Photos: Metla/Erkki Oksanen, Kari Heliövaara

Species monitoring

Aims

In the short term, landscape-scale application of different management models may not significantly affect species assemblages. Initially, the study stands represent regular managed forest. The nature of changes during the first few years following logging mostly depends on the treatment applied at the stand level, and the pre-harvest assemblage composition. At the landscape scale, on the other hand, effects of management may not be detectable earlier than a few decades post harvest.

Evaluations of particular harvesting methods at the stand level may appear important if the treatments applied differ from those (1) studied earlier, or (2) used in routine management. For example, effects of selective, gap and partial felling on species assemblages are poorly understood. Moreover, successful monitoring of stand- and landscape-level treatments requires sufficient information on species assemblage composition prior to harvest.

At the initiation phase of this project (the first five years), the goal is to collect baseline data for long-term monitoring of species assemblages. Simultaneously, the effects of different harvesting methods on certain taxa are monitored. Of particular interest are the effects of the volume of harvested and retained live and dead trees, and the gap size used for stand regeneration.

Sampling protocols

Birds, beetles, vascular plants, polypores and dead wood will be inventoried during 2009-12. The spatial scale for birds is the landscape level, whereas for the other taxa and dead wood it is the stand level. After the first harvesting cycle, species monitoring will continue at the pre-harvest sites for three years and later on, depending on the rate of observed change, in 2-3 years and longer intervals. Forests in the Isojärvi area are dominated by Norway spruce, whereas in Ruunaa the forests are mostly Scots pine dominated. The effects of treatments on species assemblages will possibly greatly differ between spruce- (Isojärvi) and pine-dominated (Ruunaa) forests.

Birds will be inventoried using techniques with which a reasonable coverage of the study blocks will be achieved. Within each block, one 3-km long transect-count route and 16 point-count stations 200 m apart will be established. These will be inventoried 1-2 times between mid-May and mid-June each year. For full descriptions of methods, see http://www.luomus.fi/seurannat/ (currently in Finnish only) or contact the project researchers. Each study area thus contains six transects and (6 x 16) 96 point-count stations. Additional data from surrounding managed forests and protected areas will be obtained through the project's partner organizations, Metsähallitus and the Finnish Museum of Natural History.

For inventorying the other taxa, a sufficient number of study plots will be established into maturing and mature stands for long-term monitoring. In the Isojärvi study area, for example, a total of 15 cut-blocks were selected within the study area, all representing Oxalis-Myrtillus or Myrtillus type, maturing or mature, spruce forest. Three additional stands of spruce-dominated forest were selected from protected areas not subject to harvesting, and another three stands subject to clear-cutting from outside the Isojärvi area. Altogether species monitoring was initiated in 21 stands. Within this selection, harvesting intensity varies between untreated (0% of trees removed) and clear-cut (over 95% of trees removed) stands.

To collect beetles, flight-intercept window traps will be used. A total of ten traps will be set within approx. one-hectare core area within each study stand. Before harvesting the exact locations of the to-be-harvested gaps need not be known because these traps randomly capture beetles flying in these forests. However, after harvesting half of the traps (5/stand) will be placed into harvested and half (5/stand) will be placed into unharvested sections of each study stand. This way the traps will inform us about the "average" species composition, assemblage changes in gaps of different sizes, and the resistance of assemblage in unharvested sections toward varying harvesting intensity.

Vascular plants will be monitored by establishing two plant-inventory plots into each study stand. The other plot will be placed into a to-be-harvested gap, and the other into the retention section. Vegetation inventory protocol will follow that used in the permanent vegetation-monitoring plots of the National Forest Inventory program. An inventory plot consists of an r = 11.28 m (400 m2) circular area in which four systematically-placed 2-m2 plant-cover sub-plots will be established. For each sub-plot, species-specific percent cover of each bottom- and field-layer plant and moss species will be recorded. A species list of vascular plants of the whole 400-m2 plot will also be recorded, but without percent covers.

For polypore monitoring, 100 m x 20 m (0.2 ha) strips, faced to a randomly-selected direction, will be established into each study stand. From these strips, all pieces of dead wood with >5 cm in diameter and 1.3 m in length, stumps, and polypores growing on these, will be inventoried. The rest of the study stand will be inventoried for pieces of dead wood with diameter >15 cm and length >1.3 m, along with polypores growing on these. Because the study stands vary from ca. 1 to ca. 10 ha, an approx. 2-ha core area only will be inventoried in the largest stands. Polypore inventories will be done during September-November.

All very large, >15 cm in diameter, pieces of dead wood will be numbered and mapped using a hand-held GPS unit. This way dead wood originating before and after harvesting can be found and distinguished, and the polypore fauna of individual dead trees can be monitored after logging.

An example on the species monitoring setup, in this case on a gap cutting:

Figure 1A: pre-harvest	Figure 1B: post-harvest
1A: Gap cutting, pre-harvest sampling in 2009. Blue circles – vegetation plots; red crosses – window traps; orange rectangulars – polypore plots	1B: Gap cutting, post-harvest sampling in 2010. Blue circles – vegetation plots; red crosses – window traps; orange rectangulars – polypore plots