Global warming is causing plant and animal species to alter their geographic ranges and the timing of key life events such as migrating, flowering, or laying eggs — a shift that could adversely impact biodiversity as well as ecosystems, a new government report has revealed.
The range and timing-related changes are occurring faster now that they were just a few years ago, report the authors of “Impacts of Climate Change on Biodiversity, Ecosystems, and Ecosystem Services,” a technical study on how climate change is affecting living organisms and their communities.
“These geographic range and timing changes are causing cascading effects that extend through ecosystems, bringing together species that haven’t previously interacted and creating mismatches between animals and their food sources,” Nancy Grimm, a scientist at Arizona State University and a lead author of the report, said in astatement Tuesday.
According to Grimm, those so-called mismatches could potentially hamper some species chances for survival. For example, she explains that if the insects required for migrating birds emerge before their predators arrive at their destination, it could spell trouble for that avian population. Furthermore, she notes that shorter winters and earlier thaws could mean that bark beetles and other, similar pests have more time to damage ecosystems, potentially impacting the availability of food, drinkable water, wood products, or other natural resources.
“The impact of climate change on ecosystems has important implications for people and communities,” added National Wildlife Foundation (NWF) climate scientist and lead author Amanda Staudt. “Shifting climate conditions are affecting valuable ecosystem services, such as the role that coastal habitats play in dampening storm surge or the ability of our forests to provide timber and help filter our drinking water.”
The report was compiled by representatives of more than 60 scientists affiliated with the federal government, academic institutions, and other organizations. It will be used as scientific input for the forthcoming third National Climate Assessment, which is due in 2013.
“Another key finding is the mounting evidence that population declines and increased extinction risks for some plant and animal species can be directly attributed to climate change,” officials from the US Geological Survey (USGS), one of the institutions involved in the research, explained. “The most vulnerable species are those already degraded by other human-caused stressors such as pollution or exploitation, unable to shift their geographic range or timing of key life events, or that have narrow environmental or ecological tolerance.”
“The report clearly indicates that as climate change continues to impact ecological systems, a net loss of global species’ diversity, as well as major shifts in the provision of ecosystem services, are quite likely,” said USGS scientist Michelle Staudinger, who is also a lead author of the report.
Staudinger added that climate change-related shifts in the number and geographic range of some species of marine fish have already been observed, and “will almost certainly continue, resulting in some local fisheries declining or disappearing while others may grow and become more valuable if fishing communities can find socially and economically viable ways to adapt to these changes.”
The report also concluded that a natural system’s ability to prevent or at least reduce harm caused by extreme amounts of precipitation can be hampered by changes in those weather events, including an increase in frequency and severity; that changes in soil freezing, snow cover, and other wintertime phenomenon can have serious, surprising effects on ecosystems; and that coastal habitat ecosystems are more susceptible than other areas to severe storms and rising sea levels.
“Seasonally snow-covered regions are especially susceptible to climate change because small precipitation or temperature shifts can cause large ecosystem changes,” the USGS explained. “Longer growing seasons andwarmer winters are already increasing the likelihood of pest outbreaks, leading to tree mortality and more intense, extensive fires. Decreased or unreliable snowfall for winter sports and recreation will likely cause high future economic losses.”
Regarding coast areas, they added that “the Atlantic and Gulf of Mexico coasts are most vulnerable to the loss of coastal protection services provided by wetlands and coral reefs. Along the Pacific coast, long-term dune erosion caused by increasing wave heights is projected to cause problems for communities and for recreational beach activities. However, other kinds of recreation will probably improve due to better weather, with the net effect being that visitors and tourism dollars will shift away from some communities in favor of others.”
The study affirmed that the development of strategies to adapt to climate change and the side-effects it creates will be essential to ensure the preservation of biodiversity and the protection of natural resources.
The authors also noted that ecological monitoring systems need to be enhanced, and that federal and state agencies need to improve communication and data-sharing policies in order to make sure that the effects of global warming are effectively monitored throughout the US.