TY - JOUR
T1 - Shipment and storage effects on the terminal velocity of seeds
AU - Marchetto, Katherine M.
AU - Jongejans, Eelke
AU - Jennis, Matthew L.
AU - Haner, Emily M.
AU - Sullivan, Caitlin T.
AU - Kelly, Dave
AU - Shea, Katriona
N1 - Funding Information:
Acknowledgments This research was funded by the National Science Foundation (grants DEB-0315860 and DEB-0614065 awarded to K. S.). In particular, thanks to the NSF REU program for funding K. M. M. The New Zealand field work was funded by Landcare Research under the Outsmarting Weeds programme, FRST contract C10X0318. We are also grateful to Suann Yang, Carwyn Sposit, Shabina Dalal, and Pacifica Sommers for assistance with the experiments and helpful discussions. Thanks are also due to David Mortensen, Scott Isard, and two anonymous reviewers for manuscript comments.
PY - 2010/1
Y1 - 2010/1
N2 - Mechanistic models of seed dispersal by wind include terminal velocity as the main seed characteristic that influences the dispersal process and hence the resulting dispersal kernels and spread rates. Accurate measurement of the terminal velocity of seeds is therefore pivotal. However, compression during shipment through the post or during storage between collection in the field and terminal velocity measurements in the lab may affect these measurements. To evaluate the effects of shipment and storage on terminal velocity measurements, capitula of Carduus nutans, an invasive thistle species from Eurasia, were stored for 1-5 years and subjected to three different packing treatments. Seeds from capitula were then assessed for terminal velocity values, plume area, seed mass, wing loading, number of filaments per pappus, qualitative assessments of pappus damage, and number of intact dispersal units per capitulum. Compression significantly increased seed terminal velocity. However, storage duration for 1-5 years did not cause a significant increase or decrease in any of the response variables. The compression treatment was validated by shipment of seeds from New Zealand to the United States. When capitula that are to be used for terminal velocity measurements are stored or shipped, they should be packaged in incompressible containers to avoid damage to the fragile dispersal structures. Studies using capitula that were originally collected and stored for other purposes, such as transcontinental demographic studies, should rescale observed terminal velocity values to take into account possible damage.
AB - Mechanistic models of seed dispersal by wind include terminal velocity as the main seed characteristic that influences the dispersal process and hence the resulting dispersal kernels and spread rates. Accurate measurement of the terminal velocity of seeds is therefore pivotal. However, compression during shipment through the post or during storage between collection in the field and terminal velocity measurements in the lab may affect these measurements. To evaluate the effects of shipment and storage on terminal velocity measurements, capitula of Carduus nutans, an invasive thistle species from Eurasia, were stored for 1-5 years and subjected to three different packing treatments. Seeds from capitula were then assessed for terminal velocity values, plume area, seed mass, wing loading, number of filaments per pappus, qualitative assessments of pappus damage, and number of intact dispersal units per capitulum. Compression significantly increased seed terminal velocity. However, storage duration for 1-5 years did not cause a significant increase or decrease in any of the response variables. The compression treatment was validated by shipment of seeds from New Zealand to the United States. When capitula that are to be used for terminal velocity measurements are stored or shipped, they should be packaged in incompressible containers to avoid damage to the fragile dispersal structures. Studies using capitula that were originally collected and stored for other purposes, such as transcontinental demographic studies, should rescale observed terminal velocity values to take into account possible damage.
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U2 - 10.1007/s11284-009-0634-1
DO - 10.1007/s11284-009-0634-1
M3 - Article
AN - SCOPUS:77951090891
SN - 0912-3814
VL - 25
SP - 83
EP - 92
JO - Ecological Research
JF - Ecological Research
IS - 1
ER -