scholarly journals Inter- and Intraspecific Patterns in Resprouting of Trees in Undisturbed Natural Forests along an Elevational Gradient in Central Japan

Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 672 ◽  
Author(s):  
Kiyoshi Umeki ◽  
Mitsuru Kawasaki ◽  
Nobuhiko Shigyo ◽  
Toshihide Hirao

Resprouting is an important functional trait for determining community dynamics and the persistence of individuals and populations. However, community-wide research on resprouting has primarily focused on severely damaged trees. We investigated resprouting from trees in a range of undisturbed natural forests along an elevational gradient in central Japan and analyzed the data at inter- and intraspecific levels. First, we formulated interspecific relationships among resprout production, parent stem growth, multi-stemmedness, and dominance in forest communities using a structural equation model (SEM). Second, we analyzed intraspecific variation in the resprout number per stem for nine resprouting species using a hierarchical Bayesian method. We found that resprout production and parent stem growth were negatively correlated; resprouting resulted in multi-stemmed adult forms, and species with multi-stemmed forms tended to be less dominant in undisturbed forest communities. We observed various intraspecific resprouting responses to parental and environmental factors. For example, soil temperature had generally positive effects for most species, whereas dbh appeared to have only weak effects on a few species. Our SEM summarized well the direct and indirect relationships of species’ traits, including resprout production, in the undisturbed forests. The observed intraspecific patterns in the resprouting responses can serve as a starting point for understanding species’ traits within this context.


2007 ◽  
pp. 13-22 ◽  
Author(s):  
T. K. Yurkovskaya

I have focused only on some features of structure in the taiga vegetation cover. In conclusion I would like to tell some words about the causes of complicated space structure of the taiga and tundra vegetation cover. The causes of latitudinal differentiation are climatic undoubtedly, but heterogeneity of vegetation cover within the limits of tundra and taiga subzones is accounted for different factors. In tundra abiogenic factors prevail, first of all the permafrost processes. That is the reason why tundra vegetation cover is so sensible to any disturbances and so hard regenerates after various transformations. In taiga the space structure is mostly the result of self-regulation and self- restoration of biota. The abiotic factors, certainly, play significant role, but they recede to the second plan. So we showed that in the north and middle taiga the structure of vegetation cover, during the Holocene up to present time, is determined in many respects by the increasing role of mires. Suffice it to look at the map of distribution of mires in order to estimate their role in vegetation cover of the easteuropean taiga (Yurkovskaya, 1980). So, the increase of mire area on the Russian Plain in m2/year per 1000 ha varies between 200 and 700, the average increas is ca 300—400 m2/year (Elina et all., 2000). The mires favour peniplenization and unite the separate areas of forest communities into the whole by means of forming the buffer paludificated territories (various hydrophilous variants of forest communities). But if mires, at all their stability, after destroying practically don't restore, the forests even after continuous cuttings restore their structure and composition through the series of successional stages unless an ecotope is damaged completely. Hence the space structure of taiga is the result, first of all, self development and self regulation of its vegetation cover. But, as it is known, at present time the process of destruction of natural biota has gone too far that the question arises not only about supporting its state and structure but also about the survival of the mankind itself. In this regard the vegetation map of Europe is the invaluable basis, which gives the starting point for all conservational, ecological and economical measures. But it is important to learn reading and using the map. And this is one of our actual goals.



2008 ◽  
Vol 159 (4) ◽  
pp. 80-90 ◽  
Author(s):  
Bogdan Brzeziecki ◽  
Feliks Eugeniusz Bernadzki

The results of a long-term study on the natural forest dynamics of two forest communities on one sample plot within the Białowieża National Park in Poland are presented. The two investigated forest communities consist of the Pino-Quercetum and the Tilio-Carpinetum type with the major tree species Pinus sylvestris, Picea abies, Betula sp., Quercus robur, Tilia cordata and Carpinus betulus. The results reveal strong temporal dynamics of both forest communities since 1936 in terms of tree species composition and of general stand structure. The four major tree species Scots pine, birch, English oak and Norway spruce, which were dominant until 1936, have gradually been replaced by lime and hornbeam. At the same time, the analysis of structural parameters indicates a strong trend towards a homogenization of the vertical stand structure. Possible causes for these dynamics may be changes in sylviculture, climate change and atmospheric deposition. Based on the altered tree species composition it can be concluded that a simple ≪copying≫ (mimicking) of the processes taking place in natural forests may not guarantee the conservation of the multifunctional character of the respective forests.



2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Seyed Taghi Heydari ◽  
Leila Zarei ◽  
Ahmad Kalateh Sadati ◽  
Najmeh Moradi ◽  
Maryam Akbari ◽  
...  

Abstract Background The COVID-19 outbreak is a global pandemic, during which the community preventive and protective behaviors play a crucial role in the containment and control of infection. This study was designed to contribute to the existing knowledge on how risk communication (RC) and risk perception (RP) affect protective and preventive behaviors (PPB) during the COVID-19 outbreak. Methods The required data were extracted from a national online survey of Iranian adults aged 15 and older during March 15–19, 2020 (n=3213). Data analysis was performed using structural equation modeling. Results The study findings reveal that RC has direct and indirect positive effects on PB. Furthermore, this study also provides new evidence indicating that RP mediates the relationship between RC and PB and there is a two-way relationship between RC and RP. These interactions may have impact on risk communication strategies which should be adopted during this pandemic. Conclusion The study findings have remarkable implications for informing future communications as well as interventions during this ongoing outbreak and subsequent national risk events.



2021 ◽  
Vol 13 (15) ◽  
pp. 8123
Author(s):  
Delei Yang ◽  
Jun Zhu ◽  
Qingbin Cui ◽  
Qinghua He ◽  
Xian Zheng

Megaproject citizenship behavior (MCB) has been confirmed to a play vital role on megaproject performance. Although current research has argued that institution elements have had an impact on MCB diffusion, limited studies have empirically investigated the distinct effectiveness of various institution elements on driving MCB’s widespread diffusion in construction megaprojects. Based on institution theory, this study proposes a theoretical model comprising institutional elements (i.e., normative and mimetic isomorphism), owner’s support, relationship-based trust, and their effect or impact on MCB’s diffusion. Based on 171 industrial questionnaires collected from managers of contractors and designers in megaprojects. Partial least squares structural equation modeling (PLS-SEM) was used to validate the established model. The results indicated that both normative and mimetic isomorphism have positive effects on facilitating MCB diffusion, and owner’s support has shown partial mediation in promoting MCB diffusion through normative isomorphism, as well as full mediation in the promoting of MCB diffusion through mimetic isomorphism. Meanwhile, relationship-based trust exerts a positive moderating effect on the relationship between mimetic isomorphism and MCB. This study extends current literature on driving MCB diffusion from the perspective of institutional theory, contributing by providing four implications for megaprojects managers to “buy in” more extensive MCB.



2021 ◽  
Vol 13 (12) ◽  
pp. 6750
Author(s):  
Andreja Mihailović ◽  
Julija Cerović Smolović ◽  
Ivan Radević ◽  
Neli Rašović ◽  
Nikola Martinović

The main idea of this research is to examine how teleworking has affected employee perceptions of organizational efficiency and cybersecurity before and during the COVID-19 pandemic. The research is based on an analytical and empirical approach. The starting point of the research is a critical and comprehensive analysis of the relevant literature regarding the efficiency of organizations due to teleworking, digital information security, and cyber risk management. The quantitative approach is based on designing a structural equation model (SEM) on a sample of 1101 respondents from the category of employees in Montenegro. Within the model, we examine simultaneously the impact of their perceptions on the risks of teleworking, changes in cyber-attacks during teleworking, organizations’ capacity to respond to cyber-attacks, key challenges in achieving an adequate response to cyber-attacks, as well as perceptions of key challenges related to cybersecurity. The empirical aspects of our study involve constructing latent variables that correspond to different elements of employee perception; namely, their perception of organizational efficiency and the extent to which the digital information security of their organizations has been threatened during teleworking during the pandemic.



Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 309 ◽  
Author(s):  
Iván Franco-Manchón ◽  
Kauko Salo ◽  
Juan Oria-de-Rueda ◽  
José Bonet ◽  
Pablo Martín-Pinto

Natural forests and plantations of Pinus are ecologically and economically important worldwide, producing an array of goods and services, including the provision of non-wood forest products. Pinus species play an important role in Mediterranean and boreal forests. Although Pinus species seem to show an ecological adaptation to recurrent wildfires, a new era of mega fires is predicted, owing to climate changes associated with global warming. As a consequence, fungal communities, which are key players in forest ecosystems, could be strongly affected by these wildfires. The aim of this study was to observe the fungal community dynamics, and particularly the edible fungi, in maritime (Pinus pinaster Ait.), austrian pine (Pinus nigra J.F. Arnold), and scots pine (Pinus sylvestris L.) forests growing under wet Mediterranean, dry Mediterranean, and boreal climatic conditions, respectively, by comparing the mushrooms produced in severely burned Pinus forests in each area. Sporocarps were collected during the main sampling campaigns in non-burned plots, and in burned plots one year and five years after fire. A total of 182 taxa, belonging to 81 genera, were collected from the sampled plots, indicating a high level of fungal diversity in these pine forests, independent of the climatic conditions. The composition of the fungal communities was strongly affected by wildfire. Mycorrhizal taxa were impacted more severely by wildfire than the saprotrophic taxa, particularly in boreal forests—no mycorrhizal taxa were observed in the year following fire in boreal forests. Based on our observations, it seems that fungal communities of boreal P. sylvestris forests are not as adapted to high-intensity fires as the Mediterranean fungal communities of P. nigra and P. pinaster forests. This will have an impact on reducing fungal diversity and potential incomes in rural economically depressed areas that depend on income from foraged edible fungi, one of the most important non-wood forest products.



2019 ◽  
Vol 26 (7) ◽  
pp. 1607-1625
Author(s):  
Anita Gaile ◽  
Ilona Baumane-Vitolina ◽  
Erika Sumilo ◽  
Daina Skiltere ◽  
Ricardo Martin Flores

Purpose The purpose of this paper is to determine the differences in the values and behaviours of employees and entrepreneurs and to develop guidelines for employers to foster entrepreneurial thinking in their organisations. Design/methodology/approach To determine individual behaviours, the authors used the career adaptability scale developed by Savickas and Porfelli (2012), complemented with the statements regarding relationships in the workplace and reward, designed by Gattiker and Larwood (1986). The individual values were evaluated by Schwartz’s individual value framework. The career success of individuals was defined by income level and job satisfaction. Data from a sample of 473 respondents were analysed using structural equation modelling. Findings This paper reveals that there are differences in the behaviours and the values of employees and entrepreneurs. Employees are more concerned with relationships at the workplace, rewards and confidence, whereas entrepreneurs focus solely on relationships. Self-direction value has a direct positive impact. Universalism, conformism, achievement, stimulation and safety have indirect positive effects on career success for employees. There is no specific individual value driving career success for entrepreneurs. Originality/value This paper follows the recent trends in organisational culture development whereby organisations seek to incorporate the entrepreneurial mindset at all levels of the organisation. Until now, there has been scarce empirical evidence on the differences between entrepreneurial and employee values. This research provides evidence that the value gap between these two distinct groups is considerable enough to question the ability of the average employee to adopt the entrepreneurial behaviour required by modern organisations.



2020 ◽  
Vol 24 (6) ◽  
pp. 1369-1392 ◽  
Author(s):  
Elena-Mădălina Vătămănescu ◽  
Juan-Gabriel Cegarra-Navarro ◽  
Andreia Gabriela Andrei ◽  
Violeta-Mihaela Dincă ◽  
Vlad-Andrei Alexandru

Purpose In the context of resource scarcity, the affiliation of small and medium-sized enterprises (SMEs) to strategic networks has emerged as a fruitful path towards knowledge sharing as a reaction to fierce competition and with a view to enhance their innovative performance. In this framework, this paper aims to investigate the influence exerted by a specific relational design (i.e. types of strategic networks) and methodology (i.e. channels and content) of knowledge sharing on SMEs innovative performance. Design/methodology/approach A questionnaire-based survey with 102 top managers of European SMEs in the industrial field was conducted from June to August 2019 and a partial least squares structural equation modelling technique was used. The database was initially filtered to ensure the adequacy of the sample and data was analysed using the statistics software package SmartPLS 3.0. Findings The results concluded that the structural model explains 38.5% of the variance in SMEs innovative performance, indicating the positive effects exerted by offline and online and by competitive knowledge sharing on the dependent variable. Research implications The study has both theoretical and practical implications in that it sets out a reference point for the key performance indicators for strategic networks structure, formation and development and, implicitly, for the selection of the most efficient relational design and methodology. Originality/value The pivotal originality elements reside in the advancement of a more comprehensive conceptual and structural model combining a two-fold operationalization of SMEs strategic networks (founded on business abilities or on the personality of the partner) and in the investigation of knowledge transfer processes at the inter-organizational levels within a context-centric approach.



2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Yuling Sun ◽  
Zehua Liu ◽  
Hui Yang

Although many studies have suggested that the relationship between different supply chain members significantly affects agricultural product quality, suppliers’ perceptions of fairness, which greatly influence their decisions on building the relationship quality, are often overlooked. Particularly, the empirical evidence to investigate the impacts of suppliers’ fairness on the relationship quality and the factors that affect the suppliers’ fairness is missing, and therefore this knowledge gap needs to be filled by new research. Herein, we conducted a survey of 450 agricultural product suppliers and systemically analyzed the impact of antecedents on fairness perception and the impact of fairness perception on relationship quality. In addition, we developed a structural equation model and found that information sharing and price satisfaction had significantly positive effects on procedural fairness and distributive fairness, respectively. Furthermore, our studies demonstrated that procedural fairness is more important in improving the relationship quality than distributive fairness. However, supplier dependence is another important impact factor, and it greatly decreases the positive effects of suppliers’ fairness on relationship quality. In summary, the study results provide several managerial implications and extend our understanding of the importance of suppliers’ fairness in the relationship quality, which involves product development with respect to the supplier’s performance.



2015 ◽  
Vol 20 (2) ◽  
pp. 128-138 ◽  
Author(s):  
Juan Carlos Pérez Mesa ◽  
Emilio Galdeano-Gómez

Purpose – This purpose of this study is to provide empirical evidence of how cooperation is related to suppliers’ performance, a relationship that is thought to be affected by the type of customer and the extent to which the market is diversified. It analyzes horticultural exporting firms in southeastern Spain, which are the main suppliers of European markets. Together with their primary customers (large-scale retail companies such as Carrefour, Tesco and Aldi), these firms constitute a complex supply network composed of a variety of agents and sales channels. This network will be studied from the perspective of the supplier–supplier relationship that is critical to their survival. Design/methodology/approach – Starting with a detailed description of Europe’s vegetable supply chain, a hierarchical regression is used with an index of cooperation intensity, moderated by retail sales and market concentration. The authors test the hypotheses using panel data on a set of 118 horticultural marketing firms in southeast Spain for the period 2009-2011. Findings – Cooperation strategies are shown to have positive effects on performance (market creation, promotion, quality, training, joint supply purchases and research ventures). Moreover, the retail channel and market diversification are observed to have a positive effect on the relationship between cooperation and the supplier’s performance. They demonstrate that active cooperation strategies have a greater bearing on performance in those firms whose primary customers are retailers. This circumstance provides evidence of the synergies and benefits that may arise when the supplier integrates the retailer in the supply chain, but which do not arise with other types of customers. Research limitations/implications – Although this study refers to a specific sector (fruits and vegetables) and the statistical results are limited, they provide insights that may assist in understanding how other perishable produce-related industries work: such industries share many common features. Practical implications – A more stable relationship between suppliers and retailers in the perishable produce market will render the supply firm more cooperative, competitive and profitable. Increased performance does not arise from the better conditions and improved sales power offered by the customer but instead from the adaptability of the supplier. Likewise, market diversification drives the supply firm toward a cooperative strategy, making it more profitable and competitive. As a practical norm, market diversification alone will not have positive results on performance unless the firm proves capable of enhancing its capacity for cooperation. Social implications – Proper management of the agricultural produce supply chain has repercussions on all of the members of that chain, although special emphasis should be placed on producers and consumers. The availability of food, its quality and its safety depend on management during the production phase. Along these lines, and more specifically for the consumer, this work is relevant because the sector analyzed accounts for 40 per cent of the vegetables consumed in Europe. Originality/value – This article defends the supplier–supplier relationship as the starting point for the analysis of a supply network. In certain sectors, the suppliers’ ability both to solve their clients’ problems and to be profitable is conditioned on maintaining the network and, therefore, the basic focus must center on analyzing their relationships, always including the customer, who has a direct or indirect influence on those relationships. Previous research has not comprehensively addressed this issue, let alone that of a sector with agile and perishable products in which, due to its nature, decision-making about market destinations and sales channels is the order of the day.



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