Mixture of Triclopyr and Imazapyr More Effective than Triclopyr Alone for Hardwood Forest Stand Improvement

2020 ◽  
Author(s):  
Mark A Turner ◽  
William D Gulsby ◽  
Craig A Harper
Keyword(s):  
Coastal Plain ◽  
Tree Species ◽  
Significant Proportion ◽  
Forest Stand ◽  
Liquidambar Styraciflua ◽  
Minimal Risk ◽  
Herbicide Mixture ◽  
Soil Activity ◽  
Individual Trees ◽  
Better Than

Abstract Treatment of individual trees in hardwood stands typically is conducted with herbicides that have no soil activity, such as triclopyr. However, triclopyr is not effective on some tree species. Applying a mixture of triclopyr and imazapyr would broaden the spectrum of species controlled, but nontarget mortality may be problematic as imazapyr may affect other trees through soil activity. We applied herbicide via girdle-and-spray as part of a forest stand improvement treatment in four upland hardwood stands in the Upper Coastal Plain of Alabama. We compared effects of using triclopyr alone with a mixture of triclopyr and imazapyr 18 months posttreatment. Only one untreated sweetgum (Liquidambar styraciflua) out of 440 trees was killed in the stands treated with the herbicide mixture (0.5 percent nontarget mortality rate). Nontarget mortality did not differ between treatments. However, the herbicide mixture controlled hickory (Carya spp.) and sourwood (Oxydendrum arboreum) better than triclopyr alone, with 56 percent of hickory treated with triclopyr still alive 18 months later, compared with 0 percent of hickory treated with the mixture. Our results indicate a mixture of triclopyr and imazapyr provides better control than triclopyr alone, and there is minimal risk to nontarget tree species in hardwood stands when used according to label recommendations. Study Implications Forest stand improvement (FSI) is a noncommercial practice typically conducted by cutting and using herbicide to kill undesirable trees. Consideration must be given to herbicide selection, which is based on efficacy on target species while minimizing nontarget mortality of residual trees. We found that a mixture of triclopyr and imazapyr applied via girdle-and-spray was more effective for FSI than triclopyr alone, which failed to control a significant proportion of treated hickory, and resulted in essentially no nontarget mortality in mixed hardwood stands 18 months after application.

scholarly journals Individual Tree Classification Using Airborne LiDAR and Hyperspectral Data in a Natural Mixed Forest of Northeast China

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 303 ◽  
Author(s):  
Dan Zhao ◽  
Yong Pang ◽  
Lijuan Liu ◽  
Zengyuan Li
Keyword(s):  
Tree Species ◽  
Northeast China ◽  
Dominant Species ◽  
Mixed Forest ◽  
Hyperspectral Data ◽  
Airborne Lidar ◽  
Support Vector ◽  
Individual Tree ◽  
Individual Trees ◽  
Better Than

This paper proposes a method to classify individual tree species groups based on individual tree segmentation and crown-level spectrum extraction (“crown-based ITC” for abbr.) in a natural mixed forest of Northeast China, and compares with the pixel-based classification and segment summarization results (“pixel-based ITC” for abbr.). Tree species is a basic factor in forest management, and it is traditionally identified by field survey. This paper aims to explore the potential of individual tree classification in a natural, needle-leaved and broadleaved mixed forest. First, individual trees were isolated, and the spectra of individual trees were then extracted. The support vector machine (SVM) and spectrum angle mapper (SAM) classifiers were applied to classify the trees species. The pixel-based classification results from hyperspectral data and LiDAR derived individual tree isolation were compared. The results showed that the crown-based ITC classified broadleaved trees better than pixel-based ITC, while the classes distribution of the crown-based ITC was closer to the survey data. This indicated that crown-based ITC performed better than pixel-based ITC. Crown-based ITC efficiently identified the classes of the dominant and sub-dominant species. Regardless of whether SVM or SAM was used, the identification consistency relative to the field observations for the class of the dominant species was greater than 90%. In contrast, the consistencies of the classes of the sub-dominant species were approximately 60%, and the overall consistency of both the SVM and SAM was greater than 70%.

scholarly journals Modeling the long-term dynamics of tropical forests: from leaf traits to whole-tree growth patterns

2020 ◽  
Author(s):  
Gunnar Petter ◽  
Holger Kreft ◽  
Yongzhi Ong ◽  
Gerhard Zotz ◽  
Juliano Sarmento Cabral
Keyword(s):  
Tropical Forests ◽  
Functional Traits ◽  
Tree Growth ◽  
Tree Species ◽  
Leaf Traits ◽  
Forest Stand ◽  
Growth Patterns ◽  
Leaf Economic Spectrum ◽  
Individual Trees

AbstractTropical forests are the most diverse terrestrial ecosystems and home to numerous tree species with diverse ecological strategies competing for resources in space and time. Functional traits influence the ecophysiological performance of tree species, yet the relationship between traits and emergent long-term growth pattern is poorly understood. Here, we present a novel 3D forest stand model in which growth patterns of individual trees and forest stands are emergent properties of leaf traits. Individual trees are simulated as 3D functional-structural tree models (FSTMs), considering branches up to the second order and leaf dynamics at a resolution of one m3. Each species is characterized by a set of leaf traits that corresponds to a specific position on the leaf economic spectrum and determines light-driven carbon assimilation, respiration and mortality rates. Applying principles of the pipe model theory, these leaf scale-processes are coupled with within-tree carbon allocation, i.e., 3D tree growth emerges from low-level processes. By integrating these FSTMs into a dynamic forest stand model, we go beyond modern stand models to integrate structurally-detailed internal physiological processes with interspecific competition, and interactions with the environment in diverse tree communities. For model calibration and validation, we simultaneously compared a large number of emergent patterns at both the tree and forest levels in a pattern-oriented modeling framework. At the tree level, varying specific leaf area and correlated leaf traits determined the maximum height and age of a tree, as well as its size-dependent growth rate and shade tolerance. Trait variations along the leaf economic spectrum led to a continuous transition from fast-growing, short-lived and shade-intolerant to slow-growing, long-lived and shade-tolerant trees. These emerging patterns resembled well-known functional tree types, indicating a fundamental impact of leaf traits on long-term growth patterns. At the forest level, a large number of patterns taken from lowland Neotropical forests were reproduced, indicating that our forest model simulates structurally realistic forests over long time spans. Our ecophysiological approach improves the understanding of how leaf level processes scale up to the tree and the stand level, and facilitates the development of next-generation forest models for species-rich forests in which tree performance emerges directly from functional traits.

Gebirgswaldpflege – es kommt auf den Standort an | Mountain silviculture – it all depends on the site

2001 ◽  
Vol 152 (5) ◽  
pp. 169-176 ◽  
Author(s):  
Monika Frehner
Keyword(s):  
Nature Conservation ◽  
Low Temperature ◽  
Tree Species ◽  
Forest Stand ◽  
Ground Vegetation ◽  
Mountain Forests ◽  
Research Projects ◽  
Snow Mould ◽  
The Relationship ◽  
Protection Forests

The article shows that knowledge of the site of a particular forest stand, together with research results and experience, can provide information that is important for the cultivation of mountain forests, including knowledge of the composition of the tree species and the structure and growth capacity of natural forest. Furthermore, certain sites can, thus, be characterized by factors that influence restocking, such as snow mould,lush ground vegetation or low temperature. The guidelines«minimale Pflegemassnahmen» – «Minimal tending of protection forests» (WASSER und FREHNER, 1996) are based on this principle. For individual sites, warnings about natural dangers such as rock fall or statements concerning nature conservation can be made (e.g., the occurrence of tree species, suitability as a biotope for Capercaille). In conclusion, two research projects on the relationship between site and natural dangers will be presented.

scholarly journals Using Discrete-Point LiDAR to Classify Tree Species in the Riparian Pacific Northwest, USA

2021 ◽  
Vol 13 (14) ◽  
pp. 2647
Author(s):  
Julia Tatum ◽  
David Wallin
Keyword(s):  
Pacific Northwest ◽  
Tree Species ◽  
3D Structure ◽  
Alnus Rubra ◽  
Populus Balsamifera ◽  
Segmentation Method ◽  
Black Cottonwood ◽  
Riparian Landscape ◽  
Individual Trees ◽  
Species Mapping

Practical methods for tree species identification are important for both land management and scientific inquiry. LiDAR has been widely used for species mapping due to its ability to characterize 3D structure, but in structurally complex Pacific Northwest forests, additional research is needed. To address this need and to determine the feasibility of species modeling in such forests, we compared six approaches using five algorithms available in R’s lidR package and Trimble’s eCognition software to determine which approach most consistently identified individual trees across a heterogenous riparian landscape. We then classified segments into Douglas fir (Pseudotsuga menziesii), black cottonwood (Populus balsamifera ssp. trichocarpa), and red alder (Alnus rubra). Classification accuracies based on the best-performing segmentation method were 91%, 92%, and 84%, respectively. To our knowledge, this is the first study to investigate tree species modeling from LiDAR in a natural Pacific Northwest forest, and the first to model Pacific Northwest species at the landscape scale. Our results suggest that LiDAR alone may provide enough information on tree species to be useful to land managers in limited applications, even under structurally challenging conditions. With slight changes to the modeling approach, even higher accuracies may be possible.

scholarly journals Implementation and Comparison of Two Pharmacometric Tools for Model-Based Therapeutic Drug Monitoring and Precision Dosing of Daptomycin

Pharmaceutics ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 114
Author(s):  
Justine Heitzmann ◽  
Yann Thoma ◽  
Romain Bricca ◽  
Marie-Claude Gagnieu ◽  
Vincent Leclerc ◽  
...  
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
Joint Infection ◽  
Significant Proportion ◽  
Initial Dosage ◽  
Validation Dataset ◽  
Therapeutic Drug ◽  
Efficacy And Safety ◽  
Absolute Percent Error ◽  
Better Than

Daptomycin is a candidate for therapeutic drug monitoring (TDM). The objectives of this work were to implement and compare two pharmacometric tools for daptomycin TDM and precision dosing. A nonparametric population PK model developed from patients with bone and joint infection was implemented into the BestDose software. A published parametric model was imported into Tucuxi. We compared the performance of the two models in a validation dataset based on mean error (ME) and mean absolute percent error (MAPE) of individual predictions, estimated exposure and predicted doses necessary to achieve daptomycin efficacy and safety PK/PD targets. The BestDose model described the data very well in the learning dataset. In the validation dataset (94 patients, 264 concentrations), 21.3% of patients were underexposed (AUC24h < 666 mg.h/L) and 31.9% of patients were overexposed (Cmin > 24.3 mg/L) on the first TDM occasion. The BestDose model performed slightly better than the model in Tucuxi (ME = −0.13 ± 5.16 vs. −1.90 ± 6.99 mg/L, p < 0.001), but overall results were in agreement between the two models. A significant proportion of patients exhibited underexposure or overexposure to daptomycin after the initial dosage, which supports TDM. The two models may be useful for model-informed precision dosing.

scholarly journals Transformation of even-aged spruce stands at the School Forest Enterprise Kostelec nad Černými lesy: Structure and final cutting of mature stand

2012 ◽  
Vol 52 (No. 4) ◽  
pp. 158-171 ◽  
Author(s):  
J. Remeš
Keyword(s):  
Forest Stand ◽  
Growth Potential ◽  
Main Criterion ◽  
Individual Tree ◽  
Main Method ◽  
Single Tree ◽  
Mature Stand ◽  
Spruce Stands ◽  
Individual Trees ◽  
Very High

This paper deals with the transformation of pure even-aged forest stands to mixed and more uneven-aged stands on an example of selected even-aged Norway spruce stands in the School Forest Enterprise (SFE) in Kostelec nad Čern&yacute;mi lesy. A forest stand where individual tree felling was used as the main method of forest stand regeneration was chosen as a conversion example. The main criterion of tree maturity is the culmination of mean volume increment of a single tree. The analyses confirmed a very high variability in the growth potential of individual trees. The potential and actual increment was strongly influenced by the stand position of tree and by crown release. These results show a high potential level of tree growth even at the age of 120 years. From 30% to 9% of all trees on particular experimental plots achieved felling maturity.

scholarly journals Impacts of Different Tree Species of Different Sizes on Spatial Distribution of Herbaceous Plants in the Nigerian Guinea Savannah Ecological Zone

Scientifica ◽  
2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Toma Buba
Keyword(s):  
Spatial Distribution ◽  
Species Richness ◽  
Open Field ◽  
Tree Species ◽  
Herbaceous Species ◽  
Ecological Zone ◽  
Vitellaria Paradoxa ◽  
Parkia Biglobosa ◽  
Species Richness And Diversity ◽  
Individual Trees

This study was aimed at finding the impacts of different tree species and individual trees of different sizes on species richness, diversity, and composition of the herbaceous layer. All the three tree species have greatly increased species richness and diversity both within and outside their crown zones compared with the open grassland. Both species richness and diversity were found to be higher under all the three tree species than outside their crowns, which was in turn higher than the open field.Daniella oliverihas the highest species richness and diversity both within and outside its crown zone followed byVitellaria paradoxaand thenParkia biglobosa. The result also revealed that the same tree species with different sizes leads to different herbaceous species richness, diversity, and composition under and around the trees’ crowns.P. biglobosaandV. paradoxatrees with smaller sizes showed higher species richness and diversity under their crowns than the bigger ones. The dissimilarity of species composition differs between the inside and outside crown zones of the individuals of the same tree species and among the different trees species and the open field.

scholarly journals Structure and development of forest stands on permanent research plots in the Krkonoše Mts.

2010 ◽  
Vol 56 (No. 11) ◽  
pp. 518-530
Author(s):  
S. Vacek ◽  
Z. Vacek ◽  
L. Bílek ◽  
I. Nosková ◽  
O. Schwarz
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Vertical Structure ◽  
Forest Stand ◽  
Forest Stands ◽  
Vegetation Zone ◽  
Aggregation Index ◽  
Tree Species Composition ◽  
Results Management ◽  
Management Recommendations

The research is focused on structure and development of forest stands from 5th to 8th forest vegetation zone in the Krkono&scaron;e Mts. The forest stand diversity according to tree species composition and representation, horizontal and vertical structure was evaluated by using following indices: Clark-Evans aggregation index (Clark, Evans 1954), standardised Arten-profil index (Pretsch 2005) and index of complex diversity after Jaehne, Dohrenbusch (1997). Growth model SIBYLA (Fabrika, Ďursk&yacute; 2005) was used for visualizations and growth predictions of forest stands on particular plots. Based on research results, management recommendations were evaluated.

scholarly journals Reconstruction of Piñon–Juniper Woodlands in the Sky Islands of the Davis Mountains, Texas, USA

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1079
Author(s):  
Mohammad M. Bataineh ◽  
Brian P. Oswald ◽  
Hans M. Williams ◽  
Daniel R. Unger ◽  
I-Kuai Hung
Keyword(s):  
Tree Species ◽  
Reference Conditions ◽  
Age Determination ◽  
Niche Differentiation ◽  
Rate Of Change ◽  
Sky Islands ◽  
Davis Mountains ◽  
Study Sites ◽  
Pinus Spp ◽  
Individual Trees

Piñon (Pinus spp. L.)–juniper (Juniperus spp. L.) woodlands’ historical stand structures were recreated to provide reference conditions and document long-term changes in the Sky Islands of the Davis Mountains, Texas. Restoration of these isolated woodlands requires insights into the range of variability in current and historical stand structures, as well as an understanding of the spatiotemporal establishment and recruitment patterns of tree species. With drastic changes in forests and woodlands of the Southwestern United States widely reported, the main objective of this study was to reconstruct woodland tree temporal and spatial establishment patterns. A stratified random sampling approach was used to select two study sites each of 3600 m2 in area. Within each site, all individual trees were mapped, measured, and cored for age determination. Age and tree location data were used to recreate the spatiotemporal patterns of tree species establishment and recruitment. Increments in density of both Mexican piñon (Pinus cembroides var. cembroides Zucc.) and alligator juniper (Juniperus deppeana var. deppeana Steud.) reached 422 trees ha−1 in the 115-year period between 1890 and 2005; a yearly increment of 4 trees ha−1 that did not reflect a rapid rate of change in these piñon–juniper woodlands. Age distributions reflected the multi-cohort nature of these woodlands, and spatial autocorrelation measures were useful in the objective delineation of these cohorts. Temporal and functional niche differentiation of juniper was reflected in the development pattern where alligator juniper served as a pioneer species, exhibited a longer period of substantial recruitment, and had greater recruitment rates than that of Mexican piñon. Recruitment of Mexican piñon and alligator juniper occurred in an episodic fashion, with the majority of recruits being acquired between 1890 and 1949.

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