Outtakes: Whitebark pine also provides a large, nutritious seed for a few birds and mammals – in particular grizzly and black bears.

Now, whitebark pine is important, and a source of concern for many managers and biologists because it provides a number of services to us, for example it provides very large, nutritious seed that are desired by a number of birds and small mammals. And, more importantly, the seeds are actually an important food source for grizzly bears and black bears, particularly in the greater Yellowstone, but historically pretty much in the Rocky Mountains and the inner mountain region.

*** It’s very clear that within a decade, whitebark pine, as a forest component, is going to be virtually gone. And with that, the seed source, and the potential for nutcrackers to regenerate whitebark pine. So there is considerable pressure for us to start thinking about what it is that we can do to restore whitebark pine communities. ***

*** So, we may be faced with truly a North American, continent-wide epidemic of this blister rust disease. ***

*** Ultimately, these individuals are going to be key to a worldwide restoration program. Ultimately, we can’t stop whitepine blister rust. We may be able to put fire back on the landscape through a variety of techniques, particularly in areas where fire will not be allowed to burn on it’s own. But blister rust is still there. And ultimately, we’ll render these other actions useless unless there’s a seed source. And so, we may need to step and do the planting on our own. We may have to step in with a very hands-on approach to managing whitebark pine. ***

*** Now, since we have some restoration tools in our arsenal, to make the idea of incorporating whitepine restoration strategies in National Forest plans. This is a big undertaking. This also applies to the other five-needled white pines that we’ve been talking about. This is a big undertaking, because a strategy would need to be written into each National Forest plan, each forest that has five-needled white pines. ***

*** And it’s a commitment that National Forests, and National Park Service is going to need to make, in order to keep white bark pine and its ecosystem services, and its services to wildlife, including the grizzly bear, on the landscape, and to maintain the last biodiversity maintained by all our white pines in North America. There has to be a commitment to restoration. ***

Diana Tomback
Professor of Biology
University of Colorado

98% of whitebark pine lives in wilderness areas.

This is the issue of, why should we be concerned about a pine species. There are a number of reasons why we’re concerned about whitebark pine. First of all, whitebark pine is an important high-elevation pine through the Western United States. As a matter of fact, it’s present in every high elevation national park except one. And it’s present in many national forests and wilderness areas particularly in the Northern Rockies and the Northwest. The range of whitebark pine extends into Canada, along the coast ranges and the Rocky Mountains and down into the United States, through the coast ranges, the Cascades, and into the Sierra Nevada. And it’s distribution continues along the Rocky Mountains, as far south as about northwestern Wyoming. And where it occurs, it forms high-elevation communities in the sub-alpine. Now, whitebark pine is important, and a source of concern for many managers and biologists because it provides a number of services to us, for example it provides very large, nutritious seed that are desired by a number of birds and small mammals. And, more importantly, the seeds are actually an important food source for grizzly bears and black bears, particularly in the greater Yellowstone, but historically pretty much in the Rocky Mountains and the inner mountain region. We are worried about a decline in whitebark, and I’ll address that in just a moment, and the possibility of the loss of a major food source for bears. The other services that whitebark pine provides is, because it is a high-elevation species, and it grows pretty much at the upper limits of forests, it is the last species that can tolerate the stressful environment, it does a really good job of preventing soil erosion, it’s roots hold down the soil. It’s very tolerant of harsh, windy sites, so it is often our last conifers at the harshest, highest elevations. It can protract snowmelt. It forms canopies at these high elevations and shades the snow, which means that snow melt-off is a little more regular. You don’t get a flush of melt-off, which does impact us down in the valleys, where people are. We prefer having slow, dependable melt-off rather than flushes of it. Whitebark pine is an unusual pine in that it is rugged looking, it is shrubby, it’s not your typical triangular shaped conifer. It has a very rugged, windblown appearance. It’s top, or canopies we call it technically, is somewhat rounded, or squared off at the top. And it s very picturesque. And a lot of skiers, backpackers, and hikers associate the ruggedness of the whitebark pine communities with arriving at the limits of the forest. I think there is and aesthetic compound here that’s very important to us.

One main concern – now of course we haven’t talked about why we’re worried about whitebark pine at this point – let me mention that whitebark pine is considered to form critical habitat for the threatened grizzly bear population in the greater Yellowstone. I’ve already mentioned that bears will feed on it’s large seeds prior to hibernation – and let me elaborate on that because it’s a fascinating relationship. Squirrels – pine squirrels – cut cones each summer and into the fall, and they pile these cones into storage areas called mittons. And they live off the cones in these mittons throughout the winter. And grizzly bears have learned that squirrels do that. And they will actually roam through the forest when a whitebark pine cone crop is produced, which is every ~ 3 years or so. And they will look for these mittons, or hordes that the squirrels make. And when they find them, they will eat the seeds out of the cones. They’ll dig up the cones and actually crunch into them, and, very adeptly, as described by my colleague “Kate Kendall”:http://www.nrmsc.usgs.gov/research/whitebar.htm, they separate the woody cone material from the seed material, so they’re not ingesting that fiber. And they do a very good job of getting nutrition from these cones. And it’s my understanding that occasionally, if there’s an angry squirrel that’s near enough, they’ll grab the squirrel as well. But the squirrels use these mittons, and the bears have actually learned, historically, which squirrels are good at gathering a lot of cones and they’ll return to the same home ranges year after year. The bears will eat these seeds prior to hibernation, as I mentioned. Every once in a while, perhaps twice in a decade, whitebark pine will produce a huge cone crop. And the squirrels will not finish eating all the seeds from their cones by the following spring. And the bears have learned to return to the mittons after hibernation and continue feeding on these seeds. Research by Dave Matson and his colleagues shows very clearly that in years when cones are available to grizzly bears in particular, their production of cubs is greater. In other words, having a nutritious food source improves the health of the parents, healthier cubs are produced, and the survival of the cubs is enhanced. In years with whitebark pine cone crops, they actually have a population of grizzly bears that’s increasing, and that’s very important. In terms of other aspects of whitebark pine that are interesting and unique – whitebark pine seeds are, as I mentioned, are large and nutritious. They’re also heavy, and they do not bear a woody seed wing, which most pines, and other conifers bear. And it’s the woody seed wing that will actually allow the wind to blow a seed out of the cone and disperse the seed away from the tree. Well, whitebark pine is different, because, number one, the cones don’t open. They are what we call technically “indehiscent”:http://aggie-horticulture.tamu.edu/syllabi/206/htmlpages/hortdefn.html#Indehiscent – non-opening cones. And, secondly, the seeds do not have this seed wing. They apparently have no mechanism by which they can disperse them. They can’t get out of the cone, and even if they could, they’re not going to go anywhere – mostly plummet, like a rock to the ground. This is where a bird called the Clark’s nutcracker comes in. The Clark’s nutcracker is in family “Corvidae”:http://animaldiversity.ummz.umich.edu/accounts/nucifraga/n._columbiana$narrative.html, which is the same big family that crows, and jays, and magpies, and ravens belong to. The nutcracker is a very specialized bird of this family, in that it has adapted to a diet of fresh and stirred pine seeds. The nutcracker has a long bill that is very sturdy, and it has a sharp point at the end. When cones are produced, the nutcracker will land on a cone, and use this bill, or beak, to dig into the woody cone material, and the bird will rip the cone apart from the top down, accessing the seeds, and it will then remove the seeds, and place them in a throat pouch, and then fly off with the seeds. The birds will store little groups of seeds, called caches, in small holes in the ground. They will then cover the seeds up with dirt, and then after they’ve left, you honestly can’t tell that the bird has buried seeds there. The birds know they’re there. And actually have another adaptation for this interaction, which is a highly specialized spatial memory. Studies have show, both laboratory and field work, that the Clark’s Nutcracker remember where they have placed each of these seed caches, and a single individual may bring anywhere from 30,000, to 100,000 whitebark pine seeds, given a good cone crop year. They come back when other foods are scarce, and they dig these caches up, they feed the young in the nest almost exclusively from these whitebark pine seed caches. And if they don’t get around, and they usually don’t get around, to retrieving all these caches before snow melt-off in the spring and summer rains the caches of seeds will germinate. And so the bird is the primary dispenser of whitebark pine. This is a relationship that has been going on for tens of thousands of years, perhaps millions of years. So whitebark pine is unique from that standpoint. Now the nutcracker actually disperses the seeds of some other western pines, including windy pine and two pinyon pines. It contributes to seed dispersal of these other pines. But its relationship to whitebark pine is perhaps tighter in that other animals have a very tough time getting the seeds out of the cone. The nutcracker is the major species with access to these cones, and thus the primary seed dispenser.

Another thing is that, whitebark pine does a good job at holding the snow – it provides some avalanche protection for these whole mountain areas, so that’s very important for, say, ski areas and areas that are used by people recreationally. So the loss of whitebark pine has a number of complications. Just to summarize – whitebark pine then is an important wildlife food source, not just for bears and nutcrackers, but a whole variety of seed eating birds and small mammals. It provides some hydrological protection. In other words it’s protracting snowmelt. It’s preventing erosion at the highest elevations. It enables forests to go up higher, because spruce and fir and hemlock, which are the other species that tend to occur at these high elevations cannot tolerate sites as wind-blown and as stressful as whitebark pine can. It does very well on droughty sights. So what we have is a number of ecosystem services provided by whitebark pine. And I don’t think we can diminish the importance of the aesthetic component. Whitebark pine is inspirational. It is a tree that a lot of people have probably stopped and camped under, or eaten their lunch under as well.

The “distribution”:http://www.forestworld.com/public/silvics/silvics_frames.html of whitebark pine is western North America. It’s found in both Canada and the United States. Specifically, it has a two-part distribution. It’s found in the coastal ranges of Canada, at the higher elevations, down through the coastal cascade complex of the United States and then into the Sierra Nevada, pretty much down to 2/3 the length of the Sierra. Whitebark pine is also found on some of the higher ranges of the Great Basin. And then we have the second part of its distribution, which is the Rocky Mountains. Whitebark pine ranges from about 55 degrees latitude through the Rockies, down through the Canadian Rockies, into the northern Rockies of the United States, as far south as the greater Yellowstone area. The southern and easternmost extensions of whitebark pine forests are the Salt River range, the Wind River ranges of Wyoming. Now, elevationally, whitebark pine is a species of the upper sub-alpine. And, of course, the sub-alpine elevation species varies depending on the latitudes you’re at, so I’m not going to give you specific elevations, but I’ll tell you that in the Sierra Nevada, It comes in at roughly 9000 feet, and farther north, say in the Northern Rockies of the United States, it’s been around 5000-6000 feet, and that depend on the local area. And then, as you go farther north, it’s coming in at lower and lower elevations. It also changes in it’s forest types. In the Sierra Nevada, whitebark pine communities are fairly open, and they’re fairly mixed in with red fir and mountain hemlock. It depends on where in the Sierra Nevada we’re talking. And there – whitebark pine communities are self-replacing – they don’t depend on fire to a great degree. However, as you go north, into Oregon and Washington, particularly in the Northern Rockies, whitebark pine becomes more fire-dependent. The Northern Rockies of the United States, in the lower Upper sub-Alpine, whitebark pine communities are in fact fire dependent. They depend on fire, periodic fire, for replacement. In the absence of fire, whitebark pine communities give way to shade tolerant conifer communities, such as sub-alpine fir and Engelman spruce. Their fire return intervals vary, depending on where you go, and the fire severity varies as well, depending on the forest structure. Some of these whitebark pine forests depend on mixed severity fires, and some of them depend on stand-replacing fires. For example, in the greater Yellowstone, you probably see both kinds of fire regimes, mixed severity and stand replacing. Mixed severity means you can have fires of varying intensity, often-low intensity coming. And what they do is that they clean out some of the more vulnerable shade-tolerant species, particularly sub-alpine fir that forms and burns very easily. Which opens up areas for whitebark pine regeneration and whitebark pine growth and keeps it on the landscape. In the absence of fire, we lose whitebark pine, and that is one of the issues that I will be talking about.

The other forest species that occur with whitebark pine vary, depending on where you are geographically. As you go up into Canada, the farther north you go, the patchier whitebark pine becomes. As you get to the northern limits of whitebark pine, it becomes a lot patchier. You’ve got small stands of trees. In terms of the dependence on fire, when you have fire come into an area, two things are happening. One, you may be burning whitebark pine, but you’re also burning its competitors. Whitebark pine tends to be fairly tolerant as a mature tree. So there’s a slightly greater chance that some mature whitebark pine might survive fire. But in stand replacing fire situations, such as the Yellowstone fires of 1998 that’s really quite rare. Where you have created a burned area, you have created good feed-storing habitat for Clark’s nutcracker. They seem to be attracted to open areas, whether these are just open forests, or burned areas, nutcrackers seem to put a very high proportion of their caches in these areas. So nutcrackers will actually start a new generation of whitebark pine after fire. This is the historical relationship. Fire comes through. Nutcrackers will cache seeds from unburned areas. As soon as a cone crop is produced, nutcrackers will put seeds in the ground, and you will see regeneration within a year or two after that time period, generally. Certainly, conditions might be so harsh that it might take a little bit longer. Interestingly, whitebark pine is considered to be a pioneering conifer, which means it is the first in after fire. It certainly comes in as early as seeds are produced. This doesn’t mean that some fir, spruce, and lodgepole pine and some other conifers might have some seedlings started. Whitebark pine seedlings appear very robust. They seem tolerant of stressful sights. If you look at the seedling, the seedling itself is fairly thick stemmed and hearty. And so whitebark pine actually can get a toehold under harsh conditions. I had a long-term study at Yellowstone National Park where some colleagues and I have actually been following whitebark pine regeneration since the 1988 fires. And we’ve been watching forest development and whitebark pine to be sure was at the beginning of forest succession. And it contributes to relieving to some of the harshness of the environment. You get some trees in, young trees, this leads to herbaceous cover coming in, and that leads to better survival of other conifers, the seedlings of other conifers as well. So it is definitely a pioneer and an important first step in the secondary succession after disturbance in these high-elevation communities.

I’ll also mention what happens if fires are suppressed much longer than the natural or historical return intervals. And that is over time, in unfavorable sites in the upper sub-alpine, shade-tolerant conifers will gradually out-compete whitebark pine. It’s very typical to see a whitebark pine surrounded by sub-alpine fir on all sides. It’s very typical to see skeletons of whitebark pine, trees that were shaded out. Whitebark pine is very shade intolerant and it needs light, obviously, in order to survive. And this competition ends up basically killing trees, and you lose trees over time. The longer the historical return interval has passed the fewer and fewer whitebark pine trees that remain alive in these communities. Now at the height, and on stressful harsh sites, whitebark pine is self-replacing. I should mention that near tree-line, in other words, the last elevational remnants that forest trees can survive, whitebark pine often forms a dwarf tree cover called “krumholtz”:http://www.chem.ucla.edu/~alice/explorations/churchill/landscapes.htm#Krumholtz, it’s a mat-like growth form where you have very few stems that are erect and the branches are actually creeping along the ground. There is a little bit of cone production that occurs up at those elevations. But my previous research seems to indicate that it is the nutcrackers that bring seeds up to these highest elevations and will replenish the krumholtz pine community.

ES: What proportion of the forest, in terms of any location, is whitebark pine?

DT: That’s really going to vary, because shortly after fire, there’s a pretty high proportion of whitebark pine that comes in, and as you go up in elevation, whitebark pine is definitely a forest dominant. In these self-replacing stands, you find that whitebark pine is co-dominant with sub-alpine fir, occasionally some lodgepole pine, occasionally some spruce. So it varies from place to place. Some of it has to do with the luck of the draw. But there are some parts of the forest that you might find to be even almost entirely whitebark pine. And so as far as a component of the sub-alpine, it varies with time since fire, of course as suppression proceeds you’ll have less and less whitebark pine and with elevation and the stress of the site. On very windswept sites, you can find nothing but whitebark pine at times, or you might find an imbedded sub-alpine fir that’s actually getting some protection from whitebark pine. In fact it’s not uncommon at the highest elevations to find that whitebark pine is established first, and then it acts as what we call a nurse tree. Some research has been done on this by “Ray Callaway”:http://biology.dbs.umt.edu/dbs/callaway.htm at the University of Montana. Whitebark pine actually provides a favorable environment for sub-alpine fir and Engelman spruce to get started. And these grow up and they eventually become co-dominant with the whitebark pine in the stand.

ES: What do you mean by fire return intervals?

DT: We mention that the fire return interval varies geographically depending on some extant with stand structure, in other words the local forest composition. And fire return intervals are just – the ones reported in the literature – they’re based on fire scar research. And what they indicate is how long, basically between fires, on average. And I have some information that was compiled by Steve Arnot, a fire ecologist, with the Fire Sciences Lab, – he’s now retired. Various researchers working in different forests, geographically, within the range of whitebark pine have noticed return intervals of perhaps as short as 30 years, to as long as 300 to 400 years. And that last bit of data comes from Bill Riley’s work in Yellowstone National Park. So the 300 to 400 year interval would result in what we call a stand replacing burn, in other words, a severe burn that pretty much kills all the trees. A mixed severity burn would leave trees standing – it’s kind of patchy, and it varies from being very low intensity to being high intensity. So it would kill some trees, and it would miss some other trees. These tend to have more frequent return intervals. In other words, intervals that might range from 10 to 100 years or so. So whitebark pine forests then depending where they are geographically, and their structure, have these different historical fire return intervals. Now, you can’t say that the longer the return interval, the less dependent the whitebark pine is on fire. It’s not true. It still needs fire to start the whitebark pine community over again. Because in the absence of fire, even with these stand replacing burns, Whitebark pine can really diminish on the landscape to being a very little component, and in order to return it to the landscape, we need to burn and open the area up to get nutcracker seed caching again, which of course will start the successional seed caching process.

DT: The most important factor causing the decline of whitebark pine, in both Canada and the United States, is an introduced fungal disease, an exotic fungal disease – white pine blister rust. This disease is native to Asia, and it was introduced to both the East and West coasts of North America in the late 1800s and early 1900s. The problem with blister rust actually goes beyond whitebark pine. I’d like to talk a little bit about the extent of the problem caused by whitepine blister rust. Even though fire suppression in areas resulting in a decline in whitebark pine. Whitepine blister rust is actually far more deadly and problematic and actually complicates some problems regarding returning natural fire to the landscape. First of all, let me put whitebark pine in the grand scope of things. Whitebark pine is known as a five-needled white pine. And it is one of nine five-needled white pines in North America, excluding Mexico, which has additional five-needled white pines. In the Eastern United States, the only five-needled white pine that’s native is eastern white pine. And, in the Western United States, we have sugar pine, Western white pine, and southwestern white pine. These are mountain [8000-10,000 ft ed.] elevation white pines – in other words, they’re not very high. They’re not at the lowest forest boundary, they come in somewhat in the middle of the elevational range of forests. But in addition, we have our high elevation white pines, including foxtail pine, which is found in California, in the “Sierra Nevada”:http://www.palomar.edu/mnhsdivision/Foxtails/, “limber pine”:http://biology.usgs.gov/s+t/SNT/noframe/wm148.htm, which is found throughout most of the United States and Southern Canada. We’ve already talked about whitebark pine. and then a few species of bristlecone pine. We have the Rocky Mountain bristlecone pine and the Great Basin bristlecone pine. All these pines, including eastern white pine, are susceptible to whitepine blister rust because that disease is not native, and it specializes on five-needled white pine. It occurs on the five-needled white pine in Europe and Asia, but because they co-existed with whitepine blister rust for probably millions of years, they have evolved some natural resistance, and some individuals are more susceptible than others, but they’ve achieved a balance with the disease. Here in North America, five-needled white pines were not challenged previously by blister rust. And as a result, blister rust has had devastating consequences to forest biodiversity in North America. And these consequences are becoming very clear to us just within this last decade. And we have some real problems on our hand. We have a forest biodiversity problem. Now, in the Eastern United States, the problems with blister rust were recognized and there has been some action taken because Eastern white pine is an important commercial species. In the Western United States, when blister rust was detected, some actions were taken for the commercially valuable sugar pine and western white pine.

ES: Where did blister rust come into the picture?

DT: The point of introduction of white pine blister rust to the Western area of North America was at Point Grey, Canada. And unfortunately, blister rust could not have come in at a better place to spread the disease. Blister rust requires humid, cool conditions for spore production and dissemination. And, certainly the Pacific Northwest is absolutely perfect. As a result, blister rust spread very rapidly. And, before it was detected, it had already traveled hundreds of miles and made serious inroads. Unfortunately, blister rust spores are very hardy. The spores can travel 300 miles – 500 km a season if conditions are right.

So, this is a disease with some complexity to it. First of all, blister rust had a very complicated life cycle with five different spore types. For its life cycle, it requires an alternate host. And the alternate host is a group of shrubs in the genus “ribes”:http://www.uga.edu/fruit/ribes.htm. These shrubs are known as gooseberries and currants. And they are widespread throughout North America. Some species serve better as alternate hosts for blister rust than other species. Nevertheless, species that can participate in this life cycle are pretty much everywhere where these white pines occur. Now, in terms of the spore types and the life cycle, what happens is that spores are produced from fruiting “cankers “:http://www.na.fs.fed.us/spfo/pubs/howtos/ht_wpblister/toc.htm. These are eruptions in the living bark of the tree caused by blister rust. The fruiting bodies actually come out through the bark. And these spores are windblown and go from the pine to these gooseberries and currants. Further spore types are produced on the gooseberries and currants throughout the summer. The blister rust lives on the leaves and produces spore types that intensifies the infection – in other words moves to other ribes shrubs. And then finally, in late summer, spores that move from ribes into pines. Now, ribes shrubs are not killed by blister rust. They’re casual bystanders in this interaction. That’s because, when the cold weather comes, ribes drop their leaves, they’re deciduous shrubs. And they grow new leaves the following summer that may or may not be infected. However, once a pine develops a canker from blister rust, unless that pine has some resistance, that pine cannot rid itself of the blister rust infection. The point of entry for the spores are the stomata of the needles – the pores that are used for respiration, in other words. That’s where blister rust enters the needle and fungal mycelia will grow down the needle. In other words, the fine, threadlike fungal extensions will grow down the needle into the wood, into the twig. And within 2-3 years, a fruiting canker is formed. And they’ll erupt through the living bark of that twig. And, through time, the rust will move down through the branch, perhaps fruiting every year if conditions are right, sometimes skipping a year. Once a canker has fully girdled a branch, it will kill the branch, because the conduction of water and carbohydrates and other nutrients is at that point, disrupted in the tree. If that canker continues to grow, and nothing is stopping it, it will grow down the branch into the trunk of the tree. And, after some years, it can girdle the tree, produce a fruiting canker in the tree itself, in the trunk itself, and it will kill the tree. Now it takes a couple of years is a canker starts at a branch tip or in a branch to kill a tree. But, in the mean time, these cankers in the branches are stopping cone production. These trees of course bury their seed-producing cones on their branches. In the case of whitebark pine and limber pine, on the branch tips. And if enough branches die, the tree becomes essentially non-reproductive. So, you can have a living tree, but no seed production. This is a particular problem for whitebark pine and limber pine. Now, blister rust, from its point of origin, spread east and it spread south, very rapidly throughout the Pacific Northwest. It was noticed by pathologists when it showed up in Western white pine. And a great deal of worry occurred at that point. It also showed up in sugar pine. These are two major commercial species. Sugar pine produces the tallest pines in the world. The wood is very valuable, Northwestern white and sugar pine. And, in fact, western white pine in particular was the foundation of a logging economy in the Pacific Northwest. Well, trees began to die, and foresters realized that they needed to do something. It wasn’t as if no one tried to stop blister rust. Quite the contrary. As a matter of fact, about 65 million dollars were invested over a period of perhaps 35 years in an attempt to stop blister rust, and the ribes shrub was the target of this effort. There was a major ribes eradication effort that was ongoing each summer. In fact, civilians were hired – I believe this was part of the “Civilian Conservation Corps”:http://www.cr.nps.gov/history/online_books/ccc/index.htm, people who were otherwise jobless found some summer work, and students were hired. And a major effort was in place in California, Idaho, and the Greater Yellowstone pull ribes shrubs. Later on they were using heavier equipment to do that. Unfortunately, there’s no indication that this massive effort, and all this money spent did any good. The problem is that you need to know a little bit about the ecology of gooseberries and currants. They thrive on disturbance. And their seeds end up in a seed soil bank, so with this disturbance, new plants will germinate and thrive in these disturbed areas. So, unfortunately, this major eradication effort had little impact. So fortunately, the pathologists were looking for alternate methods of doing something about blister rust, stopping blister rust. It became apparent that one pathologist, Bingham, as he walked through western white pine forests, that here and there, a tree escaped blister rust. But blister rust had made an inroad so great that +90% of the trees were infected in the Northwest. This was by, say the 1950s. That’s how serious this disease is. And Bingham realized that these few trees that seemed to resist blister rust were the key to a genetics program that would enable a seed orchard to be produced and serve as a seed source – blister rust resistant stock for replenishing western white pine. And so, a major effort on the part of the U.S. Forest Service began at that point for western white pine and sugar pine. Now, in the meantime, blister rust was making some serious inroads in some high elevation pines. Including limber pine, white bark pine, and, to a lesser extant, fox tail pine. Blister rust spread very rapidly through white bark pine, and as a matter of fact, it spread east as far as Glacier National Park by 1939. Now today, we have very high infection rates in these areas that were very favorable to blister rust spread, in the Pacific Northwest and the Northern Rockies of the United States and the Southern Rockies of Canada, also the southern coastal ranges of Canada. Blister rust, to date, is pretty much everywhere throughout the range of whitebark and limber pine in Canada, albeit at lower infection levels at the more northern portion of the range. But each year, they seem to be increasing over time. In the Northern Rocky Mountains and the Pacific Northwest, white bark pine is infected at very high levels and blister rust is also in limber pine. Limber pine is sustaining very high levels of infection as well. Blister rust is, now, everywhere throughout the range of whitebark pine except the southern Sierra and some of the Great Basin ranges. It was previously thought that more arid environments would stop, or at least drastically slow the spread of white pine blister rust. But it appears this isn’t the case. And it may well be that the rust is changing, genetically, over time. Maybe because of the effects of natural selection. But blister rust is now ratcheting up in the Greater Yellowstone area, where we have whitebark pine and limber pine. And, much to people’s chagrin, it has been detected in one range of the Great Basin. And so it appears that dry environments are not immune to blister rust. In terms of limber pine, the spread has been very rapid and also a source for grave concern. Blister rust is now as far east as the Black Hills of South Dakota. Blister rust is found throughout limber pine across Montana and Wyoming. And in 1998, blister rust was finally found in Northern Colorado – it crossed the boundary between Wyoming and Colorado, and all indications are that it’s heading south.

Now I haven’t discussed the Bristlecone pines – and the fact is that laboratory work indicates that the bristlecone pines, including ancient Great Basin bristlecone pines, for example – we have wonderful old stands of trees that are 4000 years of age in the “White Mountains of California”:http://www.calwild.org/campaigns/cwhc_act/whitemtns.php. Well, the bristlecone pines, as I said, are susceptible. And blister rust is in fact in their backyard. We have blister rust in the Sierra Nevada, not too far to the west and north of ancient bristlecone pines. And in the Rocky Mountains, we have the Rocky Mountain bristlecone pine of different species, and limber pine has been infected in Northern Colorado. And so it will be a matter of time.

Now, Southwestern white pine is a species that I haven’t mentioned. And we actually have a separate infection in Southwestern white pine that is distinct from the distribution of blister rust in the rest of the west, Infection in Southwestern white pine was noticed in the 1990s, in the Sacramento Mountain area – this is southern New Mexico. And the blister rust seems to be spreading north into the mountain ranges just north of the Sacramento. So, scientists have been attempting to figure out how blister rust got to the Sacramento Mountains – they’re very isolated. “Brian Geils”:http://www.rmrs.nau.edu/rust/Geils2000.pdf, for example, has been working with colleagues at wind transport of blister rust spores, trying to identify a climate event that could possible have spread blister rust, either down from the north or from California. And so far, their work seems to suggest that this infection may have come from the southern tip of the Sierra Nevada, where sugar pine is infected from blister rust. Whitebark pine is not infected in the southern Sierra but sugar pine is infected throughout. I should mention that sugar pine, and western white pine, are infected completely throughout the range by blister rust, and some studies done at Sequoia Springs Canyon suggest that it’s impacting the forest ecology of sugar pine, and more work need to be done to look at the ecological consequences of blister rust in these five-needled white pine species.

ES: What are some of the infection levels though of whitebark pine?

DT: Certainly, we are very concerned about losses of five-needled white pines in general, because they harbor considerable biodiversity – they represent different forest habitat types and are home to a variety of plants, and vertebrates, and invertebrates. But, here we’re especially concerned about whitebark pine. Certainly because whitebark pine plays a role that we like to call a keystone role where it occurs. It is a keystone because where it occurs, it fosters biodiversity. It’s presence basically increases the biodiversity of it communities that it occurs in – and that is through providing the nutritious food source, by helping develop forests after fire, by providing nurse tree types of services, and mitigating the harshness of the post fire conditions. So, a number of us like to consider whitebark pine a keystone species where it occurs. By technical definition, a keystone species is a species that promotes biodiversity that increases biodiversity disproportionate to its own biomass in the community. And, whitebark pine’s effects go beyond just its presence in a given location. Because, for example, bears can feed on the seeds. Bears are present throughout a much larger area, and some of these other vertebrates use the whitebark pine seeds. Whitebark pine also provides important habitat for blue grass, and deer, and elk, and moose. And, the communities have different wildlife functions at different stages of succession as well. You get three-toed black back woodpeckers in after fire and a variety of birds and mammals converge on whitebark pine forests after fires. Other woodpeckers such as flickers and gray jays – and then of course nutcrackers are caching in this area as well. So we’re particularly concerned about whitebark pine, and it’s critical habitat for grizzly bears in the greater Yellowstone. And we’re concerned about losses throughout its range. To date, these losses have been quite severe. for example, in the Northern Rocky Mountains, stands show infection rates up to 100%, and average about 84%. Places like Glacier National Park have very few living whitebark pine remaining, and those that remain are infected by blister rust. And the adjacent areas in the Northern Rockies show similar infection levels. Whitebark pine is disappearing, and it is disappearing as a seed source as well. Blister rust infection levels vary geographically, and as I mentioned they are highest in the Pacific Northwest and in the Rocky Mountains, and Southern Canada, and the Coastal Ranges of Southern Canada as well. *** It’s very clear that within a decade, whitebark pine, as a forest component, is going to be virtually gone. And with that, the seed source, and the potential for nutcrackers to regenerate whitebark pine. So there is considerable pressure for us to start thinking about what it is that we can do to restore whitebark pine communities. ***

Now, I should hesitate to point out that in areas farther to the south in the United States, such as the greater Yellowstone, the Coastal Ranges, Oregon – on other words the Cascades Range, the Sierra Nevada, infection levels are not as high. But they are increasing. And recent surveys indicate that perhaps 50% of the trees in Oregon are infected by blister rust, and blister rust is intensifying over time. Now, if past action predicts future performance by whitepine blister rust, we can expect this disease to continue to spread throughout the range of all five-needled white pines. Now, I mentioned there are five-needled pines in Mexico, and this is another worry. Ribes shrubs are found in Mexico. Southwestern white pine continues in its distribution south, to north of Mexico City. And Mexican white pine, a pine that is threatened as it is and restricted to just a few forests, we’re concerned that blister rust may go all the way down and put further pressure on these pines. *** So, we may be faced with truly a North American, continent-wide epidemic of this blister rust disease. ***

ES: Could you describe a little bit about what to look for in finding blister rust on trees?

DT: When blister rust goes down into a branch, it produces a swelling. And even thought the blister rust has not yet fruited, you can tell that there’s something a little out of whack with that branch. There’s actually sort of a pea-formed expansion of the branch. And, at some point, fruiting bodies will reproduce through the branch. Now, when blister rust has been present in a branch and has fruited, the bark is actually disrupted. You’ll see irregularities in the bark that accompanies the swelling. And the same thing holds for the trunk of the tree. You may not see the swelling, but the bark is disrupted. Sometimes it is actually dark. And sometimes, you can actually see, depending on the species of the tree, the blister rust growth under the thin bark. For example, western white pine and limber pine we can sometimes see the boundary of the blister rust. Blister rust itself is somewhat red-orange in appearance. And this will clue you in to the fact that the tree is afflicted. There are other symptoms of blister rust. There’s resin that is actually produced, or secreted, by the fruiting cankers. And that’s because the bark has been disrupted. And, sometimes pine squirrels will come into the tree and feed on the fruiting cankers. So you’ll see branches that are gnawed off, even girdled by the squirrel. That’s a good symptom of blister rust being present in the tree. Sometimes you’ll see ants crawling to feed on the resin that’s dripping down. And that is another symptom that means that you have to look a little more closely. i should also mention that when blister rust has been present in a stand of trees for a while, it is very typical for a tree to have more than one canker. As a matter of fact, a tree can have tens of cankers, and maybe as many as a hundred cankers if it is a large tree. It’s virtually impossible, without climbing a tree and scrutinizing every inch of it, to count how many cankers are occurring on the tree, because these cankers can start out on small branches and twigs, and they’re very small. So there are a number of symptoms that clue you in to the presence of blister rust. Unfortunately, these multiple cankers present a major problem. If you were to be working to keep blister rust from killing a particular tree, it might be possible to prune a single canker out of a tree by pruning off a branch. But when you have these high infection levels, these high intensities of infection, the spore rate must be extremely heavy in these forests. Pruning is just not going to hold blister rust at bay because there are just so many cankers on these trees. One other point I’ll mention is that humid, cold conditions are very important for the transmission of blister rust spores from ribes. And some years there may be no transmission, particularly if you’re in a drought year. It appears that all it takes is one favorable year to start a new wave of blister rust cankers in the forest. And, pathologists are actually very good at being able to date when a canker started, and perhaps how long it’s been on the tree by looking at where it is and how long it’s grown. So they’ve been able to date these cankers pretty effectively and figure out when blister rust first appeared in a community.

ES:

DT: Bob Keenan and Steve Arnot eventually received the support of the Fire Sciences Lab to pioneer some restoration projects which were an outgrowth of some of our findings. Steve and Bob together put in a number of demonstration projects in the Northern Rockies where they used Silvocultural treatments and prescribed burning in order to stop the advancing succession, and to reverse the succession and renew whitebark pine communities. In addition, we realized that in areas where seed sources had been pretty fairly destroyed by blister rust, another strategy is needed, and whitebark pine, like Bingham found for western white pine, and we find for sugar pine, has a very small percentage of individuals that appear to have a very small resistance to blister rust. *** Ultimately, these individuals are going to be key to a worldwide restoration program. Ultimately, we can’t stop whitepine blister rust. We may be able to put fire back on the landscape through a variety of techniques, particularly in areas where fire will not be allowed to burn on it’s own. But blister rust is still there. And ultimately, we’ll render these other actions useless unless there’s a seed source. And so, we may need to step and do the planting on our own. We may have to step in with a very hands-on approach to managing whitebark pine. *** Now, just a few years ago, in 2000, Mary Frances Mahalovich, a forest geneticist with the U.S. Forest Service, started a project of gathering whitebark pine seeds from possibly rust-resistant trees. So this is a second prong of the strategy for restoration of whitebark pine communities – the first strategy being, you need to ratchet back succession to a point where you replace your whitebark pine in your community, start your successional processes over again to restore whitebark pine. But where you don’t have fields available, this has to be connected with actually planting rust-resistant seedling, or, we hope we get to the point where seeds can be directly placed in the ground. The U.S. Forest Service Nursery in Coeur d’Alene, Idaho, has been a wonderful pioneer in growing whitebark pine seedlings — this is trickier than it sounds. The seeds are really tough to germinate. They usually require two layers of dormancy in the ground before seedlings will actually be produced. And the nursery has actually pioneered some techniques to speed this up. So they are really a great center for growing whitebark pine for these restoration efforts. Anyhow, getting back to Mary Franced Mahalovich’s strategy, she put out a call for seeds in potentially rust resistant individuals from a variety of National Forests in the Pacific Northwest and the Intermountain Region. And she screened the seedlings produced from these seeds for known blister rust resistance. And it is her intention to begin a seed orchard such as what was done for western whitepine and for sugar pine as a source for rust resistant seeds. Now, getting back to our whitebark pine research and restoration ideas, we feel that an important strategy, and I think Mary Frances would agree with us, is to not wait for the seed orchard to be produced, but to start moving along and to make use of these rust-resistant individuals that are scattered throughout our forests. In other words, then they themselves could be considered a seed orchard or a seed producer. And their seeds should be harvested when available, and seedlings grown and out-planted in areas where pine has succumbed to blister rust or in places where the seed source is pretty much gone, and we might have fire that has come through or perhaps forest districts are learning to open up the forests using prescribed burning and silvocultural technique. So, we are developing a number of tools for the restoration of whitebark pine. And this will apply as well to limber pine and some of the other higher elevation pines such as bristlecone, down the road as blister rust spreads.

*** Now a good question at this point that someone might ask is: Isn’t there a way to stop blister rust? Isn’t there anything we can do to directly stop this disease? And I have to say that there is nothing, at this point in time that has been developed, that will stop the spread of blister rust. There are a number of fungicides that were developed and applied, but there were a number of problems with fungicides. First of all, the area and extent of these five-needled white pines is tremendous. And these pines would need to be sprayed pretty much by hand. The manpower we’re talking about is incredible, and not realistic. But secondly, we have no idea what the effects are of spreading these fungicides, and spraying them in the environment, what the impact will be on biodiversity, on the other inhabitants of these five-needled white pine communities. From an expense standpoint, and from an ecological standpoint, these fungicides are just not practical. Now, in the Eastern United States, particularly, they have managed to control the spread of blister rust through ribe eradication and through pruning cankers off trees. And that’s realistic on a very limited scale. Perhaps, for example, a ski area has stand of whitebark pine that might be very useful for preventing avalanche or protecting soil erosion, and perhaps the ski area might be able to prune cankers, maybe even possibly spray, except that there may be ecological problems that we may be unaware of with spraying. But they may be able to pull ribes – these are things that might limit the mortality in these stands – at least buy them some time until some planting has been done. That’s possible. But in terms of a forest management strategy, this is completely unrealistic. *** Now, since we have some restoration tools in our arsenal, to make the idea of incorporating whitepine restoration strategies in National Forest plans. This is a big undertaking. This also applies to the other five-needled white pines that we’ve been talking about. This is a big undertaking, because a strategy would need to be written into each National Forest plan, each forest that has five-needled white pines. *** The problems with writing these strategies are the realization that you can’t do this once on a limited scale and you’re done with it. These restoration strategies have got to be ongoing and repeated over time until rust resistant stock has pretty much come to characterize most of our white pine forest, or at least enough of them that rust resistant seeds can then be disseminated by nutcrackers or wind, depending on the white pine you’re talking about and spread, and eventually come to characterize the forest. Blister rust will not go away. Our best hope is naturalizing this disease, which means a prevalence of rust resistant individuals throughout the forest, so blister rust will no longer cause the destruction and the mortality that it currently is. This is a major commitment. *** And it’s a commitment that National Forests, and National Park Service is going to need to make, in order to keep white bark pine and its ecosystem services, and its services to wildlife, including the grizzly bear, on the landscape. And to maintain the last biodiversity maintained by all our white pines in North America. There has to be a commitment to restoration.

[End Tape I]

Whitebarkfound.org

We are just barely at the beginning of making some inroads in this, and fortunately consciousness raising has occurred among a lot of scientists, particularly among pathologists and ecologists in the western offices of the U.S. Forest Service, probably throughout the U.S. Forest Service, because blister rust is a continent-wide problem, or a country-wide problem in the United States and Canada. So people are really now very interested in starting some programs to implement restoration techniques. As a matter of fact, in the United States, a report has actually been drafted by a committee of pathologists that represent both the East and Western U.S., and this report is being sent to Washington, basically outlining the extant of the problem with whitepine blister rust and what can be done. And similarly, in Canada, the problem is being recognized, and just last February, Parks Canada held a workshop to discuss whitebark and Limber pine. Several of us from this whitebark pine research team I mentioned were actually invited up to talk about what we’re doing for whitebark pine. But this problem is reaching the highest levels. Now, Canada just passed their first endangered species legislation, and it’s actually called the Species at Risk Act. They now have a legislative mechanism for getting some attention to species that are truly in precarious positions. And it has suggested that blister is serious enough in Canada that whitebark and limber pine should be considered for listing under the SARA. Now, another thing that we’re trying to do, in the United States, in parallel with government agencies such as the National Park Service and the U.S. Forest Service are doing, a group of us from the Whitebark Pine Research Team actually formed a non-profit organization known as the Whitebark Pine Ecosystem Foundation, and this was officially formed in 2001. And the purpose of this foundation is to educate the public, and various research agencies, about the importance of whitebark pine, and the need for restoration. We have of projects, and partnerships going on with the Forest Service and a colleague in Canada, Watterton National Parks, Andy Smith, who’s been very active in our organization. We are trying to disseminate information that will lead to action. And eventually, since we’re still a very young non-profit, we hope to be able to fund some restoration projects. So we hope that we can help provide funds for non-profits, other non-profits, and for forest service districts, to help them carry out some identified restoration projects. Actually, next year as well, the Whitebark Pine Ecosystem Foundation is putting on a workshop that’s called Monitoring Whitebark Pine for Blister Rust Methods Workshop. We’ll be developing a methodology for monitoring whitebark pine forests to keep track of how serious blister rust is in them, and we are arguing for a uniformity of methods so that this information can be collated in a central repository, which is now being put together by Northern Region forest health protection folks. And we’re encouraging people who have data on the incidents of limber pine and whitebark pine to be contributed to this database. Anyhow, the Whitebark Pine Ecosystem Foundation has members, and people contribute a modest annual membership fee, we have an color magazine called Nutcracker Notes, where we disseminate the latest research findings about whitebark pine in particular, but also about limber pine and any of the other five-needled white pines, and we certainly encourage people to join. The money is going to a very important project, in terms of trying to keep whitebark pine on the landscape. We have a website, which is “www.whitebarkfound.org”:http://www.whitebarkfound.org/, and the whitebark pine story is presented on the website, and recent activities and some papers as well.

ES:

DT: I think that within one generation, without having us actively go in and manage whitebark pine communities, we’re going to see local extirpations, local extinction of whitebark pine. There are some folks that are actively concerned that as blister rust spreads, there could actually be range-wide extinction of some of these species if there isn’t some hands-on help. Because having just a couple of trees here and there are not enough to perpetuate a population. And a good reason is that, remember all the animals that we mentioned that eat the seeds? There’s a better chance that seeds will get eaten, particularly if we only have one or two trees left in a whole forest, those seeds will disappear and be consumed. They won’t get into the ground. It’s definitely possible in a species like whitebark that depends on Nutcrackers for dissemination, we could lose most populations, if not the entire species. The problems that with a dependence on Nutcrackers, that as fewer and fewer of whitebark pine trees are producing cones and are alive, fewer and fewer nutcrackers will check these stands of trees out and will be concentrating their time in areas where other pines are producing seeds. Nutcrackers do eat the seeds of other conifers, and they won’t ultimately go extinct. They’ll seek refuge in Ponderosa Pine, some of the Pinyons, which aren’t affected by this blister rust – they have a native blister rust actually. So nutcrackers won’t go extinct, their population levels will certainly decline. And I don’t know what the implication of that is. We think we only have a fairly short horizon here where we can still do something. The most important issue here is collecting seeds from a diversity of whitebark pine seeds to maintain genetic variation in whatever it is that we’re going to out planting. So time is in fact of the essence in these restoration efforts.

ES:

DT: There are a number of problems, of course, that are impacting our forests. Some of them, unfortunately, divert attention from other problems. We’re all concerned about fire in the west, and we’re concerned about natural epidemics. For example, we have the resurgence of Mountain pine beetle, which in fact can further. Whitebark pine has a food challenge that is making restoration efforts particularly difficult. In the Western U.S., Mountain Pine beetle infestations have upsurged, and a number of scientists believe that this is a result of the drought that we have had – it makes trees more susceptible to Mountain pine beetle. Well, whitebark pine is one of these trees. Mountain pine beetle naturally infests whitebark pine. But, with the coming of the drought, we see it intensifying. This is a major problem because, the beetles may inhabit and kill whitebark pine trees that are whitebark pine resistant. I’ve mentioned that we there are only a small percentage of trees that show some degree of resistance to blister rust. If these trees are killed by mountain pine beetle, then we lose the very foundation of the restoration program, namely the production of rust-resistant seeds that can be used to either to start a seed orchard or to plant locally. So we are very worried, we are very concerned right now of about this upsurge. Studies recently by Diana Fix at the University of Montana indicate that whitebark pine, under drought conditions, is not able to ward off Mountain pine beetle, and may be more susceptible because it can’t put the resin response when pine beetles drill into trees. Mountain pine beetle is a natural forest health pest, a recurring forest health challenge. And many trees are carried in upsurges of Mountain pine beetle epidemics. Whitebark pine has that history as well. As a matter of fact, in the northern Rocky Mountains, there were a number of trees that were killed in epidemics dating to the 1930s. Some of these continued through to the 1960s, and here we have a new cycle that appears to be occurring. For example, in Glacier National Park, it’s true that we have trees killed by blister rust, infected by blister rust, but previous epidemics of Mountain pine beetle did their best in terms of killing whitebark pine trees. Now we have the new infestation with blister rust on top of that, with fire suppression on top of that, too many challenges, and whitebark pine is in a dire situation.