TY  - JOUR
A1  - Uphus, Lars
A1  - Lüpke, Marvin
A1  - Yuan, Ye
A1  - Benjamin, Caryl
A1  - Englmeier, Jana
A1  - Fricke, Ute
A1  - Ganuza, Cristina
A1  - Schwindl, Michael
A1  - Uhler, Johannes
A1  - Menzel, Annette
T1  - Climate effects on vertical forest phenology of Fagus sylvatica L., sensed by Sentinel-2, time lapse camera, and visual ground observations
JF  - Remote Sensing
N2  - Contemporary climate change leads to earlier spring phenological events in Europe. In forests, in which overstory strongly regulates the microclimate beneath, it is not clear if further change equally shifts the timing of leaf unfolding for the over- and understory of main deciduous forest species, such as Fagus sylvatica L. (European beech). Furthermore, it is not known yet how this vertical phenological (mis)match — the phenological difference between overstory and understory — affects the remotely sensed satellite signal. To investigate this, we disentangled the start of season (SOS) of overstory F.sylvatica foliage from understory F. sylvatica foliage in forests, within nine quadrants of 5.8 × 5.8 km, stratified over a temperature gradient of 2.5 °C in Bavaria, southeast Germany, in the spring seasons of 2019 and 2020 using time lapse cameras and visual ground observations. We explained SOS dates and vertical phenological (mis)match by canopy temperature and compared these to Sentinel-2 derived SOS in response to canopy temperature. We found that overstory SOS advanced with higher mean April canopy temperature (visual ground observations: −2.86 days per °C; cameras: −2.57 days per °C). However, understory SOS was not significantly affected by canopy temperature. This led to an increase of vertical phenological mismatch with increased canopy temperature (visual ground observations: +3.90 days per °C; cameras: +2.52 days per °C). These results matched Sentinel-2-derived SOS responses, as pixels of higher canopy height advanced more by increased canopy temperature than pixels of lower canopy height. The results may indicate that, with further climate change, spring phenology of F. sylvatica overstory will advance more than F. sylvatica understory, leading to increased vertical phenological mismatch in temperate deciduous forests. This may have major ecological effects, but also methodological consequences for the field of remote sensing, as what the signal senses highly depends on the pixel mean canopy height and the vertical (mis)match.
KW  - overstory
KW  - understory
KW  - Sentinel-2
KW  - time lapse cameras
KW  - vertical mismatch
KW  - phenological escape
KW  - climate change
KW  - European beech
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-248419
SN  - 2072-4292
VL  - 13
IS  - 19
ER  - 
TY  - JOUR
A1  - Uhler, Johannes
A1  - Redlich, Sarah
A1  - Zhang, Jie
A1  - Hothorn, Torsten
A1  - Tobisch, Cynthia
A1  - Ewald, Jörg
A1  - Thorn, Simon
A1  - Seibold, Sebastian
A1  - Mitesser, Oliver
A1  - Morinère, Jérôme
A1  - Bozicevic, Vedran
A1  - Benjamin, Caryl S.
A1  - Englmeier, Jana
A1  - Fricke, Ute
A1  - Ganuza, Cristina
A1  - Haensel, Maria
A1  - Riebl, Rebekka
A1  - Rojas-Botero, Sandra
A1  - Rummler, Thomas
A1  - Uphus, Lars
A1  - Schmidt, Stefan
A1  - Steffan-Dewenter, Ingolf
A1  - Müller, Jörg
T1  - Relationships of insect biomass and richness with land use along a climate gradient
JF  - Nature Communications
N2  - Recently reported insect declines have raised both political and social concern. Although the declines have been attributed to land use and climate change, supporting evidence suffers from low taxonomic resolution, short time series, a focus on local scales, and the collinearity of the identified drivers. In this study, we conducted a systematic assessment of insect populations in southern Germany, which showed that differences in insect biomass and richness are highly context dependent. We found the largest difference in biomass between semi-natural and urban environments (-42%), whereas differences in total richness (-29%) and the richness of threatened species (-56%) were largest from semi-natural to agricultural environments. These results point to urbanization and agriculture as major drivers of decline. We also found that richness and biomass increase monotonously with increasing temperature, independent of habitat. The contrasting patterns of insect biomass and richness question the use of these indicators as mutual surrogates. Our study provides support for the implementation of more comprehensive measures aimed at habitat restoration in order to halt insect declines.
KW  - biodiversity
KW  - ecology
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265058
VL  - 12
IS  - 1
ER  -