Butterfly community shifts over two centuries.

Area of Science:

• Community ecology
• Long-term ecological studies
• Biodiversity research

Background:

• Environmental changes impact species distribution and community composition.
• Long-term ecological data are crucial for understanding temporal shifts.
• Butterfly and burnet moth communities are sensitive indicators of environmental health.

Purpose of the Study:

• To analyze changes in species composition of a southeastern German butterfly and burnet moth community over nearly two centuries (1840-2013).
• To assess the impact of environmental changes on habitat specialists versus generalists.
• To identify trends in species loss and community similarity over time.

Main Methods:

• Analysis of historical species occurrence data from 1840-2013.
• Classification of species based on ecological tolerance and habitat specialization.
• Correlation of species composition changes with climate data (temperature, precipitation) and habitat factors.

Main Results:

• Species richness declined from 117 in 1840 to 71 in 2013.
• The proportion of habitat specialists decreased, while habitat generalists increased.
• Species with restricted dispersal and those requiring nutrient-poor soils experienced significant losses.

Conclusions:

• Long-term environmental changes, potentially including climate change and nitrogen deposition, have altered community composition.
• There is a decreasing similarity in species composition between decades, indicating ongoing shifts.
• Conservation strategies are essential, especially for threatened and protected species experiencing declines.