Temperature niche composition change inside and outside protected areas under climate warming.

Area of Science:

• Ecology
• Climate Change Biology
• Conservation Biology

Background:

• Protected areas are crucial for biodiversity conservation but their efficacy under climate change is uncertain.
• Climate warming is altering species distributions and community composition globally.
• Understanding how protected areas influence these changes is vital for effective conservation strategies.

Purpose of the Study:

• To assess climate-driven shifts in bird community temperature niches within and outside protected areas in southern Canada.
• To test if protected areas harbor more cold-dwelling species and exhibit slower warming trends compared to unprotected areas.
• To quantify the impact of protection status on the rate of community temperature index change.

Main Methods:

• Utilized long-term (1997-2019) Breeding Bird Survey of Canada data.
• Calculated the Community Temperature Index (CTI) annually for bird communities inside and outside protected areas.
• Employed linear mixed-effect models to analyze temporal CTI changes and a jackknife approach to identify key species.

Main Results:

• Bird communities inside protected areas had a lower CTI (indicating more cold-dwelling species) than those outside.
• Contrary to hypotheses, CTI increased faster within protected areas than outside.
• Warm-dwelling species were the primary drivers of the increasing CTI in both protected and unprotected areas.

Conclusions:

• Protected areas currently offer some refuge for cold-dwelling species but are not immune to climate warming impacts.
• The rapid increase in CTI within protected areas suggests they may only temporarily delay the compositional shifts driven by climate change.
• Conservation strategies must adapt to account for the dynamic nature of species communities under a warming climate.