spring 1998 conservation almanac newsletter, trinity county resource conservation district

8/3/2019 Spring 1998 Conservation Almanac Newsletter, Trinity County Resource Conservation District

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Conservation AlmanacConservation AlmanacConservation AlmanacConservation AlmanacTrinity County Resource Conservation District

Spring 1998 Vol. VII No. 2

In This Issue:

Weaverville Basin Trail GranGrass Valley Creek Project Report Complete

Sediment Risers : Purpose and FunctioCaltrans Requests RCD Aid with Projec

RCD Receives DF&G GranEmployee Featur

The Battle Against YellowStarthistle

Can We StopCan We StopCan We StopCan We Stopthe Thrivingthe Thrivingthe Thrivingthe Thriving

Thistle?Thistle?Thistle?Thistle?

OOOOne of the most noxiousweeds in Trinity Countyis yellow starthistle(Centaurea solstitialis),

which infests roadsides, pastures, hayfields, and other disturbed areas.Since its introduction from Europe inthe mid-1800s, yellow starthistle has

spread through California at analarming rate, infesting an estimated10 million acres. Its rapid spread hasbeen to the detriment of Californiasnative flora, particularly thegrasslands. Conservationists nowworry that yellow starthistle is aserious ecological threat to thebiodiversity of Californias flora.

Yellow starthistle is such aninvasive weed because of its highlysuccessful biology, which allows it to

out-compete and displace native

plants. It is an annual that germinatesafter the fall rains and is wellestablished by the spring, when native

perennials plants are just beginning todevelop. Yellow starthistle also sendsdown a long taproot, which enables itto obtain moisture even on hot, drysites, when other plants are underwater stress. Yellow starthistle alsoproduces an enormous quantity ofseed each year, with seeds remainingviable in the soil for up to ten years.

Despite yellow starthistlesspread, several methods have beendeveloped for controlling this weed.

Unfortunately, no single treatment orapplication will work on its own. Butby using one or several of these

techniques, repeated at theappropriate time over several years, itis possible to control, or eveneradicate, yellow starthistle.

Commonly used methods forcontrolling yellow star thistle arecultivation, mowing, livestockgrazing, biological controls, seeding,prescribed burning, and chemicalcontrol.

Cultivation

An effective way to controlyellow starthistle is to till infestedareas after the first fall rains toeliminate any starthistle seedlings.Because tilling will also bring buriedseeds up to the surface, the areashould be tilled a second time in thespring to remove this second flush ofseedlings. A third tillage may benecessary in late spring or earlysummer to remove subsequentstarthistle germination. Although

(Continued on page 2

Dont Wait! Spring is the time

to control starthistle on your

property!


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Page 2 Trinity County Resource Conservation District Spring Issue 1998

Livestock Grazing

Short-duration, high-intensity grazing with cattle, sheepand goats is another effective toolfor controlling yellow starthistle,especially in pastures and otherlarge areas. As with mowing,

timing is critical for grazing to beeffective. Plants need to be grazedduring the bolting stage in Mayand June, when the plants aresending up erect stems and beforespines appear on the plants (seephoto at right). Yellow starthistleshould never be grazed in Marchand April, during the rosette stage,when plants only have a basalrosette of leaves and no stems arepresent. Grazing during this stage

will only encourage the growth ofthe starthistle.

After initial grazing, one tothree additional grazing periods attwo-week intervals (May throughAugust) are needed to crop any re-growth of starthistle. Althoughgrazing alone will control (preventspread of) yellow starthistle, thistechnique will not eradicate(completely eliminate) infestations.

Horses should not be

grazed on starthistle, becauseprolonged ingestion can lead to thefatal nervous disorder, equinenigropallidal encephalomalacia orchewing disease.

Biological Controls

In 1994 the AgriculturalCommissioner released populationsof insects that prey upon yellowstarthistle, at several locationsthroughout Trinity County. These

natural predators included theyellow starthistle bud weevil,Bangasternus orientalis. It washoped that these insects wouldestablish populations to keepstarthistle in check.Although the use of biologicalagents to control starthistle is

promising, more time andresearch is needed to see if thesecontrols will be effective.

Seeding

Although the methodsmentioned so far will controlstarthistle, additional measures

are needed to re-establish otherplants, especially in areas ofheavy infestation. Seeding withperennial grasses has been tested,but results have been mixed. Theslow-growing perennials tend tobe out-competed by fast growingstarthistle. Although research hassuggested herbicides are neededinitially to establish grass stands,the hazards associated withherbicides must be considered.

Also, hand pulling starthistles isan effective alternative tochemicals in smaller plots wheresuch physical treatment isfeasible. Once established,perennial grass stands have thepotential to reduce starthistle by

(Continued on page 3)

tilling will remove seedlings, it willalso expose the bare soil, making itprone to erosion. It is important,therefore, to seed after treatments toestablish ground cover. To establishother plants in the area, it isrecommended that tillage be done

for two years to reduce thestarthistle seedbank, followed byseeding with a perennial grassmixture.

Mowing

Mowing is an easy tool thatlandowners can use to controlrelatively small yellow starthistleinfestations; however, timing iscritical for mowing to be effective.Starthistle should be mowed in its

budding stage, when about 5% ofthe flower heads are in bloom, andflowers are bright yellow in color. Ifmowed before this early floweringstage, the number of starthistleplants will only be increased, whilelate mowing may help to distributemature seed.

Not only does timing have to beconsidered when mowing, but alsothe height of the mower blade.Adjust the mowing height so that

the main stem is cut below thebranches, as shown in the drawingbelow.

Additional mowing, one to threetimes during the growing season inlate May through September, will beneeded to crop any re-growth.

Yellow starthistle in the bolting, pre-

spiny stage. At this stage, control bylivestock is optimum

When mowing starthistle, make sure

you cut below the lowest stems.

Do Not

Cut Here

Cut


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shading and out-competing it forwater. Subsequent measures, such asperiodic mowing or grazing, wouldbe needed to prevent starthistle fromre-emerging. Recommendedgrasses include native species suchas blue wildrye (Elymus glaucus)and California brome (Bromus

carinatus), and pasture grass such asBerber orchardgrass and Lunapubescent wheatgrass. Research hasalso shown the potential for highdensity seeding of forage annualssuch as Lana vetch (Vicia villosa)and subterranean clover (Trifoliumsubterraneum).

Prescribed Burning

Recent studies have shownthat controlled burning can

dramatically reduce yellowstarthistle infestations. Burns need tobe conducted in late spring beforestarthistle seed has matured, andshould be done consecutively for atleast two to three years. This yearthe RCD and the CaliforniaDepartment of Forestry and FirePrevention will be conducting aprescribed burn in Hayfork to see ifthis technique will be effectivein controlling yellow starthistle in

Trinity County.

Chemical Control

Although chemicalherbicides have been used to controlyellow starthistle and re-establishperennial plants, many people worryabout the hazards of thesechemicals. Due to suchenvironmental concerns the RCDdiscourages the use of herbicides forcontrolling yellow starthistle .

For further information oncontrolling yellow starthistle, pleasecontact Christina Veverka at (530)623-6004 for a free pamphletdetailing the techniques mentionedin this article. For morecomprehensive information on the

subject, landowners can orderThomsen et al, Yellow StarthistleBiology and Controlfor $8.00 fromUniversity of California. publications at (510) 642-2431.

Trail Tracks

Weaverville Basin TrailSystem

Receives Grant

TTTT

he Weaverville BasinTrail Committee has justbeen notified that it will

be a recipient of a$1,000 grant from the nationalConservation Fund's AmericanGreenways Program in Arlington,VA, sponsored by the DuPontCorporation.The grant will be usedto help update, revise andformalize the trail system map;develop a brochure describing thetrail system to assist in thepromotion of tourism; and to installadditional signage for trailidentification.

The Weaverville BasinTrail System was one of 42awards the Conservation Fund willmake this year and was selectedout of 220 applicants from 31states. The American GreenwaysDuPont Awards Program providesgrants of up to $2,500 as seedmoney to non-profit organizationsand government agencies to helpdevelop new, action-orientedprojects displaying innovative local

efforts toward conservation ofhabitat and historic sites, outdoorrecreation and greenwaydevelopment.

In addition to receiving theaward, the Weaverville Basin TrailSystem of historic routes that havebeen preserved, mapped andmaintained by communityvolunteers will be showcased as anational model, according to theConservation Fund's president,Patrick Noonan. The American

Greenways DuPont Award GrantsReview Committee consisted ofland use and conservation expertsfrom around the country and wasdirected by the CEOs of DuPont,The Conservation Fund and theNational Geographic Society.

RCD Seeks TeacherParticipation In

Education

Programs

The RCD is hoping toexpand its in-schoolresource conservationeducation programs next

year. If you are a teacher in a Trinity

County school and you are interestedin supplementing your sciencecurriculum, we would be interested inassisting you with watershededucation during the 1998-1999school year. Watershed educationalcomponents include soil science,forestry, aquatics, and wildlife.Emphasis in these educational units isplaced on hands-on discoverylearning, and the curriculum willinclude holistic, ecological

approaches to resource use andconservation.

The RCD is still available tocoordinate and implement Adopt-A-Watershed curriculum for those whohave participated in this servicelearning curriculum or any interestedin having their classes adopt awatershed. Presently, the RCD is alsoexploring the possibility ofimplementing other populareducational strategies for watershed

education such asProject WetandProject WILDand will continuesponsoring students to compete in theCalifornia Envirothon and StateSpeak-off contests. The RCD alsosponsors students to attend a RangeCamp each June.


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confluence with the Trinity River.These ensure that even if

sediment migrates through thestreamcourse it will be less likelydeposited into the Trinity River.

Next, the way wascleared for a full-scale restorationeffort by the purchase of privateland in GVC by the Trinity RiverRestoration Program.

The project unfolded overthree phases. The first phase

utilized extensive hand work toconstruct instream sedimentcatchment structures, which,unfortunately provedineffective in this watershedeven though such practiceshad been very effectiveelsewhere.

The second phase ofthe project changed its focusfrom trying to treat the flow of

sediment in the streamsthemselves, to the removal ofpoorly constructed roads androad crossings thatcontributed the major portionof sediment entering GVC.Emphasis shifted also from

An example of the extreme erosion that

takes place in decomposed granite soils.

RCD Publishes Report on

Grass Valley Creek

Restoration Project

The RCD, with theassistance of theNatural Resources

Conservation Service, hasrecently finished its account ofthe large restoration projectundertaken in Grass ValleyCreek (GVC) Watershed. Themajority of the work on theproject spanned from 1992through 1996, although severalaspects of the restoration workrevegetation and monitoring ofrevegetation workwill continueon a smaller scale into the nextmillennium.

In the early 1980s GVCwas identified as a major sourceof sediment impacting the TrinityRiver in the wake of theconstruction of Trinity andLewiston Dams (see relatedarticle at right). The Trinity RiverRestoration Program identifiedseveral major causes of the

degradation of anadromous fishhabitat, and GVC was identifiedas one of them. Because of thisCongress OKd a plan to restorethe GVC watershed in the wakeof disturbances to the veryunstable soils in the watersheddue to poor logging practices,particularly the construction of alarge network of roadsconstructed that didnt take intoaccount the unstable nature of

the soils.

The restoration workitself was preceded by theconstruction of large sedimentcatchment basins a third of theway downstream from theheadwaters of GVC and at its

hand work to the use of heavyequipment.

The final phase, whichis to some extent still inprogress, has focused onrevegetating the barren hillsidesand riparian (streamside) areasand monitoring vegetationtreatments for success ratesover time.

Monitoring of sedimentflow over the past several yearsindicates that the project hasbeen successful. The GVCRestoration Project reportdocuments all phases of theproject, including historicalprecursors to the restorationwork, and it offers numerousprescriptions for treatingerosional problems in unstablesoils like those in the GVCwatershed. Copies of the reportare available from the RCD for$15.00 (B&W) or $25.00(color).


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Sediment

Risers:

Purpose and

Function

IIIIf you have ever drivenback from Redding on299 and, after passingover Buckhorn Summit,

noticed strange pipe-likestructures sticking up to the right

of the highway, you will haveglimpsed the exciting world ofsedimentrisers.

OK, maybe not exciting,but certainly functional.

Sediment risers have beenused extensively in the GrassValley Creek watershed, throughwhich highway 299 passes, tominimize the impact of sedimenton Grass Valley Creek and

ultimately the Trinity River itself(into which Grass Valley Creekdrains).

Sediment risers functionby ponding water around the riser

to settle out sand-sized particlescarried by the stream. As thewater level rises around the

riser, the sediment collects at thebase of the riser and the toplayer of water, relatively free ofsediment, flows through verticalopenings in the riser and into aculvert (culverts are pipes thatallow streams to cross roads bypassing underneath them).Sediment risers are coupled tothe inlet of a culvert and create aninety-degree elbow bend inthe culvert. They are usually

installed in smaller, seasonal orephemeral creeks (also knownas draws) tributary to GrassValley Creek. Sediment basinsaround the risers mayoccasionally have to be dredgedto keep the sediment frombuilding up and entering theopenings in the riser. Duringlarge storms, when flow is high,the water level may rise to thetop of the riser and flow directly

into the opening, which is usually1-1/2 times the diameter of theculvert. Since sand-sizedsediment is heavier than water, itsettles out around the base ofthe riser before the water entersthe slotted opening or the top ofthe riser.

In the Grass ValleyCreek watershed,where the soils arehighly erodible (andtherefore highlyproductive ofsediment) culverts can

quickly becomeplugged with sedimentand other debris,causing the stream toflow across the roadsurface, oftenwashing away theroad crossing anddepositing even more

sediment in the stream orcreek.

The soils in Grass

Valley Creek watershed arehighly erosive because theyconsist in large part ofdecomposed granite (DG). DGis highly subject to weathering,breaking up into sand-sizedparticles that are easilytransported by water downhillslopes and draws to end upin tributaries and Grass ValleyCreek.

Large amounts of sand-

sized sediment can seriouslyaffect salmon spawning andrearing habitat. Salmon needcoarse, cobble-sized rocks instreambeds for their eggs. Thelarger rocks shelter the eggsand small fry from predatorsbut allow oxygenated water toflow freely around the rocks.Sand on the bottom of creek-and riverbeds starves thesalmon eggs of oxygen,

suffocating them.Sediment risers have

proven very effective instemming the flow of sedimentinto Grass Valley Creek as wellas tributaries to the South Fork,reducing impact on TrinityRiver basin salmon habitat.

Water is meant to pond around the sediment riser

and deposit accumulated sediment around the riser.

The sediment-free water then enters the riser

through small vertical openings and flows out

through the attached culvert.

Without a sediment riser a culvert can

easily get plugged with accumulated

sediment.


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were chosen because they arewater tolerant (they will be in directcontact with water), they are quickgrowing, and grow to be very tall.Not only will they lend a moreaesthetic appearance to thesesites, their full canopies will providemuch-needed shade to the creek tokeep water temperatures cool.Salmon and steelhead need coolwater temperatures for spawningand rearing.

Christina also proposedplanting in the fillslopes above theriprap (closer to the highway) toprovide a "visual shield" ofvegetation along the highway. Shesuggested the use of nativeblackberry bushes because theywill grow to spread over the riprap.These portions above the riprap arefar from the creek and becausethey get a lot of direct sunlight,plants placed here need to bedrought tolerant. Nativeblackberries once abounded inTrinity County, but they have beenall but run out by imported speciesof blackberry, particularlyHimalayan blackberry (you can tellthe difference between native andnon-native species of blackberry byexamining both the leaves and thethorns: natives have leaves inthrees while exotics have groups offive joined leaves. Also, nativeshave smaller thorns than exotics).

In addition to shrubs,Christina also proposed planting talltrees, like ponderosa pine, alongthe highway to further act as avisual barrier between the road andthe riprap.

Planting will take placebetween late November and earlyDecember this year and the projectwill take about a week to complete.Also, maintenance (primarilywatering) will have to be performedfor about two years until the plantsare well established.

Caltrans Requests RCDAid in Revegetation

Project

BBBB

rian Crane of Caltransrecently approached theRCD with a request to

help revegetate portionsof Weaver Creek betweenWeaverville and Douglas Cityrepaired in the aftermath of theJanuary 1997 storms. Thepurpose of this revegetationproject is to improve the visualappearance of the repairedsections of streambank. Highflows that winter eroded manysections of streambank along thecreek, in some places even

washing out portions of Highway299 (you probably recall with notmuch relish the detours and longdelays while you traveled betweenDouglas City and Weaverville thatwinter). Caltrans stabilizederoding streambanks andprotected them against furthererosion by lining them with rockriprap. Riprap is placed insections of streams that receivethe most flow energy during

storms.The riprap has effectively

protected the streambanks but isnot very aesthetic--appealing tothe eye. Caltrans contracted withthe RCD to plant trees and shrubsin or around the riprap to soften itsappearance. RCD RevegetationManager Christina Veverkalooked at the sites and devisedseveral ways to improve theappearance of the protected

banks when viewed from scenicHighway 299.

Part of the vegetationstrategy to beautify the highwaywill include planting cottonwoodsand alders in 82 plastic pipesinstalled within the riprap when itwas placed on site. These trees

RCD Receives Fish

and Game Grant

T

he RCD was recentlygiven the go ahead fromthe CaliforniaDepartment of Fish and

Game on a grant proposalsubmitted in December of 1997.The RCD had requested fundingfrom Fish and Game to conductan inventory of road networks onForest Service and private landsin the Upper South Fork, HappyCamp, and Plummer Creekwatersheds, which would be usedto complete watershed analysesand prioritize watershedrestoration activities within the

watersheds.Road inventories areconducted in order to determinethe amount of sediment producedor potentially produced in specificsections of a road, particularlywhere the road crosses a stream.Past road inventories haverepeatedly revealed thatundersized culverts (pipes thatallow water to flow underneathroad surfaces) are a major cause

of sediment deposition.Historically, culverts that met "50-year" storm requirements wereinadequate in handling flow fromlarge storms. High flows can clogculverts with debris and wash outroad crossings because theywere not designed for the size ofstorms that actually occur withsome regularity in thesewatersheds. A road inventoryidentifies those locations mostly

likely to fail during large stormsand the resultant high flowsassociated with them. Roadinventories also identify otherportions on roads where poordrainage can lead to erosion andsubsequent deposition ofsediment into creeks or the SouthFork of the Trinity River .


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to ideas and information, theyalso have to dosomething withthem, and this doing is theway they learn it. Its creativityin the service of growth, notjust a trophy to hang on a wallto say I painted that. Thatkind of creativity is less

interesting to me.Most recently, Scott has

seen music as his maincreative focus. Scott performsregularly around Weaverville,always hoping that whenpeople come to listen that theylisten pasthim to the storieshe tells in his songs about thelives of ordinary peoplewrestling with their commonhuman lot and its attendantdilemmas. There'ssomething that binds us alltogether, even though it's hard

to define. I think,sometimes, that aheroic approach toordinary life emergesin the music I listento, and it's somethingI want to pass on topeople through

performing music. Imake demands on studentsand audiences to listen closelyand to think, but I also wantthem to enjoy themselves. Thetwo are not separate,something that's beenforgotten, I think, bymainstream television, movies,and the recording industrywith their constant emphasison entertainment value:

novelty and shock. Life is hardbut its also good. Simplethings people have known forgenerations are the mostimportant things. Im stilllearning that.

maintain healthy ecosystemsfor plants, animals, andpeople to thrive in.

Scott's work andeducational background areextremely varied. He holds aBachelor's degree in VisualArt and a Master's degree inEducation, as well as aCalifornia teaching credential.He has taught many subjects,both in universities andpublic schools, and currently,besides his work with theRCD, he teaches andperforms music part time invarious Trinity Countyschools through the Artists inthe Schools

program.I have lived a variedlife because I've had so manyinterests. It took me years tofigure out how I wasgoing to combineinterests in art, writing,music, teaching, andthe outdoors. I'm stillstruggling with it tosome degree, but I thinkthe link that combines

all that I do is creativity.Creativity is a term that isoverused nowadays, but itstrue for me. Along the way Istarted to see art or writing orwhatever I was doing not asjust a product, but as a wayof being. Mostly, creativity, isa way of processinginformation, ideas, andemotions so that I canunderstand and use them.

Thus, writing a technicalreport can be as creative tome as writing a song orpainting an image--all ofwhich I do regularly.Creativity is also an importantaspect of my teaching, for itsnot enough to expose people

Employee Feature

Scott BrennanScott BrennanScott BrennanScott Brennan----SmithSmithSmithSmith

S

cott Brennan-Smith isthe RCDs EducationSpecialist, whose job it

is to inform both members ofthe public and school-agechildren about responsibleland use and the science thatlies behind it. Until recentlymost of the in-schooleducation the RCD undertookwas implemented by theAmeriCorps Watershed Project,and Scotts work focusedmostly on publications (thisnewsletter and varioustechnical publications). Ivereally liked working withdesktop publishing software,as well as the process ofcrafting publications. Its themaker part of me: I likelooking at a tangible product.But now Im ready for achange, and if this changetakes me into the schools to doconservation education directly

with students, I wouldwelcome that. Id like to see aprogram that gives a balancedview of resource use andenvironmental protection. Ithink the best approach is toappreciate that people need toutilize natural resources but toprotect them as well, to

spring 1998 conservation almanac newsletter, trinity county resource conservation district

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