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Semi-natural grasslands : the effects of cutting frequency on long-term changes of floristic Composition

100%

Kramberger B. , Kaligaric M.

Polish Journal of Ecology

2008

tom Vol. 56, nr 1

33-43

The objective of the experiment was to study the effects of different frequencies of cutting on long-term changes in the floristic composition of grassland, with an emphasis on the effects of very late cutting. Cutting at 2, 4, 6, 8, 10 and 12-weekly intervals was applied from 1995 to 2006 in a randomized block experiment on semi-natural grassland fertilized with 170 kg N, 40 kg P and 150 kg K ha[^-1]. The floristic composition of treatments was determined in May 1995, 1999, 2002 and 2006. In the final year (2006) the proportion of grasses in the dry matter of harvest was highest (77%) in the treatment with the least frequent cuts, and it was the highest obtained during the whole experiment. Under very frequent cuts, the proportion of grasses ranged only from 45 to 57%. Among legumes, only Trifolium repens L. was represented in high proportions in the dry matter of the harvest (from 19 to 25%) in 2006, but only in the treatments involving high cutting frequencies. The proportion of non-legume forbs in treatments involving low cutting frequency did not exceed other treatments; moreover, their proportion in the dry matter of the harvest in the treatment with the lowest cutting frequency decreased significantly to the lowest value (19%). The increased proportion of grasses in treatments with low cutting frequency indicates that a very late cut does not necessarily mean that forbs increase in the floristic composition, but can help grasses to retain their dominant and stable proportion in the semi-natural sward. Consequently when farmers are being provided with financial incentives with the aim of protecting diversity and the natural environment, it is worth recommending also a very late cutting, which includes natural reseeding to a greater extent. This can help to find a compromise between farmers' expectations of stable yield and quality forage, and the public interest in having grasslands of high biodiversity.

Reconstruction of delivery positions in the city of Celje, Slovenia

61%

Dragan D. , Vizinger T. , Intihar M. , Kramberger B. , Fosner M. , Prah K.

Transport Problems

2013

tom T. 8, z. 2

11--23

The paper addresses the problem of the reconstruction and allocation of delivery positions in the urban area. The aim is to achieve the optimal reorganization of urban freight transport in old town core in the municipality of Celje. Optimal allocation relies on optimization based on the Monte Carlo simulation and represents a first stage of a two-stage optimization approach to re-design the existing urban freight transport. The number of optimal delivery positions is required to be as minimal as possible, which can still assure a maximal service area within the prescribed radius, while keeping the minimal walking distances of delivery personnel between the nearest delivery position and the customer’s physical location. The main issues of the used heuristic allocation algorithm and the presentation of calculated results are provided. In the near future, the calculated delivery positions are going to be used for the purpose of physical implementation in order to improve the existing delivery transport.

Der Artikel behandelt das Problem der Wiederaufbau und Allokation von den Lieferung Positionen in einem städtischen Gebiet. Der Zweck ist die optimale Reorganisation des städtischen Güterverkehrs im alten Stadtkern in der Gemeinde Celje zu Erreichen. Die optimale Allokation basiert auf der Optimierung auf Basis der Monte-Carlo-Simulationen und stellt die erste Stufe einer zweistufigen Optimierung Verfahren zur Re-Designs der bestehenden städtischen Güterverkehrs. Die Anzahl der optimalen Lieferpositionen sollte so wenig wie möglich sein, aber trotzdem einen maximalen Service-Bereich innerhalb des vorgeschriebenen Radius gewährleisten. Gleichzeitig sollte die Entfernung zwischen den nächstgelegenen Lieferpositionen und Kunden Positionen kleinstmöglich sein. Die wichtigsten Themen des verwendeten Heuristic Zuordnungsalgorithmus und die Darstellung der berechneten Ergebnisse sind gegeben. Die Standorte der berechneten Lieferung Positionen werden zum Zwecke der physikalischen Implementierung genutzt, um den bestehenden Güterverkehr zu verbessern