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Silva Fennica 1926-1997
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Articles by Hannu Saarenmaa

Category: Article

article id 5614, category Article
Mika Jääskelä, Kari Heliövaara, Mikko Peltonen, Hannu Saarenmaa. (1997). Comparison of protection methods of pine stacks against Tomicus piniperda. Silva Fennica vol. 31 no. 2 article id 5614. https://doi.org/10.14214/sf.a8515

Three most promising protection methods of pine pulp wood stacks against the attacks of Tomicus piniperda L. were compared. The methods were the covering of stacks by fibreglass-strengthened paper or twofold achrylene netting, removing the upper parts of stacks, and enhanced planning of the placement of the timber store using ARC/INFO GIS-software. T. piniperda was observed to strongly prefer the upper parts of the stacks: 90 % of the beetles occurred within 0.5 meters of the top of the stacks. Covering of the stacks decreased the attack density of T. piniperda, and the protection effect of covering was 80 %. Due to long transport distances and fragmentation of forest landscape the relocation of timber store was found to be an unsuitable method in the practical level. Also, taking into account the costs of the method, removing of the upper parts of stacks was considered to be the optimal solution.

  • Jääskelä, ORCID ID:E-mail:
  • Heliövaara, ORCID ID:E-mail:
  • Peltonen, ORCID ID:E-mail:
  • Saarenmaa, ORCID ID:E-mail:
article id 5479, category Article
Douglas K. Loh, Hannu Saarenmaa. (1992). Design of integrated forest resource information systems. Silva Fennica vol. 26 no. 2 article id 5479. https://doi.org/10.14214/sf.a15640

Managing forests and other natural resources requires merging of data and knowledge from many fields. Research efforts in many countries have simultaneously aimed at computer applications to help managing the large amounts of data involved and the complexities of decision making. This has invariably led to large integrated systems. An integrated system is software that consists of modules for various tasks in natural resource management, spatial analysis, simulation and optimization, diagnostic reasoning, levels, and communicating with the user.

The paper presents an overview of the need, levels and historical development of integrated systems. Newly emerged technologies, especially object-oriented programming and the X Window System with its associated environment have given new flexibility and transparency to the designs. The client-server architecture is found out as an ideal model for integrated systems. The paper describes an implementation of these ideas, the INFORMS system that supports the information needs of district level forest management planning.

The PDF includes an abstract in Finnish.

  • Loh, ORCID ID:E-mail:
  • Saarenmaa, ORCID ID:E-mail:
article id 5425, category Article
Hannu Saarenmaa. (1990). Frame- and rule-based knowledge representation in an expert system for integrated management of bark beetles. Silva Fennica vol. 24 no. 2 article id 5425. https://doi.org/10.14214/sf.a15579

Decision making in the forest protection involves diagnosing the pest, making predictions of the effects of the pest on forest, knowing the possible control tactics, and cost/benefit integration. To cope with all that, a generalist forest manager needs a tool like an expert system to support decisions.

This paper presents an expert system that approaches the goals of integrated pest management. With the systm, the user can make diagnosis and predictions of 12 North European bark beetles. Written in Common LISP and Flavors, the expert system has a combined frame- and rule-based knowledge representation. Frames are used to represent the hierarchy of insect taxonomy in diagnosis. Prediction is made with qualitative reasoning with rules. The interface engine applies both forward and backward chaining. The system has a graphical user interface that supports exploring the sensitivity of advice on input.

It is concluded that expert systems and artificial intelligence have high applicability everywhere in forestry where complicated decisions have to be made. Especially, an integrated pest management system in forestry is largely equivalent to a computerized decision-making aid.

The PDF includes an abstract in Finnish.

  • Saarenmaa, ORCID ID:E-mail:
article id 5003, category Article
Hannu Saarenmaa. (1978). Kaarnakuoriaisten (Col., Scolytidae) esiintyminen eräässä kanadanmajavan (Castor canadensis Kuhl) aiheuttaman tulvan seurauksena kuolleessa metsikössä. Silva Fennica vol. 12 no. 3 article id 5003. https://doi.org/10.14214/sf.a14857
English title: The occurrence of bark beetles (Col., Scolytidae) in a dead spruce stand flooded by beavers (Castor canadensis Kuhl.) .

 

The aim of the study was to determine which kinds of insects had infected the Norway spruce (Picea abies (L.) H. Karst.) in different stands killed by flooding caused by beavers (Castor canadensis Kuhl), and if there was any danger that they would subsequently cause damage in the surrounding forests. The effect of tree diameter and certain stand characteristics on the fauna of dead trees are discussed. The occurrence of different insect combinations and qualifications for their coexistence were studied.

Pityogenes chalcographus L., Trypodendron lineatum O., Hylurgops palliatus Gyll. and Dryocetes autographus Ratz. occurred most abundantly. 20 phloem or wood boring species were observed in 5 regular succession types. Secondary species occurred in a virgin stand while Ips typographus L. was found at the edge of a felling area. Owing to the flooding, species preferring moist conditions were abundant. In this case damages had not spread to the surrounding forests which, however, might be possible under certain conditions.

The PDF includes a summary in English.

  • Saarenmaa, ORCID ID:E-mail:

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