Does community‐level floral abundance affect the pollination success of a rewardless orchid, Calanthe reflexaMaxim.?

Abstract

Decreases in pollinator abundance may particularly constrain plants that lack floral rewards, since they are poor competitors for pollinators in the plant community. Here, we documented the pollination ecology of a rewardless orchid, Calanthe reflexa Maxim., and examined effects of forest understory degradation by deer browsing on pollination success of the species in the light of a change in the abundance of neighboring flowering plants in 2010 and 2011. Bombus species were the only pollinators at each site and the flowering phenology of C. reflexa did not overlap with that of other rewarding plants.Pollinator visit rates (assessed by time-lapse photography), and pollinia removal rate were higher in the undegraded understory site than the degraded site in both years, while the fruit set ratio did not differ between the sites in 2011. Coverage by neighboring flowering plants was extremely low in the degraded site. Our results suggest that, although its flowering phenology and consequently lower interspecific competition of C. reflexa with rewarding plants for attracting bumblebees, neighboring flowering plants may play an important role for maintaining the visitation frequency of bumblebees of C. reflexa and contribute to its pollination success.

Which food-mimic floral traits and environmental factors influence fecundity in a rare orchid,Calanthe yaoshanensis?

“…The floral spur of C. yaoshanensis contains no nectar, as in the five insect‐pollinated Calanthe spp. studied previously (Zhang et al ., ; Sugiura, ; Sakata et al ., ; Suetsugu & Fukushima, ). The flower of C. yaoshanensis shows much the same suite of floral characters as described in many other epidendroid species that are food mimics and are pollinated by large insects.…”

“…distributed in Japan was also extremely low, ranging from 0–9.0% in C. reflexa Maxim. (Sakata et al ., ) to 8.3–17.3% in C. striata Lindl. (Sugiura, ), 1.20–6.49% in C. discolor (Suetsugu & Fukushima, ) and c .…”

“…with short spurs or no spurs are pollinated by large‐bodied bees in the family Apidae (e.g. the genera: Apis , Bombus , Eucera and Xylocopa ; Sugiura et al ., ; Sugiura, ; Sakata et al ., ; Suetsugu & Fukushima, ). Osmia cornifrons (Megachilidae), Apis cerana ssp.…”

“…Catling, ; Juillet et al ., ; Delle‐Vedove et al ., ; Sugiura, ). Eight species self‐pollinate mechanically (Catling, ; Jacquemyn et al ., ), and the remaining five species are entomophilous, but their floral presentation appeals to different insects, suggesting some degree of adaptive radiation of food mimicry (Sugiura & Miyanaga, ; Sugiura, Yoshida & Maeta, ; Zhang et al ., ; Sugiura, ; Sakata, Sakaguchi & Yamasaki, ; Suetsugu & Fukushima, ; Zhai et al ., ). A male Redena similis (Danaidae) carried the pollinarium of C. triplicata (Willem.)…”

Flexible pollination system in an unpalatable shrub Daphne miyabeana (Thymelaeaceae)

“…; Yumoto & Matsuda ), which consequently caused negative indirect effects on plant reproduction through cascading effects of pollination linkages (Vazquez & Simberloff ; Sakata et al . ; Sakata & Yamasaki ). Recent studies have found that at sites with severe deer browsing, the visitation rate of bumblebees decreased because of severe reductions in the coverage of autumn‐flowering herbaceous plants (Kato & Okuyama ; Okuda et al .…”