Redwood Reader

106.Glomalin and Cumulative Impacts
THere has been a lot of talk about cumulative impacts of multiple logging in watersheds spread out over the years. From almost any point in Humboldt we see stripped hillsides and meager rivers. This issue is hotly debated as improved methods have reduced surface erosion to some extent, and regeneration appears solid. Why then do the streams fill with silt causing flooding and scour in relatively small rainfall events? Why are so many area streams going dry late in the summer? It is obvious something unexplained bt current knowledge is happening. It could take a long time to figure it out. Luckily, we have a model we can look to with fewer variables, and larger ecenomic impacts. Commercial farming.
Farmers, like foresters and tree growers, have known of the role of fungi in keeping their holdings productive. Farmers deal with cleared land and single crops, reducing the number of species associated with the main crop to one or a few. Douglas fir has over three thousand fungal associates, mycelia that connect different species of plants. Farmland was turned over every year, destroying most of the years glomalin production and returning it to the atmosphere as carbon dioxide. Even so, glomalin was shown to accumulate in the field edges where no plowing had occurred for 15 years. They have learned that if they don't plow or otherwise disturb the surface, the cropland will accumulate carbon as topsoil. The topsoil gives tilth and provides pore space for water and air and easy growing conditions for the roots. The farmers need less fertilizer, less fuel, less work and less water for better production from the same acreage using no-till methods. And they are able to sell this carbon storage capacity to companies seeking to offset greenhouse gas emissions..
Forests are far more complex but we can come away with some real insights. Forests are like cities with each individual shaping their own environment collectively affecting an ecosystem. Mycorhizzial succession is similar to redevelopment wherein a piece of land is reworked to achieve higher benefit for the entire system, with each individual dependant on the collective effort, the infrastructure in this case to store water for defense against drought, insects and disease by means of canopy, duff and root zone soil conditioning. It is the canopys job to slow and disperse rainfall and guide it into the root zone. The duff further slows precipitation absorbing and filtering it, while protecting soil organisms and the conditioned soil in the root zone from erosive and detrimental forces.
Multiple species and individuals colonize the area constantly improving or repairing their system. Failure to do so leads to widespread decline and lowered ability to adapt to threats or maintain defense. In order to accomplish this trees are taxed a percentage of their photosynthetic product, which is used by the fungi to collect nutrients. It is then shen from the living fungi as refuse, gluing soil particles together creating pore space, thus biologically conditioning the soil. The systems develop relationships with understory species and animals that contribute to and depend on the total system and acting as decayers, seed dispersers, fertilizers and so forth.
In this sense development nad clear cuts do incredible damage to the soil system, with the result that it is easily eroded in winter and dust in the summer, watersheds handle less and less precipitation, ground water disappears from headwater areas. Just at a glance, 25 feet of sponge material will hold more water than eight or ten feet. What happens to that loss of capacity in a heavy storm? What happens to that reduction of stored water in a drought? How will forests fight insects with sap if they are short on water?
Roads contribute by collecting and concentrating precipitation, diverting it from its natural swales, removing duff and liquifying glomalin saturated soil when discharged down the hiillside causing various forms of erosion, all of which contributes sediment to the stream system at the bottom of the watershed. Road use also creates a lot of dust, which is washed into the streams early each winter as fines, which act as cement in the stream botton making it unsuitable for spawning habitat.
As time goes by these cumulative impacts add up to a very reduced capacity for the forest to defend itself. There are stories from Germany that tell of people picking up every stick and leaf in the forest. the result was total loss of those tree species in the third rotation. THe loss of organic litter is the stated reason given today, but in light of glomalin several other scenarios present themselve, such as insufficient soil moisture or loss of mycorhizzia.
ONe other cumulative impact of glomalin destruction may be global warming. When science realizes how much carbon was stored in the landscape and set free by development, much of the current analysis will be found wanting. The good news is that higher CO2 levels accelerate plant growth, especially in the root zone and sugar production. We see this as a new resident repairing his living space as fast as possible, and taking advantage of the aerial fertilization of CO2. This gives us the advantage of rapid revegetation but now realize it takes a long time to create a forest and that preserving growing systems must be the regulatory goal.
Glomalin made money for the farmers. It could make money by reducing the amount cut per acre while expanding the amount of land available to select cut. There is potential for carbon storage but we can predict industry denial until a lot of published science gets out there.. Positive management by reducing fire risk allows many kinds of activitty not detrimental to the overall health of the system. We note the condition of Eastern forests that have grown up after development, especially parks and other protected lands and wonder how much glomalin could accumulate naturally (it does have a life span) when unhindered. It seems likely that this would cause more carbohydrates to be trapped belowground than rotting surface vegetation, and that glomalin molecules may have promise as a synthetic or producable fuel. While there is a ton of research to be done, actionable rules of thumb that answer those gut feelings that something else is going on come easily, once the role of glomalin is accepted.
In the age of computers we can count anything once we have something to count and compare. The discovery of glomalin allows us to quantify forest production and its conditionning ability, storage capacity, rate of growth, and yield of water as well as timber. Development or other land use can be seen as a percentage of total glomalin production with pavement and housing as complete loss and other uses a percentage. This is all factored over time, steepness, soil type, precipitation rates and vegetative cover and we can guesstimate the rate of absorbtion and loss of soil moisture, and eventually derive allowable levels of disruption that don't create further damage to the system while providing economic uses. That is finding the sustainability capacity of the region. In this sense water bearing is a real result of careful management and is able to be improved over time with our new knowledge.
Glomalin destruction is the root cause of the cumulative impacts we see aroound us. Cumulative impacts are the sum total of sediment cut loose over years once the soil glue holding it in place is destroyed by removing vegetation and exposing the soil to water, wind and sunlightt. We witness sedimentation, landslides, flooding, dust, forest decline and lowered surface water availability when the vegetation is removed and the forest floor disturbed. In this region short rotations of second growth mean the forest will not be able to renew the water holding capacity and the system will continue to deteriorate. Desertification is complete collapse and the ultimate cumulative impact. We cannot control the weather but we must take better advantage of it.
It will take a long time to return to pre-Colombian conditions, like steep landscapes and sediment filled rivers. We can however, educate people and ask for minimization of glomalin destruction, We can push awareness of glomalin as a greenhouse gas control and try to enter the storage market. We benefit from preservation because it allows mature forests to operate as mature forests providing the benefits we expect but find increasingly rare in our forests. The regrowth of this system is what we are trying to accomplish in the vague term ecological restoration. We need to educate people that land needs to be set aside for these purposes, and that horses and bikes and ATV's all negatively impact the very factors of production. We will tailor recreational and commercial land uses to take advantage of the natural systems in a way that minimizes harm. Industry will need to be exempt for exploitation of natural systems but we have regulatory know how, acceptable limits, and in the case of carbon credits, opportunity cost.