Air Date: Week of June 9, 2000
Climate change - in the form of warmer, wetter weather - is encouraging European blister rust to infect pine nut trees in Yellowstone. As Jyl Hoyt reports, this could be disastrous for grizzly bears, who rely on pine nuts for food.
CURWOOD: This is Living on Earth. I'm Steve Curwood. In Bonn, Germany, this month, talks continued to revise and refine the Kyoto Protocol to combat climate change. Meanwhile, evidence continues to mount showing that life on Earth is being disrupted by global warming. For example, in Yellowstone National Park, rising temperatures are affecting white bark pine trees, part of the food chain for animals, including endangered grizzly bears. Grizzly bears, it seems, love pine nuts. From member station KBSX in Boise, Idaho, Jyl Hoyt reports.
(Soft voices, clanking)
HOYT: It's just after dawn in Yellowstone's Lamar Valley. There, biologist Lance Craighead adjusts his spotting scope, searching for another glimpse of the mother grizzly and three cubs who just ambled into the trees.
CRAIGHEAD: They were sort of frisky and they were jumping around and exploring, and poking around and looking at different things.
HOYT: Lance Craighead suspects the bears are heading for timber line, looking for food. Grizzlies often raid the white bark pine nuts that red squirrels collect and bury in the fall.
CRAIGHEAD: So way up in the higher areas, like up on that big ridge, there, above those cliffs, you can see some white bark pines. Some years they'll have really big crops of pine nuts, and the pine nuts are probably the most high-energy food available to grizzlies at any time of year. But it's especially important in the fall.
HOYT: Bears must eat enough each fall to get them through hibernation. And if females don't have enough fat, their fertility diminishes. White bark pine nuts can provide up to 40 percent of a bear's fat needs. But white bark pine trees are at risk because of global climate change. The trees need cool temperatures to grow, and warm weather forces them up mountainsides, limiting their range, says Chuck Schwartz, head of the Inter-agency Grizzly Bear Study Team. Higher elevations may be too cold for the white bark pine. And remember, he says, mountains are shaped like cones.
SCHWARTZ: The higher up the cone you get, the closer to the point you get, the smaller the zones will be. So there will be less available acreage for white bark pine.
HOYT: Government scientists like Chuck Schwartz are often at odds with independent biologists when it comes to protection of grizzly bears. But on this point they agree: The climate change can pose a risk to bears. He speculates that climate change may also be creating conditions in and around Yellowstone National Park that encourage the spread of European blister rust, a plant disease carried here inadvertently in 1906 that has already infected forests in the Pacific Northwest.
SCHWARTZ: It impacted the trees significantly, and there are areas now where nearly 98 percent of the white bark, the historic white bark, is gone.
HOYT: Warmer, moister air produces the fog banks that blister rust thrives in. The rust infects and girdles the tree, and it eventually dies. Foresters say blister rust is moving closer to Yellowstone. During the past five years, the number of infected trees has increased by 40 percent in the Gallatin National Forest, just south of the park where grizzlies often forage for food.
HOYT: White bark pine trees protect the bears in two ways. They provide grizzlies with food, plus their remote location shields the animals from humans. But white bark pines don't produce nut crops every year. During unproductive years, grizzlies often head to river bottoms searching for food, into areas where there are people. And that means trouble, says Louisa Wilcox, who heads the Sierra Club Grizzly Bear Ecosystem Project.
WILCOX: Grizzlies walk into these areas, perhaps not meaning to get into trouble, run into dog food on a porch, a bird feeder that's been left out, get a taste of something that's pretty tasty -- and because they have good memories, never forget it. And then within short order become a management problem, in which there is some need to dart and move the bear, or kill the bear altogether.
HOYT: Federal researchers say three times more grizzly bears die during years with no white bark pine nut crops than during years when the nuts are plentiful. With fewer than 400 grizzlies left in Yellowstone, according to several estimates, a modest increase in their deaths could have a serious impact on their population. In the meantime, foresters are developing a rust-resistant strain of the white bark pine. Government officials may plant these saplings if the disease continues its dramatic spread. But it takes 100 years for a tree to produce a usable crop of nuts.
PECK: Did somebody see another bear?
HOYT: Brian Peck of the Sierra Club Bear Project spies another bear through the spotting scope.
PECK: And this is a very dark, almost black grizzly bear. And he's just above the elk. Oh, right in the open now. Ho, ho, ho.
HOYT: People like Brian Peck, who thrill at the sight of grizzly bears and work to protect them, say the key to their preservation is understanding the connectedness of different species.
SCHWARTZ: Human influence can have profound effects on this particular species, and it's kind of an indicator species of the health of wild systems.
HOYT: Chuck Schwartz of the Inter-agency Grizzly Bear Study Team says blister rust is only the latest in a long series of human-caused threats that challenge the health of the wild Yellowstone ecosystem.
PECK: It's walking across, just out for his morning stroll.
HOYT: For Living on Earth, I'm Jyl Hoyt in Yellowstone National Park.
PECK: Oh, he's doing a little digging. There we go. (Laughs)
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Mabadiliko ya hali ya hewa - katika fomu ya hali ya hewa ya joto, ya unyevu - ni kuhamasisha Ulaya blister kutu kuambukiza pine karanga miti katika Yellowstone. J. Hoyt anasema kwamba hilo linaweza kuwa jambo lenye kuumiza sana kwa dubu wanaoishi kwenye misitu ya msonobari. CURWOOD: Hii ni Kuishi Duniani. Mimi ni Steve Curwood. Mkutano wa Bonn, Ujerumani, uliofanyika mwezi uliopita, ulihusisha mazungumzo ya kuimarisha na kurekebisha Mkataba wa Kyoto wa kupambana na mabadiliko ya hali ya hewa. Wakati huohuo, uthibitisho unaendelea kuongezeka unaoonyesha kwamba uhai duniani unaharibiwa na ongezeko la joto duniani. Kwa mfano, katika Mbuga ya Kitaifa ya Yellowstone, ongezeko la joto linaathiri miti ya pine nyeupe, ambayo ni sehemu ya mlolongo wa chakula cha wanyama, kutia ndani dubu wa rangi ya kijivu walio hatarini mwa kutoweka. Yaonekana, dubu wa rangi ya kijivu hupenda karanga za msonobari. KBC ya Boise, Idaho, Marekani "Hiyo ni ""mwisho wa siku"" katika Yellowstone's Lamar Valley." Akiwa huko, mwanabiolojia Lance Craighead anabadilisha darubini yake ya kuona, akitafuta kuona tena mama huyo wa mbweha na watoto wake watatu ambao wametembea kwenye miti. CRAIGHEAD: Walikuwa aina ya playful na walikuwa kuruka kuzunguka na kuchunguza, na poking kuzunguka na kuangalia mambo tofauti. Lance Craighead anaamini kwamba dubu hao wanaelekea kwenye mstari wa mbao, wakitafuta chakula. Mara nyingi mbweha huvamia karanga nyeupe za misonobari ambazo squirrels nyekundu hukusanya na kuzizika wakati wa vuli. CRAIGHEAD: Hivyo njia juu katika maeneo ya juu, kama juu ya kwamba ridge kubwa, huko, juu ya wale miamba, unaweza kuona baadhi ya pine bark nyeupe. Katika miaka ya mwisho, mimea ya mchele ni muhimu kwa ajili ya chakula cha grizzly. Lakini ni muhimu hasa katika vuli. "Hawa ni ""mbwa-mwitu"" ambao wanahitaji chakula cha kutosha kila vuli ili kuweza kuvumilia usingizi wa majira ya baridi kali." Na ikiwa wanawake hawana mafuta ya kutosha, uzazi wao hupungua. Nyota za pine nyeupe zinaweza kutoa hadi asilimia 40 ya mafuta ya dubu. Lakini miti ya misonobari nyeupe iko hatarini kwa sababu ya mabadiliko ya hali ya hewa duniani. Miti hiyo inahitaji joto la chini ili kukua, na hali ya hewa ya joto inawalazimisha kupanda milimani, ikipunguza eneo lao, anasema Chuck Schwartz, mkuu wa Inter-Agency Grizzly Bear Study Team. Huenda maeneo ya juu yakawa baridi sana kwa ajili ya msonobari mweupe. Na kumbuka, anasema, milima ina umbo la koni. Kwa sababu ya kuwa juu zaidi ya koni, karibu zaidi na hatua, maeneo madogo yatakuwa. Kwa hiyo kutakuwa na eneo dogo zaidi la kupanda misonobari nyeupe. "Mwanasayansi wa serikali kama vile Chuck Schwartz mara nyingi wanapingana na wanabiolojia wa kujitegemea linapokuja suala la ulinzi wa dubu wa kijivu. """ Lakini wanakubaliana juu ya jambo hili: Mabadiliko ya hali ya hewa yaweza kuwa hatari kwa dubu. "Mwanasayansi huyo anasema mabadiliko ya hali ya hewa yanaweza pia kuunda hali ndani na karibu na Hifadhi ya Taifa ya Yellowstone ambayo huchochea kuenea kwa ""kunajisi"" kwa mviringo wa Ulaya, ugonjwa wa mimea uliopelekwa hapa bila kukusudia mnamo 1906 ambao tayari umeambukiza misitu ya Kaskazini Magharibi mwa Pasifiki." Mimea ya mti huo imeharibika sana na sasa kuna maeneo ambayo karibu asilimia 98 ya magamba yake meupe yamepotea. Hewa yenye joto na unyevu hutokeza mabwawa ya ukungu ambamo kutu ya matope huenea. Chumvi hiyo huambukiza na kufunika mti huo, na hatimaye hufa. Walinzi wa misitu wanasema kutu ya matope inakaribia Yellowstone. Katika miaka mitano iliyopita, idadi ya miti iliyoambukizwa imeongezeka kwa asilimia 40 katika Msitu wa Kitaifa wa Gallatin, kusini tu ya mbuga hiyo ambapo mbwa aina ya grizzly mara nyingi hutafuta chakula. Mti wa White Bark Pine unawaokoa dubu kwa njia mbili. Wao huwapa ndege hao chakula, na kwa kuwa wako mbali, hawawezi kuwasiliana na wanadamu. Lakini misonobari yenye magamba meupe haizalishi matunda ya karanga kila mwaka. Katika miaka isiyo na mazao, mara nyingi mbweha huelekea kwenye sakafu ya mito wakitafuta chakula, katika maeneo ambako kuna watu. "Kama ilivyoelezwa hapo juu, ""Mwanamke huyo ni mmoja wa viongozi wa Sierra Club Grizzly Bear Ecosystem Project." Grizzly huenda katika maeneo haya, labda bila nia ya kupata shida, kukimbia katika chakula cha mbwa kwenye veranda, chakula cha ndege ambacho kimesalia nje, kupata ladha ya kitu ambacho ni ladha nzuri, na kwa sababu wana kumbukumbu nzuri, kamwe usisahau. Kwa hivyo, kwa sababu ya hali hii, ni muhimu sana kuondoa tatizo la usimamizi, na kwa hivyo, ni muhimu kuondoa au kuondoa dubu. Watafiti wa serikali wanasema dubu wengi hufa katika miaka ambayo hakuna mazao ya karanga za pine kuliko wakati ambapo matunda ni mengi. Kwa kuwa kuna zaidi ya ndege 400 za grizzly katika Yellowstone, ongezeko dogo la vifo vyao linaweza kuwa na athari kubwa kwa idadi yao. Wakati huohuo, wakulima wa misitu wanaendeleza aina ya msonobari mweupe ambayo haiwezi kutu. Maofisa wa serikali wanaweza kupanda miche hiyo ikiwa ugonjwa huo utaendelea kuenea sana. Inachukua miaka 100 kwa mti kuzalisha matunda ya karanga. Je, mtu yeyote aliona dubu mwingine? Brian Peck, mkurugenzi wa mradi wa Sierra Club Bear, anaangalia dubu mwingine kupitia darubini. "Mfano wa ""mwitu"" ni dubu mweusi wa rangi ya kijivu, ambaye ni mnyama wa kijivu." Na yeye ni tu juu ya elk. Oh, haki katika wazi sasa. Ho, ho, ho. Brian Peck, ambaye anafurahia kuona dubu wa rangi ya kijivu na anafanya kazi ili kuwalinda, anasema ufunguo wa kuhifadhiwa kwao ni kuelewa uhusiano wa spishi tofauti. "Shawz: ""Uthubutu wa binadamu unaweza kuwa na athari kubwa kwa spishi hii maalum, na ni aina ya kiashiria cha afya ya mifumo ya mwitu.""" Chuck Schwartz, wa Inter-Agency Grizzly Bear Study Team, anasema kwamba kutu ni moja tu ya hatari za binadamu zinazohatarisha mazingira ya Yellowstone. "Mwanamume huyo alishangaa sana, ""Nilikuwa nikitembea nje kwa matembezi ya asubuhi." "Kama ""Kila kitu kinaweza kuwa"" katika Jewel Hoyt, Yellowstone National Park" Peck: Oh, yeye ni kufanya kuchimba kidogo. Tuko hapo. (Kicheko) Kuishi duniani anataka kusikia kutoka kwenu! "Kama vile ""Kila kitu kinaweza kuwa na thamani"" (Kile kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichoandikwa na Kilichochochochochochochochochochochochochochochochochochochochochochochochochochochochochochochochochochochochochochochochochochochocho Kuishi duniani ni programu ya vyombo vya habari huru na hutegemea kabisa michango kutoka kwa wasikilizaji na taasisi zinazounga mkono huduma ya umma. Tafadhali kuchangia sasa ili kuhifadhi sauti huru ya mazingira. Sailors For The Sea: Kuwa mabadiliko unataka bahari. Ubunifu wa kufanya ulimwengu kuwa mahali pazuri zaidi, mahali pa kudumu pa kuishi. "Mfano wa mradi huo ni Grantham Foundation for the Protection of the Environment, ambayo inashikilia jukumu la ""kulinda na kuboresha afya ya mazingira ya dunia.""" Kuchangia kuishi duniani na kupokea, kama zawadi yetu kwa ajili yenu, archival kuchapisha moja ya Mark Seth Lender ya ajabu wanyama-pori picha. Fuata kiungo ili kuona mkusanyiko wa sasa wa picha za Mark. Kununua nakala ya saini ya Mark Seth Lender ya kitabu Smeagull the Seagull & msaada Kuishi juu ya Dunia