TY - JOUR A1 - Bae, Soyeon A1 - Müller, Jörg A1 - Förster, Bernhard A1 - Hilmers, Torben A1 - Hochrein, Sophia A1 - Jacobs, Martin A1 - Leroy, Benjamin M. L. A1 - Pretzsch, Hans A1 - Weisser, Wolfgang W. A1 - Mitesser, Oliver T1 - Tracking the temporal dynamics of insect defoliation by high‐resolution radar satellite data JF - Methods in Ecology and Evolution N2 - Quantifying tree defoliation by insects over large areas is a major challenge in forest management, but it is essential in ecosystem assessments of disturbance and resistance against herbivory. However, the trajectory from leaf-flush to insect defoliation to refoliation in broadleaf trees is highly variable. Its tracking requires high temporal- and spatial-resolution data, particularly in fragmented forests. In a unique replicated field experiment manipulating gypsy moth Lymantria dispar densities in mixed-oak forests, we examined the utility of publicly accessible satellite-borne radar (Sentinel-1) to track the fine-scale temporal trajectory of defoliation. The ratio of backscatter intensity between two polarizations from radar data of the growing season constituted a canopy development index (CDI) and a normalized CDI (NCDI), which were validated by optical (Sentinel-2) and terrestrial laser scanning (TLS) data as well by intensive caterpillar sampling from canopy fogging. The CDI and NCDI strongly correlated with optical and TLS data (Spearman's ρ = 0.79 and 0.84, respectively). The ΔNCDII\(_{Defoliation(A−C)}\) significantly explained caterpillar abundance (R\(^{2}\) = 0.52). The NCDI at critical timesteps and ΔNCDI related to defoliation and refoliation well discriminated between heavily and lightly defoliated forests. We demonstrate that the high spatial and temporal resolution and the cloud independence of Sentinel-1 radar potentially enable spatially unrestricted measurements of the highly dynamic canopy herbivory. This can help monitor insect pests, improve the prediction of outbreaks and facilitate the monitoring of forest disturbance, one of the high priority Essential Biodiversity Variables, in the near future. KW - Sentinel-1 KW - canopy herbivory KW - defoliation severity KW - gypsy moth KW - insect disturbance KW - intra-annual time-series KW - Lymantria dispar KW - remote sensing Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-258222 VL - 13 IS - 1 ER - TY - JOUR A1 - Storms, Mona A1 - Jakhar, Aryan A1 - Mitesser, Oliver A1 - Jechow, Andreas A1 - Hölker, Franz A1 - Degen, Tobias A1 - Hovestadt, Thomas A1 - Degen, Jacqueline T1 - The rising moon promotes mate finding in moths JF - Communications Biology N2 - To counteract insect decline, it is essential to understand the underlying causes, especially for key pollinators such as nocturnal moths whose ability to orientate can easily be influenced by ambient light conditions. These comprise natural light sources as well as artificial light, but their specific relevance for moth orientation is still unknown. We investigated the influence of moonlight on the reproductive behavior of privet hawkmoths (Sphinx ligustri) at a relatively dark site where the Milky Way was visible while the horizon was illuminated by distant light sources and skyglow. We show that male moths use the moon for orientation and reach females significantly faster with increasing moon elevation. Furthermore, the choice of flight direction depended on the cardinal position of the moon but not on the illumination of the horizon caused by artificial light, indicating that the moon plays a key role in the orientation of male moths. KW - animal behaviour KW - biodiversity KW - conservation biology KW - entomology KW - urban ecology Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-301365 VL - 5 ER - TY - JOUR A1 - Englmeier, Jana A1 - von Hoermann, Christian A1 - Rieker, Daniel A1 - Benbow, Marc Eric A1 - Benjamin, Caryl A1 - Fricke, Ute A1 - Ganuza, Cristina A1 - Haensel, Maria A1 - Lackner, Tomáš A1 - Mitesser, Oliver A1 - Redlich, Sarah A1 - Riebl, Rebekka A1 - Rojas-Botero, Sandra A1 - Rummler, Thomas A1 - Salamon, Jörg-Alfred A1 - Sommer, David A1 - Steffan-Dewenter, Ingolf A1 - Tobisch, Cynthia A1 - Uhler, Johannes A1 - Uphus, Lars A1 - Zhang, Jie A1 - Müller, Jörg T1 - Dung-visiting beetle diversity is mainly affected by land use, while community specialization is driven by climate JF - Ecology and Evolution N2 - Dung beetles are important actors in the self-regulation of ecosystems by driving nutrient cycling, bioturbation, and pest suppression. Urbanization and the sprawl of agricultural areas, however, destroy natural habitats and may threaten dung beetle diversity. In addition, climate change may cause shifts in geographical distribution and community composition. We used a space-for-time approach to test the effects of land use and climate on α-diversity, local community specialization (H\(_2\)′) on dung resources, and γ-diversity of dung-visiting beetles. For this, we used pitfall traps baited with four different dung types at 115 study sites, distributed over a spatial extent of 300 km × 300 km and 1000 m in elevation. Study sites were established in four local land-use types: forests, grasslands, arable sites, and settlements, embedded in near-natural, agricultural, or urban landscapes. Our results show that abundance and species density of dung-visiting beetles were negatively affected by agricultural land use at both spatial scales, whereas γ-diversity at the local scale was negatively affected by settlements and on a landscape scale equally by agricultural and urban land use. Increasing precipitation diminished dung-visiting beetle abundance, and higher temperatures reduced community specialization on dung types and γ-diversity. These results indicate that intensive land use and high temperatures may cause a loss in dung-visiting beetle diversity and alter community networks. A decrease in dung-visiting beetle diversity may disturb decomposition processes at both local and landscape scales and alter ecosystem functioning, which may lead to drastic ecological and economic damage. KW - coleoptera KW - coprophagous beetles KW - decomposition KW - global change KW - hill numbers KW - network analysis Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312846 SN - 2045-7758 VL - 12 IS - 10 ER -