Yet, we found no shift in the treeline over the past 70 years, despite an increase in temperature in all four study sites. Moreover, the treeline elevation decreases with increasing distance from the coast and with aspect (south > north). The treeline is characterized by a diffuse form, with trees growing on steep limestone slopes (>50°) and shallow soils. Here, we integrated high-resolution aerial imagery with local climatic and topographic characteristics to study the treeline dynamic from 1945 to 2015 on the semi-arid Mediterranean island of Crete, Greece.ĭuring the study period, the mean annual temperature at the treeline increased by 0.81 ☌, while the average precipitation decreased by 170 mm. Treelines are expected to respond to climate warming by shifting to higher elevations, but it is unclear whether they can track temperature changes. The recent rise in temperature and shifting precipitation regimes threaten ecosystems around the globe to different degrees. The demonstrated QFIM approach is compatible with strong-field excitation and sub-micrometer resolution-introducing a direct route towards ultrafast field imaging of complex nanodevices in-operando. By capturing ultrafast movies, we spatio-temporally resolve a Terahertz resonance inside a bowtie antenna and unveil the propagation of a Terahertz waveguide excitation deeply in the sub-wavelength regime. Our approach, termed Quantum-probe Field Microscopy (QFIM), combines far-field imaging of visible photons with phase-resolved sampling of electric waveforms. Here, we harness the quantum-confined Stark-effect to encode ultrafast electric near-fields into colloidal quantum dot luminescence. Still, intrinsic constraints on sample geometry, acquisition speed and field strength limit their applicability.
However, only few imaging schemes are able to resolve sub-wavelength fields in the THz range, such as scanning-probe techniques, electro-optic sampling, and ultrafast electron microscopy.
Microscopic electric fields govern the majority of elementary excitations in condensed matter and drive electronics at frequencies approaching the Terahertz (THz) regime.
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