Moderate intensity burn- all exposed plant parts killed but tree needles not burned up. Fire converts trees into snags. Snags fall down over time and become downed woody material. Downed woody material is broken down by soil plants and animals and eventually becomes part of the soil. Once decomposed woody material becomes part of the soil it is called soil organimc matter. Soil organic matter is what makes earth black. Soil organic matter is very important for soil fertility because it holds water and nutrients like a sponge.

Within most of the burn patches, the fire usually is hot enough to kill the exposed parts of all plants. The recovering forest is even-aged and initially made up of fire tolerant species.

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Fire Severity

Fire severity basically measures how long and hot the fire burned in one spot. An easy way to tell how severe a fire was is to measure how deep the fire burned into the forest floor. Large wildfires are usually low to moderate severity which means that some of the forest floor burns up but most roots and buried seeds survive. Because of that, many of the plants that were there before the fire sprout quickly. Other plants sprout from seeds that have been lying dormant in the soil for as many as 100 years waiting for the next fire to come.

Fire kills exposed plant parts, burns up fine branches and burns into the forest floor.     Winter logging leaves plants except trees and has little impact on the forest floor.

Within most of the burn patches, fire usually burns long and hot enough to create an excellent seedbed but not enough to kill roots or destroy buried seeds.

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Fire Rejuvenates Forests
The soil in a coniferous forest becomes less fertile as a natural part of aging. This basically happens for two reasons. First, nutrients are taken out of circulation as tree trunks grow larger, a moss layer develops and more dead branches and leaves fall than can be broken down by soil plants and animals. Second, soil characteristics change so that fewer nutrients are available for plants. For example, the soil becomes more acidic as a natural by-product of plants taking up nutrients and micro-organisms composting the forest floor.
It is hard for new plants to establish in an old forest. Established plants already have a good foothold, the thick, moss-covered forest floor is a poor seedbed and nutrient availability is low. Fire breaths new life into the forest by killing competing plants, releasing nutrients, increasing soil fertility and creating an excellent seedbed for most of the plants commonly found in eastern Manitoba.
Vigorous Post-Fire Recovery On Peatlands On Uplands 
 

Fire rejuvenates coniferous forests. Fire stops the decline in soil fertility that happens naturally in coniferous forest. Fire creates very good growing conditions for the plants that are commonly found in the forest. Fire releases seeds in the cones of some kinds of plants and stimulates the sprouting of some dormant buried seeds.

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Affecting A Cut-Block Like Fire- The Operator's Role
The operator is key to successfully achieving the overall goal of keeping the forest healthy while logging. The operator's goal is for cut-blocks to look, feel and operate like a natural forest as quickly as possible. We do this by operating in ways that leave cut-blocks and retention areas as close as possible to the way that fire would leave them. Of course, recently logged areas will be very different from burned areas in some ways. However, with modified practices that include follow-up activities such as prescribed burning and seeding we think that cut-blocks will look, feel and operate like a natural forest within ten years for most of the forest's pieces. Up to twenty years may be required for large downed woody material. Long-term monitoring will tell us how good of a job we are doing.

 

Our Goal: A cut-block should look, feel and operate like a natural forest as soon as possible after logging.

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What Are The Major Differences Between The Effects Of Wildfire And Current Logging Operations?
These graphs show how much wildfire and logging change some parts of the forest.
(based on information collected in the region)

What Does This Mean On The Ground?
The ways that the operator helps logged areas recover to something like a natural forest are to:
(1)    Clear-cut all merchantable trees except scattered jack pine and black spruce trees.
•    Clear-cutting creates an even age structure within stands and exposes the forest floor to the sun.
•    Retention trees absorb nutrients released by logging, provide large downed woody material, provide a seed source and provide some shade for tree seedlings
(4)    Scatter slash and tree tops around the cut-block. This keeps most of the nutrients in the trees on the site.
(5)    Leave aspen and birch standing except on harvest trails. This helps to minimize suckering and sprouting.
(6)    Kill all balsam fir, white spruce and tamarack either by cutting them down, knocking them down or killing them during post-harvest silviculture. This prevents a shift in overstory composition towards fire intolerant species and outbreaks of insects and diseases.
(7)    Leave snags standing where possible.
(8)    Avoid trampling black spruce seedlings and saplings. This helps retain nutrients on the site and bring regeneration closer to a natural density.
(9)    Disturb only the duff layer of the soil, where possible.
(10)    Avoid rutting and compaction.
(11)    Avoid sensitive ecosystems.

Scattered retention of commercial trees with protection of small black spruce regeneration.

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Cutting Patterns