The Biodiversity Observing System Simulation Experiment (BOSSE) v1.0

The Observing System Simulation Experiments are simulation tools that support the development, benchmarking, and evaluation of remote sensing missions and methods. The study of biodiversity, from remote sensing, and particularly that of plant diversity,  is an emerging topic with potentially beneficial outcomes for global-scale monitoring and conservation. However, advances in this field are limited by insufficient systematic, standardized, and global field datasets that enable a comprehensive linkage of the plant diversity aspects with the variability of the spectral signals captured by remote sensing instruments. This typically makes the findings site- and method-dependent, preventing the validation of new methods in a sufficiently wide range of ecosystems, seasons, and vegetation types. Pioneering modelling works have proven as valuable tools to answer methodological questions, screen potentially reliable methods, detect spuriousness, and identify strengths and limitations of remote sensing to infer plant diversity. However, these simulations have been develop using simplistic assumptions so far.

Here, we present the Biodiversity Observing System Simulation Experiment (BOSSE) v1.0, a simulation tool able to represent vegetation taxonomy and functional traits and a wide range of physically linked spectral signals and ecosystem functions in space and time. BOSSE simulates maps of vegetation species and their (functional) traits that evolve in time as a function of biometeorological drivers. From these dynamic scenes, BOSSE can simulate hyperspectral reflectance factors, sun-induced chlorophyll fluorescence, land surface temperature, and provide estimates of plant functional traits based on these signals. BOSSE can simulate observations of varying spectral configurations and spatial and temporal resolutions, mimicking current and future remote sensing missions. Remote sensing imagery can be generated with an hourly temporal resolution, and the spatial resolution can be degraded to assess the impact of this feature in the estimation of plant diversity. Ecosystem functions (mainly related to carbon, water, and energy fluxes) can be generated at hourly steps to develop robust methods that allow for testing the variability of biodiversity-ecosystem function (BEF) relationships, which is still an open question in ecological research.

BOSSE is an open-source Python model that we make available to the community to support the development of new remote sensing-based biodiversity products and assess the role of biodiversity in ecosystem functions. Moreover, it could also be useful to address other methodological questions regarding the study of vegetation. BOSSE does not aim to substitute the still-necessary observational data and studies but to support their design and interpretation.