While the Limerick Forest website is in flux, we've put this page up on the pinicola site. .

LFAC members were invited to a Forest Nutrient Management educational workshop sponsored by the LFAC Forest Resources Subcommittee and LFAC Education and Communications Subcommittee, on Saturday, 18 November 2006 at the Bishops Mills Natural History Centre. The goal of the meeting was to come to an agreement about what to include in the Nutrient Management section of the 20 year management plan. Background reading included pdf's of a general Nutrient Management Workshop document, some of my comments and related articles and Pieter Trip and Cliff Rogers "Big Tree" document. This was a very exciting meeting which resulted in general agreement that the Limerick Forest management plan stipulate the replacement of nutrients to compensate for those lost in harvest, and beyond that to aboriginal levels of nutrient retention. The forest nutrient revolution is now launched for Ontario!

Cliff Rogers opened the meeting by introducing the speakers, myself, Pieter Tripp of the Grenville Land Stewardship Council, and Phillip Fry of Old Field Garden. It was striking that our diverse Ph.D.'s, in herpetology, plant physiology, and philosophy, had led us to a convergent concern for the nutrient status of eastern Ontario forests.

I presented a history of Aleta and my concerns for forest nutrients, beginning with an account of undergraduate instruction in Liebig's Law of the Minimum at Cornell in the 1960's ("yield is proportional to the amount of the most limiting nutrient, whichever nutrient it may be... if the deficient nutrient is supplied, yields may be improved to the point that some other nutrient is needed in greater quantity than the soil can provide, and the Law of the Minimum would apply in turn to that nutrient.")

And how the Hubbard Brook watershed experiments impressed on plant ecologists that this rule applied to forests as well as to agricultural crops. These long-term studies showed that both the removal of nutrients in harvested materials and the disturbances associated with logging led to losses of the delicately held nutrients that sustained northern forests, and that acid rain made a forest's hold on its nutrients more tenuous than it would naturally be.

I showed a painting of a field near Bishops Mills, and discussed how "In annual-based agriculture, nutrients must be held over the winter in the soil, or added as fertilizer as the crop grows"

In tropical rainforests it was easy to understand that most nutrients were held in the biomass, because these were among the lushest places on the planet, but had some of the poorest soil, often only 2-4 cm deep. Through the 1970's and 1980's the realization spread north that this was also true of temperate and boreal forests, and that the deeper soils of northern forests only meant that the processing of nutrients through the forest floor was somewhat slower than it was in the tropics.

I then quoted the 1987 caption for two local mini-landscapes for our unpublished book Fragile Inheritance: A Painter's Ecology of Glaciated North America: "The brushy thin-soiled limestone barrens were rich hardwood forest before settlement, grazing, cultivation, and erosion. The first commodity taken from this land was likely mineral nutrients, potash, from the burning of forest trees. The soil now supports only a scant growth of short grasses, lichens, and sprawling Strawberries, and in patches is utterly bare... Most of the nutrients of a forest on such shallow soil are not held in the soil, but in the bodies of living organisms, and must be taken up by the roots of plants as soon as they are released if they are not to be lost. To maintain a balance of richness here, the living forest must remain unbroken. Rather than feeding livestock, which carry away nitrogen and phosphorus in meat and bone, the forest [referring to a second painting] has been used as a sugar bush, and the products removed from it are carbohydrates, wood and maple sugar, made from water and air. Used in this way, and despite trampling by Cattle, the plant community retains much of its structure, and the soil its fertility -- Bishops Mills, Grenville Co., Ont., 6-8 May 1987." (these paintings being currently unavailable, the scenes were represented by photographs taken in the sodden conditions of November 2006, which are not reproduced here).

-- fred schueler, page created 18 Nov 2006, last updated 6 Dec 2007.

Limerick Forest website
Bishops Mills Natural History Centre

Nutrient Management Policy for Limerick Forest

Objective of the policy: retention and accretion of mineral nutrients, with the goal of achieving pre-settlement nutrient levels.

Recognizing that this nutrient management policy is an innovation in Ontario forestry, an ongoing economic analysis shall be undertaken to track the financial and regulatory impacts and implications of the following practices:

* Balance nutrient outflow (from harvest) with nutrient inflow.

* Gradually increase the nutrient inflow and retention to promote a healthy successional forest.

* Study the nutrient status of Limerick Forest on an ongoing basis and utilize the accumulated information as a model to guide future forest management decisions.

(this is the version of the policy, adopted by the whole of LFAC, and used in the 20 Year Management Plan. In what follows I use an earlier wording for these clauses of the policy)

COMMENTARY ON THE ABOVE TEXT: Considering the limiting role of nutrients changes the whole way one looks at the forest. Sickliness and reduced growth of trees aren't just due to crowding and shading, they're also due to nutrient limitation. Spring wildflowers aren't just a wonderland of beauty, they're also a buffer against nutrient loss in spring runoff. Dogs running in the woods aren't just a nuisance to Grouse, Rabbits, and hikers, they're also a major source of plant nutrients. Logs lying on the surface aren't just wasted firewood and a home for Salamanders, they're coarse woody debris facilitating nitrogen fixation and feeding nutrients into the next generation of trees. And the Salamanders themselves aren't just herpetological wonders, they're an index of forest health and productivity.

It's important to recognize that nutrient addition isn't appropriate for many Limerick habitats. Any programme of fertilization will have to preserve the integrity of low-nutrient ecosystems, because nutrients are lost by burial (or wasted from the point of view of the forest) in wetlands, and are pollutants in streams, and because the biodiversity of wetland and barren habitats often arises from adaptations to low nutrient levels. Nutrient additions to plantations and natural forests will have to be made in such a way as to prevent leakage (waste) of nutrients from forests into barrens, wetlands, and streams (cf Conservation Authorities' strictures against septic and fertilizer leakage from the shores of cottagey lakes).

One might suppose that a nutrient management policy should not undermine efforts to attain the generous annual "allowable" cut that we've experienced since 2001. But, the "allowable cut" targets must be based on the actual growth of trees in stands similar to those to be logged. If we use growth tables based on "eastern Ontario" we'll overestimate growth, because Limerick Forest is composed of the sites where nutrients were so exhausted that the land reverted to the Counties for back taxes, so it's an impoverished subset of plantations in eastern Ontario. We've seen evidence for the hypothesis that nutrient limitation results (effectively) in zero growth in the plantations, and with zero growth the annual allowable cut is zero.

To show that this hypothesis is wrong, it would just be necessary to demonstrate that there's sufficient growth to sustain harvesting, but if it's right we can't expect to harvest in the usual way and expect substantial regeneration. We've also heard the hypothesis that only fertilization will allow growth of a 'mature' forest and continued removal of wood, but that requires more reflection and data for its evaluation than the "no net growth" hypothesis).

The main point that we have to make is that we cannot endorse any amount of cutting at present. With zero or marginal growth, there should be no cutting, or at least no harvesting. If we do nothing and the trees die anyway, maybe the harvest would make sense. The scrub land that remains would be a haven for ATV sports. Limerick Forest is not a cash vault. It's a new forest that is barely out of its seeds. We have learned a lot about the diversity of a natural forest and Limerick is sadly lacking most of that natural diversity. We have in Limerick a tree farm, but we call it a forest.

The problem is that if there's really the nutrient crisis we've seen evidence of, the forest is already dying. We can do two things: harvest it now, or nurture it. People would be shocked to learn about the depleted state of our forests. Most of residents of the Counties friends know nothing about forestry but they sure do love the trees. We must do well by our friends. We must work to protect the life sap of our forests. Telephone poles are in demand, but why grow a Red Pine to pole height? Why not nourish that tree and grow a giant. That's where the big money will be found. And think about the tourist opportunities of a giant forest here in our region. If a Red Pine can grow to great heights, why not create the best environment to make that possible?

Objective of the plan: retention and accretion of of mineral macro-nutrients, with the goal of re-achieving climax nutrient levels.

Macro nutrients are those represented on bagged fertilizer by the three numbers: Nitrogen-Phosphorus; Potassium, NPK, the building blocks of protein, energy-transfer, and membrane osmosis, respectively (and over-simplifiedly).

One reason that the profession of forestry has historically ignored the nutrient status of forests is the wide range of problems associated with fertilization: these include cost of the fertilizer, the cost of transportation, the difficulty of applying fertilizer in wild communities, and the unintended consequences of the intervention, both of the enhanced growth it promotes (both on-site, and as pollution downstream), of the other species that may come with the fertilizer, and of the physical consequences of the dispersal.

The piles of Deer pellets one sees in the woods are a model for how fertilizer should optimally be deployed: dispersed litre-scale piles of enriched organic material deposited on the surface of the forest floor. Deer (Odocoileus virginianus) can reflect the problems as well, since we're undertaking this project in the face of a burgeoning Deer population, they're going to be attracted (along with Insect "pests" and other herbivores) to browse down the enhanced vegetation, and they concentrate a lot of nutrients in ther carcases, which are carried off entire by hunting and other mortality.
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The seasons of maximum growth are the ones when fertilizer can be most completely taken up by Plants and Fungi, but it's also the seasons when the plants are most susceptible to crushing, osmotic burning, or other damage. The seasons optimal for the deposition of fertilizer (winter) are the ones when organisms are least able to take it up.

It is assumed that this policy will first apply to the Conifer plantations, and will be extended to Broadleaf production forest as experience is gained in the plantations, and policy is developed for logging in the Broadleaf stands, and possibly also to stands reserved as "oldgrowth," since high nutrient levels and big trees are characteristic of oldgrowth forests on mesic sites.

1) It is the policy of Limerick Forest management to balance nutrient outflow (from harvest) with inflow of nutrients.

This will require estimating or measuring the nutrients removed in logs, and the application, to the stands from which they are removed, of a equivalent quantity of the three macro-nutrients.

Possible Action: target selected trees for optimum growth and optimum income, and fertilize the selected trees

Possible Action: fertilize stands 2-5 years after harvest, so the community will have recovered from the disturbance of logging before the fertilizer is applied.

Possible Action: fertilize stands 2-5 years before harvest, so the community is enriched by the same amount of NPK as will be removed, before the logging.

2) It is the policy of Limerick Forest management to increase gradually the nutrient inflow and retention to promote a healthy successional forest.

This means both adding more nutrients than are removed by harvest, and reintroducing species from the oldgrowth community that will retain nutrients in their bodies during particular seasons and situations.

If we're going to continue to be the 'artificially enhanced' forest that's implied by planting the Conifers in the first place, we've got to now establish the diverse forest floor flora that's needed to hold nutrients in the fall and the spring, and to retain nutrients by rapid growth when trees are removed by logging or natural mortality. Many of these species have very large seeds which are dispersed by Ants, so they don't spread very fast into re-established forests: all the Mosses, Ferns, Clubmosses and Orchids that dominate the forest floor in the Limerick plantations were blown in as spores. The important paper here is Bellemare, J. M. G. and D. Foster. 2002. Legacies of the agricultural past in the forested present: an assessment of historical land-use effects on rich mesic forests. Journal of Biogeography 29: 1401-1420. (abstract)/(whole paper as pdf)

Action: explore nutrient sources and application techniques in light of environmental problems and the doubtless substantial difficulties of implementation imposed by existing government regulations and local prejudice:

a) energy-intensive commercial fertilizers -- note the high cost, and that pelletized mineral fertilizers burn holes in the skin of Amphibians

b) manure dispersal from both factory-farms and smaller operations (could also handle degraded hay or other agricultural wastes) -- note that fresh and liquid manure are distinctly different materials, and that a diversity on agricultural operations may need ecologically beneficial ways of disposing of their manures under the new nutrient management plans http://www.omafra.gov.on.ca/english/agops/index.html .

c) on-site milling of logs (so sawdust and slab are left in the woods). We'd also have to consider the nutrient amendments from Horse logging.

d) sled outhouses to be gradually moved along between rows of plantations to deposit human waste on top of the soil and rootweb.

e) encouragement of nitrogen-fixing woody plants (Alder, Myrica gale, and (yuck) Robinia).

f) harvesting aquatic and roadside invasive plants (Phragmites, Frogbit, Myriophyllum spicatum) and dumping them in nearby woods.

g) human biosolids and septic tank pumpings -- note that this would need a tracking system to follow fate of persistent pollutants.

h) spreading of nutrient-rich industrial wastes -- note that this also would need a tracking system to follow fate of any persistent pollutants.

i) garden waste/Cat litter/pooper scooped dumping areas -- specify each bagful to be dumped with a 1-metre gap from previous dumps, and not on top of any distinctive plants.

Action: Over time, introduce a wider range of tree and forest-floor species and augment nutrient availability by developing practical methods.

Action: establish the diverse forest floor flora that's needed to hold nutrients in the fall and the spring, by clonal planting of big-seeded forest floor herbs that are currently largely absent from Limerick.

Future Action: Broaden the target areas for the introduction of slowly-dispersing species and adding nutrients

3) It is the policy of Limerick Forest management to study the nutrient status of Limerick Forest on an ongoing basis and to utilize the accumulated information as a model to guide future forest management decisions

-- looking forward to carbon credits as well as to understanding tree growth (the biogeochemical ecology of Limerick Forest has not been studied -- we don't even know the pH of the soil).

Action: track the response to nutrient levels by photographing cross-sections of as many of the trees cut in Limerick as possible -- the time will come whan these can be digitized and placed in a model of overall nutrient status.

Action: Create a model of nutrient and energy (fixed carbon) flows in each section of Limerick Forest This could be obtained by a "Limerick Nutrient Bursary" for a graduate student at Carleton, Ottawa, or Queens, the first recipient would be committed to develop the model as a thesis, and subsequent recipients would be committed to do their research in Limerick, on some biogeochemical topic, and see that the model is kept up-to-date. This bursary could be funded by a fund-raising programme by LFAC, which would also present good opportunities for education about nutrients.

Action: stay aware of invasives that may short-circuit locally native nutrient recycling (such as Earthworms and Garlic Mustard), and of regional effects like acid rain or neotropical migrant decline that may affect how the forest lives.

4) Recognizing that these nutrient management policies are innovations in Ontario Forestry, an ongoing economic analysis shall be undertaken to track the financial and regulatory impacts and implications of these policies.

My father always maintained that "Anything prevalent enough to be identified as a waste, is in fact a resource," and in this project we're going to have to locate the situations in which the opportunity to fertilize the plantations (at least) of Limerick is a resource to the producers, of what to us is a resource of nutrients. This will mean we're going to have to evaluate "in kind" donations much more closely than we have in the past, as those producing the waste we might use are those who may be least sensitive to the processes involved.

Action: the LFAC Nutrient Management sub-sub Committee will have to pool all its knowledge, and that of everyone they can gooogle up or dragoon, to sketch out the consequences of these ideas. Watch this space for future developments...