Willoughby Marsh, located in the Niagara Falls region of Ontario, Canada, is a protected area recognized for its important role in conserving biodiversity. This report examines how climate change is already affecting the marsh and what is likely to happen in the coming decades under various global warming scenarios. The analysis draws on climate models and biodiversity projections for over 135,000 species, offering a detailed picture of changes in temperature, precipitation, land cover, and species survival.
Key Facts About Willoughby Marsh:
- The marsh is among the top 36% of the world’s non-marine protected areas for projected biodiversity resilience at 4°C of warming.
- From 2000 to 2010, the population in the area around the marsh increased by over 32,000 and is projected to reach nearly 600,000 by 2100, putting more pressure on the ecosystem.
- Land cover is changing: Between 1992 and 2020, broadleaved deciduous tree cover decreased by 7%, while areas with mixed natural vegetation and cropland increased by 5.3%.
Observed and Projected Climate Change:
- Temperatures are rising across all months. For example, the average high temperature in July increased from 26.2°C (1961-1990) to 26.5°C (1991-2020), and could rise by another 6.1°C if global warming reaches 4°C.
- Average monthly temperatures have already increased by 0.2 to 1.3°C depending on the month, and could rise by up to 6.3°C at 4°C global warming.
- Precipitation is also increasing, especially in winter and spring months. For instance, average January precipitation rose from 63.4 mm to 82.9 mm in recent decades, with projected increases up to 19.3 mm by 4°C warming.
- Both droughts and waterlogging events have become more frequent and severe, with drought months nearly doubling between 1961-1990 and 1986-2015.
Biodiversity Impacts – Animals, Birds, and Insects:
- Overall species richness is projected to drop from current levels to 86.3% at 1.5°C warming and only 59.5% at 4°C warming.
Animals (Chordata):
- Risk of local extinction for all animals rises from 5.8% at 1.5°C to 20.2% at 4°C.
- For mammals, local extinction risk increases from 6.7% at 1.5°C to 32.9% at 4°C.
- Amphibians face a risk rising from 8.3% to 34.4%.
- Reptiles, from 7.5% to 24.6%.
- Birds (Aves) are somewhat less sensitive, but still see risk increase from 5.4% to 17.6%.
Insects (Arthropoda):
- Overall, insect local extinction risk increases from 10.1% at 1.5°C to 38.1% at 4°C.
- Spiders: 19.7% to 52.4% risk.
- Bees: 6.3% to 28.9%.
- Butterflies: 16.3% to 45.3%.
- Flies are particularly vulnerable, with risk rising from 18.9% to 69.8% at 4°C.
Refugia and Conservation Challenges:
- At 1.5°C and 2°C warming, Willoughby Marsh is likely to remain a climatic refugium for most species, meaning it will stay suitable for at least 75% of species.
- Above 2°C, the number of refugia drops sharply, especially for sensitive groups like mosses, flies, and spiders.
Conclusions:
Willoughby Marsh is currently a relatively resilient protected area, but rising temperatures and increased human pressure pose significant threats to its ecosystems. The risk of local extinction for key animal groups increases significantly with higher warming, especially for insects and amphibians. The report stresses that conservation efforts must anticipate these changes using adaptive, climate-aware strategies, rather than relying on static protection alone.
References:
Price, J., Forstenhäusler, N., Graham, E., Osborn, T.J., & Warren, R. (2024). Report on the observed climate, projected climate, and projected biodiversity changes for Willoughby Marsh under differing levels of warming. Report of the Wallace Initiative.