Large-scale changes in community composition: determining land use and climate change signals

Area of Science:

• Ecology
• Environmental Science
• Ornithology

Background:

• Species extinction is driven by human land use and climate change, potentially reorganizing global ecosystems.
• Investigating the combined impacts of land use and climate change on ecological communities is rare.

Purpose of the Study:

• To quantify changes in Dutch breeding bird communities over 25 years.
• To evaluate the chronological sequence of the community temperature index (CTI) and community specialisation index (CSI).
• To assess the causal connection between climate, land use change, and bird community dynamics.

Main Methods:

• Time lag analysis was used to study Dutch breeding bird communities over 25 years.
• Community Temperature Index (CTI) was evaluated to reflect community response to temperature increase.
• Community Specialisation Index (CSI) was analyzed to reflect community response to land use change.

Main Results:

• Dutch breeding bird fauna showed distinct directional change, with significant shifts in both CTI and CSI.
• Habitat-specific responses were observed: farmland communities showed declining CTI and CSI, while forest and heath communities had increasing CTI and stable CSI.
• Coastal assemblages exhibited increased CTI and decreased CSI, whereas wetland birds showed rapid community change without significant CTI or CSI trends.

Conclusions:

• The interaction between climate and land use changes varies significantly across different habitats.
• Comparing trends in CSI and CTI provides a valuable method for tracking the impacts of climate and land use on biodiversity.
• Understanding these dynamics is crucial for conservation efforts amid ongoing environmental change.