and edge (representing early life and recent deposition, respectively) for all three species sampled from the southern Adriatic Sea in 2010 (n = 28). For S. officinalis, cuttlebone δ13C and δ18O values were both lower relative to S. elegans and S. orbignyana at the core by approximately 1.0–2.0 and 3.0 ‰, respectively. Differences between core and edge in cuttlebone δ13C and δ18O were also observed for S. officinalis with observed values at the cuttlebone edge (recent) exceeding core (early life) values by 2.5 ‰ for δ13C and 1.4 ‰ for δ18O. Differences in isotopic composition across S. officinalis cuttlebones are possibly reflective of ontogenetic migrations from nearshore nurseries (lower seawater δ13C and δ18O values) to offshore overwintering habitats (higher seawater δ13C and δ18O values). Overall, results from this study suggest that cuttlebone δ13C and δ18O hold promise as natural tags for determining the degree of spatial connectivity between nearshore and offshore environments used by cuttlefish. 相似文献
263.
Derek R. Faust Nathan Knowles Elaine Magruder David A. Haukos George P. Cobb Jonathan D. Maul 《毒物与环境化学》2013,95(9):1746-1757
Playa wetlands are important components of the Southern High Plains (USA) landscape as they are the major aquatic surface feature. Chemical contaminants associated with playas have been documented, particularly for grassland and agricultural watersheds, but not for playas in urban settings. The objectives of this study were to determine concentrations of inorganic and organic contaminants in sediments from an urban playa within the I-20 Wildlife Preserve and Jenna Welch Nature Study Center in Midland, TX, and evaluate toxicity of these sediments to Hyalella azteca. Concentrations of most trace elements were below sediment quality guidelines with exceptions of lead, cadmium, and arsenic. Concentrations of organic contaminants, particularly PAHs, DDT, DDE, and malathion, were above sediment quality guidelines at various locations within the playa. Decreased survival was observed among H. azteca exposed to sediment from a single location when compared those exposed to reference sediments. This location also produced maximum observed concentrations for five of seven trace elements, potentially due to its location at the lowest elevation within the playa. This study documented concentrations of contaminants in sediments of an urban playa associated with past and present land uses in its urban setting, including those from automotive emissions and historical pesticide use. 相似文献
264.
265.
Wright SJ Kitajima K Kraft NJ Reich PB Wright IJ Bunker DE Condit R Dalling JW Davies SJ Díaz S Engelbrecht BM Harms KE Hubbell SP Marks CO Ruiz-Jaen MC Salvador CM Zanne AE 《Ecology》2010,91(12):3664-3674
A trade-off between growth and mortality rates characterizes tree species in closed canopy forests. This trade-off is maintained by inherent differences among species and spatial variation in light availability caused by canopy-opening disturbances. We evaluated conditions under which the trade-off is expressed and relationships with four key functional traits for 103 tree species from Barro Colorado Island, Panama. The trade-off is strongest for saplings for growth rates of the fastest growing individuals and mortality rates of the slowest growing individuals (r2 = 0.69), intermediate for saplings for average growth rates and overall mortality rates (r2 = 0.46), and much weaker for large trees (r2 < or = 0.10). This parallels likely levels of spatial variation in light availability, which is greatest for fast- vs. slow-growing saplings and least for large trees with foliage in the forest canopy. Inherent attributes of species contributing to the trade-off include abilities to disperse, acquire resources, grow rapidly, and tolerate shade and other stresses. There is growing interest in the possibility that functional traits might provide insight into such ecological differences and a growing consensus that seed mass (SM), leaf mass per area (LMA), wood density (WD), and maximum height (H(max)) are key traits among forest trees. Seed mass, LMA, WD, and H(max) are predicted to be small for light-demanding species with rapid growth and mortality and large for shade-tolerant species with slow growth and mortality. Six of these trait-demographic rate predictions were realized for saplings; however, with the exception of WD, the relationships were weak (r2 < 0.1 for three and r2 < 0.2 for five of the six remaining relationships). The four traits together explained 43-44% of interspecific variation in species positions on the growth-mortality trade-off; however, WD alone accounted for > 80% of the explained variation and, after WD was included, LMA and H(max) made insignificant contributions. Virtually the full range of values of SM, LMA, and H(max) occurred at all positions on the growth-mortality trade-off. Although WD provides a promising start, a successful trait-based ecology of tropical forest trees will require consideration of additional traits. 相似文献
266.
Nathan Frey 《Environmental Hazards》2018,17(1):40-55
Individuals’ relationships to place play an important role in their interactions with their residential environments. Prior research has suggested that neighbourhood satisfaction is closely related to neighbourhood attachment, and that attachment is linked to disaster recovery. This study uses data from a survey of residents of the East Shore neighbourhoods of Staten Island, New York, an area that experienced severe storm surge flooding during Hurricane Sandy, to test the association between neighbourhood satisfaction and self-reported recovery from the storm. Perceived recovery from Sandy is treated as the dependent variable in several ordinal logistic regression models. The key independent variable measure tested is neighbourhood satisfaction rating. A statistically significant direct positive relationship is found between neighbourhood satisfaction and perceived recovery from Sandy. This finding is robust across multiple models with various controls and other covariates. These results suggest that place satisfaction may contribute to disaster recovery. 相似文献
267.
Elliott JE Wilson LK Langelier KW Norstrom RJ 《Environmental pollution (Barking, Essex : 1987)》1996,94(1):9-18
Between 1989 and 1994, we obtained 278 carcasses of bald eagles (Haliaeetus leucocephalus) found dead or dying in British Columbia, Canada. All specimens were necropsied and the cause of death determined wherever possible. Livers from a subset of 75 birds were analyzed for polychlorinated biphenyl (PCB) and organochlorine (OC) pesticide residues. A further subset of 19 eagles found dead around the Strait of Georgia, an area of known pulp mill pollution, in summer, and therefore presumably resident birds, were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and non-ortho PCBs. Liver concentrations ranged from less than 1 to 190 mg/kg for DDE, and up to 72 mg/kg for total PCBs. Concentrations of other OCs were generally less than 1 mg/kg, with the exception of chlordane-related compounds which were occasionally over 2 mg/kg. All birds analyzed for PCDDs and PCDFs contained detectable concentrations of the major 2,3,7,8-substituted isomers. Some birds were very contaminated; one eagle found near a kraft pulp mill site in 1990 contained: 400 ng/kg 2,3,7,8-TCDD, 1400 ng/kg 1,2,3,7,8-PnCDD and 4400 ng/kg 1,2,3,6,7,8-HxCDD. Birds with higher PCB and dichlorodiphenyldichloroethane (DDE) concentrations appeared to weigh less, and there was a significant negative relationship between both PCBs and DDE and numeric scoring of body condition, reflecting the well known process of starvation-induced mobilization of body lipids and contaminants. Birds with higher 2,3,7,8-TCDD concentrations tended to have unusually low concentrations of 2,3,7,8-TCDF, interpreted to indicate hepatic cytochrome P4501A-type induction by TCDD and subsequent metabolism of TCDF. 相似文献
268.
Rocío López de la Lama Nathan Bennett Janette Bulkan David Boyd Kai M. A. Chan 《Conservation biology》2023,37(4):e14068
Privately protected areas (PPAs) are a potentially innovative conservation tool. Legal recognition is necessary for their success, especially where there are institutional challenges to nature conservation, such as in South America. Although PPAs have increased in South America since the early 2000s, there is a critical information gap pertaining to their legal frameworks. We analyzed the level of landowner commitment to and governmental support for PPAs across countries in South America that officially recognize PPAs. We analyzed the legal framework governing PPAs and reviewed literature on them. This process was done in English and Spanish. The information we gathered was validated by 16 conservation experts from 10 South American countries. Because Peru is 1 of only 2 South American countries where local communities create and manage PPAs, we studied Peruvian PPAs in more detail by examining official creation documents and interviewing 13 local conservation professionals. We found inadequate minimum duration of PPAs and vague guidelines for conducting economic activities within them and a lack of governmental support (e.g., financial and technical support) for PPAs. Support was limited to the exemption from rural property taxes, which are relatively low compared with countries outside South America. In Peru, PPAs run by individuals and communities needed different legal frameworks because they were created with different objectives and had different sizes and duration of commitments. The prompt improvement of legal frameworks across South America is necessary for PPAs to achieve their aim of being places for enduring nature conservation in the region. 相似文献
269.
Nathan L. Kirk Jason P. Andras C. Drew Harvell Scott R. Santos Mary Alice Coffroth 《Marine Biology》2009,156(8):1609-1623
Numerous marine invertebrates form endosymbiotic relationships with dinoflagellates in the genus Symbiodinium. However, few studies have examined the fine-scale population structure of these symbionts. Here, we describe the genetic
structure of Symbiodinium type “B1/B184” inhabiting the gorgonian Gorgonia
ventalina along the Florida Keys. Six polymorphic microsatellite loci were utilized to examine 16 populations along the Upper, Middle,
and Lower Keys spanning a range of ~200 km. Multiple statistical tests detected significant differentiation in 54–92% of the
120 possible pairwise comparisons between localities, suggesting low levels of gene flow in these dinoflagellates. In general,
populations clustered by geographic region and/or reefs in close proximity. Some of the sharpest population differentiation
was detected between Symbiodinium from deep and shallow sites on the same reef. In spite of the high degree of population structure, alleles and genotypes
were shared among localities, indicating some connectivity between Symbiodinium populations associated with G. ventalina.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
270.
The influence of spatial and size scale on phylogenetic relatedness in tropical forest communities 总被引:5,自引:0,他引:5
The relative importance of biotic, abiotic, and stochastic processes in structuring ecological communities continues to be a central focus in community ecology. In order to assess the role of phylogenetic relatedness on the nature of biodiversity we first quantified the degree of phylogenetic niche conservatism of several plant traits linked to plant form and function. Next we quantified the degree of phylogenetic relatedness across two fundamental scaling dimensions: plant size and neighborhood size. The results show that phylogenetic niche conservatism is likely widespread, indicating that closely related species are more functionally similar than distantly related species. Utilizing this information we show that three of five tropical forest dynamics plots (FDPs) exhibit similar scale-dependent patterns of phylogenetic structuring using only a spatial scaling axis. When spatial- and size-scaling axes were analyzed in concert, phylogenetic overdispersion of co-occurring species was most important at small spatial scales and in four of five FDPs for the largest size class. These results suggest that phylogenetic relatedness is increasingly important: (1) at small spatial scales, where phylogenetic overdispersion is more common, and (2) in large size classes, where phylogenetic overdispersion becomes more common throughout ontogeny. Collectively, our results highlight the critical spatial and size scales at which the degree of phylogenetic relatedness between constituent species influences the structuring of tropical forest diversity. 相似文献