Climate Change in California. Part 1

the jains reserve near idlewild narrowly escaped an arson fire this fall here wild azaleas and wear lenin lilies bloom alongside a creek western bluebird split among ponderosa pines and nasty little wooden birdhouses by biologists inside video cameras record them twenty four seven the birds and the only media stars here scientists at the james reserve also spy on colonies of bacteria carpets of mars and even tree roots biologist mike allen of uc riverside says they're trying to get a better handle on how natural processes work and how the landscape might respond to climate change well we can get these general projections of global warming or how they actually feed down to the individual site an individual species is a question that we can't currently answer that in california by communities habitats are already under a certain amount of strauss stresses is probably an understatement there under a lot of pressure was just

simply the number of people and their need for housing and highways but in addition to that is the potential for climate change people have also altered the region's fire cycles igniting to many at lower elevations and suppressing naturally occurring fires higher up add drought and beatles and the result in the same bernardino national forest is about a million dead and dying trees while scientists can't predict exactly what will happen with global warming uc san diego climate researcher dan kammen says it's a pretty good bet california will turn substantially warmer during the next century for precipitation we really are very certain whether we're gonna get wetter drier or state practically the same i think one thing that one can say from the climate models is that we'll still have the bulk of our precipitation in the way in wintertime and we'll have a dry hot

summers it does look like the hot dry part of the system will be intensified but he were spared major precipitation changes warming could still adds stress to local ecosystems some scientists expect rising temperatures will increase the frequency and severity of fires in the american west hugh saturday is an ecologist with the us forest service scott of interactions are crates of faith that more prefer more even from a prefab but it's warmer in a wet feet in which means greater growth we have more graphic more shrub treat me put actually on moral leader growth which means when summer comes along it gets really really dry and the plumber october then you have even more fuel on the ground than we've got now think that's actually very very scary proposition mike allen of uc riverside says more carbon dioxide in the air is likely to exacerbate problems with invasive species the big concern is non native grasses which ignite and transport fire easily juliet the nitrogen that comes in as

our of our ocean year subsidizing that growth particularly in your grass is so either nitrogen or c o two would have an effect but it would be limited but you have the two of them together and their synergistic allan says more of the hillsides are likely to catch fire over and over again and if we shift from a thirty five to forty year fire cycle for example in coastal sage which is natural for the coastal sage that the vegetation to a three to five year regime which occurs under these grasses and it simply does not allow the time for shrubs to actually get established the ceilings get burned off to frequently to ever establish and many of things like birds on that catchers are dependent upon those shrubs the us forest service has tried to project how southern california forests might look in the future very different forest service biologist say abundant species like

ponderosa pine could decline less common species might thrive mike allen says people also rely on forests and shrub lands to store and purify water and to clean and cool the air and if there's one thing we've learned over the past twenty years it's the things don't just change gradually they feed back on each other and they get thresholds and then there's a dramatic change in our thresholds that's also why we have to be very careful with what we do to learn so he and other scientists will continue to pry into the private lives of swallows microbes and pine trees but my gallons aware that so often with ecology we don't fully understand the damage until it's done in idyllwild whole society all at nine point three kpcc