Robinia pseudoacacia L. Flower Analyzed by Using An Unmanned Aerial Vehicle (UAV)

Remote Sensing

Hans Pretzsch¹  Christin Carl¹  Peter Biber¹  Dirk Landgraf²  Marieke van der Maaten-Theunissen³ 

[1] Forest Growth and Yield Science, School of Life Sciences Weihenstephan, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany;Forestry and Ecosystem Management, University of Applied Science Erfurt, Leipziger Straße 77, 99085 Erfurt, Germany;Institute of Botany and Landscape Ecology, University of Greifswald, Soldmannstrasse 15, 17489 Greifswald, Germany;

关键词: unmanned aerial vehicles (UAVs);    tree blossoms;    Robinia pseudoacacia L.;    honeybees;   

DOI  :  10.3390/rs9111091

来源: DOAJ

【 摘 要 】

Tree flowers are important for flower–insect relationships, seeds, fruits, and honey production. Flowers are difficult to analyze, particularly in complex ecosystems such as forests. However, unmanned aerial vehicles (UAVs) enable detailed analyses with high spatial resolution, and avoid destruction of sensitive ecosystems. In this study, we hypothesize that UAVs can be used to estimate the number of existing flowers, the quantity of nectar, and habitat potential for honeybees (Apis mellifera). To test this idea, in 2017 we combined UAV image analysis with manual counting and weighing of the flowers of eight-year-old black locust (Robinia pseudoacacia L.) trees to calculate the number of flowers, their surface area, and their volume. Estimates of flower surface area ranged from 2.97 to 0.03% as the flying altitude above the crowns increased from 2.6 m to 92.6 m. Second, for the horizontal analysis, a 133 m2 flower area at a one-hectare black locust plantation was monitored in 2017 by a UAV. Flower numbers ranged from 1913 to 15,559 per tree with an average surface area of 1.92 cm2 and average volume of 5.96 cm3. The UAV monitored 11% of the total surface and 3% of the total volume. Consequently, at the one-hectare black locust study area we estimate 5.3 million flowers (69 kg honey), which is sufficient for one bee hive to survive for one year.

【 授权许可】

Unknown