Probing of mortality rate by staying alive: The growth‐reproduction trade‐off in a spatially heterogeneous environment

We studied regeneration patterns of the four canopy dominants, Abiessachalinensis (Fr. Schm.) Masters, Piceajezoensis (Sieb. et Zucc.) Cam, Piceaglehnii (Fr. Schm.) Masters, and Betulaermanii Cham., of an old-growth (>400 years) boreal coniferous forest in northern Japan. Age and size structure, height growth, and diameter growth of tree populations in a 40 × 40 m plot were analyzed. Seedling establishment was restricted to nurse logs and mounds (98%), where the influence of dwarf bamboo (Sasasenanensis (Franch. et Sav.) Rehd.) was limited. Abiessachalinensis had a high density (10 263/ha) but a high mortality (8.4%/year for saplings, 1.7%/year for canopy trees) and a short canopy residence time. It also showed a more rapid tree-ring width increase after disturbances. Piceaglehnii had a low density (1450/ha) but a low mortality (6.9%/year for saplings, 0.1%/year for canopy trees) and a longer residence time in the canopy. Piceajezoensis had an intermediate density (8206/ha) and its mortality rate for canopy trees (0.9%/year) was lower than that of A. sachalinensis, although its sapling mortality rate (8.1%/year) was similar to that of A. sachalinensis. Betulaermanii had a higher mortality (14.1%/year for saplings, 2.4%/year for canopy trees) than the conifers. On the other hand, B. ermanii had the highest height growth and P. glehnii had the lowest. The mortality and average height growth of saplings showed a trade-off relationship. The trade-off relation in life history strategy may contribute to the coexistence of these species. The proportion of the gap area created in the forest was 1.2–2.4%/year, and a forest turnover time calculated from aboveground volumes was 87–99 years. These values were similar to a weighted mean of the estimated life times of the constituent species, 71 years for A. sachalinensis, 123 years for P. jezoensis, and 49 years for B. ermanii.

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Right phenotype, wrong place: predator-induced plasticity is costly in a mismatched environment

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2019.2347 ◽

2019 ◽

Vol 286 (1916) ◽

pp. 20192347 ◽

Cited By ~ 2

Author(s):

Anne A. Innes-Gold ◽

Nicholas Y. Zuczek ◽

Justin C. Touchon

Keyword(s):

Natural Selection ◽

Survival Benefit ◽

Morphological Changes ◽

Survival Rates ◽

Environmental Cost ◽

Heterogeneous Environment ◽

Trade Off ◽

Risk Of Predation ◽

Dendropsophus Ebraccatus ◽

Wrong Place

Like many animals, tadpoles often produce different, predator-specific phenotypes when exposed to risk of predation. It is generally assumed that such plasticity enhances survival in the presence of the predator and is costly elsewhere, but evidence remains surprisingly scarce. We measured (1) the survival trade-off of opposing phenotypes developed by Dendropsophus ebraccatus tadpoles when exposed to different predators and (2) which specific aspects of morphology drive any potential survival benefit or cost. Tadpoles developed predator-specific phenotypes after being reared with caged fish or dragonfly predators for two weeks. In 24 h predation trials with either a fish or a dragonfly, survival was highest in the groups with their matched predator, and lowest among with those the mismatched predator, with predator-naive controls being relatively intermediate. Then, using a large group of phenotypically variable predator-naive tadpoles, we found that increased survival rates are directly related to the morphological changes that are induced by each predator. This demonstrates that induced phenotypes are indeed adaptive and the product of natural selection. Furthermore, our data provide clear evidence of an environmental cost for phenotypic plasticity in a heterogeneous environment. Such costs are fundamental for understanding the evolution and maintenance of inducible phenotypes.

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Palmer Amaranth (Amaranthus palmeri) Demographic and Biological Characteristics in Wide-Row Soybean

Weed Science ◽

10.1017/wsc.2017.12 ◽

2017 ◽

Vol 65 (4) ◽

pp. 491-503 ◽

Cited By ~ 10

Author(s):

Nicholas E. Korres ◽

Jason K. Norsworthy

Keyword(s):

Mortality Rate ◽

Population Density ◽

Seed Production ◽

Biomass Production ◽

High Density ◽

Palmer Amaranth ◽

Low Density ◽

Seedling Mortality ◽

Trade Off ◽

Flowering Initiation

Knowledge of Palmer amaranth demographics and biology is essential for the development and implementation of weed management strategies. A field experiment was conducted to investigate the effects of Palmer amaranth density on seedling mortality, flowering initiation, and flowering progress throughout the growing season and biomass production and fecundity in wide-row soybean. The experimental design was a randomized complete block design with three levels of Palmer amaranth density-clusters: high, medium, and low. Palmer amaranth mortality rate was greater at high Palmer amaranth population density-cluster, reaching a peak within 30 to 40 d after Palmer amaranth emergence (DAE) (0.55 and 0.80 for 2014 and 2015, respectively), in comparison with mortality rate at medium and lower density-clusters. Likewise, as Palmer amaranth density increased, biomass and seed production per unit area of the weed also increased. Biomass production at the high density-cluster in 2014 was 664.7 g m−2compared with 542.9 and 422.1 g m−2at medium and low density-clusters, respectively. Similarly, biomass production at high density-cluster in 2015 was 100.6 g m−2compared with 37.3 and 34.2 at medium and low density-clusters, respectively. In addition, seeds produced at high density-cluster were 1.5 million and 245,400 seeds m−2for 2014 and 2015, respectively. Seed production was reduced by 29% and 54% in 2014 and by 65% and 75% in 2015 at medium and low density-clusters, respectively. Earlier flowering initiation (i.e., between 30 to 40 DAE) occurred in higher Palmer amaranth density-clusters, indicating a trade-off between reproduction and survival at high densities and more stressed environments for species survival. Palmer amaranth male-to-female sex ratio was greater at high densities, 1.3 and 1.9, compared with lower densities of 0.6 to 0.7 and 0.7 to 0.8 in 2014 and 2015, respectively. The plasticity of Palmer amaranth population and population-structure regulation, vegetative growth, and flowering shifts at various levels of intraspecific competition (i.e., high vs. low population density-clusters) and the trade-off between these biological transitions merits further investigation.

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Slower senescence in a wild insect population in years with a more female-biased sex ratio

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2019.0286 ◽

2019 ◽

Vol 286 (1900) ◽

pp. 20190286 ◽

Cited By ~ 5

Author(s):

Rolando Rodríguez-Muñoz ◽

Jelle J. Boonekamp ◽

David Fisher ◽

Paul Hopwood ◽

Tom Tregenza

Keyword(s):

Mortality Rate ◽

Sex Ratio ◽

Reproductive Investment ◽

Field Cricket ◽

Short Supply ◽

Trade Off ◽

Factors Affecting ◽

Baseline Mortality ◽

Gryllus Campestris ◽

Biased Sex Ratio

Life-history theories of senescence are based on the existence of a trade-off in resource allocation between body maintenance and reproduction. This putative trade-off means that environmental and demographic factors affecting the costs of reproduction should be associated with changes in patterns of senescence. In many species, competition among males is a major component of male reproductive investment, and hence variation in the sex ratio is expected to affect rates of senescence. We test this prediction using nine years of demographic and behavioural data from a wild population of the annual field cricket Gryllus campestris. Over these generations, the sex ratio at adulthood varied substantially, from years with an equal number of each sex to years with twice as many females as males. Consistent with the predictions of theory, we found that in years with a greater proportion of females, both sexes experienced a slower increase in mortality rate with age. Additionally, phenotypic senescence in males was slower in years when there were more females. Sex ratio did not affect the baseline mortality rate in males, but females suffered higher age-independent mortality rates when males were in short supply.

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Mortality Rate Versus Funeral Rate in Clinical Medicine

Gastroenterology ◽

10.1016/s0016-5085(64)80034-2 ◽

1964 ◽

Vol 46 (6) ◽

pp. 788-791 ◽

Cited By ~ 16

Author(s):

Thomas C. Chalmers

Keyword(s):

Mortality Rate ◽

Clinical Medicine ◽

Rate Versus

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Abstract #810900: One-Year Mortality Rate After Osteoporotic Hip Fracture in Bucharest Romania

Endocrine Practice ◽

10.1016/s1530-891x(20)39839-6 ◽

2020 ◽

Vol 26 ◽

pp. 78-79

Author(s):

Ramona Dobre

Keyword(s):

Hip Fracture ◽

Mortality Rate ◽

Osteoporotic Hip Fracture ◽

One Year

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A Flow-Preserving Algorithm for the Time-Cost Trade-Off Problem

IIE Transactions ◽

10.1080/05695558208974589 ◽

1982 ◽

Vol 14 (2) ◽

pp. 109-113 ◽

Cited By ~ 4

Author(s):

Suleyman Tufekci

Keyword(s):

Time Cost ◽

Trade Off

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Surgical and endovascular hybrid approach in peripheral arterial disease of the lower limbs

VASA ◽

10.1024/0301-1526/a000561 ◽

2016 ◽

Vol 45 (5) ◽

pp. 417-422 ◽

Cited By ~ 7

Author(s):

Anouk Grandjean ◽

Katia Iglesias ◽

Céline Dubuis ◽

Sébastien Déglise ◽

Jean-Marc Corpataux ◽

...

Keyword(s):

Mortality Rate ◽

Peripheral Arterial Disease ◽

Limb Salvage ◽

Hybrid Approach ◽

Arterial Disease ◽

Early Mortality ◽

Secondary Patency ◽

Limb Salvage Rate ◽

Peripheral Arterial ◽

Salvage Rate

Abstract. Background: Multilevel peripheral arterial disease is frequently observed in patients with intermittent claudication or critical limb ischemia. This report evaluates the efficacy of one-stage hybrid revascularization in patients with multilevel arterial peripheral disease. Patients and methods: A retrospective analysis of a prospective database included all consecutive patients treated by a hybrid approach for a multilevel arterial peripheral disease. The primary outcome was the patency rate at 6 months and 1 year. Secondary outcomes were early and midterm complication rate, limb salvage and mortality rate. Statistical analysis, including a Kaplan-Meier estimate and univariate and multivariate Cox regression analyses were carried out with the primary, primary assisted and secondary patency, comparing the impact of various risk factors in pre- and post-operative treatments. Results: 64 patients were included in the study, with a mean follow-up time of 428 days (range: 4 − 1140). The technical success rate was 100 %. The primary, primary assisted and secondary patency rates at 1 year were 39 %, 66 % and 81 %, respectively. The limb-salvage rate was 94 %. The early mortality rate was 3.1 %. Early and midterm complication rates were 15.4 % and 6.4 %, respectively. The early mortality rate was 3.1 %. Conclusions: The hybrid approach is a major alternative in the treatment of peripheral arterial disease in multilevel disease and comorbid patients, with low complication and mortality rates and a high limb-salvage rate.

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Dual Goals for Speed and Accuracy on the Same Performance Task

Journal of Personnel Psychology ◽

10.1027/1866-5888/a000063 ◽

2012 ◽

Vol 11 (3) ◽

pp. 118-126 ◽

Cited By ~ 3

Author(s):

Olive Emil Wetter ◽

Jürgen Wegge ◽

Klaus Jonas ◽

Klaus-Helmut Schmidt

Keyword(s):

Memory Scanning ◽

Performance Task ◽

Performance Tasks ◽

Trade Off ◽

Test Experiment ◽

Trade Offs ◽

New Finding ◽

Sternberg Paradigm ◽

Speed Accuracy ◽

Speed And Accuracy

In most work contexts, several performance goals coexist, and conflicts between them and trade-offs can occur. Our paper is the first to contrast a dual goal for speed and accuracy with a single goal for speed on the same task. The Sternberg paradigm (Experiment 1, n = 57) and the d2 test (Experiment 2, n = 19) were used as performance tasks. Speed measures and errors revealed in both experiments that dual as well as single goals increase performance by enhancing memory scanning. However, the single speed goal triggered a speed-accuracy trade-off, favoring speed over accuracy, whereas this was not the case with the dual goal. In difficult trials, dual goals slowed down scanning processes again so that errors could be prevented. This new finding is particularly relevant for security domains, where both aspects have to be managed simultaneously.

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