Testing sexual segregation and aggregation: old ways are best

The study of sexual segregation has received increasing attention over the last two decades. Several hypotheses have been proposed to explain the existence of sexual segregation, such as the "predation risk hypothesis," the "forage selection hypothesis," and the "activity budget hypothesis." Testing which hypothesis drives sexual segregation is hampered, however, by the lack of consensus regarding a formal measurement of sexual segregation. By using a derivation of the well-known chi-square (here called the sexual segregation and aggregation statistic [SSAS]) instead of existent segregation coefficients, we offer a reliable way to test for temporal variation in the occurrence of sexual segregation and aggregation, even in cases where a large proportion of animals are observed alone. A randomization procedure provides a test for the null hypothesis of independence of the distributions of males and females among the groups. The usefulness of SSAS in the study of sexual segregation is demonstrated with three case studies on ungulate populations belonging to species with contrasting life histories and annual grouping patterns (isard, red deer, and roe deer). The existent segregation coefficients were unreliable since, for a given value, sexual segregation could or could not occur. Similarly, the existent segregation coefficients performed badly when males and females aggregated. The new SSAS was not prone to such limitations and allowed clear conclusions regarding whether males and females segregate, aggregate, or simply mix at random applicable to all species.     

OHP02 gravity wave campaign in relation to optical turbulence

Herein we present a campaign dedicated to the detection and the characterization of Gravity Waves (GW) in the Earth’s atmosphere in relation to the generation of Optical Turbulence (OT). The observations took place in France from 17 to 24 July 2002 at the Haute Provence Observatory (OHP) and simultaneously at the Sirene Observatory, some 20 km apart. From both sites, several balloons were launched that measured the classical PTU-Wind profiles and additionally the structure constant of the temperature field vertical profiles. A Generalized Scidar (GS) technique was implemented at the 1.93 m-diameter OHP telescope, providing profiles every minute. From our observations, a significant amount of GW activity was observed at both sites, but without clear evidence of correlation between the two sites. It seems from our observations that a wide spectrum of GW is present at a given altitude and that this could result in a lack of correlation between observations made from two sites 20 km apart. Most GW are non-stationary with long horizontal wavelengths (λ ∼ 100–200 km), kilometric vertical wavelengths (λ ~ 0.5–2 km) and long intrinsic period (T ~ 2–15 h). They belong in the category of “hydrostatic rotating or non-rotating waves”. Layers of optical turbulence detected by balloons and the Scidar technique correlate well with regions of GW activity. The U.S. Government’s right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.     

A new technique for ordering asymmetrical three-dimensional data sets in ecology

The aim of this paper is to tackle the problem that arises from asymmetrical data cubes formed by two crossed factors fixed by the experimenter (factor A and factor B, e.g., sites and dates) and a factor which is not controlled for (the species). The entries of this cube are densities in species. We approach this kind of data by the comparison of patterns, that is to say by analyzing first the effect of factor B on the species-factor A pattern, and second the effect of factor A on the species-factor B pattern. The analysis of patterns instead of individual responses requires a correspondence analysis. We use a method we call Foucart's correspondence analysis to coordinate the correspondence analyses of several independent matrices of species x factor A (respectively B) type, corresponding to each modality of factor B (respectively A). Such coordination makes it possible to evaluate the effect of factor B (respectively A) on the species-factor A (respectively B) pattern. The results obtained by such a procedure are much more insightful than those resulting from a classical single correspondence analysis applied to the global matrix that is obtained by simply unrolling the data cube, juxtaposing for example the individual species x factor A matrices through modalities of factor B. This is because a single global correspondence analysis combines three effects of factors in a way that cannot be determined from factorial maps (factor A, factor B, and factor A x factor B interaction) whereas the applications of Foucart's correspondence analysis clearly discriminate two different issues. Using two data sets, we illustrate that this technique proves to be particularly powerful in the analyses of ecological convergence which include several distinct data sets and in the analyses of spatiotemporal variations of species distributions.     

Altered c-Fos expression demonstrates neuronal stress in mummichog, <Emphasis Type="Italic">Fundulus heteroclitus</Emphasis>, exposed to <Emphasis Type="Italic">Pfiesteria shumwayae</Emphasis> and <Emphasis Type="Italic">Chaetoceros concavicornis</Emphasis>

To better understand sublethal effects of harmful algal blooms (HABs) on fish, mummichog, Fundulus heteroclitus (L.), were exposed in the laboratory to varying, environmentally relevant densities of Pfiesteria shumwayae (Glasgow et Burkholder, CCMP 2089, dinoflagellate) and Chaetoceros concavicornis (Mangin, CCMP 169, diatom). Two experiments were conducted during the spring of 2003 and 2004 to quantitatively examine the effects of acute (2 h) P. shumwayae and C. concavicornis algal exposure on mummichog brain activity using c-Fos expression as a marker of altered neuronal activity. Brains from HAB-exposed fish were removed, sectioned, and stained using immunocytochemistry prior to quantifying neuronal c-Fos expression. Fish exposed to P. shumwayae and C. concavicornis showed increased c-Fos expression compared to unexposed control fish. A significant dose-response relationship was observed, with increased labeling in brains of fish exposed to higher cell densities for both HAB species tested (P ≤ 0.01). Increased labeling was found in the telencephalon, optic lobes, midbrain, and portions of the medulla. The greatest increases in expression were observed in the telencephalon of P. shumwayae-exposed fish, and in the telencephalon and optic lobes of C. concavicornis-exposed fish (P ≤ 0.01). These increases in c-Fos expression are consistent with other physical and chemical stress exposures observed in fish. Neuronal stress, evidenced by c-Fos expression, demonstrates a sublethal effect of exposure and changes in brain activity in fish exposed to HAB species.     

Implementation of the EU environmental noise directive: Lessons from the first phase of strategic noise mapping and action planning in Ireland

The first phase of noise mapping and action planning in Ireland, in accordance with EU Directive 2002/49/EC, is now complete. In total this included one agglomeration, one airport and approximately 600 km of major roads outside the agglomeration. These noise maps describe the level of noise exposure of approximately 1.25 million people. The first phase of noise mapping was dealt with by five noise mapping bodies while 26 action planning authorities were involved in the development of the associated action plans. The second phase of noise mapping, due to be completed in 2012, sees a reduction in the defined thresholds describing the required agglomerations, roads and railways that have to be mapped. This will have a significant impact on the extent of mapping required. In Ireland this will result in an increased number of local authorities being required to develop strategic noise maps for their area along with the further development of associated action plans. It is appropriate at this point to review the work process and results from the first phase of noise mapping in Ireland in order to establish areas that could be improved, throughout the noise mapping project. In this paper a review of the implementation procedures focussing on (dominant) road traffic noise is presented. It is identified that more standardisation is needed and this could be achieved by the establishment of a national expert steering group.     

A Web‐Based Decision Support System for Assessing Regional Water‐Quality Conditions and Management Actions1

Booth, Nathaniel L., Eric J. Everman, I‐Lin Kuo, Lori Sprague, and Lorraine Murphy, 2011. A Web‐Based Decision Support System for Assessing Regional Water‐Quality Conditions and Management Actions. Journal of the American Water Resources Association (JAWRA) 47(5):1136‐1150. DOI: 10.1111/j.1752‐1688.2011.00573.x Abstract: The U.S. Geological Survey National Water Quality Assessment Program has completed a number of water‐quality prediction models for nitrogen and phosphorus for the conterminous United States as well as for regional areas of the nation. In addition to estimating water‐quality conditions at unmonitored streams, the calibrated SPAtially Referenced Regressions On Watershed attributes (SPARROW) models can be used to produce estimates of yield, flow‐weighted concentration, or load of constituents in water under various land‐use condition, change, or resource management scenarios. A web‐based decision support infrastructure has been developed to provide access to SPARROW simulation results on stream water‐quality conditions and to offer sophisticated scenario testing capabilities for research and water‐quality planning via a graphical user interface with familiar controls. The SPARROW decision support system (DSS) is delivered through a web browser over an Internet connection, making it widely accessible to the public in a format that allows users to easily display water‐quality conditions and to describe, test, and share modeled scenarios of future conditions. SPARROW models currently supported by the DSS are based on the modified digital versions of the 1:500,000‐scale River Reach File (RF1) and 1:100,000‐scale National Hydrography Dataset (medium‐resolution, NHDPlus) stream networks.     

Sources and Delivery of Nutrients to the Northwestern Gulf of Mexico from Streams in the South‐Central United States1

Rebich, Richard A., Natalie A. Houston, Scott V. Mize, Daniel K. Pearson, Patricia B. Ging, and C. Evan Hornig, 2011. Sources and Delivery of Nutrients to the Northwestern Gulf of Mexico From Streams in the South‐Central United States. Journal of the American Water Resources Association (JAWRA) 47(5):1061‐1086. DOI: 10.1111/j.1752‐1688.2011.00583.x Abstract: SPAtially Referenced Regressions On Watershed attributes (SPARROW) models were developed to estimate nutrient inputs [total nitrogen (TN) and total phosphorus (TP)] to the northwestern part of the Gulf of Mexico from streams in the South‐Central United States (U.S.). This area included drainages of the Lower Mississippi, Arkansas‐White‐Red, and Texas‐Gulf hydrologic regions. The models were standardized to reflect nutrient sources and stream conditions during 2002. Model predictions of nutrient loads (mass per time) and yields (mass per area per time) generally were greatest in streams in the eastern part of the region and along reaches near the Texas and Louisiana shoreline. The Mississippi River and Atchafalaya River watersheds, which drain nearly two‐thirds of the conterminous U.S., delivered the largest nutrient loads to the Gulf of Mexico, as expected. However, the three largest delivered TN yields were from the Trinity River/Galveston Bay, Calcasieu River, and Aransas River watersheds, while the three largest delivered TP yields were from the Calcasieu River, Mermentau River, and Trinity River/Galveston Bay watersheds. Model output indicated that the three largest sources of nitrogen from the region were atmospheric deposition (42%), commercial fertilizer (20%), and livestock manure (unconfined, 17%). The three largest sources of phosphorus were commercial fertilizer (28%), urban runoff (23%), and livestock manure (confined and unconfined, 23%).     

Age and sex influence marmot antipredator behavior during periods of heightened risk

Animals adjust their antipredator behavior according to environmental variation in risk, and to account for their ability to respond to threats. Intrinsic factors that influence an animal’s ability to respond to predators (e.g., age, body condition) should explain variation in antipredator behavior. For example, a juvenile might allocate more time to vigilance than an adult because mortality as a result of predation is often high for this age class; however, the relationship between age/vulnerability and antipredator behavior is not always clear or as predicted. We explored the influence of intrinsic factors on yellow-bellied marmot (Marmota flaviventris) antipredator behavior using data pooled from 4 years of experiments. We hypothesized that inherently vulnerable animals (e.g., young, males, and individuals in poor condition) would exhibit more antipredator behavior prior to and immediately following conspecific alarm calls. As expected, males and yearlings suppressed foraging more than females and adults following alarm call playbacks. In contrast to predictions, animals in better condition respond more than animals in below average condition. Interestingly, these intrinsic properties did not influence baseline time budgets; animals of all ages, sexes, and condition levels devoted comparable amounts of time to foraging prior to alarm calls. Our results support the hypothesis that inherent differences in vulnerability influence antipredator behavior; furthermore, it appears that a crucial, but poorly acknowledged, interaction exists between risk and state-dependence. Elevated risk may be required to reveal the workings of state-dependent behavior, and studies of antipredator behavior in a single context may draw incomplete conclusions about age- or sex-specific strategies.     

Is there a double-dividend from anti-sprawl policies?

This paper examines the welfare effects of anti-sprawl policies, such as development tax, in a simple spatial explicit urban model with two market failures - urban decline at the city core and underprovision of open space amenities at the urban fringe - and pre-existing distortionary property tax, used to fund public services and improvements to mitigate urban decline. Consistent with prior double-dividend literature, there is a tax interaction effect that occurs between the development tax and the pre-existing property tax. However, there are two fundamental differences between the tax interaction effect identified here and that of prior literature. Ours one has two components: First, there is a cost-side tax interaction effect that is ‘spatially’ concentrated at the urban fringe, as only agents at the urban fringe alter their behavior in response to the development tax. Second, there is also a benefit-side tax interaction effect, as increases in open space at the urban fringe are capitalized into housing prices throughout the city. In contrast to prior literature, we find that the empirical importance of the combined tax interaction effect is of substantially less importance and, as a consequence, the likelihood of a ‘double-dividend’ is higher than in prior studies. Further, we show that the development tax should be part of the local tax system, even in the absence of open space benefits.     

Validation of a multispecies forest dynamics model using 50-year growth from Eucalyptus forests in eastern Australia

One of the key problems confronting ecological forecasting is the validation of computer models. Here we report successful validation of a forest dynamics model Ecosystem Dynamics Simulator (EDS), adapted from the JABOWA-II forest succession model. This model and many variants derived from it have successfully simulated growth dynamics of uneven-aged mixed forests under changing environment with a moderate amount of input data. But rarely are adequate time-series data available for quantitative model validation. This study tested the performance of EDS in projecting the tree density, tree diameter at breast height (dbh), tree height, basal area and aboveground biomass of uneven-aged, mixed species sclerophyll forests in St. Mary state forests of eastern Australia. The test data were collected between 1951 and 2005. Every tree was uniquely numbered, tagged and measured in consecutive re-measurements. Projected growth attributes were compared with those observed in an independent validation dataset. The model produced satisfactory projections of tree density (91.7%), dbh (92.3%), total tree height (82.8%), basal area (89.3%) and aboveground biomass (87.6%) compared to the observed attributes. These results suggest that the EDS model can provide reasonable capability in projecting growth dynamics of uneven-aged, mixed species sclerophyll forests.