scholarly journals Alien predators are more dangerous than native predators to prey populations

2007 ◽  
Vol 274 (1615) ◽  
pp. 1237-1243 ◽  
Author(s):  
Pälvi Salo ◽  
Erkki Korpimäki ◽  
Peter B Banks ◽  
Mikael Nordström ◽  
Chris R Dickman
Keyword(s):  
Native Species ◽  
Field Experiments ◽  
Meta Analysis ◽  
Population Densities ◽  
Avian Predators ◽  
Introduced Predators ◽  
Huge Impact ◽  
Prey Populations

Alien predators are widely considered to be more harmful to prey populations than native predators. To evaluate this expectation, we conducted a meta-analysis of the responses of vertebrate prey in 45 replicated and 35 unreplicated field experiments in which the population densities of mammalian and avian predators had been manipulated. Our results showed that predator origin (native versus alien) had a highly significant effect on prey responses, with alien predators having an impact double that of native predators. Also the interaction between location (mainland versus island) and predator origin was significant, revealing the strongest effects with alien predators in mainland areas. Although both these results were mainly influenced by the huge impact of alien predators on the Australian mainland compared with their impact elsewhere, the results demonstrate that introduced predators can impose more intense suppression on remnant populations of native species and hold them further from their predator-free densities than do native predators preying upon coexisting prey.

Which Healthy Eating Nudges Work Best? A Meta-Analysis of Field Experiments

2020 ◽  
Vol 39 (3) ◽  
pp. 465-486 ◽  
Author(s):  
Romain Cadario ◽  
Pierre Chandon
Keyword(s):  
Healthy Eating ◽  
Field Experiments ◽  
Meta Analysis

The effectiveness of healthy eating nudges in field settings increases as they shift from focusing on influencing cognition to affect to behavior.

The effect of increased ground-level habitat complexity on mouse population dynamics

2003 ◽  
Vol 30 (6) ◽  
pp. 565 ◽  
Author(s):  
A. D. Arthur ◽  
R. P. Pech ◽  
A. Drew ◽  
E. Gifford ◽  
S. Henry ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Native Species ◽  
Habitat Complexity ◽  
Habitat Structure ◽  
Ground Level ◽  
Low Complexity ◽  
Mouse Population ◽  
Introduced Predators ◽  
The Impact

We investigated experimentally the influence of habitat structure on the population dynamics of house mice. Three habitat types were used. In one, dense stands of regenerating cypress pine were felled and left in situ to cover at least 40% of experimental plots, providing high complexity at ground level; in another, dense stands of regenerating pine were left intact, providing low complexity at ground level; in the third, open grassland adjacent to dense stands of regenerating pine also provided low complexity at ground level. Mouse populations occurred at higher densities in felled pine plots compared with both the standing pine and grassland plots, consistent with the hypothesis that the presence of increased habitat complexity at ground level reduced the impact of predation. Even though populations responded to the felled pine, they dropped to very low densities over winter, suggesting that the habitat was still marginal for the persistence of mice, probably due to a lack of food. The results are discussed with reference to their implications for the influence that habitat structure may have on the impact of introduced predators on native species.

The fate of nitrogen in grain cropping systems: a meta-analysis of15N field experiments

2009 ◽  
Vol 19 (8) ◽  
pp. 2167-2184 ◽  
Author(s):  
Jennifer B. Gardner ◽  
Laurie E. Drinkwater
Keyword(s):  
Field Experiments ◽  
Cropping Systems ◽  
Meta Analysis ◽  
Fate Of Nitrogen

scholarly journals Field Control of Bacterial Spot and Bacterial Speck of Tomato Using a Plant Activator

Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 481-488 ◽  
Author(s):  
F. J. Louws ◽  
M. Wilson ◽  
H. L. Campbell ◽  
D. A. Cuppels ◽  
J. B. Jones ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Systemic Acquired Resistance ◽  
Field Experiments ◽  
Production Systems ◽  
Acquired Resistance ◽  
Dry Weight ◽  
Bacterial Spot ◽  
Population Densities ◽  
Bacterial Speck ◽  
Plant Activator

Acibenzolar-S-methyl (CGA 245704 or Actigard 50WG) is a plant activator that induces systemic acquired resistance (SAR) in many different crops to a number of pathogens. Acibenzolar-S-methyl was evaluated for management of bacterial spot (Xanthomonas axonopodis pv. vesicatoria) and bacterial speck (Pseudomonas syringae pv. tomato) of tomato in 15 and 7 field experiments, respectively. Experiments were conducted over a 4-year period in Florida, Alabama, North Carolina, Ohio, and Ontario using local production systems. Applied at 35 g a.i. ha-1, acibenzolar-S-methyl reduced foliar disease severity in 14 of the 15 bacterial spot and all 7 bacterial speck experiments. Disease control was similar or superior to that obtained using a standard copper bactericide program. Acibenzolar-S-methyl also reduced bacterial fruit spot and speck incidence. Tomato yield was not affected by using the plant activator in the field when complemented with fungicides to manage foliar fungal diseases, but tomato transplant dry weight was negatively impacted. X. axonopodis pv. vesicatoria population densities on greenhouse-grown tomato transplants were reduced by acibenzolar-S-methyl treatment. Bacterial speck and spot population densities on leaves of field-grown plants were not dramatically affected. Acibenzolar-S-methyl can be integrated as a viable alternative to copper-based bactericides for field management of bacterial spot and speck, particularly where copper-resistant populations predominate.

Round goby movement patterns in a non-navigable river

2020 ◽  
Vol 77 (3) ◽  
pp. 475-483
Author(s):  
Luděk Šlapanský ◽  
Michal Janáč ◽  
Kevin Roche ◽  
Pavel Jurajda
Keyword(s):  
Native Species ◽  
Field Experiments ◽  
Round Goby ◽  
Neogobius Melanostomus ◽  
Species Dispersal ◽  
Dispersal Patterns ◽  
Long Distance ◽  
Movement Rates ◽  
Established Population ◽  
Future Management

Understanding non-native species dispersal is vital for their future management. The round goby (Neogobius melanostomus) has greatly extended its range since the 1990s, with commercial shipping being the main vector. However, our knowledge regarding their secondary dispersal from points of introduction is surprisingly limited. In this study, a series of field experiments were undertaken on a mid-sized river to assess goby dispersal patterns within an established population, following a simulated release of a large number of propagules, or at a simulated invasion front. Most of the established population remained stationary and just a few individuals undertook long-distance dispersal (principally upstream). Mean distance travelled was 1.1 m·day−1 (max. 29.6 m·day−1). While site fidelity appeared to last for most of the year (including winter), it was surprisingly relaxed during the spawning season. Concentrated release of a large number of propagules resulted in appreciably greater movement rates than in the established population, with upstream movement again dominating. In general, smaller, mostly male fish tended to move further and appeared as first colonizers in uninvaded areas.

scholarly journals Global determinants of prey naiveté to exotic predators

2020 ◽  
Vol 287 (1928) ◽  
pp. 20192978 ◽  
Author(s):  
Andrea Anton ◽  
Nathan R. Geraldi ◽  
Anthony Ricciardi ◽  
Jaimie T. A. Dick
Keyword(s):  
Meta Analysis ◽  
Antipredator Behaviour ◽  
Freshwater Systems ◽  
Conservation Targets ◽  
Mediating Factors ◽  
Time Since Introduction ◽  
The Impact ◽  
Prey Naiveté ◽  
Prey Naïveté ◽  
Prey Populations

Prey naiveté—the failure of prey to recognize novel predators as threats—is thought to exacerbate the impact that exotic predators exert on prey populations. Prey naiveté varies under the influence of eco-evolutionary mediating factors, such as biogeographic isolation and prey adaptation, although an overall quantification of their influence is lacking. We conducted a global meta-analysis to test the effects of several hypothesized mediating factors on the expression of prey naiveté. Prey were overall naive towards exotic predators in marine and freshwater systems but not in terrestrial systems. Prey naiveté was most pronounced towards exotic predators that did not have native congeneric relatives in the recipient community. Time since introduction was relevant, as prey naiveté declined with the number of generations since introduction; on average, around 200 generations may be required to erode naiveté sufficiently for prey to display antipredator behaviour towards exotic predators. Given that exotic predators are a major cause of extinction, the global predictors and trends of prey naiveté presented here can inform efforts to meet conservation targets.

Rice and red rice interference. II. Rice response to population densities of three red rice (Oryza sativa) ecotypes

Weed Science ◽  
2005 ◽  
Vol 53 (5) ◽  
pp. 683-689 ◽  
Author(s):  
Leopoldo E. Estorninos ◽  
David R. Gealy ◽  
Edward E. Gbur ◽  
Ronald E. Talbert ◽  
Marilyn R. McClelland
Keyword(s):  
Aboveground Biomass ◽  
Growth Response ◽  
Field Experiments ◽  
Rice Yield ◽  
Rice Cultivar ◽  
Growth And Yield ◽  
Red Rice ◽  
Population Densities ◽  
Rice Growth ◽  
Tiller Density

Red rice, which grows taller and produces more tillers than domestic rice and shatters most of its seeds early, is a major weed in many rice-growing areas of the world. Field experiments were conducted at Stuttgart, AR in 1997 and 1998 to evaluate the growth response of the Kaybonnet (KBNT) rice cultivar to various population densities of three red rice ecotypes. The ecotypes tested were Louisiana3 (LA3), Stuttgart strawhull (Stgstraw), and Katy red rice (KatyRR). Compared with KBNT alone, LA3, the tallest of the three red rice ecotypes, reduced tiller density of KBNT 51%, aboveground biomass at 91 d after emergence (DAE) 35%, and yield 80%. Stgstraw, a medium-height red rice, reduced KBNT tiller density 49%, aboveground biomass 26%, and yield 61%. KatyRR, the shortest red rice, reduced KBNT tiller density 30%, aboveground biomass 16%, and yield 21%. Tiller density of rice was reduced by 20 to 48% when red rice density increased from 25 to 51 plants m−2. Rice biomass at 91 DAE was reduced by 9 and 44% when red rice densities were 16 and 51 plants m−2. Rice yield was reduced by 60 and 70% at red rice densities of 25 and 51 plants m−2, respectively. These results demonstrate that low populations of red rice can greatly reduce rice growth and yield and that short-statured red rice types may affect rice growth less than taller ecotypes.

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