Ecological trends in lichen photosynthesis.

Area of Science:

• Ecology
• Plant Physiology
• Biometeorology

Background:

• Lichens exhibit poikilohydric metabolism, meaning their physiological processes are highly dependent on water availability.
• Understanding lichen photosynthetic responses to environmental factors is key to predicting their distribution and ecological roles.

Purpose of the Study:

• To investigate the relationship between latitude, climatic variables, and four key aspects of lichen photosynthetic response.
• To develop predictive models for lichen photosynthetic parameters based on macroclimatic data.

Main Methods:

• Analysis of photosynthetic data from 42 fruticose and foliose lichen species.
• Examination of maximal net photosynthesis rate (Pmax), optimal temperature (Topt), light saturation point (PhARsat), and optimal water status (RWCopt or DWopt).
• Application of multiple regression analysis using macroclimatic variables.

Main Results:

• Optimal temperature (Topt) decreased with increasing latitude and increased with solar radiation and temperature.
• Optimal water status (RWCopt and DWopt) increased with annual precipitation.
• Predictive models using macroclimatic variables accurately estimated Topt and RWCopt, and also PhARsat and Pmax.

Conclusions:

• Lichen photosynthetic responses are significantly influenced by macroclimatic factors and latitude.
• Predictive models can be developed for key photosynthetic parameters, aiding in ecological assessments.
• Microclimatic factors, morphology, and metabolism can influence the generality of observed trends.