Prof_Fire

Prof_Fire OP t1_j5ue4cz wrote

Good question! As you are hinting to, a monoculture forest like a plantation isn’t going to have as much biodiversity in the understory as a more natural forest. In terms of how rapidly the ecosystem recovers following fire, it will depend on the species that were present within and adjacent to the site prior to the fire. If it’s longleaf pine tree, they will probably survive the fire. However, in more natural ecosystems, the longleaf would survive and the many understory plants (grasses, forbs, woody plants) would also survive and resprout after the burn. In pine plantations, site preparation treatments are often used to minimize vegetative that can compete with pines. These treatments tend to reduce understory diversity and cover (that’s kind of the point). Similarly, densely planted pine plantations tend to have little understory diversity due to a lack of sunlight available at the forest floor.

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Prof_Fire OP t1_j5udxec wrote

This question depends on where you look, but in many places, we aren’t yet getting enough fire on the ground! For example, fire history studies in longleaf pine across the Southeast are showing that fires occurred every 1-4 years. Although prescribed burn practitioners are burning at that frequency in some places, many other areas remain unburned, some for decades or longer! The fire scar information is generally telling us we need to grow our prescribed fire programs!

The seasonality piece is a hard one to answer. In some places, we see in the fire-scar record a lot of dormant season fires that were ignited by people. However, in other locations, we see a strong record of lightning fire. These fires tended to happen in early spring and summer. I generally think prescribed burn practitioners should aim to increase their growing season burning. However, I do understand that managers face many challenges to doing so and it’s definitely key that we get frequent fire on the ground, even if that means burning at times of year that are inconsistent with the lightning fire regime. So in short - more growing season fire but also keep up with the other burns!

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Prof_Fire OP t1_j5uc0dl wrote

In terms of published studies, the oldest fires I have found so far are in the 1600s. However, we have work underway in Florida that shows fire activity in the 1500s! We are limited by how long the trees live. However, if we collect a very old stump that was cut down over a 100 years ago, we can get back further in time. In some places, with longer-lived tree species, fire history can go back beyond a millenia!

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Prof_Fire OP t1_j5ubarf wrote

>Tell me about this study(I mean what did you actually learnt and what they teaches under this title) Does this subject related to global warming? How can I study this subject(if I wish sometime)

We learn a lot from studying fire scars in tree rings. We are able to figure out the exact years and even season of past fires, going back through time. For example, in the Piedmont of North Carolina, we recently found that fires occurred every few years over previous centuries by studying the fire scars. If you’re interested in learning more, there are a lot of great general resources!

A great introductory text to tree-ring science is:

Speer, J. H. (2010). Fundamentals of tree-ring research. University of Arizona Press.

An excellent overview article that discusses using tree rings for fire history is available here (Falk et al., 2011 - Multi-scale controls of historical forest-fire regimes: new insights from fire-scar networks):

https://www.fs.usda.gov/research/treesearch/39310

Here’s another article on next steps for tree-ring based research on fire (Harley et al., 2018 - Advancing Dendrochronological Studies of Fire in the United States):

https://www.mdpi.com/2571-6255/1/1/11

A few nice online articles/resources include:

https://scied.ucar.edu/learning-zone/how-climate-works/tree-rings-and-climate

https://www.nytimes.com/2019/04/30/science/tree-rings-climate.html

https://ltrr.arizona.edu/about/treerings

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Prof_Fire OP t1_j5uatwb wrote

Tree-ring science (also called dendrochronology) is very useful for studying the fire history of a given area. The tree rings contain evidence of past fires in the form of fire scars. These fire scars form when the heat of a fire moves past the base of the tree and causes a small injury, but doesn’t kill the tree. Fire scars can be dated using tree-ring methods to find out the exact year and approximate season of past fires that occurred at the site over the life of the tree. An essential part of the research includes crossdating - a process of pattern matching that ensures that each tree ring is dated to its exact year of formation. In longleaf pine, we are finding fire-scar evidence that proves fires occurred historically every 1-4 years.

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