Purple turtle
Member
c02 maybe not so bad after all
c02 maybe not so bad after all
In this regard, the research results of Rillig et al. (2000) are real eye-openers. Working along a naturally-occurring gradient of atmospheric CO2 concentration in the vicinity of a CO2-emitting spring in New Zealand, they studied the effects of elevated CO2 on several properties of soil fungi that were living in a mutually beneficial or symbiotic association with the roots of plants that had been growing there for at least twenty years. Their findings?
First of all, as the air's CO2 concentration increased by 300 ppm in going from the normal background level of 370 ppm to 670 ppm, percent root colonization by the soil fungi increased in essentially linear fashion ... and by nearly 4-fold. Second, the total length of fungal filaments or hyphae also experienced a linear increase with increasing levels of atmospheric CO2, in this case rising by more than 3-fold in response to the 300 ppm increase in the air's CO2 concentration. Third, root-zone concentrations of a fungal-produced protein called glomalin exhibited yet another linear increase with increasing atmospheric CO2, rising by approximately 5-fold as the air's CO2 content climbed from 370 to 670 ppm.
What are the implications of these observations? First of all, just as more and longer roots help plants hold soil together and prevent its erosion, so too do more and longer fungal hyphae protect soil from disruption and dispersion. In addition, fungal-produced glomalin acts like a biological glue, if you will, helping to bind tiny particles of soil into small aggregates that are much more difficult to break down and blow or wash away. And to have soil glomalin concentrations increase by fully 5-fold as a consequence of less than a doubling of the air's CO2 content is a truly mind-boggling benefit.
In this study, it was determined that several decades of differential atmospheric CO2 exposure had increased soil organic C and total N contents by approximately 24% each, while it had increased microbial C and N contents by more than 100% each. Hence, in the words of the scientists who did the work, "storage of C and N can increase under prolonged exposure to elevated CO2." In addition, they concluded that increased storage of soil organic matter can occur "even when soil C concentrations are already high," as they were in the situation they investigated.
Consequently, as the air's CO2 content continues to rise over the coming years and decades, the potential for soils to sequester carbon will likely prove much greater than what nearly everyone has anticipated. Not only will the soil's capacity to store carbon grow ever larger due to the ever-increasing aerial fertilization effect of atmospheric CO2 enrichment - which enhances plant growth and results in more carbon being transferred to the soil - it will also grow ever larger as increasingly active soil fungi help to keep ever greater portions of that carbon better preserved in increasingly more stable soils.
Dr. Sherwood B. Idso
c02 maybe not so bad after all
In this regard, the research results of Rillig et al. (2000) are real eye-openers. Working along a naturally-occurring gradient of atmospheric CO2 concentration in the vicinity of a CO2-emitting spring in New Zealand, they studied the effects of elevated CO2 on several properties of soil fungi that were living in a mutually beneficial or symbiotic association with the roots of plants that had been growing there for at least twenty years. Their findings?
First of all, as the air's CO2 concentration increased by 300 ppm in going from the normal background level of 370 ppm to 670 ppm, percent root colonization by the soil fungi increased in essentially linear fashion ... and by nearly 4-fold. Second, the total length of fungal filaments or hyphae also experienced a linear increase with increasing levels of atmospheric CO2, in this case rising by more than 3-fold in response to the 300 ppm increase in the air's CO2 concentration. Third, root-zone concentrations of a fungal-produced protein called glomalin exhibited yet another linear increase with increasing atmospheric CO2, rising by approximately 5-fold as the air's CO2 content climbed from 370 to 670 ppm.
What are the implications of these observations? First of all, just as more and longer roots help plants hold soil together and prevent its erosion, so too do more and longer fungal hyphae protect soil from disruption and dispersion. In addition, fungal-produced glomalin acts like a biological glue, if you will, helping to bind tiny particles of soil into small aggregates that are much more difficult to break down and blow or wash away. And to have soil glomalin concentrations increase by fully 5-fold as a consequence of less than a doubling of the air's CO2 content is a truly mind-boggling benefit.
In this study, it was determined that several decades of differential atmospheric CO2 exposure had increased soil organic C and total N contents by approximately 24% each, while it had increased microbial C and N contents by more than 100% each. Hence, in the words of the scientists who did the work, "storage of C and N can increase under prolonged exposure to elevated CO2." In addition, they concluded that increased storage of soil organic matter can occur "even when soil C concentrations are already high," as they were in the situation they investigated.
Consequently, as the air's CO2 content continues to rise over the coming years and decades, the potential for soils to sequester carbon will likely prove much greater than what nearly everyone has anticipated. Not only will the soil's capacity to store carbon grow ever larger due to the ever-increasing aerial fertilization effect of atmospheric CO2 enrichment - which enhances plant growth and results in more carbon being transferred to the soil - it will also grow ever larger as increasingly active soil fungi help to keep ever greater portions of that carbon better preserved in increasingly more stable soils.
Dr. Sherwood B. Idso
