Plant

[Primarygun]

How does pH value affect a plant?

[Mokele]

Depends on the plant. Some plants require a narrow range of pH, or they die. Others can tolerate a much broader range. Some like neutral soils, some (like my carnivorous plants) like acid soils. Maybe some like alkaline soils, but I'm not botanist.

 

From the grower-perspective, exposure to pH outside their tolerance causes wilting, blackening, and eventually death. I dunno about the more in-depth reasons, though.

 

Mokele

[Sorcerer]

Most plants prefer a pH 6.8 because of nutrient solubility and their availability at different pH's. Carnivourous plants need to get nutrients from insects, not because they arent in the swamp, but because at that pH they aren't able to be taken up by the plant.

 

Azaleas and Rhododendrons also prefer acid soils.

 

Adding lime to soils is not only important for providing calcium, but it raises the soil pH, agrregates the clay particles, making the soil more friable, and increasing drainage.

[Primarygun]

Thank you.

Photosynthesis slows down or even stops when enough glucose is produced, right?

[Sorcerer]

Not sure, but I would argue no since the plant can always store glucose as starch.

[Sorcerer]

Try to find a solubilty of ions vs pH graph, this may explain why plants prefer to live at a specific pH, when compared with the plant nutrient requirements.

[Drabav]

Also, I would add that some plants, by the nature of their refuse, alter the pH of the enviroment they are in, and eventually the diversity of the area. Eastern White Pine (P. strobus) has naturally acidic needles. When they fall to the forest floor, they do not decompose quickly because of their acidity. The acidity of the deepening blanket of needles alters the flora of bacteria and protists that reside in the soil. The acidity of the needles also alter the pH of the soil itself, detering other plant life which is not receptive to acidic soils. Thus you find monotypical stands of E. White Pine, which have made themselves a special place of their own, just by the acidity of their needles.

 

Draba v.

 

....a postscript for the hope of spring.

[Skye]

Also, I would add that some plants, by the nature of their refuse, alter the pH of the enviroment they are in, and eventually the diversity of the area....Thus you find monotypical stands of E. White Pine, which have made themselves a special place of their own, just by the acidity of their needles.

Do you think it is really increasing the diversity then, if it leads to a situation of the one dominant species?

[Drabav]

No, I believe I pointed to the diversity decreasing. Diversity is (by way of the shannon diversity index) the mesure of species richness (no of species in a particular area) in combination with evenness (the number indivduals per species to the total number of individuals). In a pine stand, there is low richness, and low evenness, thus resulting in a low SDI. It is the standard for measuring diversity. Especially among tree populations.

 

Draba v.

 

...a postscript to the hope of spring.

[ecoli]

Also dependant on Ph stability is enzymes, which have a optimum funtioning level.

[Sorcerer]

Yeah but thats internal pH, I assumed the question was refering to soil pH. Although I guess transmembrane root proteins could be affected by soil pH.