![Forest structure and organic horizon analysis along a fire chronosequence in the low elevation forests of western Montana [An article from: Forest Ecology and Management]](https://www.ebooknetworking.net/books/B00/0RR/bigB000RR2TEG.jpg)
Forest structure and organic horizon analysis along a fire chronosequence in the low elevation forests of western Montana [An article from: Forest Ecology and Management]
Book Details
Author(s)M.D. MacKenzie, T.H. DeLuca, A. Sala
PublisherElsevier
ISBN / ASINB000RR2TEG
ISBN-13978B000RR2TE6
MarketplaceFrance 🇫🇷
Description
This digital document is a journal article from Forest Ecology and Management, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
Although fire consumes much of the forest floor, few studies have examined the change in forest floor characteristics with increasing time since fire. Mixed forests of ponderosa pine (Pinus ponderosa Doug. Ex. laws) and Douglas-fir (Pseudotsuga mensizii (Mirb.) Franco) in the inland northwest once burned with greater frequency than today. Fire exclusion over the last 100 years is believed to have caused a shift in forest structure, forest floor decomposition and nitrogen availability. However, no research has clearly demonstrated this in forests of the dry inland northwest. The objective of this study was to determine how fire exclusion has shaped forest structure and understory composition in ponderosa pine/Douglas-fir forests and how these changes have altered forest floor characteristics. Stand level and understory vegetation characteristics, organic horizon depth and biochemistry were analyzed along a 132-year chronosequence at 25 sites in second growth forests of western Montana. Principle components analysis confirmed that time since fire was significantly correlated to most biotic variables, including nutrient availability and indicates that the disturbance regime is tightly coupled to ecosystem function. Douglas-fir basal area, total shrubs and forest floor thickness were observed to increase with time since fire. Graminoids and forbs did not change significantly with time since fire. There was a significant increase in the content of total C, total N, NH"4^+ and potential mineralizable N (PMN) in the forest floor, while NO"3^- content decreased significantly with time since fire. Total phenols increased significantly and were positively correlated with forest floor thickness, total shrub cover, PMN and NH"4^+, but not correlated with NO"3^- content, suggesting that phenolic compounds accumulate with time and may affect N transformations.
Description:
Although fire consumes much of the forest floor, few studies have examined the change in forest floor characteristics with increasing time since fire. Mixed forests of ponderosa pine (Pinus ponderosa Doug. Ex. laws) and Douglas-fir (Pseudotsuga mensizii (Mirb.) Franco) in the inland northwest once burned with greater frequency than today. Fire exclusion over the last 100 years is believed to have caused a shift in forest structure, forest floor decomposition and nitrogen availability. However, no research has clearly demonstrated this in forests of the dry inland northwest. The objective of this study was to determine how fire exclusion has shaped forest structure and understory composition in ponderosa pine/Douglas-fir forests and how these changes have altered forest floor characteristics. Stand level and understory vegetation characteristics, organic horizon depth and biochemistry were analyzed along a 132-year chronosequence at 25 sites in second growth forests of western Montana. Principle components analysis confirmed that time since fire was significantly correlated to most biotic variables, including nutrient availability and indicates that the disturbance regime is tightly coupled to ecosystem function. Douglas-fir basal area, total shrubs and forest floor thickness were observed to increase with time since fire. Graminoids and forbs did not change significantly with time since fire. There was a significant increase in the content of total C, total N, NH"4^+ and potential mineralizable N (PMN) in the forest floor, while NO"3^- content decreased significantly with time since fire. Total phenols increased significantly and were positively correlated with forest floor thickness, total shrub cover, PMN and NH"4^+, but not correlated with NO"3^- content, suggesting that phenolic compounds accumulate with time and may affect N transformations.
