Giving Species Space to Move
Giving Species Space to Move
One of the great unknowns in the climate change debate is the effect ofregional alterations on individual species. Connie Millar, a geneticist from thePacific Southwest Research Station, discusses the importance of allowing aspecies to move, even as space becomes more precious and fenced off.Astrobiology Magazine — Connie Millar studies responses of forests to climatechange, both dramatic and subtle. Summer research finds her near the crest ofthe Sierra Nevada and Great Basin ranges measuring the advance and retreat ofmountain meadows and snowfields or coring gnarled, weather-beaten pines for treerings to decipher high-elevation climate change.
A research geneticist with the Pacific Southwest Research Station since 1987,Millar joined with other station scientists to form the interdisciplinary SierraNevada Research Center (SNRC) in 2002. Within the SNRC,Millar’s research groupfocuses on climate as an ecosystem architect: how it affects forest structureand species composition.
With her collaborators, Millar also looks at how climate catalyzes andcombines with other natural agents of change such as fire, disease, insectinfestations, and flooding, as well as with human-related impacts such asgrazing, fire suppression,and timber harvest. Millar received her Ph.D. inGenetics and M.S. in Wildland Resources Science fromthe University ofCalifornia, Berkeley. She also holds a B.S. in Forest Science from theUniversity of Washington. Millar is a PEW scholar in Conservation and theEnvironment. Prior to her interest in climate change research, Millar focused onforest genetics, especially the way genes ebb and flow across landscapes overtime.She is a recognized expert in the evolutionary dynamics of pines. Millartalked with writer Anne M. Rosenthal as published orignally by the US ForestService, where Millar described species diversity and terrestrial conservation.
Q. Forest managers no longer see fire as a scourge to be prevented. Instead,theyview fire as an inevitable, natural process integral to forest management.Do you anticipate a paradigm shift of similar magnitude for climate change?
Yes in fact, the shift both in viewpoint and management approaches could beevengreater. Traditionally, forest managers have attributed changing conditionsin forests toreadily apparent natural processes like fire, insects, disease, andfloods. But often,climate change is the underlying reason for landscapealterations. Sometimes what is blamed on overgrazing, fire suppression, invasivespecies, or other human-related factors is also a result of climatechange.Today, managers are beginning to consider climate both natural andmodified by humans as the major cause of forest changes. This realization, orparadigm shift, will markedly change how forests are monitored and managed.
Q. With the importance of climate change coming to light, what shouldmanagers be thinking about?
Managers could consider whether treating secondary factors will besuccessful. If the goal is short-term mitigation, for example to preserve treesfor timber harvest, then fighting fire, insects, or disease is reasonable.Populations and places least sensitive toclimate change may often besuccessfully managed for resilience in the short run.
Sometimes the stated objective is to stop change that is, to preserve inperpetuity aspecies, population, or landscape the way it currently exists or torestore it to a former condition. However, attempting to preserve the past isfutile if the landscape is highlysensitive to climate change. In these cases,change may be inevitable, and resisting it could lead to abrupt and undesiredconsequences in the future. Forests established during pre-settlement times (the1800s) are poor models for restoration today; they are even worse models forforests adapted to future warming conditions. Pre-settlement forests developedin response to the harshest period of the Little Ice Age, which ended during thelate 19th century, and are generally not best adapted to the changing climatesof the present and future.
Forest transformations as a result of climate change may occur within a humanlife-time. To gain insight into what lies ahead, managers could look at howcomparable landscapes responded historically and combine this knowledge withinformation onpredicted climate change.
Q. How does this new outlook affect conservation of rare and endangeredspecies?
Over time plants and animals may cycle, as a result of climate change,between being rareand widespread. If populations are shrinking because climaticconditions are changing, aspecies may no longer survive well within its formerrange. Alternately, if climate is favorablein other parts of a species’ range,populations are likely to thrive and expand there. It sounds like species needspace to move.
The fossil record shows that species have often responded to climate changebyadjusting their ranges. They died out in some locations and pioneered others.By maximizing the size and diversity of management units and keeping land usesflexible,managers might make it possible for species to adjust to climate changeby moving.
Managers could also consider species introductions in areas where climatechange is encouraging habitat growth congenial to the species in question. Thesesites may not have been occupied by the species in the recent past, because thesite’s ecosystem was different. This should be done only after carefulassessment of the species’ history and potential effects of introducing aspecies to a new environment.