Limiting Factors in the Wild

Edexcel A-level BiologyPhotosynthesisLesson 20 of 20

In a laboratory, one factor is changed while the others are held constant. In the wild, light intensity, carbon dioxide concentration and temperature all change through the day and the year, so the limiting factor changes too.

At dawn, light intensity is low and it is the limiting factor. As the Sun rises, light intensity increases. By midday on a bright summer day in the UK, light is usually no longer limiting and the low atmospheric carbon dioxide concentration (about 0.04%) often limits the rate instead. On a cold, bright winter morning, temperature may be limiting. Plants on a woodland floor are shaded by the canopy, so light limits their photosynthesis for most of the day. At night there is no photosynthesis at all.

More in Photosynthesis

• The Calvin Cycle
• The Products of Photosynthesis
• C4 Plants
• Rubisco
• Limiting Factors of Photosynthesis
• Light
• Carbon Dioxide
• Temperature

All 20 lessons in Photosynthesis · All Edexcel A-level Biology topics