Redwood Reader

This blog was named Redwood Reader because I drive through the redwoods on the way to my experimental site, which is just over the hill from Rockefeller Forest. However, most of my writing has been about Douglas fir, as the main constituent of the properties. When I realized Douglas fir and redwood had many common properties, I stuck with generalities. However, I have collected a mountain of material on soils and other components of redwood forest that are often searched for when folks find Redwood Reader.
Soil Ecology and the Redwoods, Dr Paul Zinke, 1964, gives a fine account of the limitations of the redwood zone focusing on soils and water. He explains the role of fog but an even more important point is comparison of late summer soil moisture to spring levels. He also points out the likelihood of Douglas fir to invade poorer sites, which may be an indicator of mycorhizzia influence on the landscape.
Searching for more information I found the Las Pilatas Nursery's on-line encyclopedia articles on soils, hardpan, compaction, native ecosystem restoration and mycorhizzia helpful. I gave a local flavor to the articles posted by Zelnick and Sons at www.chesco/treeman.com. It also matched up well with data from OSU about the role of mycorhizzia fungi in forest ecosystems and food webs. I could see dozens of species of fungi on the ground, let alone go digging for those fruiting underground, which is an amazingly busy place as it is.
The role of fog is an issue that also needs better quantification. After giving fog high marks for acting like summer rain, it occurred to me that the ground is often wet beneath certain Doug fir trees, the tall ones, and that not much of it seemed to penetrate the ground either. While I don't live in the South Fork of the Eel River, sixty inches of fog drip across the whole landscape is just way too high an estimate. Also, it does seem to be a regular feature, and in this way maybe we can make sense of the fact that shallow roots on thin soils may count on capturing more fog because it doesn't go as deep as other tree species. As a member of a community, lateral rooting over large areas together with soil li8mitations give rise to an alternate dry season strategy, perhaps older than the deeper penetration of various other species. I would put Douglas fir in a middle category, with an eye toward the percentage that seem to have large roots that grow downward almost like a tap root- maybe ten percent. Douglas fir is a newer species in the scale of time and seems to have taken advantage of many different ways of adapting and enhancing its environment.
A good idea of the state of mycological research in ectomycorhizzia forest systems can be found at http://www.mykoweb.com/ in the series of articles Mycorrhizas. by Steve Trudell. All five articles give a lot of clues about where new research might look, for example, dual fungi mycorhizzias, snow plant suppression of certain species, possibly showing suppressant or pheromonal response below ground to species, and the fact that most forest systems have not yet been studied. It is clear there is a mountain of work to do, some essential and some just there to be done. He concludes with a statement that extra radical expression of the fungi in the environment is the next step.
We can say for certain this would include glomalin, and hopefully reveal its nature as a soil component, its role along with bacteria and other soil organisms in the creation of aggregates which have the effect of available water storage and soil stability. Glomalin surveys will not tell us what species are current but shows the amount of biodeposited material contained in the soil. We now know its universal presence but in question are the depth of deposits and the rate of decay. Seven to ten years are sufficient to regrow ground cover and provide at least a surface glomalin layer. Rilligs' research is showing higher rates of deposition at the deeper soil levels. This would seem to support my contention that deeper layers of glomalin in the soil do not get replenished by the new growth, leaving Douglas fir region clear-cuts prone to slides decades after the ground has been recovered by greenery. This in particular is why I avoided redwoods, as stump sprouting further complicates the picture, with diminished capacity for feeding subsoil food webs. We see this touched on tangentially in Part Five, about the mechanisms that drive fruiting. Finally, glomalin may be seen as a biofilm created by a community of organisms for the benefit of all
The Scottish forest modellers also included ergosterol in their study. This is interesting. Ergosterol, a precursor of Vitamin D, plays a similar role to cholesterols in animal cells, forming the cell walls in fungi. By quantifying ergosterol in the soil the researchers are able to get a snapshot of recent fungal activity, varying in the study by the month. Glomalin, a residual product sloughed off and durable in the soil, shows fungal activity over time. A steady 3 mg/l were found, in the range of the initial field crops reports and way below the 15 mg/l in the wild borders of the fields, or the 100 mg/l found in volcanic soils in Hawaii. but then the story breaks down because no soil profile delimits the depth of deposition, no depth of sample or age of area under study are given. We need long term observations and at varying depths to find the optimal point at which we can begin thinking about sustainable harvests and exportable water.
The health of a forest ecosystem is also dependant on the number and nature of the individuals that make it up. We see that several species of native phytophthera do not aggressively attack oak and tanoak stands like p.ramorum. Is the new species the problem, or is it taking advantage of a relatively new scheme of things in the coastal forests? It is not possible to state the nature of infected sites but there is a good chance not much remains in the way of the original relationships between plants. It seems quite likely Sudden Oak Death would have more trouble in old growth, like so many other invasive species taking advantage of sudden changes in conditions. Then again chestnut and potato blight spread with ease. Many of these will run rampant until some normal limiting factor kicks in- a cold summer, drought, flooding, shade, salt water, fresh water, a return of naturally suppressant species. The one factor limiting SOD I have read is that none appears in areas that have burned in the last fifty years or so, certainly questionable and a good place to start in the field of ideas. I am searching for my list of mycorhizzia associated with redwood.