Recruitment dynamics of the grove-dominant tree Microberlinia bisulcata in African rain forest: extending the light response versus adult longevity trade-off concept

The photosynthetic light response of Amazonian semi-deciduous forest trees of the rain forest–savanna transition near Sinop Mato Grosso, Brazil was measured between July 2000 and September 2003 to test the hypothesis that the photosynthetic capacity of trees acclimated to different growth light environments will decline during the dry season. Maximum photosynthesis (Amax) and stomatal conductance (gmax) were significantly higher during the wet season; however, the physiological response to drought was not a clear function of growth light environment. For some species, such as Psychotria sp. growing in the mid-canopy, internal leaf CO2 concentration (Ci) was >30% lower during the dry season suggesting that declines in Amax were caused in part by stomatal limitations to CO2 diffusion. For other species, such as Brosimum lactescens growing at the top of the canopy, Tovomita schomburgkii growing in the mid-canopy, and Dinizia excelsa growing in the understorey, dry season Ci declined by <20% suggesting that factors independent of CO2 diffusion were more important in limiting Amax. Dry-season declines in gmax appeared to be important for maintaining a more consistent leaf water potential for some species (T. schomburgkii and D. excelsa) but not others (Psychotria sp.). These results indicate that while seasonal drought exerts an important limitation on the physiological capacity of semi-deciduous Amazonian forest trees, the mechanism of this limitation may differ between species.

Download Full-text

Polyandry and trade-off between fecundity and longevity in female Dichelops furcatus (Hemiptera: Pentatomidae)

Bulletin of Entomological Research ◽

10.1017/s0007485319000427 ◽

2019 ◽

Vol 110 (1) ◽

pp. 155-160

Author(s):

M.F. Cingolani ◽

M.F. Roggiero ◽

M.C. Barakat ◽

G.G. Liljesthröm

Keyword(s):

Life History ◽

Multiple Mating ◽

Relevant Information ◽

Reproductive Period ◽

Phytophagous Insects ◽

Adult Longevity ◽

Trade Off ◽

Single Mating ◽

Female Longevity ◽

Demographic Attributes

AbstractA trade-off is a relationship between two life history characteristics principally reproduction and adult longevity that are fundamental in predicting the optimal life history in any given environment. Mating is indispensable for sexual reproduction, but also can impose risks to females. Nevertheless, in the majority of insects, females allow multiple mating. Dichelops furcatus (Hemiptera: Pentatomidae) is a pest of wheat and corn in Argentina and southern Brazil, but little is known about its reproduction (i.e., the characteristics of the process that results in offspring). We analyzed reproductive attributes of D. furcatus, and the effect of single mating vs. multiple matings, evaluating the trade-off between fecundity and adult female longevity. We found that mating is not required for D. furcatus to oviposit, and multiple copulations were costly in terms of reduced longevity. Although multicopulated females lived a shorter period, only the pre- and post-reproductive periods were shortened. Fecundity was not affected but fertility was incremented in multicopulated females. Females copulated only once oviposited most of the eggs in the first half of the reproductive period, while eggs oviposited in the second half were all inviable (did not hatch). Studying demographic attributes of phytophagous insects provides relevant information to better understand the population dynamics of pests.

Download Full-text

Leaf Traits Determine the Growth‐Survival Trade‐Off across Rain Forest Tree Species

The American Naturalist ◽

10.1086/503056 ◽

2006 ◽

Vol 167 (5) ◽

pp. 758-765 ◽

Cited By ~ 114

Author(s):

F. J. Sterck ◽

L. Poorter ◽

F. Schieving

Keyword(s):

Tree Species ◽

Rain Forest ◽

Leaf Traits ◽

Forest Tree ◽

Trade Off ◽

Forest Tree Species

Download Full-text

A conifer-angiosperm divergence in the growth vs. shade tolerance trade-off underlies the dynamics of a New Zealand warm-temperate rain forest

Journal of Ecology ◽

10.1111/1365-2745.12368 ◽

2015 ◽

Vol 103 (2) ◽

pp. 479-488 ◽

Cited By ~ 18

Author(s):

Christopher H. Lusk ◽

Murray A. Jorgensen ◽

Peter J. Bellingham

Keyword(s):

New Zealand ◽

Rain Forest ◽

Shade Tolerance ◽

Trade Off ◽

Temperate Rain Forest ◽

Warm Temperate

Download Full-text

Leaf Traits Determine the Growth-Survival Trade-off across Rain Forest Tree Species

The American Naturalist ◽

10.2307/3844782 ◽

2006 ◽

Vol 167 (5) ◽

pp. 758 ◽

Cited By ~ 1

Author(s):

Sterck ◽

Poorter ◽

Schieving

Keyword(s):

Tree Species ◽

Rain Forest ◽

Leaf Traits ◽

Forest Tree ◽

Trade Off ◽

Forest Tree Species

Download Full-text

XRF and PIXE Analysis of light and Dark Adapted Ocular Tissue

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053619 ◽

1982 ◽

Vol 40 ◽

pp. 190-191

Author(s):

B. J. Panessa ◽

H. W. Kraner ◽

J. B. Warren ◽

K. W. Jones

Keyword(s):

Trace Metals ◽

Pigment Epithelium ◽

Nerve Impulse ◽

Light Response ◽

Ocular Tissue ◽

Emission Spectrometry ◽

Retinol Dehydrogenase ◽

Pixe Analysis ◽

X Ray ◽

Optimal Function

During photoexcitation the retina requires specific electrolytes and trace metals for optimal function (Na, Mg, Cl, K, Ca, S, P, Cu and Zn). According to Hagins (1981), photoexcitation and generation of a nerve impulse involves the movement of Ca from the rhodopsin-ladened membranes of the rod outer segment (ROS) to the plasmalemma, which in turn decreases the in-flow of Na into the photoreceptor, resulting in hyperpolarization. In toad isolated retinas, the presence of Ba has been found to increase the amplitude and prolong the delay of the light response (Brown and Flaming, 1978). Trace metals such as Cu, Zn and Se are essential for the activity of the metalloenzymes of the retina and retina pigment epithelium (RPE) (i.e. carbonic anhydrase, retinol dehydrogenase, tyrosinase, glutathione peroxidase, superoxide dismutase...). Therefore the content and fluctuations of these elements in the retina and choroid are of fundamental importance for the maintenance of vision. This paper presents elemental data from light and dark adapted frog ocular tissues examined by electron beam induced x-ray microanalysis, x-ray fluorescence spectrometry (XRF) and proton induced x-ray emission spectrometry (PIXE).

Download Full-text

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

Download Full-text

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.

Download Full-text