Plant–pollinator interactions in tropical monsoon forests in Southeast Asia

Abstract

Forests with different flora and vegetation types harbor different assemblages of flower visitors, and plant–pollinator interactions vary among forests. In monsoon‐dominated East and Southeast Asia, there is a characteristic gradient in climate along latitude, creating a broad spectrum of forest types with potentially diverse pollinator communities. To detect a geographical pattern of plant–pollinator interactions, we investigated flowering phenology and pollinator assemblages in the least‐studied forest type, i.e., tropical monsoon forest, in the Vientiane plain in Laos. Throughout the 5‐year study, we observed 171 plant species blooming and detected flower visitors on 145 species. Flowering occurred throughout the year, although the number of flowering plant species peaked at the end of dry season. The dominant canopy trees, including Dipterocarpaceae, bloomed annually, in contrast to the supra‐annual general flowering that occurs in Southeast Asian tropical rain forests. Among the 134 native plant species, 68 were pollinated by hymenopterans and others by lepidopterans, beetles, flies, or diverse insects. Among the observed bees, Xylocopa, megachilids, and honeybees mainly contributed to the pollination of canopy trees, whereas long‐tongued Amegilla bees pollinated diverse perennials with long corolla tubes. This is the first community‐level study of plant–pollinator interactions in an Asian tropical monsoon forest ecosystem.

Pollination ecology and fruiting behavior of Pavetta indica L. (Rubiaceae), a keystone shrub species in the southern Eastern Ghats forest, Andhra Pradesh, India

“…Therefore, the breeding system functional in P. indica is one step evolved in the path of avoiding selfing through autonomous autogamy and the recorded fruit set rate in open-pollinations is a function of vector-mediated self-and cross-pollination. Kato et al (2008) . kerii by Pieridae and R. sootepensis by Hesperiidae.…”

“…Burkhardt (1964) and Faegri & van der Pijl (1979) described that butterflyflowers usually possess large, white, pink, red, yellow or blue, narrow, tubular flowers with deep nectaries and often yellow rings or other markings on the petals which function as nectar guides. Further, Kato et al (2008) stated that the secondary pollen presentation system is often found in butterfly-pollinated species with a long slender corolla-tube and far exserted style. In the present study also, P. indica principally pollinated by butterflies and hawk moths display the characteristics stated by these authors but in this species, nectar guides are totally absent.…”

“…The flowers are also used as a cosmetic after bathing. The plant produces white, tubular, actinomorphic, hermaphroditic flowers which are foraged and pollinated by Papilionid butterflies (Momose et al 1998;Kato et al 2008). Since there is very little information on the pollination biology of Pavetta genus in general and the medicinally important species, P. indica in particular despite its medicinal importance, we initiated this study using field and laboratory approaches to investigate the details of its pollination ecology.…”

Seasonal prevalence of arthropods after line thinning of overstocked Japanese cedar (Cryptomeria japonica D. Don) plantations in central Japan

“…The seasonal changes may vary among forest types. In Southeast Asian tropical rain forests, Kato et al (2008) found year-round flower visitors where flowering occurred throughout the year in the presence of supra-annual flowering plants. In this study, the pollen feeders were only abundant in early spring, reflecting their strong habitat and food specificity.…”

Genetic diversity and differentiation of an endangered tree species, Afzelia xylocarpa (Kurz) craib in Thailand revealed by nuclear microsatellite markers

“…This result was further confirmed by the AMOVA analysis, with 91.57% of the genetic variation existed within populations (Table 4). Afzelia (Caesalpinioideae) species are pollinated by large Xylocopa bee (Kato et al, 2008) to be capable of flying distances of several kilometers thus affecting pollen dispersal between plants at great distances. The gene flow estimates (Nm) was estimated at 3.13, indicating a very high migration rate among 15 populations.…”