Protected area effectiveness decreases for butterfly diversity under climate change in Hong Kong

Background/Question/Methods

Uncertainty exists whether static protected areas designed to protect biodiversity under current conditions will continue to meet conservation goals if climate change causes community or ecosystem shifts. Previous research on this subject has proven equivocal with some studies finding that protected areas fail conservation objectives and others finding that objectives are largely met. However, limitations in the present literature are apparent. Seldom do these studies focus on protected area networks in the Asian tropics and most work at relatively large scales (10~100km). Using butterflies as target species along with species distribution modeling, we evaluated the conservation effectiveness of protected areas in Hong Kong at a fine scale (1 km) and projected how the ability to protect biodiversity would change under different climate change scenarios. Hong Kong has a high coverage of protected areas at 40% of the administrative region making it a key test case for examining the effectiveness of protected areas under global warming.

Results/Conclusions

In a gap analysis, we found that 3.3% of butterfly species at present are considered to be under represented and that 13.3% of butterfly diversity hotspots are protected. Under climate change, 8.8% to 40.1% of current diversity is projected to be lost depending on CO2 emissions and global circulation model scenarios. Additionally, we found that the proportion of butterflies under-represented by the protected areas would increase by 0.3-7.2%. The number of species exhibiting very restricted distributions would increase by 9.6-25.5%. Although a higher percentage (30.4-86.7% increase) of diversity hotspots would also be protected under climate change, proportionally those hotspots do not hold as many species as present conditions. Furthermore, we found that the differentiation between hotspots and non-hotspots under climate change was diminished. These results indicate that under climate change, protected areas may not serve as entirely sufficient strategies for conservation. Our results also emphasize the importance of setting multiple conservation targets based on prioritization schemes to evaluate biodiversity threats and the necessity of mitigation plans under a warming climate.