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Your search keyword '"Harder, Lawrence D."' showing total 49 results
Start Over Author "Harder, Lawrence D." Publisher wiley
49 results on '"Harder, Lawrence D."'

10. Coordinated species importation policies are needed to reduce serious invasions globally: The case of alien bumblebees in South America

Author

Aizen, Marcelo A., primary, Smith‐Ramírez, Cecilia, additional, Morales, Carolina L., additional, Vieli, Lorena, additional, Sáez, Agustín, additional, Barahona‐Segovia, Rodrigo M., additional, Arbetman, Marina P., additional, Montalva, José, additional, Garibaldi, Lucas A., additional, Inouye, David W., additional, and Harder, Lawrence D., additional

Published
2018
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48. Variation in ovule and seed size and associated size-number trade-offs in angiosperms.

Author

Greenway CA and Harder LD

Abstract

Unlike pollen and seed size, the extent and causes of variation in ovule size remain unexplored. Based on 45 angiosperm species, we assessed whether intra- and interspecific variation in ovule size is consistent with cost minimization during ovule production or allows maternal plants to dominate conflict with their seeds concerning resource investment. Despite considerable intraspecific variation in ovule volume (mean CV = 0.356), ovule production by few species was subject to a size-number trade-off. Among the sampled species, ovule volume varied two orders of magnitude, whereas seed volume varied four orders of magnitude. Ovule volume varied positively among species with flower mass and negatively with ovule number. Tenuinucellate ovules were generally larger that crassinucellate ovules, and species with apical placentation (which mostly have uniovulate ovaries) had smaller ovules than those with other placentation types. Seed volume varied positively among species with fruit mass and seed development time, but negatively with seed number. Seeds grew a median 93-fold larger than the ovules from which they originated. Our results provide equivocal evidence that selection minimizes ovule size to allow efficient resource allocation after fertilization, but stronger evidence that ovule size affords maternal plants an advantage in parent-offspring conflict.

Published
2007
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49. Functional associations of floret and inflorescence traits among grass species.

Author

Friedman J and Harder LD

Abstract

The aerodynamics of wind pollination selects for an intimate relation between form and function in anemophilous plants. Inflorescence architecture and floral morphology vary extensively within the Poaceae, but the functional implication of this variation remains largely unknown. Here we quantify associations between floret, culm, and inflorescence characteristics for 25 grass species in Kananaskis, Alberta, Canada, and consider whether different architectures may implement unique mechanisms to aid pollination. The species cluster into four categories defined by all combinations of floret size (small vs. large) and inflorescence architecture (compact vs. diffuse). Species differed significantly for all 18 traits that we measured, with 12 traits differing only between floret-size classes, three differing only between inflorescence types, and three differing among both (independently or by an interaction). Based on these morphological associations, we discuss the aerodynamic and functional consequences of each category for wind pollination. The independence of inflorescence and floral traits has probably allowed exploration of all possible combinations of inflorescence architecture and floret size during the evolution of the Poaceae.

Published
2005
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