Event Details

Mr Caleb Mensah, a visiting researcher from University of Energy and Natural Resources, will present the latest news from their work establishing the first FluxNet flux tower site in W Africa.

The strong effects of climate change are expected to negatively impact the long-term resilience and function of forest ecosystems, which could lead to changes in forest carbon balance and productivity. However, these forest responses may vary with local conditions and forest types. Accordingly, my research studies were carried out to determine gross primary productivity (GPP) sensitivity to changes in environmental parameters. Central European beech (at Štítná) and spruce species (at Bílý Kříž and Rájec), growing under contrasting climatic conditions, were studied. The comparative analyses of GPP were based on a five-year-long dataset of eddy covariance fluxes during the main growing season (2012–2016). Results of forest GPP responses with changes in environmental factors from a traditional Stepwise multiple linear regression model (SMLR) were used and compared with Random forest (RF) analyses. To demonstrate how actual GPP trends compare to potential GPP (GPPpot) courses expected under near-optimal environmental conditions, we computed normalized GPP (GPPnorm) with values between 0 and 1 as the ratio of the estimated daily sum of GPP to GPPpot. The study confirmed the well-known effect of the total intensity of the photosynthetically active radiation and its diffuse fraction on GPPnorm across all the forest types. However, the study also showed the secondary effects of other environmental variables on forest productivity depending on the species and local climatic conditions. The reduction in forest productivity in the beech forest in Štítná was presumed to be mainly induced by edaphic drought (anisohydric behaviour). In contrast, reduced forest productivity at the spruce forest sites was presumably induced by both meteorological and hydrological drought events, especially in the moderately dry climate in Rájec. In conclusion, the findings of this study may help to quantitatively assess the fate of widespread cultures under extreme climatic events and may help to delimitate the areas of their sustainable production.

Speaker Mr Caleb Mensah currently works as a lecturer and researcher at both the Department of Atmospheric and Climate Science and the Earth Observation Research and Innovation Centre of the University of Energy and Natural Resources (UENR), Sunyani- Ghana respectively. He has expertise in the analysis of fluxes of matter and energy across different ecosystems using the eddy covariance method. His research focuses on plant response and acclimation to climatic stress conditions across different forest ecosystems. He contributed to the establishment of an Eddy covariance station in a tropical Ghanaian moist semi-deciduous forest to monitor the fluxes of carbon and energy between the atmosphere and the forest, which is critical in better understanding the carbon sequestration capacity of African forests in mitigating climate change.

This session will be chaired by Dr Kirsti Ashworth, Royal Society Dorothy Hodgkin Research Fellow and research lead of the SAPLING Lab at Lancaster Environment Centre, where research focuses on the interactions and feedbacks between the biosphere, atmosphere and society.

Joining the seminar

This session will be held in-person only in Lancaster Environment Centre's Training Rooms (directions on Mazemap).

The live seminar will be recorded and the video uploaded to Lancaster Environment Centre's YouTube channel in due course.

Please contact Kirsti Ashworth if you would like to arrange to meet with the speaker.

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