scholarly journals Silvicultural prescriptions for mixed-species forest stands. A European review and perspective

2021 ◽  
Author(s):  
Hans Pretzsch ◽  
Werner Poschenrieder ◽  
Enno Uhl ◽  
Gediminas Brazaitis ◽  
Ekaterina Makrickiene ◽  
...  
Keyword(s):  
Structural Heterogeneity ◽  
Forest Stands ◽  
Mixed Species ◽  
Temporal Separation ◽  
Tree Number ◽  
Methodological Approaches ◽  
Species Specific ◽  
Space Requirements ◽  
And Control ◽  
Silvicultural Prescriptions

AbstractCompared with far-developed measures and methods for mono-specific forest stands, the silvicultural prescriptions for mixed-species stands are at their early beginning. However, they are essential for the well-conceived establishment, design, and control of mixed-species stands, currently promoted in many countries worldwide. Here, we review the state of the art and we further develop silvicultural prescriptions for mixed-species stands for steering of experiments, stand modeling, and silviculture. We review which aspects of tree species mixing are most relevant for management goal achievement. We found the maintenance of species diversity and structural heterogeneity for ecological purpose, stabilizing productivity, and social-economic performance as main objectives. We give an overview of quantitatively formulated silvicultural prescriptions for steering mixed-species stands for forest practice, long-term experiments, forest stand models. Compared with the sophisticated guidelines for mono-specific stands, prescriptions for mixed stand are often mainly qualitative and vague. Then, we introduce methodological approaches in development for steering mixture: measures for spatial and temporal separation, species-specific growing space requirements for crop trees, coefficients for equivalence and density modification, and basic relationships for steering tree number and area-based mixing proportions. Finally, we draw conclusions for further development of methodological approaches for silvicultural steering of experiments, implementation in stand simulators, and for silvicultural operations. We see the need for improving the quantitative spatially explicit rules based at tree or cohort level, for substantiating the knowledge on species-specific allometry, growing area, tree-to-tree distances, and position-dependent competition indices for steering tree removal. We discuss the prospects and limitations of establishing silvicultural prescriptions for mixed-species stands that inevitably will be more complicated than those for mono-specific stands, and we draw conclusions for next steps in science and practice.

scholarly journals Correction to: Silvicultural prescriptions for mixed-species forest stands. A European review and perspective

2021 ◽  
Author(s):  
Hans Pretzsch ◽  
Werner Poschenrieder ◽  
Enno Uhl ◽  
Gediminas Brazaitis ◽  
Ekaterina Makrickiene ◽  
...  
Keyword(s):  
Forest Stands ◽  
Mixed Species ◽  
European Review ◽  
Silvicultural Prescriptions ◽  
Mixed Species Forest

scholarly journals Experimental Assessment of the Influence of Gull-Billed Terns on Nest Site Choice of Black Skimmers

The Condor ◽  
2002 ◽  
Vol 104 (1) ◽  
pp. 174-177
Author(s):  
Sandra M. Pius ◽  
Paul L. Leberg
Keyword(s):  
Nest Site ◽  
Close Association ◽  
Habitat Partitioning ◽  
Mixed Species ◽  
Experimental Assessment ◽  
Nest Site Choice ◽  
Species Specific ◽  
And Control

Abstract The hypothesis that members of one species might benefit from nesting with heterospecifics has been proposed to explain the existence of mixed-species breeding colonies. Black Skimmers (Rhynchops niger) usually nest in close association with one of several tern species (Sterna spp.); benefits of this association might lead skimmers to use different nesting substrates than terns, thus facilitating coexistence. Manipulating availability of substrates, we found that skimmers exclusively nested on substrates normally occupied by terns, indicating that habitat partitioning detected in previous studies was not a result of species-specific preferences. Using arrays of tern, skimmer, and control decoys, we found that skimmers nested more often with conspecifics than with terns. Our results suggest that the tendency of skimmers to nest in association with terns, but on different substrates, may be more influenced by nesting sequence than from a preference to nest near terns. Estimación Experimental de la Influencia de Sterna nilotica sobre la Selección de Sitios de Nidificación de Rhynchops niger Resumen. La hipótesis que sugiere que miembros de una especie podrían recibir beneficios al anidar con organismos de diferentes especies ha sido propuesta para explicar la tendencia de algunas aves coloniales a formar grupos interespecíficos de nidificación. Individuos de Rhynchops niger generalmente anidan en asociación con alguna de las diferentes especies de golondrinas marinas (Sterna spp.). Los beneficios de esta asociación podrían hacer que R. niger utilice diferentes substratos para anidar que aquellos utilizados por las golondrinas lo cual facilitaría su coexistencia. Al manipular la disponibilidad de los substratos, se encontró que R. niger anida en substratos ocupados normalmente por golondrinas; indicando que la repartición del hábitat observada en estudios previos no es el resultado de preferencias especie-específicas. Encontramos que los rayadores anidaron más comúnmente con miembros de su misma especie que con golondrinas cuando se les dio la opción de elegir entre grupos al utilizar líneas de señuelos. Nuestros resultados sugieren que la tendencia de R. niger a anidar en asociación con golondrinas en diferentes substratos podría estar más influenciada por la secuencia de nidificación, que por la preferencia de anidar en proximidad a las golondrinas marinas.

scholarly journals Density regulation of mixed and mono-specific forest stands as a continuum: a new concept based on species-specific coefficients for density equivalence and density modification

2019 ◽  
Vol 93 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Hans Pretzsch ◽  
Miren del Río
Keyword(s):  
Extreme Case ◽  
Stand Density ◽  
Growth And Yield ◽  
Practical Implementation ◽  
Forest Stands ◽  
Mixed Species ◽  
Mixed Stands ◽  
Additional Species ◽  
Mean Values ◽  
Species Specific

Abstract A wealth of recent research has improved our understanding of the structure, growth and yield of mixed-species stands. However, appropriate quantitative concepts for their silvicultural regulation remain scarce. Due to the species-specific stand densities, growing area requirements and potential over-density, the density and mixing regulation in mixed stands is much more intricate than in monospecific stands. Here, we introduce the species-specific coefficients: density equivalence coefficients (DEC), for density equivalence; and density modification coefficient (DMC), for density modification in mixed species stands. DEC is suitable for the conversion of the stand density and growing area requirement of one species into that of another species. DMC estimates the modification of maximum stand density by tree species mixing using as reference the maximum stand density of one of the species. First, we introduce the theoretical concept of these coefficients. Second, we derive the mean values of these coefficients based on long-term experiments using different mixtures of European beech. Third, we apply DEC and DMC for flexible regulation of the stand density and mixing proportion. Thus, silvicultural regulation of monospecific stands and mixed-species stands forms a continuum, where monospecific stands represent an extreme case of mixed-species stands. Lastly, we discuss the advantages and limitations of these concepts. Future directions comprise the inclusion of additional species, their integration in guidelines and simulation models, and their establishment for the quantitative regulation of experimental plots and the practical implementation in forest stands.

ASSESSMENT OF VERTICAL INTEGRATION POTENTIAL EFFECTIVENESS FOR INDUSTRIAL ENTERPRISES

2021 ◽  
Vol 2 (4) ◽  
pp. 58-66
Author(s):  
K. I. ZAKURIN ◽  
◽  
M. V. VOLKOVA ◽  
Yu. G. GERTSIK ◽  
◽  
...  
Keyword(s):  
Vertical Integration ◽  
Cost Reduction ◽  
Value Chains ◽  
Industrial Enterprises ◽  
Technological Chain ◽  
Industrial Markets ◽  
Methodological Approaches ◽  
Business Structures ◽  
Fierce Competition ◽  
And Control

Fierce competition in industrial markets is pushing companies to seek sources of cost reduction and control rise. Stable cross-sectoral links within value chains contribute to the emergence of the possibility of integrating business structures. To make a competent decision to merge, a consistent analysis of the situation in the industry market, in the technological chain and at a particular enterprise is required. For this purpose, in this article, general methodological approaches and assessment indicators are collected in an algorithm, recommendations are given for determining the feasibility of vertical integration.

scholarly journals How prevalent is Plasmodium malariae in Rondônia, Western Brazilian Amazon?

2000 ◽  
Vol 33 (5) ◽  
pp. 489-492 ◽  
Author(s):  
Marisa Torres Vidal Cavasini ◽  
Weber Luidi Ribeiro ◽  
Fumihiko Kawamoto ◽  
Marcelo Urbano Ferreira
Keyword(s):  
Polymerase Chain Reaction ◽  
Plasmodium Species ◽  
Brazilian Amazon ◽  
Plasmodium Malariae ◽  
Mixed Species ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Polymerase Chain ◽  
Potential Impact ◽  
And Control

We have compared results of Plasmodium species identification obtained with conventional on-site microscopy of Giemsa-stained thick smears (GTS) and a semi-nested polymerase chain reaction (PCR) in 96 malaria patients from Rondônia, Western Brazilian Amazon. Mixed-species infections were detected by PCR in 30% patients, but no such case had been found on GTS. Moreover, P. malariae infections were detected in 9 of 96 patients (10%) by PCR, but were not identified by local microscopists. The potential impact of species misidentification on malaria treatment and control is discussed.

scholarly journals Research on the Evolution of Methodological Approaches to Accounting and Auditing of Estimated Values in the Context of Digitalization

2020 ◽  
Vol 7 (6) ◽  
pp. 64-74
Author(s):  
I. N. Bogataya ◽  
E. M. Evstaf’eva
Keyword(s):  
Balance Sheet ◽  
Digital Technologies ◽  
Digital Transformation ◽  
Information Base ◽  
The Russian Federation ◽  
Methodological Approaches ◽  
Sound Management ◽  
And Control ◽  
Current Stage

The article is devoted to the issues of development of methodological approaches to accounting and auditing of estimated values and their changes in the conditions of digitalization. The purpose of the research is to study modern methodological approaches to accounting and auditing of estimated values, taking into account the specifics of the current stage of digital transformation, and to develop the main directions for their improvement in order to improve the quality of the information base in order to be able to make sound management decisions. The theoretical and methodological basis of the research consists of the evolutionary-adaptive theory, balance sheet theory, risk-based approach, methods contained in IFRS, ISA, FSB in the field of accounting and auditing of estimated values, regulatory legal acts of the Russian Federation, research in the field of modern international and Russian accounting and auditing practice. The research methodology included a review of accounting and auditing practices in the field of estimated values. The main features of accounting and auditing of estimated values are defined. Methodological approaches to improving accounting and auditing of estimated values that are based on digital technologies are proposed. Implementation of the proposed methodological approaches to accounting and auditing of estimated values in the context of digitalization will significantly improve the quality of accounting and control support for business.

Structural heterogeneity in farm structures: a configurational approach

2019 ◽  
Vol 10 (1) ◽  
pp. 65-83
Author(s):  
Bruno Varella Miranda ◽  
Anna Grandori
Keyword(s):  
Structural Heterogeneity ◽  
System Level ◽  
Large Set ◽  
Legal Form ◽  
Content Type ◽  
Property Rights Protection ◽  
Farm Structures ◽  
Development Paths ◽  
And Control ◽  
Corporate Farm

Purpose The purpose of this paper is to provide a multidimensional framework for the identification, description and comparative analysis of alternative farm structures and their properties for economic development. Design/methodology/approach Integrating previous typologies and considering a large set of examples, the authors identify six attributes that are necessary to characterize and compare farm structures: size; strategy; organizational form; legal form; who the owners are; and degree of separation of ownership and control. They also discuss potential complementarities between those organizational attributes and specific features of the institutions of developing and emerging countries, such as contract enforcement and property rights protection regime, and developed capital markets and corporate law. Findings Conceptually and empirically, effective farm structures can deviate from the templates traditionally considered – “small family-owned farm” or “large factory-like corporate farm,” combining structural attributes in diverse ways. The dimensionalization of farm structures also helps in revealing complementary institutional traits at the regional or larger system level that may foster development processes. Research limitations/implications The paper is limited to theory building and case-based evidence. Nevertheless, it provides dimensions that can be measured on a larger scale and by quantitative studies. Originality/value This paper sheds light on organizational diversity in agriculture and on a wider set of feasible development paths.

scholarly journals Stand Structure and Composition 32 Years after Precommercial Thinning Treatments in a Mixed Northern Conifer Stand in Central Maine

2011 ◽  
Vol 28 (2) ◽  
pp. 92-96 ◽  
Author(s):  
Aaron R. Weiskittel ◽  
Laura S. Kenefic ◽  
Rongxia Li ◽  
John Brissette
Keyword(s):  
Stand Structure ◽  
Abies Balsamea ◽  
Basal Area ◽  
Long Term Effects ◽  
Mixed Species ◽  
Precommercial Thinning ◽  
Large Trees ◽  
Stand Attributes ◽  
And Control

Abstract The effects of four precommercial thinning (PCT) treatments on an even-aged northern conifer stand in Maine were investigated by examining stand structure and composition 32 years after treatment. Replicated treatments applied in 1976 included: (1) control (no PCT), (2) row thinning (rowthin; 5-ft-wide row removal with 3-ft-wide residual strips), (3) row thinning with crop tree release (rowthin+CTR; 5-ft-wide row removal with crop tree release at 8-ft intervals in 3-ft-wide residual strips), and (4) crop tree release (CTR; release of selected crop trees at 8×8-ft intervals). PCT plots had more large trees and fewer small trees than the control in 2008. There were no other significant differences between the rowthin and control. The rowthin+CTR and CTR treatments had lower total and hardwood basal area (BA) and higher merchantable conifer BA than the control. CTR also resulted in more red spruce (Picea rubens [Sarg.]) and less balsam fir (Abies balsamea [L.]) than the other treatments. Although stand structures for rowthin+CTR and CTR were similar, the percentage of spruce in CTR was greater. Although the less-intensive rowthin+CTR treatment may provide many of the same benefits as CTR, the latter would be the preferred treatment if increasing the spruce component of a stand is an objective. Overall, early thinning treatments were found to have long-term effects on key stand attributes, even more than 30 years after treatment in areas with mixed species composition and moderate site potential.

Partitioning and predicting forage biomass from total aboveground biomass of regenerating tree species using dimensional analyses

2019 ◽  
Vol 49 (3) ◽  
pp. 309-316 ◽  
Author(s):  
Quinn Morgan ◽  
Tamara L. Johnstone-Yellin ◽  
Cornelia C. Pinchot ◽  
Matthew Peters ◽  
Alejandro A. Royo
Keyword(s):  
Aboveground Biomass ◽  
Habitat Structure ◽  
Average Diameter ◽  
Stem Height ◽  
Basal Diameter ◽  
Site Specific ◽  
Species Specific ◽  
And Control ◽  
Forest Renewal ◽  
Sampling Variable

Foresters and wildlife biologists use biomass estimates as proxies of habitat structure, productivity, and carrying capacity. Determining biomass, however, is challenging without destructive harvests. We provide a dimensional analysis approach to partition browse biomass (BB) from total aboveground biomass (AGB) of six regenerating hardwoods in the Allegheny forests of Pennsylvania, USA. First, we determined the average diameter of browsed twigs for each species. Then, we created a subset of potential browsable twig and foliage biomass from total AGB in 439 individuals harvested within paired exclosure (fenced) and control (unfenced) plots at 15 sites. We fit species-specific allometric equations to estimate BB and AGB using basal diameter and height as predictors and tested the effects of fencing. Although overall stem height and BB were greater within exclosures, fencing did not significantly affect relationships between either predictor and BB or AGB, thereby enabling general and robust (R2 ≥ 0.80) equations for most species. Our work provides biomass equations for regionally dominant species and size classes that are underrepresented in the literature, yet critical to forest renewal and wildlife. Moreover, by sampling variable sites and levels of browse pressure, reported equations lessen site-specific biases. Finally, our methodology provides a template to generate forage biomass prediction equations for other plant and ungulate species.

Modeling stand water budgets of mixed temperate broad-leaved forest stands by considering variations in species specific drought response

2010 ◽  
Vol 150 (10) ◽  
pp. 1347-1357 ◽  
Author(s):  
Sebastian Bittner ◽  
Ulrike Talkner ◽  
Inga Krämer ◽  
Friedrich Beese ◽  
Dirk Hölscher ◽  
...  
Keyword(s):  
Drought Response ◽  
Forest Stands ◽  
Water Budgets ◽  
Broad Leaved Forest ◽  
Species Specific ◽  
Leaved Forest
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