The Autorotation Boundary in the Flight of Samaras

Yasuda, Kunio; Azuma, Akira

doi:10.1006/jtbi.1996.0299

Cited by 54 publications

(43 citation statements)

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“…These samaras are adapted to wind dispersal and have one seed in the centre of each wing. Diaspores rotate along their axis and are rigid and sturdy (Kowarik and S€ aumel, 2007) which enables a variety of flying methods, with autorotation being the most common (Lentink et al, 2009;Yasuda and Azuma, 1997). Water dispersal has also been reported in this species (Kaproth and McGraw, 2008;Kowarik and S€ aumel, 2008).…”

Section: Study Area and Speciesmentioning

confidence: 95%

Gone with the wind and the stream: Dispersal in the invasive species Ailanthus altissima

2016

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a b s t r a c tDispersal is a key process in plant invasions and is strongly related to diaspore morphology. Often, dispersal comprises more than one step, and morphologies adapted to a primary dispersal mechanism can aid or detract from a secondary one. The aim of this work was to assess the relationship between primary wind dispersal and secondary water dispersal in Ailanthus altissima, an invasive tree species. Wind and water dispersal potential and their association with the morphological characteristics of samaras were assessed under controlled conditions to ensure the repeatability of the measurements. We found a direct positive relationship between primary wind and secondary water dispersal in A. altissima. The main morphological characteristics of the samara that affected the success of the two types of dispersal were side perimeter and mass. However, a possibility of dispersal specialisation exists, as one morphological characteristic (samara width) affects wind dispersal negatively but water dispersal positively, and dispersal potential and samara morphology have been shown to differ across individuals.

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Section: Study Area and Speciesmentioning

confidence: 95%

Gone with the wind and the stream: Dispersal in the invasive species Ailanthus altissima

2016

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“…The geometry and kinematics of rotary seeds have been described previously (Azuma and Yasuda, 1989;Greene and Johnson, 1990;Minami and Azuma, 2003;Yasuda and Azuma, 1997). To characterize representative kinematics, images of the rotary seeds spinning at a stationary height during free fall were recorded using a high-speed digital camera (Redlake, HG-100K/HG-LE, Pasadena, CA, USA) at a frame rate of 250framess -1 , as this was sufficient to resolve the rotational motion of the seeds.…”

Section: Geometry and Kinematicsmentioning

confidence: 99%

“…Ansari et al (Ansari et al, 2009) studied experimentally the flow around a constant-speed rotating wing and described the flow features of the LEV for two Reynolds numbers (500 and 15,000). The aerodynamic characteristics of autorotating seeds have been analyzed theoretically and experimentally (Azuma and Yasuda, 1989;Yasuda and Azuma, 1997). Recently, identified the LEV as the high-lift source in rotary seeds and described its detailed flow structure in terms of vorticity, spanwise flow and vorticity transport in and behind the vortex for spanwise regions at 25, 50 and 75% span.…”

Section: Introductionmentioning

confidence: 99%

Stereoscopic particle image velocimetry measurements of the three-dimensional flow field of a descending autorotating Mahogany seed (Swietenia macrophylla)

Salcedo

Treviño

Vargas

et al. 2013

Journal of Experimental Biology

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SUMMARYAn experimental investigation of near field aerodynamics of wind dispersed rotary seeds has been performed using stereoscopic digital particle image velocimetry (DPIV). The detailed three-dimensional flow structure of the leading-edge vortex (LEV) of autorotating mahogany seeds (Swietenia macrophylla) in a low-speed vertical wind tunnel is revealed for the first time. The results confirm that the presence of strong spanwise flow and strain produced by centrifugal forces through a spiral vortex are responsible for the attachment and stability of the LEV, with its core forming a cone pattern with a gradual increase in vortex size. The LEV appears at 25% of the wingspan, increases in size and strength outboard along the wing, and reaches its maximum stability and spanwise velocity at 75% of the wingspan. At a region between 90 and 100% of the wingspan, the strength and stability of the vortex core decreases and the LEV re-orientation/inflection with the tip vortex takes place. In this study, the instantaneous flow structure and the instantaneous velocity and vorticity fields measured in planes parallel to the free stream direction are presented as contour plots using an inertial and a non-inertial frame of reference. Results for the mean aerodynamic thrust coefficients as a function of the Reynolds number are presented to supplement the DPIV data.

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“…These samaras are adapted to wind dispersal and have one seed in the centre of each wing. The samaras rotate along their axis and are rigid and sturdy (Kowarik & Säumel 2007) to enable a variety of flying methods, with autorotation being the most common (Yasuda & Azuma 1997;Lentink et al 2009). …”

Section: Study Area and Speciesmentioning

confidence: 99%

Estimating wind dispersal potential inAilanthus altissima: The need to consider the three-dimensional structure of samaras

Planchuelo

Catalán

Delgado

et al. 2016

Plant Biosystems - An International Journal Dealing with all As

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Plant dispersal is a very important ecological phenomenon, as it can enable species to move away from the parent plant. This contributes to shaping communities, determining patterns of distribution, landscape configuration, plant invasions and evolutionary processes. Measuring dispersal distance directly is difficult and thus, diaspore morphology can be used to make estimates. Previous research on the topic often resorts to analysing the diaspore's morphology as if it was a bi-dimensional structure; when in many cases, diaspores have three-dimensional qualities. In this study, we show how estimates of wind dispersal potential of Ailanthus altissima can be considerably improved using morphological variables that succeed in describing the three-dimensional nature of samaras. We suggest that this reasoning could be extensively applied to research involving not only other species, but also multi-specific scenarios with a wide range of diaspore morphologies.

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The Autorotation Boundary in the Flight of Samaras

Cited by 54 publications

References 0 publications

Gone with the wind and the stream: Dispersal in the invasive species Ailanthus altissima

Gone with the wind and the stream: Dispersal in the invasive species Ailanthus altissima

Stereoscopic particle image velocimetry measurements of the three-dimensional flow field of a descending autorotating Mahogany seed (Swietenia macrophylla)

Estimating wind dispersal potential inAilanthus altissima: The need to consider the three-dimensional structure of samaras

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