DOI: 10.6084/m9.figshare.13088930
title: longandata.csv

description: AbstractThis data set examines the effects of flowering time and pollinator management, including managed honeybee colonies and ground flower cover, on the pollination of the tropical fruit tree, longan (<i>Dimocarpus longan</i> Lour.), comparing between in-season flowering (naturally) and off-season flowering (chemically-induced) in Chiang Mai province, Northern Thailand.We collected data of number of visitor species, number of fruitset within 2 weeks and mature fruits in both closed and opened experiment. visitation rates of flower visitor groups (wild bees, honeybees, flies) in differrent treatment in-season flowering, off-season flowering with honeybee hives, and off-season flowering without honeybee hives.Methods<strong>Study sites</strong>: This data was primarily collected in monocultural longan orchards in Chiang Mai province, Northern Thailand (18°47′43″N 98°59′55″E) from November 2018 to July 2019. The altitude in this region ranges from 310 to 3565 m.a.s.l. The range of temperature and humidity from November 2018 to July 2019 was 24 – 31 °C and 47% to 72 %. A total of nine longan orchards of the cultivar E-Daw with similar size (2.5-3.2 ha) were selected, minimally 10 km apart. Each orchard included planted longan and native herbaceous species. Spacing of the longan trees was generally 6 m × 6 m for the selected cultivar.Three longan orchards were used for each treatment (off-season with honeybee hives; off-season without honeybee hives and in-season without honeybee hives).<b>Sampling flowers, flower-visitors and flower-visitor interactions: </b>We marked a 10 × 20 m plot in each orchard and we identified the plant species and counted the number of flowers in bloom of ground flora and noted the percent covered with flowers in each study plot. Visitor frequency and richness were recorded in fair weather (i.e. sunny and without rain, with the temperature ranging from 26 °C to 28 °C) between 0700 and 1100. We only collected data on insects when they came into contact with the ﬂower. We sampled the number of floral visitors from the flowers of ten longan trees in each orchard. For each observed longan tree, we used 15-min. pollinator observation sessions within four 1×1m2 quadrats placed at a height of the midpoint of the tree facing each of the four cardinal directions of the tree (north, south, east, and west). We categorized visitors into four groups: 1) western honey bees (<i>A. mellifera</i>); 2) Asian honey bees (<i>A. cerana</i>); 3) wild bees (stingless bees and other wild bees); 4) flies. <strong>Reproductive success of longan</strong>: To assess the effect of flowering time on reproductive success, we measured fruit-set and yield resulting from ten open-pollinated (marked with twist-ties) and ten control inflorescences per tree, ten trees per orchard. Each chosen inflorescence had a similar number of flower buds (3000-3500 buds). For the control, ten inflorescences from each tree were covered with a light fabric bag pre-flowering (30 x 30 cm). After all flowering ceased, the bags were removed and fruit weights were recorded when fruits ripened. As the first flowers/fruits drop wave occurred 2–4 weeks after flowering (Pham, Herrero, & Hormaza, 2016), we counted the number of fruits per inflorescence for each study tree c. 14 days after flowering period (so that our measure of pollination success was not affected by any potential effects of resource limitation). We also counted the number of mature fruit at the same time as the farmer harvested the longans.