Ground floor vegetation assessment within the intensive (Level II) monitoring of forest ecosystems in Germany: chances and challenges

Abstract

As a part of the 'Intensive Forest Monitoring Programme' of ICP Forests, ground floor vegetation has been surveyed along with parameters of other relevant components of the forest ecosystems and their environment at 80 permanent plots all over Germany. Its floristic composition and their changes can therefore be linked to a wide variety of potentially influencing factors, scrutinising recent hypotheses on floristic changes, mainly soil eutrophication and acidification due to air pollutants. Results of a broad-scaled feasibility study are presented and critically discussed with regard to future in-depth evaluations. After an overview on the most abundant species, the syntaxonomic allocation of the plots is given. An ordination reveals a gradient from nutrient and base rich soils to poor acidic soils. Floristic dynamics are mainly aligned with the main axis, but conclusions about the medium-term development cannot be stated yet. Ordination and subsequent statistics are recommended to open up a wide field for explorative investigations. Indicator values for soil acidity and nutrient supply corroborate the main floristic gradient. Based on an empirical species-area relationship (SAR), species numbers for a common plot size of 400 m 2 were calculated. Basic relationships among different diversity measures and between diversity measures and basic stand and site-related parameters were elaborated. Recommendations focus on enhancements of the assessment of ground floor vegetation within the context of the Level II monitoring like annual sampling or harmonisation of the plot sizes.

Assessment of flora diversity in a minor river valley using ecological indicator values, Geographical Information Systems and Digital Elevation Models

“…from given soil properties [26,27,[40][41][42][43][44][45]. According to Lawesson et al [43], the wide success of the Ellenberg system is probably associated with the fact that for a majority of species autecological characteristics and life history in general are not too different throughout Europe.…”

“…Among these ecological indicator values, the soil reaction is a relatively frequent subject of studies [26,27,[41][42][43]45]. However, some authors have criticized Ellenberg's R scale.…”

“…DEM derivatives related to species occurrence [22] and vegetation diversity [23] are also analyzed. Multivariate canonical analyses are currently in common use for identifying repeatable patterns in species distribution in terms of environmental factors [9,22,[24][25][26][27][28].…”

The estimation of aboveground biomass and nutrient pools of understorey plants in closed Norway spruce forests and on clearcuts

“…Non-destructive estimation methods that use relationships between biomass and vegetation cover have been devised for several vegetation types (Siccama et al 1970;Röttgermann et al 2000;Muukkonen et al 2006), but do not regard nutrient pools. Thus, intensive monitoring programs such as the European Level-II-network (Schulze et al 2000;De Vries et al 2003;Seidling 2005) have so far considered understorey vegetation only in terms of its indicator quality and contribution to forest biodiversity.…”

Ground vegetation as an important factor in the biodiversity of forest ecosystems and its evaluation in regard to nitrogen deposition

“…Vegetation is a source of the primary production of ecosystem; it controls gas exchange with the atmosphere and plays an important role in the biocycles of both water and nutrients within the ecosystem. It is also an important indicator of the status of forest ecosystems for the relatively easy and inexpensive assessment of ground vegetation monitoring and constitutes an acknowledged basis for biodiversity assessment (Buriánek 1993;Neumann, Starlinger 2001;Petriccione 2002;Seidling 2005;Salemaa, Hamberg 2007). Knowledge of the autecology of many different species enables the interpretation of changes in vegetation in relation to corresponding changes in environmental factors.…”