Theoretical and practical criteria for the selection of ecosystem monitoring plots in Swiss forests

Abstract

A great deal of attention has been paid to the selection of nature reserves. These are important from a conservation viewpoint but, for long-term evaluations, it is important to monitor ecosystems. The need for long-term monitoring plots has been recognized for some time in forest ecology. Of the natural ecosystems, forests are some of the most difficult to monitor because of the time-scales involved in the life-spans of the dominant organisms (100 → 1000 years). The selection of long-term forest ecosystem monitoring plots is a critical process involving decisions that need to remain valid for many years. Traditional sampling theory suggests that some form of systematic or random sampling may be appropriate, but this is usually inappropriate for the selection of ecosystem monitoring plots. Instead, the selection of plots more closely resembles some of the procedures that are used in the selection of nature reserves. In Switzerland, a monitoring programme has been established which uses a number of criteria for the selection of sites. These include site homogeneity, the abundance and sensitivity of the plant communities to change and the presence of pre-existing data series or monitoring equipment. In addition, the human factor is incorporated by selecting sites from throughout the country, with the willingness of the local forest managers to help with the project being an important factor influencing the final choice of plots. In contrast to most inventories, statistical representativeness is not a requirement for the programme, as the plots are treated as a series of case studies.

Microclimate in forests with varying leaf area index and soil moisture: potential implications for seedling establishment in a changing climate

“…We used meteorological and soil moisture data collected from 1998 to 2011 at 11 of 19 sites within the ongoing Swiss Long-term Forest Ecosystem Research Programme LWF (Innes 1995). Sites represent a wide range of forest ecosystems (Table 1) with respect to species composition, stand structure, altitude and climate and may therefore be representative for most forest ecosystems within central Europe and other temperate climate zones.…”

Microsite patterns of conifer seedling establishment and growth in a mixed stand in the southern Alps

“…and the slope is facing north with an average inclination of 35%. Within the stand, a 1.5-ha plot was studied that is part of the Swiss Long-Term Forest Ecosystem Research Programme (Innes, 1995). Climate data for the site were interpolated from data of nearby meteorological stations (Schweizerische Meteorologische Anstalt, 1984.…”

Measurement instability and temporal bias in chemical soil monitoring: sources and control measures

“…Due to this, it is suggested to consider the monitoring sites as a series of independent case studies (Innes 1995). Although there are efforts to select representative sites (e.g., Schroeder et al 2004), they are mainly based indirectly on landuse classes or at best on landscape but hardly on the measurement target (e.g., trace metals) itself.…”