Getting burnt means that the plant is damaged by high light. I know immersed grown Java fern and Anubias in green house need sun screen protection, and shade loving terrestrial plants like Hostas can get burnt under full sun.
But submerged grown plants have water protection so it is not the same. According to Jeffcroll chart, when light reaches the saturation point of a plant, growth will plateau out, not implying burnt out.
Has anyone experienced low light plants get burnt out by high light under water?
when light reaches the saturation point of a plant, growth will plateau out, not implying burnt out.
Right but what is the cause of the slowdown? Lack of say CO2 or a nutrient? Or more uncontrollable factors such as the rise of toxic O2, enzyme shortage ect.
Sadly it's all sort of co-mingled.
Really got to keep in mind "high light" in an aquarium can be like 100PAR.. High light outdoors or in a greenhouse can be 750-2000 PAR.
Not to mention outdoors has a ton of damaging UV and baking IR..
Sooo oddly our "high light" is low light to terrestrials.
And spectrum is "softer"..
AND (some) plants can adapt..
Other shade-tolerant species (e.g., iripilbark tree) show moderate (Oberbauer and Strain, 1986) or large (e.g., coffee; Friend, 1984) increases in light-saturated photosynthesis under a high light regime during development. Capacity to adjust maximum photosynthesis to utilize the light regime in which they were grown was demonstrated for 14 early-, middle-, and late-successional species grown in full sunlight and in the shade (Bazzaz and Carlson, 1982).
In a sense we sort of look at it as backwards..
Certain plants can tolerate shade.. some can't
Shade-intolerant species tend to respond to high light regimes with much increased photosynthetic capacity. For example, the rate of light-saturated photosynthesis of seedlings of such shade intolerant species as idigbo, afara, and obeche grown at high light intensities was approximately twice as high as that of shaded seedlings. By comparison, seedlings of the shade-tolerant kuka showed little change in photosynthesis whether grown at high or low light intensities.
Shade tolerance, defined as the ability to survive and grow under low light, plays an important role in the succession of forest plant communities. The mechanism of adaptation of plants to shading has become an important topic in ecology research. In this paper, we reviewed shade tole-rance of various forest plants and examined their adaptability in terms of morphology and physiology, and discussed the plasticity on growth traits, biomass distribution, crown structure, leaf morphology and physiology, leaf anatomical structure, photosynthetic parameters, carbohydrate allocation, water and nutrient utilization related to shade tolerance of forest plants. Finally, we discussed some problems with previous studies, and proposed possible future research issues.
Look at it another way..
DLI for ferns ect is 4-6.
DLI for 100 "PAR" over a period of 10 hours is 3.6...
300 "par" over 10 hours is a DLI of 10.8
Shade plants (annuals and perennials) 6-10
now after all my blah blah blahing..
An article on the favorable conditions for algae growth..
I'll let the more ambitious go through the whole thing..