Journal
REMOTE SENSING
Volume 9, Issue 11, Pages -Publisher
MDPI
DOI: 10.3390/rs9111189
Keywords
drought; evergreen; midday depression; photochemical reflectance index (PRI); photosynthesis; remote sensing; warming; water index (WI)
Categories
Funding
- Spanish Government [CGL2016-79835-P]
- European Research Council [SyG-2013-610028 IMBALANCE-P]
- Catalan Government [SGR 2014-274]
- Chinese Scholarship Council
Ask authors/readers for more resources
Climatic warming and drying are having profound impacts on terrestrial carbon cycling by altering plant physiological traits and photosynthetic processes, particularly for species in the semi-arid Mediterranean ecosystems. More effective methods of remote sensing are needed to accurately assess the physiological responses and seasonal photosynthetic activities of evergreen species to climate change. We evaluated the stand reflectance in parallel to the diurnal and seasonal changes in gas exchange, fluorescence and water contents of leaves and soil for a Mediterranean evergreen shrub, Erica multiflora, submitted to long-term experimental warming and drought. We also calculated a differential photochemical reflectance index (PRI, morning PRI subtracted from midday PRI) to assess the diurnal responses of photosynthesis (A) to warming and drought. The results indicated that the PRI, but not the normalized difference vegetation index (NDVI), was able to assess the seasonal changes of photosynthesis. Changes in water index (WI) were consistent with seasonal foliar water content (WC). In the warming treatment, A value was higher than control in winter but Yield was significantly lower in both summer and autumn, demonstrating the positive effect of the warming on the photosynthesis in winter and the negative effect in summer and autumn, i.e., increased photosynthetic midday depression in summer and autumn, when temperatures were much higher than in winter. Drought treatment increased the midday depression of photosynthesis in summer. Importantly, PRI was significantly correlated with A both under warming and drought, indicating the applicability of PRI for tracking the midday depression of photosynthetic processes. Using PRI and PRI to monitor the variability in photosynthesis could provide a simple method to remotely sense photosynthetic seasonality and midday depression in response to ongoing and future environmental stresses.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available