Articles containing the keyword 'forest healt'

A range of different indices are available for assessing the health of trees in forests. An even larger range can be used for the assessment of the health of forest ecosystems. Most studies made in connection with ”forest decline” and the impact of air pollution and other environmental stresses on forests have concentrated on the assessment of crown transparency and crown discoloration in individual trees. These are non-specific indicators which are now known to be sometimes of relatively little value when determining the health of a forest ecosystem. Numerous problems exist with both, and the standardisation of assessments between and even within countries has not been achieved. Consequently, studies claiming to compare ”defoliation” between different countries cannot be substantiated. The emphasis on crown transparency and crown discoloration has resulted in the neglect of a number of other indices that could be of considerable value. These include a variety of visual measures of crown condition and also several non-visual bioindicators. Some of these techniques are objective, reducing the present reliance on observed standardization. A large number of potential techniques are currently at the research stage and have yet to be adequately tested in field trials. This represent an area where a substantial amount of further research is required.

• Innes, E-mail: ji@mm.unknown

• Wulff, Swedish University of Agricultural Sciences, Department of Forest Resource Management, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: soren.wulff@slu.se
• Roberge, Swedish University of Agricultural Sciences, Department of Forest Resource Management, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: cornelia.roberge@slu.se
• Ringvall, Swedish University of Agricultural Sciences, Department of Forest Resource Management, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: anna.ringvall@slu.se
• Holm, Swedish University of Agricultural Sciences, Department of Forest Resource Management, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: soren.holm@slu.se
• Ståhl, Swedish University of Agricultural Sciences, Department of Forest Resource Management, Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: goran.stahl@slu.se

• Martín-García, Sustainable Forest Management Research Institute, University of Valladolid – INIA, Avenida de Madrid 57, 34004 Palencia, Spain, and Forestry Engineering, University of Extremadura, Plasencia, Spain E-mail: jorgemg@pvs.uva.es
• Espiga, Sustainable Forest Management Research Institute, University of Valladolid – INIA, Palencia, Spain E-mail: ee@nn.es
• Pando, Statistics and Operations Research Department, University of Valladolid, Spain E-mail: vp@nn.es
• Diez, Sustainable Forest Management Research Institute, University of Valladolid – INIA, Palencia, Spain E-mail: jjd@nn.es

Forests are affected by climate change in various ways. This includes abiotic factors such as droughts, but also biotic damage by pest insects. There are numerous examples from cases where pest insects have benefitted from longer growing seasons or from warmer summers. Similarly, new pest insects have been able to expand their range due to climatic conditions that have changed from hostile to tolerable. Such seems to be the case with the nun moth (Lymantria monacha), an important defoliator of coniferous trees in Europe. For centuries, the species has had massive outbreaks across Central-Europe, while it has been a rare inhabitant in Northern Europe. Recently, the nun moth population in Finland has not only expanded in range, but also grown more abundant. This research note describes the results from the first years (2018–2019) of a monitoring program that is being conducted with pheromone traps across central and southern Finland. So far, the northernmost individuals were trapped near the 64 N degrees. However, there were more southern locations where no moths were trapped. The species was present in every trapping site below the latitude of 62 N degrees. More importantly, at some sites the abundance of the nun moth suggested that local forest damage may already occur. Given the current climatic scenarios for Fennoscandia, it is likely that the nun moth populations will continue to grow, which is why systematic surveys on their abundance and range expansions will be topical.

• Melin, Natural Resources Institute Finland, Yliopistokatu 6b, FI-80100 Joensuu, Finland https://orcid.org/0000-0001-7290-9203 E-mail: markus.melin@luke.fi
• Viiri, Natural Resources Institute Finland, Yliopistokatu 6b, FI-80100 Joensuu, Finland; UPM-Kymmene Oyj, UPM Forest, Åkerlundinkatu 11 B, FI-33100 Tampere, Finland E-mail: heli.viiri@upm.com
• Tikkanen, University of Eastern Finland, School of Forest Sciences, Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: olli-pekka.tikkanen@uef.fi
• Elfving, Natural Resources Institute Finland, Yliopistokatu 6b, FI-80100 Joensuu, Finland; University of Oulu, Department of Biology, Pentti Kaiteran katu 1, FI-90014 Oulu, Finland E-mail: riku.elfving@gmail.com
• Neuvonen, University of Turku, Biodiversity Unit, Kevo Subarctic Research Institute, FI-20014 Turku, Finland E-mail: seppo.neuvonen@utu.fi