In recent years, scientists have documented countless species shifting their ranges toward the poles, higher into the mountains, and deeper into the seas in response to the changing climate.
~ Sonia Shah
As our group of volunteers spread out across the buffer zone of the former nuclear weapons plant, we gathered native grass seeds to supplement commercial seed for revegetating the disturbed areas. Since the area had been restricted for security reasons, no grazing had impaired the native ecosystem. We had been shown the native species, grasses and forbs, and the various non-native invasives, and our collections were screened to make sure we hadn’t inadvertently gathered the wrong ones.
Taking a break and stretching my back from collecting, I looked east at the urban and exurban areas, clearly visible from our perch on the bench lands that run between the developed prairies and the tree-covered foothills of the Rockies. A few trees, mostly pinon and a few pines had managed to migrate down the hills onto the flat land, and the sprawl of houses and lawns and deciduous trees had encroached up the other side. Historically, this bench of land running parallel to the foothills had a thriving tallgrass ecosystem with scattered pine trees.
I know that climate change, whether human-caused or not, will make this spot drier (or wetter) and warmer (or colder) in the future, possibly in the next thirty years or so. I wondered whether our obsession with ‘native’ vegetation was misplaced. The local verticality of the environment had a significant effect on the ecosystems. Within a few miles the vegetation change that mirrored the geography was clearly visible.
Other places have recorded the effects of climate change on vegetation and animal life. Journalist Sonia Shah observes, “Deciduous shrubs of willow, birch, and alder have spread into the low Arctic tundra. Brightly colored tropical parrotfish and rabbitfish have arrived in the temperate kelp forests of the eastern Mediterranean. Elkhorn corals from the Caribbean now sprout in thickets off the coast of Galveston, Texas.”
Reporter Navin Singh Khadka has noted, “Vegetation is expanding at high altitudes in the Himalayas, including in the Everest region, new research has shown… The researchers found plant life in areas where vegetation was not previously known to grow.”
These changes usually happen over time, allowing for the natural shifting of ecozones, including plants and the animals that rely on them. In localized catastrophes, such as the California forest fires, adjacent untouched areas provide the seed stock for gradual restoration of the damaged areas. Cataclysmic events, like the recent (and ongoing) wildfires in Australia may require decades or centuries for the ecosystems to recover —if they ever do.
Out on our site, we discussed the merits of anticipating climate and vegetation changes. Maybe we should go into the foothills and collect Ponderosa pine cones and scatter them across the site to facilitate ‘natural’ changes. Would the currently ‘native’ seeds that we collected be the ones that prefer the changed climate? Restoration of disturbed lands has been carried out for decades, and in the U.S. is required for many activities. Usually, the restoration target is whatever the natural ecosystem would have been without the disturbance.
However, with climate change, what the ‘natural’ condition would be without the disturbance is unclear. Can we account for the changes we should expect? What timeline should we use? Change is constant in nature, but the timeline is not.
One thing we do know is that some likely changes will have an effect on us. Shah says, “The trend is expected to continue as the climate crisis deepens, with species that societies rely upon for a wide range of economic, cultural, and recreational value shifting their ranges to survive. ‘The entire trajectory of natural capital, from aesthetic to economic,’ says University of Florida wildlife ecologist Brett Scheffers, ‘is going to be moving.’”
And it’s not just natural systems. Food production, disease occurrence, and habitable zones are all expected to change, and local and national economies will be disrupted and may be threatened.
We need to pay attention, and do what we can to anticipate the coming changes. You’re never going to weather the storm by ignoring it.
Sonia Shah, Native Species or Invasive? The Distinction Blurs as the World Warms, 1/14/20, YaleEnvironment360
Navin Singh Khadka, Plant Life ‘Expanding Over The Himalayas’, 1/10/20, BBC World Service
Steve Tarlton, Crystal Ball, 1/16/20, Writes of Nature
Steve Tarlton, Is Climate Change Contagious?, 10/31/19, Writes of Nature