On managing California bay laurels to improve oak health

Removing young bay laurels and burning the remains. Photo by Lee Klinger.

Several friends and tree professionals have contacted me about my thoughts on the following article by Peter Femrite that recently appeared in the San Francisco Chronicle:

Saving oak trees by chopping down bay trees

Workers began chopping down 250 California bay laurels this week in the Santa Cruz Mountains so that 49 signature oak trees might be saved from the infectious scourge known as sudden oak death.

The tree-removal project is an attempt by the Midpeninsula Regional Open Space District to prevent the spread of the tree-killing pathogen, which uses bay trees to scatter spores in the forest.

(h/t to R Zingaro for alerting me to this article)

First, there are important points here with which I agree. The bays are clearly major vectors for sudden oak death disease. I do believe that selective removal of bays will lower the incidence of sudden oak death (SOD). However, I am bothered by the singular focus on the disease. I would rather the focus of efforts be made toward promoting the overall health of the forest ecosystem.

Acid rain in Big Sur – May 2011

Acid rain falling on Big Sur. Photo by Lee Klinger.

It has been an unusually rainy spring here in Big Sur. We received 1.86″ of rain in May and have just had another full on winter storm here in the first week of June. I’ll be summarizing the 2010-2011 rain season data once it is clear the rainy season had ended.

The rains in May were notably acidic. There were five measurable rainfall events with pH values ranging between 4.46 to 4.63. The table below shows all the results for May 2011.

Interview with SustainableWorld’s Channel

SustainableWorld’s Channel did a recent interview with me at La Casa de Maria (Santa Barbara, CA) about oak health, native people, and fire mimicry and has posted a portion of the interview on YouTube. Here is the video:

The potential role of peatland dynamics in ice-age initiation

As I mentioned in a previous post I am putting up some of my earlier work on feedback mechanisms by which the planet cools itself. This background will be useful in an upcoming post on planetary temperature regulation.

The potential role of peatland dynamics in ice-age initiation

by Lee F. Klinger, John A. Taylor, & Lars G. Franzen

Quaternary Research 45: 89-92 (1996)

Summary – Physical and chemical coupling of peatland vegetation, soils and landforms and atmosphere creates feedbacks which may be important in ice-age initiation. A box diffusion CO2 exchange model shows that a transient forcing of 500Gt C (the amount proposed to have accumulated in peatlands during the last interglacial-glacial transition) over 5000 yr results in a lowering of atmospheric CO2 by about 40 ppm. Proxy data indicate that a decrease in atmospheric CO2 may have occurred over the last 5000 years up to pre-industrial times, and the amount (~22 ppm lowering in 5000 yrs) is similar to that calculated from Holocene peatland expansion. These results suggest that models should consider the role of peatlands in ice-age initiation.

View the entire paper here.

In Fig. 2 (see below) we present evidence that prior to the industrial era atmospheric CO2 was undergoing a decline. We attribute the decline to large-scale landscape transformation involving the replacement of forests by peatlands. Peatlands store immense amounts of carbon and, as described in an earlier publication, are potentially powerful organs that help cool the planet.

Peatland formation and ice ages: a possible Gaian mechanism related to vegetation succession

To prepare readers for some upcoming posts on the implications of Gaia theory in climate change predictions I would like to provide some background literature of my earlier work in this area. Below is a paper I gave at the American Geophysical Union Chapman Conference on the Gaia Hypothesis held in San Diego, CA in 1988. This paper was published as a chapter in a 1991 book on the proceedings of the conference: Scientists on Gaia. Here is the summary of my paper:

Peatland formation and ice ages: a possible Gaian mechanism related to vegetation succession

by Lee F. Klinger

Summary – Terrestrial areas, which support over 99% of the earth’s biomass, have considerable potential for being involved in biosphere-atmosphere feedback loops as postulated by the Gaia hypothesis. This paper presents a model of a possible Gaian mechanism related to landscape-level successional changes during a glacial-interglacial cycle. The model is based on the view that terrestrial successions converge toward bogs, rather than toward old-growth forest, and that bogs represent structurally and compositionally stable (climax) communities. The model also assumes, as in classical successional theory, that during the course of succession the biota modifies the environment, both the soil and the atmosphere, to favor the progression of succession toward the climax state. Feedback mechanisms between peatlands (landscapes of bogs and bog forests) and the atmosphere are proposed which should favor the initiation and maintenance of relatively stable, ice age climates. These cooling mechanisms are related to increased albedo, increased evapotranspiration, and decreased atmospheric CO2 associated with the succession from woodlands to peatlands. Ice core and ocean core data for CO2, CH4, and delta 13C and delta 14C isotope ratios are consistent with the proposed terrestrial dynamics involving organic carbon.

Here is the full reference for my paper:

Klinger, L.F. 1991. Peatland formation and ice ages: a possible Gaian mechanism related to vegetation succession (Chap. 28). In: S.H. Schneider & P.J. Boston (eds.), Scientists on Gaia. The MIT Press, Cambridge, pp. 247-255.

Forest vegetation and soil succession

Readers who are interested in more details of the general theory and empirical studies of forest decline and soil acidification please consult this paper:

Forest vegetation and soil succession

by Lee Klinger MA PhD

Presented at: Treework Environmental Practice Seminar XIII
Linnean Society, Burlington House, London, UK – 30^th June 2009

Summary

Forest communities are complex systems comprised of populations of organisms representing every kingdom of life – plants, animals, fungi, protists, and monists – living and growing together on the land. They are part of a larger group of communities that constitute the regional ecosystem, or landscape. Forest communities are developmentally related to the surrounding communities in ways that can be characterized through chronosequence studies. Chronosequences from southeast Alaska and subarctic Canada are described and interpreted as indicating that, while early successional processes facilitate forest growth and productivity, later successional processes tend to slow and inhibit forest growth and regeneration. In many places forests are seen to have transitioned into peat bogs over the course of several thousand years. This is thought to reflect the true climax nature of bog ecosystems.

Forest to bog transitions are linked to two main developmental processes: podzolization and paludification. Podzolization affects many northern forests and involves the translocation of iron, aluminium, clays and organic compounds in response to vegetation, especially mosses, acidifying and leaching the soils. This is often followed by paludification, which occurs as peat-forming mosses, such as Sphagnum species, become established and expand.

From the perspective of succession, forests are seen to flourish under early successional conditions, conditions that are enhanced by periodic or regular disturbances. However, where disturbances are eliminated, forests begin to show decline as a consequence of natural successional changes. This work points to the potential for managing forest ecosystems through the maintenance of disturbance regimes and the remediation of acidification tendencies in the vegetation and soils.

Download the complete paper here.

Trees, Roots, Fungi, & Soils (Part 2)

On June 30 of this year I presented a paper titled “Forest Vegetation and Soil Succession” at a gathering of UK and US arboriculturists at the Linnean Society, Burlington House, London. The event, “Trees, Roots, Fungi, & Soils 2″, was the second of two meetings on the topic of soils in arboriculture organized by Neville Fay of Treework Environmental Practice.

The first meeting, “Trees, Roots, Fungi, & Soils 1″, was held in November of 2008 at the National Museum at Cardiff, Wales. At that meeting I presented the paper “A holistic approach to mitigating pathogenic effects on trees”. A copy of that paper can be found here.

Catharine Stott attended the second meeting in London and has written an excellent recap of the talks here.

Excerpts from Catharine Stott’s article:

“Independent scientist Dr Lee Klinger was once again over from California with a fascinating take on climax vegetation. He explained that, contrary to popular belief, forests and woodlands continue to evolve beyond what we regard as their climax state of ancient trees, particularly if there is no natural disturbance to halt and hinder succession. Indeed, if left alone and undisturbed, forest vegetation will succeed into peat bogs. Dr Klinger cited his studies of ancient forests and successions of vegetation on the slopes of Mount Edgecombe in Alaska, where all stages of vegetation succession can be seen. He argued that if we want to keep our old growth forests as forests, it is important that we allow and perhaps manage natural disturbances, such as landslips and fires.”

“In summing up the day, Neville Fay spoke more about Treework Environmental Practice’s plans to develop arboricultural practices that focus more coherently on the soil environment as a means of assessment and treatment. He has a suspicion that in the future arboriculturists will become soil specialists and relatively speaking most assessment and work will take place in that region, and very little to the crown. Without ignoring the huge weight of nursery and in vitro experimental investigation, his preferred approach is from an ecosystem perspective, hoping to find ways to look at the whole tree growing in its context, informed more by the organic model. With this in mind he is working with Laverstoke Laboratories, Lee Klinger, Olaf Ribeiro, Myerscough College and others to explore soil factors associated with rapid decline in mature trees and to compare a range of remediation measures.”

A copy of the June 2009 paper I gave at the Linnean Society is available here.