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Posted by: atowhee | September 10, 2018

WHY ALL THOSE DEAD DOUGLAS FIRS?

ADDED INFORMATION: a well-informed biologist informed this amateur that insects and possibly some diseases are involved in the conifer die-off.  This article in a Jackson County newspaper names the flat-headed fir borer,  and it lists other drought-intolerant tree species that are dying in some instances.  The article also points out that Doug firs are at the eastern edge of their range along the western slope of the Cascades.

See bottom of the blog for a strong response from another birder on the Doug fir story.

I recently drove up and down Interstate 5 between Salem and Ashland and couldn’t help notice the many dead Douglas firs. It is drought that kills these trees.  I talked with Aleysha Christianson of the OSU extension service in Roseburg. She said south of the Willamette valley along the I-5 corridor the Doug firs have spread into areas where oaks once dominated.  That is due to fire suppression which pre-historically would have removed the firs.  The species is not as drought resistant as oaks or madrone or even incense cedar so when these trees are too close together the stress and dryness kill off some of all of a strand. Here is typical scene, along I-5 in Douglas County, crow alive, tree not:dead dfThinning is the best answer to preserving some of those Doug firs that have survived so far.  It is not likely that conditions will get wetter with climate change.  Even where die-offs occur it is likely the prolific Doug firs will re-seed and try again, repeatedly shading out young oaks which grow much slower despite their stolid tolerance of drought.  That’s doubly true of madrone that can actually be killed by some helpful landowner watering them when young.  I have a friend in Jackson County who managed to grow two of three madrone saplings he planted on a rocky, south-facing slope…by ignoring them on hot, dry August days as he watered his other saplings

The state forestry department tells me there are pine beetle infestations in the Oregon forests, but not as severe as the widespread pine death in California’s central Sierra.

BIRDING I-5

A short stop at the one wet marsh in Ankeny NWR: plenty of Long-billed Dowitcher with an occasional snipe sneaking in and imitating the dowitcher feeding teeter-totter.  Least Sandpipers and one Pectoral.  Both yellowlegs present, only one Lesser.  Yellowthroat still in the reeds, and a single Yellow-headed Blackbird was feeding on the mudflats.IMG_1831Fog made photography difficult at 640AM.  Below the snipe has yellow V above his back, rest are LB Dowitchers.ankn-1_LIankn-4ankn-5One portion of the immense Barn Swallow flock at Ankneyanky-10Young Western Bluebird at Canyonville rest area, the best along I-5 in Oregon.blubrd2brbl yngYoung male Brewer’s Blackbird… he’s got the eye already but that glossy plumage comes later.brbl-yng2Two American Goldfinch in a rest area lawn:

amgo-I5No Osprey seen anywhere along the highway, dozens of TVs, a few Red-tails and Kestrel.  Bars Swallow flocks on migration.

South Umpqua River at Myrtle Creek.  I did see a young Bald Eagle there and a female Common Merganser.myrtcrksmokSmoke began to get bad south of Canyonville.  In Ashland some people were wearing masks outdoors. Even above 4500 feet elevation in Cascades in Jackson County smoke was bad and visibility impaired. Above: smoke haze at Merlin.  Below: Ashland.smok23Ankeny NWR, Marion, Oregon, US
Sep 7, 2018
21 species

Cinnamon Teal (Spatula cyanoptera)  X
Mallard (Anas platyrhynchos)  X
Pied-billed Grebe (Podilymbus podiceps)  X
Eurasian Collared-Dove (Streptopelia decaocto)  X
Least Sandpiper (Calidris minutilla)  20
Pectoral Sandpiper (Calidris melanotos)  1
Long-billed Dowitcher (Limnodromus scolopaceus)  25
Wilson’s Snipe (Gallinago delicata)  3
Greater Yellowlegs (Tringa melanoleuca)  6
Lesser Yellowlegs (Tringa flavipes)  1
Cooper’s Hawk (Accipiter cooperii)  1
Red-tailed Hawk (Buteo jamaicensis)  1
American Crow (Corvus brachyrhynchos)  X
Barn Swallow (American) (Hirundo rustica erythrogaster)  200
European Starling (Sturnus vulgaris)  X
American Goldfinch (Spinus tristis)  X
Song Sparrow (Melospiza melodia)  X
Yellow-headed Blackbird (Xanthocephalus xanthocephalus)  1
Red-winged Blackbird (Agelaius phoeniceus)  X
Brewer’s Blackbird (Euphagus cyanocephalus)  X
Common Yellowthroat (Geothlypis trichas)  1


Joel Geier wrote:

 

I’ve been seeing a lot of dead/dying Douglas-firs this summer, presumably due to the extended period of dry conditions.

Most of these are in areas of the Willamette Valley — and north into Washington’s Puget Trough region — where Douglas-firs would have been sparse prior to settlement by Anglo-Americans in the mid-1800s, when this region was dominated by oaks and grasslands.

This is in fact a strong argument for investing in restoration of historical oak savanna habitats: They are likely to be more resilient in the face of continuing anthropogenic climate change. Trying to “save” low-elevation, non-old-growth stands of Douglas-firs through elaborate thinning projects etc. seems misguided.  Better to log them off and, where possible, use the revenue to restore our critically endangered Willamette Valley oak/grassland ecosystems (including oak-madrone woodlands).

I know this is a hard sell in a state that has both a financial and romantic attachment to conifer forests, and even has a Douglas-fir on the state license plate. But the invasion of the Willamette Valley by Douglas-firs is a very recent phenomenon — mainly since the 1880s, and even more, with the post-World War II changes in agriculture and residential patterns.

Just the other day I was looking up some information on the historic town site of Tampico, which was a notoriously bawdy rival to Corvallis along the Territorial Highway through the edge of the Coast Range, in the early post-settlement period. Among the few remaining traces of the town are three large Douglas-firs that were *planted*  by the townsfolk. The town site is now nearly surrounded, in three directions, by Douglas-fir forests that were planted by OSU in historic oak savanna (and in the fourth direction is a weird plantation of some type of exotic pines, perhaps European, that I’ve never keyed out). 

But think of that … in the 1860s people were purposely *planting* Douglas-firs out in the valley, and those trees are still distinguishable today. It shows how scarce Doug firs were out in the valley, at that time.

 

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Responses

  1. Good info, thanks. Hate to hear about Doug firs not making it though.


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