Modeling inputs of large woody debris to streams from falling trees

1990 ◽  
Vol 20 (10) ◽  
pp. 1593-1601 ◽  
Author(s):  
John Van Sickle ◽  
Stanley V. Gregory
Keyword(s):  
Size Distribution ◽  
Probabilistic Model ◽  
Tree Mortality ◽  
Woody Debris ◽  
Mortality Rates ◽  
Tree Size ◽  
Large Woody Debris ◽  
Cascade Mountains ◽  
Management Zones ◽  
Riparian Management

A probabilistic model predicts means and variances of the total number and volume of large woody debris pieces falling into a stream reach per unit time. The estimates of debris input are based on the density (trees/area), tree size distribution, and tree-fall probability of the riparian stand adjacent to the reach. Distributions of volume, length, and orientation of delivered debris pieces are also predicted. The model is applied to an old-growth coniferous stand in Oregon's Cascade Mountains. Observed debris inputs from the riparian stand exceeded the inputs predicted from tree mortality rates typical of similar nonriparian stands. Debris pieces observed in the stream were generally shorter, with less volume per piece, than those predicted by the model, probably because of bole breakage during tree fall. As a second application, predicted debris inputs from riparian management zones of various widths are compared with the input expected from an unharvested stand.

scholarly journals Simulating the Effects of Forest Management on Large Woody Debris in Streams in Northern Idaho

2007 ◽  
Vol 22 (2) ◽  
pp. 81-87 ◽  
Author(s):  
Mark Teply ◽  
Dale McGreer ◽  
Dennis Schult ◽  
Patrick Seymour
Keyword(s):  
Riparian Forest ◽  
Woody Debris ◽  
Timber Harvest ◽  
Forest Harvesting ◽  
Large Woody Debris ◽  
Growth And Yield ◽  
Directional Bias ◽  
Riparian Management ◽  
Significant Difference ◽  
Northern Idaho

Abstract Existing models for simulating large woody debris (LWD) loads of forest streams were adapted for forest conditions in northern Idaho. Effects of riparian management prescriptions implemented for streams within a habitat conservation planning area for bull trout and other sensitive species were evaluated based on riparian and instream LWD conditions observed along 58 randomly selected stream segments. A wood budgeting system presented by Welty et al. (2002. Riparian aquatic interaction simulator (RAIS): A model of riparian forest dynamics for the generation of large woody debris and shade. For. Ecol. Manage. 162:299–318) was employed through use of observed starting instream LWD loads and generalized depletion rates. LWD recruitment estimates were based on locally relevant growth and yield simulators, taper equations, and adjustments for tree fall directional bias. LWD loading, expressed as the number of qualifying pieces per 1,000 ft of stream, was examined under two scenarios: a no-harvest scenario and a harvest scenario. Results indicated no significant difference in the frequency distribution of simulated LWD loading between the no-harvest and harvest scenarios over a 100-year prediction period. Examination of our assumptions indicated that LWD loading was likely underestimated and less variable than would be expected. However, these assumptions had equal effects on each scenario, enabling us to confidently interpret the effects of timber harvest. The nature and extent of riparian forest harvesting evaluated in this simulation is similar to levels being considered elsewhere in the region. Therefore, simulation techniques demonstrated here could be applied elsewhere in the region for evaluating the potential effects of riparian management on fisheries resources.

Temporal dynamics of large woody debris in small streams of the Alberta foothills, Canada

2009 ◽  
Vol 39 (6) ◽  
pp. 1159-1170 ◽  
Author(s):  
S.R. Powell ◽  
L.D. Daniels ◽  
T.A. Jones
Keyword(s):  
Tree Mortality ◽  
Temporal Dynamics ◽  
Woody Debris ◽  
Riparian Forests ◽  
Large Woody Debris ◽  
Time Since Death ◽  
Small Streams ◽  
Short And Long Term ◽  
And Function

Large woody debris (LWD) is a key link between riparian forests and streams; however, the temporal dynamics of in-stream wood remains poorly quantified. Using dendrochronology, we evaluated the dynamics of five Pinus -dominated and five Picea -dominated riparian forests in the foothills of Alberta and cross-dated the ring widths of 186 pieces of LWD. Time since death of LWD ranged from 2 to 143 years, with maximums of 86 and 143 years for Pinus and Picea, respectively. Recruitment of Pinus LWD was influenced by stand-replacing fires followed by self-thinning about 40 years after stand establishment. In uneven-aged Picea-dominated forests, tree mortality and LWD recruitment were due to fine-scale disturbances. Time since death increased significantly with decay and position classes, which resulted in changes in LWD function through time. LWD persisted in the bridge position for about 30 years. Bridged LWD was least decayed, was significantly longer, and had greater volume than LWD in other positions. LWD remained in partial bridge and loose positions about 15 years and >80 years when submerged in water and buried in sediment. Given the persistence of LWD, we conclude that management that alters wood abundance and recruitment has short- and long-term implications for the structure and function of small streams.

scholarly journals Cross-scale interaction of host tree size and climatic water deficit governs bark beetle-induced tree mortality

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michael J. Koontz ◽  
Andrew M. Latimer ◽  
Leif A. Mortenson ◽  
Christopher J. Fettig ◽  
Malcolm P. North
Keyword(s):  
Water Deficit ◽  
Sierra Nevada ◽  
Bark Beetle ◽  
Ponderosa Pine ◽  
Tree Mortality ◽  
Mortality Rates ◽  
Dendroctonus Brevicomis ◽  
Scale Interactions ◽  
Climatic Water Deficit ◽  
Host Mortality

AbstractThe recent Californian hot drought (2012–2016) precipitated unprecedented ponderosa pine (Pinus ponderosa) mortality, largely attributable to the western pine beetle (Dendroctonus brevicomis; WPB). Broad-scale climate conditions can directly shape tree mortality patterns, but mortality rates respond non-linearly to climate when local-scale forest characteristics influence the behavior of tree-killing bark beetles (e.g., WPB). To test for these cross-scale interactions, we conduct aerial drone surveys at 32 sites along a gradient of climatic water deficit (CWD) spanning 350 km of latitude and 1000 m of elevation in WPB-impacted Sierra Nevada forests. We map, measure, and classify over 450,000 trees within 9 km2, validating measurements with coincident field plots. We find greater size, proportion, and density of ponderosa pine (the WPB host) increase host mortality rates, as does greater CWD. Critically, we find a CWD/host size interaction such that larger trees amplify host mortality rates in hot/dry sites. Management strategies for climate change adaptation should consider how bark beetle disturbances can depend on cross-scale interactions, which challenge our ability to predict and understand patterns of tree mortality.

scholarly journals Deriving Tree Size Distributions of Tropical Forests from Lidar

2021 ◽  
Vol 13 (1) ◽  
pp. 131
Author(s):  
Franziska Taubert ◽  
Rico Fischer ◽  
Nikolai Knapp ◽  
Andreas Huth
Keyword(s):  
Size Distribution ◽  
Spatial Scales ◽  
Basal Area ◽  
Tree Height ◽  
Tree Size ◽  
Diameter Distribution ◽  
Forest Inventories ◽  
Allometric Relations ◽  
Lidar Measurements ◽  
Derived Data

Remote sensing is an important tool to monitor forests to rapidly detect changes due to global change and other threats. Here, we present a novel methodology to infer the tree size distribution from light detection and ranging (lidar) measurements. Our approach is based on a theoretical leaf–tree matrix derived from allometric relations of trees. Using the leaf–tree matrix, we compute the tree size distribution that fit to the observed leaf area density profile via lidar. To validate our approach, we analyzed the stem diameter distribution of a tropical forest in Panama and compared lidar-derived data with data from forest inventories at different spatial scales (0.04 ha to 50 ha). Our estimates had a high accuracy at scales above 1 ha (1 ha: root mean square error (RMSE) 67.6 trees ha−1/normalized RMSE 18.8%/R² 0.76; 50 ha: 22.8 trees ha−1/6.2%/0.89). Estimates for smaller scales (1-ha to 0.04-ha) were reliably for forests with low height, dense canopy or low tree height heterogeneity. Estimates for the basal area were accurate at the 1-ha scale (RMSE 4.7 tree ha−1, bias 0.8 m² ha−1) but less accurate at smaller scales. Our methodology, further tested at additional sites, provides a useful approach to determine the tree size distribution of forests by integrating information on tree allometries.

Large Woody Debris Input and Its Influence on Channel Structure in Agricultural Lands of Southeast Brazil

2011 ◽  
Vol 48 (4) ◽  
pp. 750-763 ◽  
Author(s):  
Felipe Rossetti de Paula ◽  
Silvio Frosini de Barros Ferraz ◽  
Pedro Gerhard ◽  
Carlos Alberto Vettorazzi ◽  
Anderson Ferreira
Keyword(s):  
Woody Debris ◽  
Channel Structure ◽  
Large Woody Debris ◽  
Agricultural Lands ◽  
Southeast Brazil

scholarly journals Quantification of potential recruitment of large woody debris in mountain catchments considering the effects of vegetation on hydraulic and geotechnical bank erosion and shallow landslides

2018 ◽  
Vol 40 ◽  
pp. 02046 ◽  
Author(s):  
Eric Gasser ◽  
Andrew Simon ◽  
Paolo Perona ◽  
Luuk Dorren ◽  
Johannes Hübl ◽  
...  
Keyword(s):  
Woody Debris ◽  
Probabilistic Approach ◽  
Temporal Distribution ◽  
Bank Erosion ◽  
Shallow Landslides ◽  
Large Woody Debris ◽  
Correction Coefficient ◽  
Model Framework ◽  
Modelling Framework ◽  
Spatio Temporal

Large woody debris (LWD) exacerbates flood damages near civil structures and in urbanized areas and the awareness of LWD as a risk is becoming more and more relevant. The recruitment of “fresh” large woody debris has been documented to play a significant role of the total amount of wood transported during flood events in mountain catchments. Predominately, LWD recruitment due to hydraulic and geotechnical bank erosion and shallow landslides contribute to high volumes of wood during floods. Quantifying the effects of vegetation on channel and slope processes is extremely complex. This manuscript therefore presents the concepts that are being implemented in a new modelling framework that aims to improve the quantification of vegetation effects on LWD recruitment processes. One of the focuses of the model framework is the implementation of the effect of spatio-temporal distribution of root reinforcement in recruitment processes such as bank erosion and shallow landslides in mountain catchments. Further, spatio-temporal precipitation patterns will be considered using a probabilistic approach to account for the spatio-temporal precipitation variability to estimate a LWD recruitment correction coefficient. Preliminary results are herein presented and discussed in form of a case study in the Swiss Prealps.

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