Search results for "Ecological succession"

Emulating natural disturbances in boreal Norway spruce forests: Effects on ground beetles (Coleoptera, Carabidae)

2014

The disturbance regime of boreal forests has been substantially altered by human influence in northern Europe. In this context, emulations of natural disturbance have become increasingly common as management tools to minimize negative effects of forestry on biodiversity. In a large-scale habitat-restoration experiment conducted in Norway spruce stands in southern Finland, we tested the effects of controlled burning, partial harvesting, and increasing the amount of downed wood on ground beetles (carabids). We also evaluated the effects of moisture gradients within harvested sites. We collected beetles seven years after the treatments. The moisture gradient was the strongest determinant of ca…

Founding-family-controlled firms, intergenerational succession, and firm value

2022

Using a unique, hand-collected data sample and panel-data econometric techniques, we analyse the impact of founding-family control and intergenerational succession on the value of Chilean listed companies. After controlling for firm- and ownership-specific characteristics, we find an inverse U-shaped relationship between a founding family’s degree of ownership and firm value. Hence, family ownership at first increases firm value. However, when family ownership exceeds a threshold of about 38 percent of outstanding shares, the family takes advantage of its power in the firm and extracts wealth from minority shareholders. Further, if the founder of the company is the CEO or chairman of the bo…

Non-family employees in small family business succession: the case of psychological ownership

2013

This study is analysing non-family employees' perceptions on psychological ownership during the family business succession process. Three small family companies were chosen for the multiple case studies. The results of this study show that non-family employees are participating on the small family business succession and they do possess a strong psychological ownership towards the family business, their own work, and the founder generation. Non-family employees recognise the changing management and leadership in successions. Non-family employees' psychological ownership increases in succession. This has got influence on commitment and well being in unique way according to personal character…

Developing Entrepreneurship In Small Enterprises – The Succession Process Supported By Apprenticeship Training As A Context For Learning

2008

Facies stacking and extinctions across the Triassic–Jurassic boundary in a peritidal succession from western Sicily

2017

An uppermost Triassic–lowermost Jurassic carbonate platform succession, which is 430 m thick, in northwestern Sicily is described with the aim to provide new data on the sedimentological and biological variations across the Triassic–Jurassic boundary in peritidal environments. The studied succession belonged to the rimmed carbonate shelf that developed during the upper Triassic along the margins of the Ionian Tethys. The peritidal sediments consist of metre-scale shallowing-upward cycles formed by subtidal, intertidal and supratidal facies. Three main informal units are differentiated along the section on the basis of the variations recorded by the subtidal facies. The lower and middle unit…

Formation processes at a high resolution Middle Paleolithic site: Cueva Antón (Murcia, Spain)

2013

Cueva Anton is a Middle Paleolithic rockshelter located in the valley of the River Mula (Murcia, Spain). The archeological investigation of the site, which began with salvage work in 1991, resumed in 2006 and is still ongoing, uncovered a succession spanning most of MIS 3 and MIS 4 (ca. 75–36 ka) and featuring a well preserved human occupation record. This paper presents the first information about site stratigraphy and site formation processes. Geoarcheological data collected in the field and through micromorphological observation show that the archeological succession at Cueva Anton is mainly composed of alluvial sediments, with thin intercalations of gravitational and slope material. The…

Säugetiere, Fisch-Otolithen, Ostracoden, Mollusken und Charophyten aus den Süßwasser- Schichten (Oligozän) von Wolfsheim im Mainzer Becken

2000

The Suswasser-Schichten (Freshwater Beds) (Oligocene) in the Mainz Basin are a paleontologically poorly studied formation. A succession of predominantly lacustrine marls from Wolfsheim can be attributed to the Suswasser-Schichten on basis of a palaeoecological and biostratigraphic analysis of its mammal teeth, fish otoliths, ostracods, mollusks, foraminifera and charophytes. The occurrence of the mammal speciesToeniodus aff.hexalophodus andIssiodoromys minor (primitive form) enables an attribution of the Suswasser-Schichten to the reference level MP 24 of the eurasiatic mammal biostratigraphic zonation. As the reference fauna of level MP 24 is believed to occur in a lithostratigraphically m…

Evaluation of a technical revegetation action performed on foredunes at Devesa de la Albufera, Valencia, Spain

2010

We have evaluated the level of restoration achieved by a technical revegetation action carried out on reconstructed foredunes at the Devesa de la Albufera and compared this level with that achieved by spontaneous succession. Foredunes 1, 3, 6 and 20 y old since revegetated (1, 3, 6 and 20 y, respectively) were considered as spatially separated stages representing a successional trend in the development of the restored plant community. Lower and similar levels of diversity (richness and H´ and Pielou´s indexes) and coverage, respectively, were found on dunes corresponding to the oldest stage of technical revegetation compared with that of the reference site. Diversity and coverage parameters…

Evaluation of different similarity indices as measures of succession in arthropod communities of the forest floor after clear-cutting.

1979

Communities of spiders (Araneae) and beetles (Coleoptera) living in the soil and litter of clear-cut areas were compared with those of intact forest stands. Sixteen different indices of similarity were tested on three sets of material: spiders and beetles examined during one year in three clear-cut areas felled 3, 6 and 9 years earlier, and spiders in one clear-cut area examined during 7 successive years after felling. Other sources of evidence showed that succession in the spider community was divergent for at least 7 years after felling. The indices that seemed to express the changes best were: (1) Kendall's rank correlation test, (2) the Bray-Curtis measure, (3) Renkonen's percentage sim…

Effects of forest regeneration on the structure of bird communities in northern Finland

1985

Breeding bird communities in five stages of secondary forest succession were studied in northeastern Finland in 1980–82. Three groups of communities were distinguished: open land, brush phase and forest communities, dominated by Motacilla alba and Oenanthe oenanthe, Phylloscopus trochilus and Anthus trivialis, Phylloscopus trochilus and Fringilla montifringilla, respectively. Pair density, number of species, biomass of adult birds and species diversity increased in the course of succession, none of these, however, monotonously. Average bird weight showed a decreasing trend although the variation was considerable. The degree of specialization in communities (measured by ratios derived from n…