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471.
Flood Matthew T. D’Souza Nishita Rose Joan B. Aw Tiong Gim 《Food and environmental virology》2021,13(3):303-315
Food and Environmental Virology - Wastewater surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging public health tool to understand the spread of Coronavirus... 相似文献
472.
Functional and phylogenetic diversity as predictors of biodiversity--ecosystem-function relationships 总被引:3,自引:0,他引:3
How closely does variability in ecologically important traits reflect evolutionary divergence? The use of phylogenetic diversity (PD) to predict biodiversity effects on ecosystem functioning, and more generally the use of phylogenetic information in community ecology, depends in part on the answer to this question. However, comparisons of the predictive power of phylogenetic diversity and functional diversity (FD) have not been conducted across a range of experiments. To address how phylogenetic diversity and functional trait variation control biodiversity effects on biomass production, we summarized the results of 29 grassland plant experiments where both the phylogeny of plant species used in the experiments is well described and where extensive trait data are available. Functional trait variation was only partially related to phylogenetic distances between species, and the resulting FD values therefore correlate only partially with PD. Despite these differences, FD and PD predicted biodiversity effects across all experiments with similar strength, including in subsets that excluded plots with legumes and that focused on fertilization experiments. Two- and three-trait combinations of the five traits used here (leaf nitrogen percentage, height, specific root length, leaf mass per unit area, and nitrogen fixation) resulted in the FD values with the greatest predictive power. Both PD and FD can be valuable predictors of the effect of biodiversity on ecosystem functioning, which suggests that a focus on both community trait diversity and evolutionary history can improve understanding of the consequences of biodiversity loss. 相似文献
473.
Gabriel P. Hughes Annie E. Spikes Jeffrey D. Holland Matthew D. Ginzel 《Chemoecology》2011,21(2):99-105
Contact pheromones mediate mate recognition and play important roles in mating systems of longhorned beetles (Coleoptera:
Cerambycidae). One common bioassay of contact chemoreception in cerambycids involves presenting a freeze-killed female to
a male in a Petri dish arena. If the male attempts to mate with the female carcass, it confirms that mate recognition signals
are present and intact and behavior is not involved. Cuticular hydrocarbons are then stripped from the female with successive
solvent washes, rendering her unattractive to males and also resulting in a crude extract containing the cuticular hydrocarbons.
To test the bioactivity of the crude extract, the same female is then treated with the extract and presented again to the
male. Males of some species, including Megacyllene robiniae (F?rster), respond less readily to reconstituted females than to those same beetles before they were solvent-extracted. In
the present study, we test the hypothesis that the contact pheromone of M. robiniae, Z9:C25, exists as a layer on the surface of the epicuticle. We used solid phase microextraction (SPME) to sample cuticular hydrocarbons
of female beetles after they were freeze-killed, solvent washed, and treated with crude cuticular extracts. We found that
extracting cuticular hydrocarbons from females and applying the resulting crude extract back onto the solvent-washed cadaver
scrambles the wax layer and decreases the abundance of the contact pheromone presented on the surface of the insect. 相似文献
474.
Sarah Foster Billie Giles-Corti Matthew Knuiman 《Journal of environmental psychology》2011,31(1):79-88
There is growing evidence that residents are more likely to walk in attractive neighbourhoods, and that negative visual cues can deter residents from engaging in physical activity. This study explored the premise that house design and upkeep could inhibit the incidence of physical disorder in suburban streets, thus contributing to a more pleasant walking environment for pedestrians. Street segments (n = 443) in new residential developments (n = 61) in Perth, Western Australia, were audited for house attributes that facilitate natural surveillance (e.g., porch/verandah) or indicate territoriality (e.g., garden/lawn upkeep), and physical incivilities. A composite index of street-level house attributes yielded highly significant associations with disorder (trend test p = 0.001) and graffiti (trend test p = 0.005), signifying that the cumulative effect of several key attributes had greater potential to discourage incivilities in the street than any single characteristic. The findings suggest house design and upkeep may contribute to the creation of safe, inviting streets for pedestrians. 相似文献
475.
Hernandez-Ramirez G Brouder SM Ruark MD Turco RF 《Journal of environmental quality》2011,40(4):1229-1240
Artificial subsurface drainage in cropland creates pathways for nutrient movement into surface water; quantification of the relative impacts of common and theoretically improved management systems on these nutrient losses remains incomplete. This study was conducted to assess diverse management effects on long-term patterns (1998-2006) of NO, NH, and PO loads (). We monitored water flow and nutrient concentrations at subsurface drains in lysimeter plots planted to continuous corn ( L.) (CC), both phases of corn-soybean [ (L.) Merr.] rotations (corn, CS; soybean, SC), and restored prairie grass (PG). Corn plots were fertilized with preplant or sidedress urea-NHNO (UAN) or liquid swine manure injected in the fall (FM) or spring (SM). Restored PG reduced NO eightfold compared with fields receiving UAN (2.5 vs. 19.9 kg N ha yr; < 0.001), yet varying UAN application rates and timings did not affect NO across all CCUANs and CSUANs. The NO from CCFM (33.3 kg N ha yr) were substantially higher than for all other cropped fields including CCSM (average 19.8 kg N ha yr, < 0.001). With respect to NH and PO, only manured soils recorded high but episodic losses in certain years. Compared with the average of all other treatments, CCSM increased NH in the spring of 1999 (217 vs. 680 g N ha yr), while CCFM raised PO in the winter of 2005 (23 vs. 441 g P ha yr). Our results demonstrate that fall manuring increased nutrient losses in subsurface-drained cropland, and hence this practice should be redesigned for improvement or discouraged. 相似文献
476.
Western North America is experiencing a dramatic expansion of piñon (Pinus spp.) and juniper (Juniperus spp.) (P-J) trees into shrub-steppe communities. Feature extracted data acquired from remotely sensed imagery can help managers rapidly and accurately assess this land cover change in order to manage rangeland ecosystems at a landscape-scale. The objectives of this study were to: (1) develop an effective and efficient method for accurately quantifying P-J tree canopy cover and density directly from high resolution photographs and (2) compare feature-extracted data to typical in-situ datasets used by land managers. Tree cover was extracted from aerial-photography using Feature Analyst®. Tree density was calculated as the sum of the total number of individual polygons (trees) within the tree cover output file after isolation using a negative buffer post-processing technique. Feature-extracted data were compared to ground reference measurements from Utah’s Division of Wildlife Resources Range Trend Project (DWR-RTP). We found that the proposed feature-extraction techniques used for measuring cover and density were highly correlated to ground reference and DWR-RTP datasets. Feature-extracted measurements of cover generally showed a near 1:1 relationship to these data, while tree density was underestimated; however, after calibration for juvenile trees, a near 1:1 relationship was realized. Feature-extraction techniques used in this study provide an efficient method for assessing important rangeland indicators, including: density, cover, and extent of P-J tree encroachment. Correlations found between field and feature-extracted data provide evidence to support extrapolation between the two approaches when assessing woodland encroachment. 相似文献
477.
478.
A brief guide to model selection,multimodel inference and model averaging in behavioural ecology using Akaike’s information criterion 总被引:1,自引:0,他引:1
Akaike’s information criterion (AIC) is increasingly being used in analyses in the field of ecology. This measure allows one
to compare and rank multiple competing models and to estimate which of them best approximates the “true” process underlying
the biological phenomenon under study. Behavioural ecologists have been slow to adopt this statistical tool, perhaps because
of unfounded fears regarding the complexity of the technique. Here, we provide, using recent examples from the behavioural
ecology literature, a simple introductory guide to AIC: what it is, how and when to apply it and what it achieves. We discuss
multimodel inference using AIC—a procedure which should be used where no one model is strongly supported. Finally, we highlight
a few of the pitfalls and problems that can be encountered by novice practitioners. 相似文献
479.
Grant E. Brown Maud C. O. Ferrari Patrick H. Malka Marie-Anne Oligny Matthew Romano Douglas P. Chivers 《Behavioral ecology and sociobiology》2011,65(6):1267-1276
Under conditions of spatial and/or temporal variability in predation risk, prey organisms often rely on acquired predator
recognition to balance the trade-offs between energy intake and risk avoidance. The question of ‘for how long’ should prey
retain this learned information is poorly understood. Here, we test the hypothesis that the growth rate experienced by prey
should influence the length of the ‘memory window’. In a series of laboratory experiments, we manipulated growth rate of juvenile
rainbow trout and conditioned them to recognize a novel predator cue. We subsequently tested for learned recognition either
24 h or 8 days post-conditioning. Our results suggest that trout with high versus low growth rates did not differ in their
response to learned predator cues when tested 24 h post-conditioning. However, trout on a high growth rate exhibited no response
to the predator cues after 8 days (i.e. did not retain the recognition of the predator odour), whereas trout on a lower growth
rate retained a strong recognition of the predator. Trout that differed in their growth rate only after conditioning did not
differ in their patterns of retention, demonstrating growth rate after learning does not influence retention. Trout of different
initial sizes fed a similar diet (percent body mass per day) showed no difference in retention of the predator cue. Together,
these data suggest that growth rate at the time of conditioning determines the ‘memory window’ of trout. The implications
for threat-sensitive predator avoidance models are described. 相似文献
480.
Thompson MP Calkin DE Gilbertson-Day JW Ager AA 《Environmental monitoring and assessment》2011,179(1-4):217-239
In this article, we describe the design and development of a quantitative, geospatial risk assessment tool intended to facilitate monitoring trends in wildfire risk over time and to provide information useful in prioritizing fuels treatments and mitigation measures. The research effort is designed to develop, from a strategic view, a first approximation of how both fire likelihood and intensity influence risk to social, economic, and ecological values at regional and national scales. Three main components are required to generate wildfire risk outputs: (1) burn probability maps generated from wildfire simulations, (2) spatially identified highly valued resources (HVRs), and (3) response functions that describe the effects of fire (beneficial or detrimental) on the HVR. Analyzing fire effects has to date presented a major challenge to integrated risk assessments, due to a limited understanding of the type and magnitude of changes wrought by wildfire to ecological and other nonmarket values. This work advances wildfire effects analysis, recognizing knowledge uncertainty and appropriately managing it through the use of an expert systems approach. Specifically, this work entailed consultation with 10 fire and fuels program management officials from federal agencies with fire management responsibilities in order to define quantitative resource response relationships as a function of fire intensity. Here, we demonstrate a proof-of-concept application of the wildland fire risk assessment tool, using the state of Oregon as a case study. 相似文献