Florivory indirectly decreases the plant reproductive output through changes in pollinator attraction.

Kaoru Tsuji,Takayuki Ohgushi

doi:10.1002/ece3.3921

Abstract

Species often interact indirectly with each other via their traits. There is increasing appreciation of trait‐mediated indirect effects linking multiple interactions. Flowers interact with both pollinators and floral herbivores, and the flower‐pollinator interaction may be modified by indirect effects of floral herbivores (i.e., florivores) on flower traits such as flower size attracting pollinators. To explore whether flower size affects the flower‐pollinator interaction, we used Eurya japonica flowers. We examined whether artificial florivory decreased fruit and seed production, and also whether flower size affected florivory and the number of floral visitors. The petal removal treatment (i.e., artificial florivory) showed approximately 50% reduction in both fruit and seed set in natural pollination but not in artificial pollination. Furthermore, flower size increased the number of floral visitors, although it did not affect the frequency of florivory. Our results demonstrate that petal removal indirectly decreased 75% of female reproductive output via decreased flower visits by pollinators and that flower size mediated indirect interactions between florivory and floral visitors.

Highlights

To examine whether flower size alters the strength of flower-florivore-pollinator interactions, we studied the interaction of Eurya japonica plants and its associated pollinators and florivores
Pollinated artificially (AP) and naturally (NP). Besides these three we examined whether bud size determined flower size because treatments, we set another treatment to evaluate the effect of arflorivory occurred in bud period and floral visitors were attracted tificial florivory before pollination (AF before artificial pollination (AP))
We examined whether the flower size affected were set as follows (Figure 1a): florivory level and/or the number of visitors on blooming plant, based on the fact of a strong positive correlation between bud size and flower size

Summary

February

Stigmas intact (i.e., petal removal [PR]) using a pair of tweezers, as same period, to examine seed production, we counted the number of flowers lacking all petals were common following heavy florivory. Four treatments received artificial pollination (AP) from 3 to 24 on the treated twigs and fruits on another untreated twig (N). 2.3 | Measurement of bud and flower size timing of florivory on female reproductive output, we removed stigmas after pollination. To confirm whether bud size determines flower size, we measured on fruit and seed set, we removed petals of both artificially and the size of buds and blooming flowers. We tagged 11 buds each of naturally pollinated flowers. 1. No pollination (C): twigs were covered from 9 February to 6 the tagged flowers on the day after flowers opened during the August 2013.

AP and AF following a few days later

Findings

C O N FL ICTOFINTEREST