PhenoGrass

Context

Phenology, the study of recurring biological events and the causes of their timing, is an important indicator for climate change and variability. Plant phenology is strongly connected to the carbon and water cycle of ecosystems. Consequently, the knowledge and understanding of phenological processes, such as leaf unfolding and senescence, and their controlling factors is required in ecosystem studies and climate research.

Typically, phenology is determined by manual ground observation (see external pageCOST Action 725call_made), while studies using digital camera images to determine phenology are still relatively scarce. We have been using a similar set-up at the Lägeren, one of our forest sites.

Within this project, we have been using a fix-installed webcam (Stardot Netcam SC 5MP) to observe phenology in a grassland ecosystem with a hourly resolution. We want to explore possibilities but also limitations of such a nondestructive estimate of phenology to study biodiversity and its effects on gas- and water exchanges. Therefore, we also take biweekly measurements of vegetation biomass, LAI, etc.

See the latest picture of the Früebüel site.

Publications

Ahrends HA, Brügger R, Schenk J, Michna P, Jeanneret F, Wanner H, Eugster W (2008) Qualitative phenological observations of a mixed beech forest in northern Switzerland with digital photography. Journal Geophysical Research 113: G04004

Ahrends HE, Etzold S, Kutsch WL, Stoeckli R, Bruegger R, Jeanneret F, Wanner H, Buchmann N, Eugster W (2009) Phenology and carbon dioxide fluxes: use of digital photography for process-based interpretation at the ecosystem scale. Climate Research 39: 261–274