US national parks have extremely early spring due to climate change

US national parks

Many US national parks are already at the extreme warm end of their historical temperature distributions.

Because of rapidly warming conditions, people need to enhance park resource management to adjust the timing of activities, such as treating invasive species, operating visitor facilities, and scheduling climate-related events (e.g., flower festivals and fall leaf-viewing).

In a recent study, researchers estimate the start of spring in US national parks based on climate models. They find that spring is extremely early in many parks this year, and this reflect the influence of climate change. The finding is published in Ecosphere.

Researchers from Natural Resource Stewardship and Science, USA National Phenology Network, University of Arizona, Cornell University, and University of Wisconsin–Milwaukee conducted the study.

In national parks, seasonal changes in vegetation, such as pollen, seed, and fruit production, are important drivers of ecological processes in parks, and phenology has thus been identified as a key indicator for park monitoring.

Phenology is the study of recurring phenomena, such as animal migration, especially as influenced by climatic conditions. It can show the most proximate biological responses to climate change.

In the study, researchers estimated the start of spring based on climatically modeled dates of first leaf and first bloom in plant species in 276 US natural parks.

The analysis evaluated the recent timing of spring onset (past 10–30 years) in each park relative to its historical range of variability across the past 112 years (1901–2012).

The result showed that among the 276 high latitude to subtropical parks, spring was advancing in approximately three-quarters of parks (76%), and 53% of parks were experiencing “extreme” early springs that exceed 95% of historical conditions.

This finding demonstrates how changes in climate seasonality are important for understanding ecological responses to climate change. Furthermore, it shows spatial variability in climate change requires different management methods.

Researchers suggest that the study can inform climate change adaptation challenges and opportunities in these parks. It also provides important information for resource management and planning in other protected areas.

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Citation: Weltzin J, et al. (2016). Climate change is advancing spring onset across the U.S. national park system. Ecosphere, published online. DOI: 10.1002/ecs2.1465.
Figure legend: This image is for illustrative purposes only.