scholarly journals Assessment of Ponderosa Pine Vigor Using 4-Band Aerial Imagery in South Central Oregon: Crown Objects to Landscapes

2021 ◽  
Author(s):  
Charlie Schrader-Patton ◽  
Nancy Grulke ◽  
Craig Bienz
Keyword(s):  
Ponderosa Pine ◽  
Forest Health ◽  
Stand Density ◽  
Aerial Imagery ◽  
Individual Tree ◽  
South Central ◽  
Western Us ◽  
Moderate Drought ◽  
Wildfire Suppression ◽  
Gis Software

Ponderosa pine is an integral part of the forested landscape in the western US; it is the dominant tree species on landscapes that provide critical ecosystem services. Moderate drought tolerance allows it to occupy the transition zone between forests and open woodlands and grasslands. Increases in stand density resulting from wildfire suppression, combined with lengthening, intensifying and more frequent droughts have resulted in reduced tree vigor and stand health in dry ponderosa pine throughout its range. To address a management need for efficient landscape-level surveys of forest health, we used Random Forests to develop an object-oriented classification of individual tree crowns (ITCs) into vigor classes using existing, agency acquired 4-band aerial imagery. Classes of tree vigor were based on quantitative physiological and morphological attributes established in a previous study. We applied our model across a landscape dominated by ponderosa pine with a variety of forest treatments to assess their impacts on tree vigor and stand health. We found that stands that were both thinned and burned had the lowest proportion of low vigor ITCs, and that stands treated before the 2014-2016 drought had lower proportions of low vigor ITCs than stands treated more recently (2016). Upland stands had significantly higher proportions of low vigor trees than lowland stands. Maps identifying the low vigor ITCs would assist managers in identifying priority stands for treatment and marking trees for harvest or retention. These maps can be created using already available imagery and GIS software.

scholarly journals Assessment of Ponderosa Pine Vigor Using Four-Band Aerial Imagery in South Central Oregon: Crown Objects to Landscapes

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 612
Author(s):  
Charlie Schrader-Patton ◽  
Nancy Grulke ◽  
Craig Bienz
Keyword(s):  
Ponderosa Pine ◽  
Forest Health ◽  
Stand Density ◽  
Aerial Imagery ◽  
Individual Tree ◽  
South Central ◽  
Western Us ◽  
Moderate Drought ◽  
Wildfire Suppression ◽  
Gis Software

Ponderosa pine is an integral part of the forested landscape in the western US; it is the dominant tree species on landscapes that provide critical ecosystem services. Moderate drought tolerance allows it to occupy the transition zone between forests, open woodlands, and grasslands. Increases in stand density resulting from wildfire suppression, combined with lengthening, intensifying, and more frequent droughts have resulted in reduced tree vigor and stand health in dry ponderosa pine throughout its range. To address a management need for efficient landscape-level surveys of forest health, we used Random Forests to develop an object-oriented classification of individual tree crowns (ITCs) into vigor classes using existing, agency-acquired four-band aerial imagery. Classes of tree vigor were based on quantitative physiological and morphological attributes established in a previous study. We applied our model across a landscape dominated by ponderosa pine with a variety of forest treatments to assess their impacts on tree vigor and stand health. We found that stands that were both thinned and burned had the lowest proportion of low-vigor ITCs, and that stands treated before the 2014–2016 drought had lower proportions of low-vigor ITCs than stands treated more recently (2016). Upland stands had significantly higher proportions of low-vigor trees than lowland stands. Maps identifying the low-vigor ITCs would assist managers in identifying priority stands for treatment and marking trees for harvest or retention. These maps can be created using already available imagery and GIS software.

scholarly journals Precommercial Thinning in a Ponderosa Pine Stand Affected by Armillaria Root Disease in Central Oregon: 30 Years of Growth and Mortality

1999 ◽  
Vol 14 (3) ◽  
pp. 144-148 ◽  
Author(s):  
Gregory M. Filip ◽  
Stephen A. Fitzgerald ◽  
Lisa M. Ganio
Keyword(s):  
Ponderosa Pine ◽  
Tree Mortality ◽  
Basal Area ◽  
Stand Density ◽  
Root Disease ◽  
Diameter Growth ◽  
Individual Tree ◽  
Precommercial Thinning ◽  
Tree Diameter ◽  
Armillaria Root Disease

Abstract A 30-yr-old stand of ponderosa pine was precommercially thinned in 1966 to determine the effects of thinning on tree growth and mortality caused by Armillaria root disease in central Oregon. After 30 yr, crop tree mortality was significantly (P = 0.02) less in thinned plots than in unthinned plots. Tree diameter growth was not significantly (P = 0.17) increased by thinning. Crop-tree basal area/ac growth was significantly (P = 0.03) greater in thinned plots. Apparently, from a root disease perspective, precommercial thinning of pure ponderosa stands significantly decreases the incidence of crop-tree mortality after 30 yr and significantly increases basal area/ac growth but not individual tree diameter growth. Recommendations for thinning based on stand density index (SDI) are given. West. J. Appl. For. 14(3):144-148.

scholarly journals A Direct Measure of Stand Density Based on Stand Growth

2020 ◽  
Author(s):  
Thomas J Dean ◽  
Anthony W D’Amato ◽  
Brian J Palik ◽  
Mike A Battaglia ◽  
Constance A Harrington
Keyword(s):  
Ponderosa Pine ◽  
Site Occupancy ◽  
Stand Density ◽  
Site Quality ◽  
Direct Measure ◽  
Canopy Architecture ◽  
Height Increment ◽  
Individual Tree ◽  
Growing Stock ◽  
Volume Increment

Abstract Standardizing gross volume increment on periodic height increment of the dominant trees is a means of minimizing the effects of site quality and age in growth–growing-stock relations; however, volume increment per height increment contains more information than just a normalization method for fitting growth models. This study builds on previous work suggesting that the cumulative sum of the ratios between individual-tree volume increment and height increment may be a direct measure of stand density. We used data from several levels of growing-stock studies for Douglas-fir, ponderosa pine, and red pine to explore this hypothesis. Regression analysis indicated that the sum of the ratios is proportional to(Dqx⋅N), the underlying equation form of Reineke’s stand density index. Stem growth is a function of canopy dynamics, and additional analyses showed that volume added per unit of height growth was also related to canopy architecture, increasing with decreasing live-crown ratio and increasing foliage density. The linkages between growth, canopy architecture, intermediary canopy dynamics, and (Dqx⋅N) support the hypothesis that the sum of the tree ratios between volume increment and height increment is a direct measure of site occupancy due to its association between growth and corresponding resource use. Study Implications Stand density indices are fundamental to managing the development of forest stands to achieve habitat and production goals, and advanced statistical techniques are providing silviculturists with more precise tools to manage density. However, the increased precision is only available with data from self-thinning stands, rare in managed forests. Furthermore, silviculturists must assume that constant fractions of relative stand density are parallel to fitted self-thinning trajectories. The results of this study show that the slope of the stand density gradient can be determined without data from self-thinning stands and the gradient in stand density runs parallel to the trajectory of self-thinning stands.

scholarly journals Influence of Agisoft Metashape Parameters on UAS Structure from Motion Individual Tree Detection from Canopy Height Models

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 250
Author(s):  
Wade T. Tinkham ◽  
Neal C. Swayze
Keyword(s):  
Structure From Motion ◽  
Ponderosa Pine ◽  
Point Cloud ◽  
Image Resolution ◽  
Canopy Height ◽  
Computer Hardware ◽  
Forest Monitoring ◽  
Individual Tree ◽  
Ponderosa Pine Forests ◽  
Tree Detection

Applications of unmanned aerial systems for forest monitoring are increasing and drive a need to understand how image processing workflows impact end-user products’ accuracy from tree detection methods. Increasing image overlap and making acquisitions at lower altitudes improve how structure from motion point clouds represents forest canopies. However, only limited testing has evaluated how image resolution and point cloud filtering impact the detection of individual tree locations and heights. We evaluate how Agisoft Metashape’s build dense cloud Quality (image resolution) and depth map filter settings influence tree detection from canopy height models in ponderosa pine forests. Finer resolution imagery with minimal filtering provided the best visual representation of vegetation detail for trees of all sizes. These same settings maximized tree detection F-score at >0.72 for overstory (>7 m tall) and >0.60 for understory trees. Additionally, overstory tree height bias and precision improve as image resolution becomes finer. Overstory and understory tree detection in open-canopy conifer systems might be optimized using the finest resolution imagery that computer hardware enables, while applying minimal point cloud filtering. The extended processing time and data storage demands of high-resolution imagery must be balanced against small reductions in tree detection performance when down-scaling image resolution to allow the processing of greater data extents.

scholarly journals Adjudicating Perspectives on Forest Structure: How Do Airborne, Terrestrial, and Mobile Lidar-Derived Estimates Compare?

2021 ◽  
Vol 13 (12) ◽  
pp. 2297
Author(s):  
Jonathon J. Donager ◽  
Andrew J. Sánchez Meador ◽  
Ryan C. Blackburn
Keyword(s):  
Ponderosa Pine ◽  
Laser Scanning ◽  
Canopy Cover ◽  
Basal Area ◽  
Tree Height ◽  
Absolute Error ◽  
Forest Monitoring ◽  
Individual Tree ◽  
Structural Configurations ◽  
Individual Trees

Applications of lidar in ecosystem conservation and management continue to expand as technology has rapidly evolved. An accounting of relative accuracy and errors among lidar platforms within a range of forest types and structural configurations was needed. Within a ponderosa pine forest in northern Arizona, we compare vegetation attributes at the tree-, plot-, and stand-scales derived from three lidar platforms: fixed-wing airborne (ALS), fixed-location terrestrial (TLS), and hand-held mobile laser scanning (MLS). We present a methodology to segment individual trees from TLS and MLS datasets, incorporating eigen-value and density metrics to locate trees, then assigning point returns to trees using a graph-theory shortest-path approach. Overall, we found MLS consistently provided more accurate structural metrics at the tree- (e.g., mean absolute error for DBH in cm was 4.8, 5.0, and 9.1 for MLS, TLS and ALS, respectively) and plot-scale (e.g., R2 for field observed and lidar-derived basal area, m2 ha−1, was 0.986, 0.974, and 0.851 for MLS, TLS, and ALS, respectively) as compared to ALS and TLS. While TLS data produced estimates similar to MLS, attributes derived from TLS often underpredicted structural values due to occlusion. Additionally, ALS data provided accurate estimates of tree height for larger trees, yet consistently missed and underpredicted small trees (≤35 cm). MLS produced accurate estimates of canopy cover and landscape metrics up to 50 m from plot center. TLS tended to underpredict both canopy cover and patch metrics with constant bias due to occlusion. Taking full advantage of minimal occlusion effects, MLS data consistently provided the best individual tree and plot-based metrics, with ALS providing the best estimates for volume, biomass, and canopy cover. Overall, we found MLS data logistically simple, quickly acquirable, and accurate for small area inventories, assessments, and monitoring activities. We suggest further work exploring the active use of MLS for forest monitoring and inventory.

Potential for Individual Tree Monitoring in Ponderosa Pine-Dominated Forests Using Unmanned Aerial System Structure from Motion Point Clouds

2021 ◽  
Author(s):  
Matthew B. Creasy ◽  
Wade Travis Tinkham ◽  
Chad M. Hoffman ◽  
Jody C. Vogeler
Keyword(s):  
Forest Structure ◽  
Ponderosa Pine ◽  
Laser Scanning ◽  
Point Clouds ◽  
System Structure ◽  
Detection Methods ◽  
Unmanned Aerial System ◽  
Individual Tree ◽  
Detection Rates ◽  
Ponderosa Pine Forests

Characterization of forest structure is important for management-related decision making, monitoring, and adaptive management. Increasingly, observations of forest structure are needed at both finer resolutions and across greater extents to support spatially explicit management planning. Unmanned aerial system (UAS)-based photogrammetry provides an airborne method of forest structure data acquisition at a significantly lower cost and time commitment than existing methods such as airborne laser scanning (LiDAR). This study utilizes nearly 5,000 stem-mapped trees in ponderosa pine-dominated forests to evaluate several algorithms for detecting individual tree locations and characterizing crown area across tree sizes. Our results indicate that adaptive variable-window detection methods with UAS-based canopy height models have greater tree detection rates compared to fixed window analysis across a range of tree sizes. Using the UAS approach, probability of detecting individual trees decreases from 97% for dominant overstory to 67% for suppressed understory trees. Additionally, crown radii were correctly determined within 0.5 m for approximately two-thirds of sampled trees. These findings highlight the potential for UAS photogrammetry to characterize forest structure through the detection of trees and tree groups in open-canopy ponderosa pine forests. Further work should investigate how these methods transfer to more diverse species compositions and forest structures.

scholarly journals High- and low-temperature pyrolysis profiles describe volatile organic compound emissions from western US wildfire fuels

2018 ◽  
Author(s):  
Kanako Sekimoto ◽  
Abigail R. Koss ◽  
Jessica B. Gilman ◽  
Vanessa Selimovic ◽  
Matthew M. Coggon ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Biomass Burning ◽  
Ponderosa Pine ◽  
Fine Particles ◽  
Voc Emissions ◽  
Western Us ◽  
Volatile Organic ◽  
Low Temperature Pyrolysis ◽  
Pyrolysis Processes

Abstract. Biomass burning is a large source of volatile organic compounds (VOCs) and many other trace species to the atmosphere, which can act as precursors to the formation of secondary pollutants such as ozone and fine particles. Measurements collected with a proton-transfer-reaction time-of-flight mass spectrometer during the FIREX 2016 laboratory intensive were analyzed with Positive Matrix Factorization (PMF), in order to understand the instantaneous variability in VOC emissions from biomass burning, and to simplify the description of these types of emissions. Despite the complexity and variability of emissions, we found that a solution including just two emission profiles, which are mass spectral representations of the relative abundances of emitted VOCs, explained on average 85 % of the VOC emissions across various fuels representative of the western US (including various coniferous and chaparral fuels). In addition, the profiles were remarkably similar across almost all of the fuel types tested. For example, the correlation coefficient r of each profile between Ponderosa pine (coniferous tree) and Manzanita (chaparral) is higher than 0.9. We identified the two VOC profiles as resulting from high-temperature and low-temperature pyrolysis processes known to form VOCs in biomass burning. High-temperature and low-temperature pyrolysis processes do not correspond exactly to the commonly used flaming and smoldering categories as described by modified combustion efficiency (MCE). The average atmospheric properties (e.g. OH reactivity, volatility, etc.) of the high- and low-temperature profiles are significantly different. We also found that the two VOC profiles can describe previously reported VOC data for laboratory and field burns. This indicates that the high- and low-temperature pyrolysis profiles could be widely useful to model VOC emissions from many types of biomass burning in the western US, with a few exceptions such as burns of duff and rotten wood.

scholarly journals Stand structure links up canopy processes and forest management

2009 ◽  
Vol 51 (1) ◽  
pp. 40-48
Author(s):  
Toomas Frey
Keyword(s):  
Forest Management ◽  
Stand Structure ◽  
Net Primary Production ◽  
Stand Density ◽  
Tree Height ◽  
Belowground Biomass ◽  
Unit Mass ◽  
Total Biomass ◽  
Individual Tree ◽  
Mean Values

Stand structure links up canopy processes and forest management Above- and belowground biomass and net primary production (Pn) of a maturing Norway spruce (Picea abies (L.) Karst.) forest (80 years old) established on brown soil in central Estonia were 227, 50 and 19.3 Mg ha correspondingly. Stand structure is determined mostly by mean height and stand density, used widely in forestry, but both are difficult to measure with high precision in respect of canopy processes in individual trees. However, trunk form quotient (q2) and proportion of living crown in relation to tree height are useful parameters allowing describe stand structure tree by tree. Based on 7 model trees, leaf unit mass assimilation activity and total biomass respiration per unit mass were determined graphically as mean values for the whole tree growth during 80 years of age. There are still several possible approaches not used carefully enough to integrate experimental work at instrumented towers with actual forestry measurement. Dependence of physiological characteristics on individual tree parameters is the missing link between canopy processes and forest management.

scholarly journals Long-term influence of stand thinning and repeated fertilization on forage production in young lodgepole pine forests

2017 ◽  
Vol 47 (8) ◽  
pp. 1123-1130 ◽  
Author(s):  
Pontus M.F. Lindgren ◽  
Thomas P. Sullivan ◽  
Douglas B. Ransome ◽  
Druscilla S. Sullivan ◽  
Lisa Zabek
Keyword(s):  
Pinus Contorta ◽  
Large Scale ◽  
Bos Taurus ◽  
Lodgepole Pine ◽  
Stand Density ◽  
Stand Age ◽  
Forage Production ◽  
South Central ◽  
Stand Thinning

Integration of trees with forage and livestock production as silvopastoralism is another potential component of intensive forest management. Stand thinning and fertilization may enhance growth of crop trees and understory forage for livestock. We tested the hypothesis that large-scale precommercial thinning (PCT) (particularly heavy thinning to ≤1000 stems·ha−1) and repeated fertilization, up to 20 years after the onset of treatments, would enhance production of graminoids, forbs, and shrubs as cattle (Bos taurus L.) forage. Results are from two long-term studies: (1) PCT (1988–2013) and (2) PCT with fertilization (PCT–FERT) (1993–2013) of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands in south-central British Columbia, Canada. Mean biomass estimates of graminoids, forbs, total herbs, and shrubs were not affected by stand density. However, fertilization enhanced mean biomass estimates of graminoids, forbs, and total herbs, but not shrubs. Thus, the density part of our hypothesis was not supported, but the nutrient addition part was supported at least for the herbaceous components. Biomass of the herbaceous understory was maintained as a silvopasture component for up to 20 years (stand age 13 to 33 years) in fertilized heavily thinned stands prior to canopy closure.

Sign in / Sign up

Export Citation Format

Share Document