DOI: 10.5061/dryad.d7q03
title: Data from: The consequences of demand-driven seed provisioning for sexual differences in reproductive investment in Thalictrum occidentale (Ranunculaceae)

description: Many iteroparous angiosperms may benefit from flexible annual resource
 allocation in response to variable reproductive opportunities induced by
 external conditions. If maximal reproductive investment is fixed, lack of
 reproductive sinks would cause resource redistribution to other sinks.
 Alternatively, reproductive investment may vary depending on the demand of
 reproductive sinks, changing source-sink relations. In particular,
 differential responses by males and females to the demands of flower and
 seed production may cause sexual dimorphism. We assess the occurrence of
 demand-driven seed allocation by females and its implications for sexual
 differences in reproductive investment, including the dynamics of mass and
 carbon allocation and the physiological cost of reproduction, for a
 dioecious, perennial herb, Thalictrum occidentale. We specifically
 quantified allocation responses to partial defoliation, which reduced
 current resource supply, and partial flower/fruit removal, which reduced
 the aggregate demand of reproductive sinks. During flowering, males
 preferentially invested carbon and mass in flowers at the expense of
 vegetative organs, whereas females allocated less mass to flowers and
 invested more in new-rhizome production for future performance than males.
 In contrast, during early fruiting, both sexes had new rhizomes of similar
 size and a doubling of reproductive mass by females after flowering
 resulted in similar total reproductive investment for both sexes.
 Manipulation of the source-sink balance did not influence carbon
 allocation, except that partial fruit removal increased new-rhizome mass
 compared to intact plants. Females with many fertilized ovules invested
 proportionally more in seed number and mass per seed than females with few
 fertilized ovules, indicating both demand-driven seed maturation and its
 elimination of seed size-number trade-off. Furthermore, males consistently
 exhibited size-dependent flower production, whereas females exhibited
 size-dependent flower production only if they had not reproduced during
 the previous year. Synthesis: This study demonstrates that sexual
 differences in policies of reproductive investment and the timing of the
 physiological costs of reproduction impose contrasting allocation
 schedules. Males invested in reproduction proportionally with their size,
 whereas females invested flexibly in seeds in response to the demand of
 developing embryos. Thus, the contrasting certainty and timing of
 reproductive resource requirements between the sexes contribute to sexual
 dimorphism.
description: Cost of
 reproductionTitle: Effect of past
 (2011) reproduction on 2012 flower production. Description: These data
 present flower number during 2012 for plants subject to limited or free
 reproduction during 2011. Analysis of these data is presented in Table S3.
 See “legend” worksheet for explanation of columns in “data”
 worksheet.Flower
 MassTitle: Total flower mass
 and number. Description: Flower mass and number for intact and defoliated
 plants during 2008 and 2011. Analysis of these data is presented in Table
 3. See "legend" worksheet for explanation of columns in
 "data" worksheet.Fruit Mass
 2008Title: Total fruit mass
 and number. Description: Fruit mass and number for intact and defoliated
 plants during 2008. Analysis of these data is presented in Table 3. See
 "legend" worksheet for explanation of columns in
 "data" worksheet.Ida etal Mass & 13C
 2008Title: Dry mass and 13C
 data, 2008. Description: Data for 13C and dry mass allocation among six
 tissues from 2008, including intact and defoliated plants and those
 subject to partial fruit removal. Analyses of various subsets of these
 data are presented in Tables 1 and S2a. See "legend" worksheet
 for explanation of columns in "data"
 worksheet.Ida etal Mass & 13C
 2011 floweringTitle: Dry mass and 13C
 data, 2011. Description: Data for 13C and dry mass allocation among six
 tissues for flowering plants in the intact and partial flower-removal
 treatments during 2011. Analysis of these data is presented in Table S2b.
 See "legend" worksheet for explanation of columns in
 "data" worksheet.Seed
 productionTitle: Total seed mass
 and number. Description: Seed mass and number for intact plants and those
 subject to partial flower or fruit removal during 2008. Analysis of these
 data is presented in Table 2. See "legend" worksheet for
 explanation of columns in "data" worksheet.