Evaluating macrolichens and environmental variables as predictors of the diversity of epiphytic microlichens

In contrast to the frequently assessed macrolichens, microlichens are rarely considered in biodiversity assessments despite their high species richness. Microlichens require generally a higher species identification effort than macrolichens. Thus, microlichens are more expensive to assess. Here we evaluate if macrolichen richness can be used as an indicator of total and threatened microlichen richness. Furthermore, we tested if different sets of environmental variables (modelled climatic variables, forest structure, altitude, etc.) improve the regression models based on macrolichens only or even replace the macrolichens as predictors. Multiple linear regressions were used to model species richness of microlichens, and Poisson regressions for threatened microlichens. On 237 forest plots (200 m2) distributed randomly across Switzerland, 77 macrolichens and 219 microlichens occurred. Macrolichen richness was positively related to the richness of microlichens (=0·27) and, in combination with threatened macrolichens as an additional predictor, also to the number of threatened microlichens (=0·14). Environmental variables alone and in different combinations explained between 0·20 and 0·41 () of the total variation of microlichen richness, and between 0·09 and 0·29 () of the total variation of threatened microlichen richness. All models based on environmental variables were considerably improved when macrolichens were included. Furthermore, macrolichen richness turned out to be the most important variable in explaining species richness of all, as well as threatened microlichens. The best models for total microlichen richness reached a of 0·56. Threatened microlichens were more difficult to model with the best model reaching a of 0·29. We conclude that in biodiversity assessments with scarce resources, lichen sampling could be focused on the better known macrolichens, at least in many temperate lowland and mountain forests. In combination with environmental variables, reliable predictions of microlichen richness can be expected. If the focus is on threatened microlichens, however, models were not reliable and specialized taxonomists are necessary to assess these species in the fiel

Predicting the potential spatial distributions of epiphytic lichen species at the landscape scale

The potential spatial distributions of six epiphytic lichen species were assessed in Switzerland (41 000 km2) as a function of various key climatic drivers and forest types using logistic regression models. Cetrelia cetrarioides is ‘near threatened', Lobaria pulmonaria is ‘vulnerable', and Graphis scripta, Hypogymnia physodes, Lecanora cadubriae, Letharia vulpina are not endangered according to the Red List assessment based on IUCN criteria. Lichen presence and absence were derived from the SwissLichens database that contains spatially explicit information on both species presence and absence. The spatial lichen niches are predicted with R2 values between 0·5 and 0·75 and AUC values between 0·63 and 0·94. Model evaluation shows that the models perform well. Lichenologists reviewed the spatial predictions of lichen species on the basis of their expert knowledge and concluded that parsimonious regression models may suffice for successful prediction of the potential spatial niche distributions of epiphytic lichen specie

Prediction of lichen diversity in an UNESCO biosphere reserve - correlation of high resolution remote sensing data with field samples

The present study focuses on developing models to predict lichen species richness in a UNESCO Biosphere Reserve of the Swiss Pre-Alps following a gradient of land-use intensity combining remote sensing data and regression models. The predictive power of the models and the obtained r ranging from 0.5 for lichens on soil to 0.8 for lichens on trees can be regarded as satisfactory to good, respectively. The study revealed that a combination of airborne and spaceborne remote sensing data produced a variety of ecological meaningful variable

Evaluating macrolichens and environmental variables as predictors of the diversity of epiphytic microlichens

ISSN:0024-2829ISSN:1096-113

The impact of changing agricultural policies on jointly used rough pastures in the Bavarian Pre-Alps - an economic and ecological scenario approach

The following paper assesses the impact of different policy options on the land use and associated biodiversity values of jointly organized low intensity grazing systems (‘Allmende’) in Southern Bavaria. We use an integrated economic and ecological modelling approach to compare the results of the scenarios with a reference situation that reflects the Common Agricultural Policy prior to the Fischler Reform. The economic sub model is based on single farms which alter their land use in response to economic stimuli. Within the economic part, key factors like the farm’s endowment with machinery, quota and buildings but also the farmer’s attitude are regarded. Within the rule based ecological sub model we analyze three main parameters: (a) protected habitats according to the EC Habitats Directive, (b) biodiversity for selected taxonomic groups (plants, lichens, ground beetles) and (c) habitat quality of selected target species (plants, butterflies). An overall evaluation of the scenarios leads to the conclusion that the impact of the Fischler reform will be fairly limited in the study area, since at the observed level of intensity the lower product prices will be compensated by higher direct payments. If all payments were strictly targeted to agri-environmental measures and set to a level which guarantees a low input management of the grass land, the overall public expenses could be reduced by approx. 100 to 200 € ha-1. In addition this setting will provide additional habitats for the target species. However, the number of agricultural employment opportunities and the agricultural value added decline severely. Regarding all indicators but the extent of protected habitats and the public costs, a scenario of complete market liberalization performs the worst

The impact of changing agricultural policies on jointly used rough pastures in the Bavarian Pre-Alps: An economic and ecological scenario approach

The paper assesses the impact of different policy options on the land use and associated biodiversity values of jointly organised low-intensity grazing systems ('Allmende') in Bavaria. We use an integrated economic and ecological modelling approach to compare three scenarios with the situation in 2003/05. We base the economic sub-model on single farms, which alter their land use in response to economic stimuli. Within the economic part, factors like the farm's endowment with machinery and quota are regarded. Within the rule-based ecological sub-model we analyse: area of protected habitats according to the EC Habitats Directive; biodiversity for selected taxonomic groups and habitat quality for different target species. An overall evaluation of the scenarios indicates that decoupling has a limited effect, because higher direct payments compensate the effect of lower product prices. If all payments are strictly targeted to agri-environmental measures and set to a level which guarantees a low-input management of the grassland, the public costs could be reduced and additional habitats for the target species could be provided. Regarding all indicators but the extent of protected habitats and the public costs, a scenario with a cessation of public payments and market liberalisation performs the worst.Agriculture CAP Decoupling Biodiversity EC Habitats Directive Agent-based modelling