1988 Landscape Management Plan Crum Creek Woods

Page 1

路 .:

Andropogon Associates) Ltd. Ecological

Plallllill}~

374 SIIIIYS LmlC

& Desi.?J'1

Philadelphia PA 19128

LANDSCAPE MANAGEMENT ACTION PLAN FOR THE CRUf'1 CREEK WOODS SWARTH,10RE COLLEGE

Prepared for

The Arthur Hoyt Scott Horticultural Foundation "Swarthmore CoiJege Swarthmore PA 19081

April 1988

Architects) Lmldscape Architats E.:r PIIl/lllcr.';;

(215) 487-0700

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Andropogon Associates, Ltd. Ecolo,?ical Planning & Dcs(~fI 374 SIIIIYS Lalle Philadelphia PA 19128

LANDSCAPE I 1ANAGEf"1ENT ACT ION PLAN FOR THE CRUM CREEK \VOODS SWARTHMORE COLLEGE v

Prepared for The Arthur Hoyt Scott Horticultural Foundation Swarthmore PA 19081

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TABLE OF CONTENTS Introduct ion

3

Landscape Management Strategi es

5

sJ:.Q.r_mWtlti:!I Mtlntlgement Strtltegies Shtlllow Temporary Iffijilllltidment low Etlrthen Berm wi th Infi ltrtlti on Trench Shtlllow Terraced Impoundments with Infiltration Trenches

5 8

Dead Wood and Brush

14

EQsion Control Strategies --"['heck Deirns-Yn GUlliesCheck logs on Slopes

16 18

10

12

Control of Exotic Inyasiye Vegetation '--------Japonese Honeysuckl e Norway Maple '

------

20 21 25

Replanting Strfttegies

~-tflrl~DltlCernent

29

floreroot Plonting

32

Action Plan: Project AreaS Project Areas Key Plan Area 1: Ftlculty Housi ng Site Area 2: ,\rnphitheatre Slope Area 3: Performing Arts Center Area 4: Music library Slope Area 5: Building 18, Alligator Rock Slope Area 6: DuPont Parki ng Lot Area 7: Elm Avenue Culvert

LAND:::;CAF'E t'1ANAGEt'lENT ACTION PLAN FOR

C~:UM

36 38 40 42 44 46 48 50

52

CREEK WOODS

2


Introduction The purpose of t.he Action Plan is t.o define (l set of management ijnlj restoration guidelines for the Crum Creek Woods v'illich can be implemented by Swarthmore College in the ne:,t few years. The focus is both short term and in-house, intended primari I y for i mplementat i on by the Grounds Depal-tment. PI-I] j ects vihi eh requi re e)(tensive fundrai si ng, constructi on documents, and outsi de bi dders are not addressed; hov,ever, the1d are noted and descritled 'Nherever possible. This Action Plan is not rneant t.o be cornprehensive. There are numerous prob 1ems unattended to here. Ho . .路vever, the plan Ijoes ernbraee a set of acti ons y路.'hi eh, if earri ad out, waul d si gnifi cantl y reduce di sturbance to the Crurn Creek Vioods and initiate habitat restoration. The rnanual sections include techniques designed to address the control of stOtTOv'.'ater, the repGir of gullies, t.he removal oi Ijeadv'iood and invasive e:,~otic vegetation, and the replanting of native forest canopy. A more complete Ije'3cription of the 8)dsting "ite conditions v'iI-lich t.his Action Plan is 'jeared to can be found in the report and accornpan~ing rnaps, "A Land'3eape f1dnagement Program ior Crurn Creek 'I'.,Ioods", 6 August 19;35, prepared b~ Andropogon Associates, Ltd. The Act i on PI an is di vi ded into t. 'NO part.s: LandscaQ8 Managernent '3trategies describe the goals and activities Yihich are the basis of this Action Plein. Trle pages in this section are Ijesigned t.o forrn the frarnework fora Forest f1anagernent f-1anual ",'{hich can be e)(panded as v'iOrkcontinues on the habitat restoration of Crum Creek Vioods. Action Plan: Project Areas identify the rnajor project areas and the recornrnended restoration strategies. V路/here relevant, selected high

prioriti:! projects tl8i:lorllj the scope of jJle Action Phln ere elso noted. It is also strongl1d recornmended that an annotat.e1j photographic log of restoration effort.s be kept for fut.ure records. The field oi rest.oration is new enough that all t.he techniques are sornevihat experirnental and the

LMDSCAPE f"IANAGU1ENT ACTION PLAN FOR CRUM CREEK 'w'OODS

3


informBtion g(lined by the Scott Horticultur(ll Foundl'ltion in the Cr-um Creek \楼oods will provide en invaluBble demonstration area. The Action Plan is confined to the east slope of Crum Creek, t~,at is, the slope adjacent to the College, rather than the slope adjacent to the Blue Route, now under construction. The strategies and techniques described herein, ~Iowever, are equally (lppliceble to the fer side of U18 valley. All Ule key meps in this report are taken from the Existing Conditions Map, 6 August 1985, prepared tly Andropogon Associates, Ltd.

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Landscape Management Strategies

Stormwater Management Strategies The mo::;t significant source of demage in the Crum CI-eek \,yoods, y,ithout Question, is 8,;cessive stolTf1'I'v'ater runoff (lnlj the erosion anlj sedilnentation U-Iat it causes. There ere tlNO major sources. The first is sUI-face I-unoff fl-om roaljs , paths, BI-flj othel- peved ereas on tJle ;'ld JBcent pI (lteau, whi Cfl overflov,s Ijown:31 ope , farming numenJUS I~ull i es and IjistUl-bing large I3I-ea8 of the fOI-est. Controlling this I-unoff to eliminate, 01- to Bt 1east reduce, Ole Ijo '0'111 Slope rnovement of v,ater is the Qoa 1 of the recolnrnerflj;'ltions. The secorflj source of stomw,ater darnage is rtmoff from builljinl~s, lawns, and paving on the plateau 'Nhich is collected in storrndrains VI'hicfl Ijiscf-Iol-ge on the slope, creatinl~ the rnost sevel-e erosion anlj deepest ravines on the site. Trie most extreme recent example is Ole revi ne vihi Cfl hes opene1j up be 1OVv nle cul'vert from the 1-1usi c Buil,jin'l Long-t.erm recommendations ere gil'en to relj8sil~n iJI8 stolTnwater s'dst.em to retain vvater ranier then simply di:3chm-ge it dO,,/·/l1s1ope. In t;ome places, both slJl-fece I-unoff end runoff dischargelj from pipes ere comtdnelj in the same revine. It is 'NOI-Hl noting nldt the reco(nn1enljations contained herein reflect a rnuch higf18r 181'el of I-etention than is the convention t.oday. Sirnil;'jrly, OIK goal hes been to provide for stOtTnwel.er retention lel-'~ely on tJI8 pleteeu nltrier than r81yinl~ on Iji:ochan~e ont.o tJle slope_ /, more t"'-;'J!jitional ep~,,-o;'lch to Ule erosion qullies woul,j be to reinfol-ce t.hern, such as 'Nith ,.,·::.hi,-,f"l,-'

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eljditional erosion. ~3uch en appl-oach "Nould create sel'ere distUl-bance to the fOI-est durinq, construction and has e I'erq poor success recorlj. Hlis meU"lod Ijoes not ad,jress surface runoff Ijirectly from the plateau, nor the issue of reestat')ishinl~ a more net.unll hydrologic regimen.

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slope. in all cases, t.he recommenljelj long-term ections in\lol'lle the rede:;ign ;'lrflj reconst.ruction of ;'j portion of the stonrlweter infrastructure to elirninat.e Hle culvert on the slope or at least reduce flows

LANDSCAPE '-1ANAGEMENT ACT I ON PLAN FOR

CRU~1

CREEK V/OODS

5


substontielly. The sitework for the Performing Arts Center should be given hi gh pri ority for appropri ate revi ew. The t'1usic Building cul'路lert is e graphic example of the pr-oblern which illustrates the nature of the long-term recommendations in U"lis repor-t. Not only is U"le ravine it has cr-eated a direct source of :,:evere rji5turbence from the top to the bottom of U'le slope and to Crum Cr-eek itself, trut the consequences of this damage extend for- treyonrj the irnmediete area. Impacts on gnJundwater hyrjr-ology will inevitatrly tre felt throughout the v'tater-sherj and will most 5e"lerely impact the most desiratrle forest species, such as the rnature stanrjs of beech and oak which ar-e still surviving on this slope. In arjrjition, nur'ner-ous small drainage courses wtli ch ere tri trutari es to the Irlfli n rflvi ne flr-e all now deepeni nq as t.hey adapt to the altered hldrjroloqic gnldient of the eroded qully. The irnpacts are still occurTinq end it will tre some time trefore tl"IB darrlaq8 can be asse:3serj. Forest r-estoration requir-es that. this problem be adrjres~:ed in a tin"lely fa:3hion find criticel to en effective solution is e r-erjuction in ttle volurrl8 of water 't路/hich is directed to this culvert. Sucl'l a project, how8ver-, is troth complicaterj and e>:pensivB Bnd cennot be accornplished by the in-houo:e activites of the 13r-ounrjs Depar-trnent. 'dhile r-etn:rfitting the storTnwater rnGnar~ement sld:,:tern is what is required to seve the \'..-oorjs, it is unfor-tun;3telld rrlor-e likely th;31. propc"3ed nevI' constxuction will grossly aggr-ava1.e the pr-oblem. Of gr-eatest concern is nle proposerj nevI' Performing Arts [enter, v'lhich is iilr-eadid sited to rrlaxirniz8 U'18 potential for negative ir"i"lpacts to the fore:::t anrj :':lope. If an Gccess n:r;3d is constl-ucted treldond the truilrjinr~, the rjflmar~e to [n.lrf) Cr-eek 'w'oorjs maid grossly corn~rr-orni:,;e the r-ernaining h;~bitat in thiit por-tion of t.he V-loorjs. These sitings also rnGxirnize the difficulties of rnanGging st.orTrn'iet.er ej'ppropriately, and rney even r-equir-e pumpinr] nmoff further up::lope to act"Jieve effective r-etenUon. It is unlikelld t.hat the existing forest cornrnunit i es woul d ::urvi\"8 t.he cr-eat i on of another IrlB j or ravi ne or additional nHloff to the exi:::tinr:J n'lvine. The r-ecomrnended short -ter-rn BeU ons, however-, 'Nhi ch are descri bed in this report, con all tre implernenterj as latror and fundinq trecorne available. It is strongly recommended that at least a portion of the regularrnai ntenance budget be ell oceterj to f ore:,t restor-aU on to i nit i at.e e r-egul er management effor-t. The project areas, priorities, and rnanagerrlent stretegies will ensur-e that even limiterj work will be focllsed on the most critical projects. The Action Plan also concentrates on the upper slopes, LANDSCAPE t'"1ANAGEf-1ENT ACTION PLM FOR CRUt'1 CPEEf( ViCtODS

6


where the problems begin. The problems on the lo\','er slope, moreover, cannot be effectively dee1t with until the upper slope is adequately stabi 1ized. Three major techniques are recommended for controlling surface runoff: 1. impounding surface runoff on the pleteBu on lawn and paved surfaces

wherever possible; 2. estBblishing a low eat-then benn along the rim of entire plateBu erjges as (l barrier to reduce overslope flow; where feasible, an infiltration trench would elso be created just upslope of t.he berm, and 3. on longer slopes, a sequence of shallow terraced impoundments ','vith both berm and recharge trenches can be used to increase retention (lt1d i nfi ltrat ion.

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Stormwater Management Strategies: Shallow Temporary Impoundment v/herever buildings are not immediately edjacent to the forest, there ere likely to be opportunities for impounding surface runoff in Breas of existing lawns end paving. The most obvious choices are arees where pet-iodic standing v\"ater already occur, such as the DuPont parking lot, .,vhere the level of impoundment can be increased to provide greater retention. In virtually all cases, tl"lere is en existing sV'I'ale into "il,'t"lich the spilhvay can be directed. Do\,vnslope v'later movement will not be eli mi nated, but it can be reduced. The success of ti'li s approach depewjs upon I'low frequent 1y it is emp 1oyed. No si ngl e sha 11 0\'1/ i rnpoundment \'vi 11 make that great a difference, but numerous small impoundments througrlout the campus can make a very significant contribution, Several appt-opriate sites are noted later, such as trle gmss at-ea behind the bleacrlers at tile playing fields, These shallo\'\' depressions can still be maintained in turf v,'t"lere desit-able and v\'ill not alter the present "look" of trle csmpus, as trlsy do not require the anti-vortex devices Elnd velocity dissipators tl"lat 'i{ould be necesssry for a large detention basin,

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"GRASSED AREA

SHALLO'w TEMPORARV 111POUNDMENT OF WATER

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IMPOUNDMENTS SHOULD BE CREATED WHEREVER AN OPPORTUNITY EXISTS, SUCH AS ALONG GRASS VERGES, (AS SHOWN) AT THE EDGES OF PLAY I NG FIELDS, LAVmS, ETC.

SHALLo\y TEMPORARV IMPOUNDmNT CREATED BV REGRADING GRASSED AREAS ",11TH Lo\y TRAFFIC KEV PLAN

Sua liow Tempor-ar-y impoundment LMWSCAF'E MANACJEr"JENT ACTION PLAN FOR CRU~1 CREEI( vmODS

9


Stormwater Management Strategies: Low Earthen Berm with Infiltration Trench

An important le'路/el of protection can be provided to the slope by establishing a low earthen berm bell-Yeen the developed portions of the ~;i te and the forest on the steeper slopes. Hli s lovy' berm ,,路vi 11 reduce the frequency of overslope movement of v,8ter and provide some lirnited stonmvater retention. Tt-te soil for HIB berm can tie obtained on site and gravel can be used to replace Hie soil to Ct-eate an infiltration trench along the forest margin. Again, only small 'v'olumes of t-unoff at-e involved here at ilny one site, but once incorporated illong U'le entire campus edge, significant protection can be afforded.

LMDSCAPE t1ANAGEt-1ENT ACT tON PLAN FOR CRUM CREEK WOODS

10


"REGRADE TO FORM A RIM BERM Y~ITH A LEVEL TOP OF NOT MORE THAN 1B" HIGH SURFACE IMPOWWMENT INFILTRATION TRENCH OF NOT f10RE THAN 2'-0" DEEP

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INFILTRATION INTO SOIL

SECTION AT EDGE OF WOODED SLOPE

RIM BERMS SHOULD BE LEVEL SO AS TO IMPOUND \¥ATER

TREE CANOPY

WOODED SLOPE

KEV PLAN

Low Earthen Berm with infiltration Trench LANDSCAPE 1'1ANAGEI'lENT ACT I ON PLAN FOR CRUM CREEK ViOCiDS

11


Stormwater Management Strategies: Shallow Terraced Impoundments

In some cases, a sequence of berms and infiltration trencrles can be used where the slope is long and srlallovi, such as the courtyard betv\leen the faculty rlousing sites.

LANDSCAPE MANAGEMENT ACT ION PLAN FOR CRUM CREEK V,IOODS

12


,

SLOPE REGRADED TO FORM BERMS AND TERRACES PLANTING SHALLO'd IMPOUNDMENT TERRACE -, GRAVEL RECHARGE

TRE~~CH

SECTION

RECHARGE TRENCHES i짜8---t--

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PLANTED BERMS

TERRACE

. KEY PLAN

Sha!J ow Terraced impoundments LANDSCAPE l'IANAGEl'IENT ACTION PLAN FOR CRU11 CREEK ViODDS

13


Landscape Management Strategies: Dead Wood & Brush

In en undisturbed natural forest, dealj trees and tlru~;i'l pla~ an important role pt-oviding sl"telter for 'Nildlife and food for Ell"tost of insects and decomposers. CBtBstrophic events, such es e tornado or en extremel~ hot wildfire, Wllich might le8',18 e,,:tensive s,vaths of destruction occur relativel~ infrequentl~ and reco'路/snj is usuall~ surprisingl~ rapid. In an urban forest fragrnent, tJ"le scenario m81j be ',len,) different. Numerous dead trees and large areas of brush rnal,) t-esult from a variet~ of impacts. Filling 0'路18r the edge of the plateau can kill trees all along the slope. Si mil flrl~, a stream e'5rTyi ng greatllj i ncr-eased vol urnes of I.wban runoff can severely undercut trl8 edl~e of the channel and topple numerous floodplain trees. Hie r-esult i n9 debri scan inrlibit natura 1 rel~enen5ti on and provi de opportunities for the in'路.w;ion of disturt'Bnc8 species. Because dead wood onlj t<n~sh can tie on asset or a liability, it is important for the landscape manager to ot";erve car-efully its impact on tbe landscape. As a rule, individual dead trees Silould tie left in tile landscape 'vVberel/er- possi b1e. TJ-Iey are used as dens by rnarild speci e8 and h8rt,or insects Emd mi cro-ot-,~ani 8ms v,bi ch ~wo','i de food for rnanld other speci es. '\"1oodpecker popul ati ons, few e,:amp 18, t15'..'8 increased drameti ca 11 y in some places vv路here ..gl,)psy rnoths h'3'y'e killed 18rl]e numbers of oak trees. Occa~;i Dna 11 y, ho,v8I/er . some se lecti 'ie c1e'3r-i n9 meld be advi ,;atll e to prevent damage to adjacent 1/8getation or to remove dead tr-ees v,hich might pose a direct threat to the 'visitor-, such as 510ng a path. Where numerous trees have fallen, the resulting twush piles can be very extensive. Dead leaves and twigs may accumUlate deeply enough to se','erely limit tbe repr'oduction of native plants. Vines, especially the di stur-bance speci es such as ~lapan8se honeysuckl e, may estab 1i sh qui ckl ~ in the open landscape vy'her-e the canopy is now gone, heaping over branches, and further i nhi bit i n9 natura 1 regener-at i on. Once well entrenched, vi ne cover rnBy persi st for decades, di sp 1aci ng more di verse LANDSCAPE I1ANAGEI"IENT ACTION PLAN FOR

CRU~1

CREEf( ViOODS

14


native habitets. Over time, such I'l site may also serve I'lS I'l source of di stw-bance speci es whi ch invade ad j acent 1andscapes. Sometimes brush is deliberately deposited on a slope v,ith the expectation that it 'will help control er-osion. \¥hile brush may be temporarily effective at limiting access and discoureging trampling, it I'll most never reduces erosion as anticipated. In fact, it may serve to obscur-e the problem while conditions worsen. It is also unBttractive and makes a forest look trashed, end, in most cases, should be removed. The f ami 1iar concern with r-emovi ng dead 'Nood and brush often is di sposal. Vehicular access may also tie restricted on many sites, making transport from the site difficult. \'V'her-e removal of dead wood and bruc;h is feasible, it is critical to ensure that it is properly disposed of once off site. This is, however, a r-elatively costly as well as wasteful option. The following describe ways to U2.e the material on site in the restoration effort itself.

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LANDSCAPE

~1ANAGEf-IENT

ACTION PLAN FOR CRUf-1 CREEK V100DS

15


Erosion Control Strategies: Check Dams in Gullies

Vlhere ,jo\''>'nslope gullies Ilave formed, 10'>'1 ,>,,'oo,jen check dams can be constructed at frequent intel-vals to reduce the velocity of I"unoff arllj encourage tI"le deposition of se,jiment along the length of the gully, It is important to acknowledge, however, tile complete restomtion of tile gul1ie,j area is not feasible until the volume of water in the gully hes been significantly I-e,juced. The gully still has to convey the runoff it receives; the purpose of the check dams is to re,juce the vel OCitl) of the water, and hence emsive capacity an,j t.o encourage the deposition of se,jiment. all elon'J the lengt.h of the gully rather then at. the bottom of tI"le slope. The check dams must be smell enough to permit tile necessen) ilO"N of water or a new chenne 1 wou],j be cut around thefA r'1anq sma 11 check dams is the best appl"IJach, rather than fe"Ner largel" cl"leck ,jams. Ti,e check dams rna,je from wood foun,j on site rat.her than pl"l3SSUret.1"eat.ed timber do not last ',lend long, tJII"8e to four years or less might be tldPi Cd 1. Therefore, they shoul,j be rep leni ~;he,j as nee,je,j, Mf or,ji ng continuel sites for ,ji~;pl)sal of logs from ,je;],j trees in t.he Y'loo,js.

LANDSCAPE

MANAGE~1ENT

ACTION PLAN FOR CRUt'j CREEK V,IOCIDS

16


UNDERMINED TREES MAY NEED TO BE REMOVED

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ERODED SWALE

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LOG CHECK DAMS-----EACH DAM SHOULD BE SPACED TO BACK WATER UP TO . THE BASE OF THE HIGHER DAM - I NCREASED EROS IiJN OF GULLY WILL OCCUR IF THIS IS NOT DONE LONG SECT I ON OF SWALE /' i ___~_ REMOVE UI'.JDERt1INED TREES if:' 7-",,/-1~"

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REGRADE AND ST AB I LI ZE S\'Y'ALE SIDES AS NECESSARY

Check Dams ifi Guliies LANDSCAPE r'1ANAGH1ENT ACT I [IN PLAN FClR CRUM CREEK vmODS

17


Erosion Control strategies: Check Logs on Slopes

'drlere no gullying hBs occun-ed, yet bare soil and limited erosion ere evident, a set-ies of logs staked along the contours can help cantt-ol erasi on. Tt-Iese low bBrri ers \-vi 11 reduce the ve 1aeity af t-unoff and may aff eet some recharge as V'ie 11. By trappi ng both vdlter and sedi ment, O-Iey encout-age natural regeneretion end provide ideal sites for ne'.'v planting.

EXISTING TREES

NEW (OW'StJRUB PLANTING NEW SO I L BEH I ND LOGS 'CHECK LOGS' PLACED ALONG CONTOURS TO SLOW FLOW OF ViATER STAKES TO SECURE LOGS

THE NUMBER AND SPACING OF CHECK LOGS SHOULD BE DETERt11NED IN THE FIELD DEPENDING ON THE DEGREE OF EROSION AND STEEPNESS OF SLOPE

Check Logs on Slopes LANDSCAPE t1ANAGEt"IENT ACTION PLAN FOR CRUt"l CREEK WOODS

16


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" < ;/ , gE+kJd,.U_I,.,,?

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//~ \.-...,.-.::.... --.-.~...•- -~-.-, .-,,-,-.. --.-~--"" Tl"ie two most serious exotic invasi'\"~ pests in ttle Crurn Creek Vioods ewe Norway rnaple and rlOneysuckle, Both/occur rnost e:>(tensively along typical Ijisturbance corridor's suetl ;'jS roa1j?: panls, railroads, and ttle developed edges, thougtl ttleir distr-ibution is fJk8~ wiljespread, The approach taken in ttlis Action Plan is to wage a continuous effort to control these species. TM broad goals are to keep unljisturbelj ar-eas frorn becorning infested by monitoring anlj rernoving invaders before tf'ley become entrenched, ViMre ttlere i:3 nwre di~;turbanC8 ar'ilj infestation, the goals are to reduce tf'le stresses on the site, and increment;511y remove e)wtics anlj replace them 'Wittl native canopy species, [n trle mo::;t1y sever-ely disturbed 1lt"eaS, the otljective is simply to cont;5in Hie e:,(otics, Ttlis approach is not unlike medical triage, v'lhich identifies tt'lose vit'lO are tl81dond aSSistance, those 'Nho do not ne81j assist;5nce, anlj U'lo::;e ""I't'lO c;sn tie t'lelpelj, Because Nor'Nay maple arllj rloneysuckle ar-e tt'ie most Hu-eaf.ening species, and tM most 'Nell estattlist'18lj on tile upper slopes, trl8y are tile major focus in tM Action Plan,

[t is worth noting, however, that Japanese knotv-I88lj is POiS81j on Hie e1jge of an invasion along Crum Creek arllj all tJle srn;511 tributand streams arllj swales, if the current r-ate of erosion continues. At present, the effort to act'lieve better control of storrnv-Iater will favor 8ventl.Hll contt'lJl of Japanese knot vieed,

LANDSCAPE

~lANAGE""lENT

ACT [ON PLMJ FOR CRUf1 CREEf( V,/OODS

20


Control of Exotic Invasive Vegetation: Japanese Honeysuckle CLonicera JaQonica)

Nati'l)e to ,jiCipan, China, and Korea, ~laptlt"i8Se honeysuckle is basicelly Bn early succe%ional in','Bder, lying dormant in mown pastures and taking a firm i'I01d in woody oldfiej,js. However, it is also found in the light shade of di sturtled WOOd1 ands. As forests ntroughout tI'le regi on ar-e i ncreasi ngl y fragmented, trley are more vunerable to honeysuckle, "Ivhich in'.ades from adjacent cleared areas. Altrlough intolerant of /'Ieavy srlade, /'loneysuck1e VI"ill persist even in tile inter-ior of a mature forest as a sparse ground cover. A trai 1i ng and mat -f on'ni ng vi ne, ~Iapi'lnese honeysuckl e, once entrenched forms, rnonospecific patc:r18s, nle rate of tJle spread of trl8 plant viCir-iss 'with tile degree of 10CEl1 infe":tation, tr'le age of the patch, and the ar-nount of disturbance on the site, Vlide1y disseminatelj by bir-ds and ":mall mammal s 1'1'1'10 eat tile berri es, once estatl1 i ":hed, honeysuckl e can rio 1d a site very successfully by its atd1ity to spread '.egetative1y -- its long trailing sterns able to mot at every node. Honeysuckle, like kudzu, was once wi del y percei ',led as 6n exeell ent grourjlj stabil i zero However, v'l'i'len young, altrlougl'l the plant r-oots frequent1ld, U'lese root sidsterns ar-e small and ",rlallow, and as the plant matures, heaping up over- the older sterns, the numtler of rooting ":ites is gr-eatly reduced and trle gr-olmd beneat~1 nle mound is vi rtua 11 yt1are, Takeo'ver tly ,Japanese ~loneysuck1e creates a ":tatic landscape by suppressing reproduction, Because of its at,ility to climb by t\,vining and the tilick, irnpenetrElb1e mass, produced by trl8 rntlny intert\'vined sterns, tree and ~:I'trub germination is usually inhibited and young saplings ar-e strangled and 8'ventua11y completely cover-ed. If a dense canopy can develop, the honeysuckle diminishes and is r-educed to a flatter, ground hugging vine; rlovYe'.er, reproduction of otrler species is still clirteiled. ,japanese /loneldslIckl e is semi -evergr-een in the mi d At1 ant i estates, keeping its leaves unti11ate November. As wittl many other ASian speCies, LANDSCAPE t"lANAGEl'lENT ACTION PLAN FOR CRUM CREEK \'lOODS

21


late fall is an excellent time to monitor arllj evaluate the extent of honeysuckl e takeover, nS these plants remai n green nfter- our neti ve ~tl ants have lost their leaves, and are then clearly visible in the landscape. In addition, the characteristic heapinq'- form of honeljsuckle is so familiar and unbiquitous, it can be easily spotted at any time of Ideer.

Treatment for Eradication \'I'here .Japanese honeysuckl e has comp 1ete 1y overvillel melj a si I.e onlj no native species are present, a black pll'lstic mulch cl'ln be uselj to kill the plants. Althougll this plastic is unsightly, it is later r-emo'.Jed and involves no hertricides. First cut end remove the heaping portions of the vines. A blade weed-whipper can be especiallid useful for cutting the sterns. The black polyethylene should be hellj tightly in place, usinl~ staples or- ::;takes. \elhere appear-Bnee is an issue, en open mesh fiber can tie used t.o secur-e (j leaf rnulcrl over the slippery plBstic. It mBy tBke at lea:3t 16 rnontils to edequl'ltely contr-ol the honeY:3uckle. 'I',II'len the plastic is removed . complete restabilization of the site is l1ecesssery. An 8r-osion cont.r-ol blanket anMor check logs and eddi ti ona 1 rep 1anti ng I'lr-e usua ll'd r-equired. \~!her-e

,Japane::;e honeysuckl e is rni xed with Ijesi rab 1e nati '.Ie speci e3, r-epeate1j Y'le8lji ng of the honeldsuckl e wi 11 gredua 11 y give a compel. it i ve elj!~e to the other plants. HO\'l8V8r-, real diligence is requir-ed. These plants rnust tie pulled up Ijently tlY Hie roots when the soil is moist and ell runners that 11a'路.路'e rooted pulled up as well. AW'lOUgll t.his approach is teljious at Hie outset. it will pr-ovide excellent control OV8r- time. Some limited U:3e of hertricides in corntrination 'Nith rerfloval e'jn be ven~ eft eeti ',Ie whi 1e r-eljuci ng tJle amount of hertri ei des requi red. Similarl!:!.. honeldsLickle gro\路ving in trees can be tacklelj by ::;ev8r-ing the stern connections to t.he ground. Again, a trlade w8ed-'rvhipper is useful or a rachet lopper. The vines can tie left to rot in the tr-ee3 if eppean'lnce is not a pn:lblern. An hertricide treetrnent of the stumps is irnpcwtant, otl'ler-wise, rfl8chanical removal of (j sometimes massive rootstock is t.he only option. \~Ihen

herbicides are used, the object is to minimize the use of U'le herbicide by corfltrining it with rnechanicel pr-oceljures. Severel successive cuttings can be extrerrlely effective in exhausting the rootstocks and at least one cutting and removal of niB top growth is required before applying the herbicide. Herbicide should be applied only to the places of resurge where U'le vine is re::;prouting, during Hie active growing season. LANDSCAPE ~1ANAGEt'lENT ACT ICIN PLAN FOR CRUt'l CREEK vmODS

22


Subsequent her-bicide applications should function largely as a monitoring operetion, cetching any recover-y sites before new root systems develop. Recommended Tre(ltment Schedule t1ay -- complete hanlj cutting end removel of vines June -- complete hend cutting and removal of vines August -- Initiel herbicide epplicetion October or November -- Follow-up monitoring end t'lerbicide application n,e rloneysuckle vines should tie cut to 12-18 inches above grounlj in t'"lay, anlj again in June, some 4 to 6 weeks t'efore tlle initial herbicide epplicetion. This will allow sufficient time for the remaining vine to r-esprout new foliage, v,'hich will n,en tie treated with the herbicide application. Because ttle pieces of the stem reroot very easily, vines shoul d not be chi ppelj on site. All the cut porti ons of vi ne shaul d be removed from the site to eliminete recontamination. If placed in mulctl or compost piles, flljequate time must pass befor-e use to ensure enough rotting to prevent introduction of the plant elsewhere, via the mulch. 5(1fety Me(lsures The herbicilje epplicator must be licensed by the State and must possess Ule necessary insurance required tly lew. All pr-ecautions and environmental hazard protections on product labels must be observed. Only ll'lbelled rlerbicides in original conteiners ot,tl'lined from the b('Jsic manufacturers rnust be used. Only clean tap w('Jter should be used for mixing anlj rates indicl'lted on the product label must not be exceeded. The sprl'lld must becerefully directed to resprout areas onlld. Avoid spreying desired plents, and minimize spray contect with the soil. To effect selective epplicetion, a vegetable dye should be added to the mixture to provilje an exact record of the area treetelj. The w8flther during application must be warm, between 75째 - 95째F is preferred, to ensure i-apid uptake by the plant. TIle air must be calm ',\lith less than 5 n-,ph ',vinljs to ovoid spray drift. Do not spray herbicide into or near water.

LANDSCAPE t'lANAGEMENT ACTION PLAN FOR CRU11 CREEK \\IOODS

23


Recommended Herbicides ond Applicotion Rotes Herbicide (lQQlication shell use: "Roundup", epplied with a 3-g(lllon backpack sprayer with 80-02 or 80-03 nozzl e. Fi 11 tenk 2/3 full with clean water; add 6 fluid ounces or 0.375 pints of "Roundup", and then finish filling tank with water. Mix thoroughly. Apply as a fine spray at a pressure of 40 to 50 "'psi to lei'lV8s and stems for complete coverage. After the first year's hel-bicide treatment, continue monitoring end retreat plants once BnnuBlly, cle(ll-ing in June if necessary i'lnd herbiciding in August.

Products G1YQflosate, "RounduQ", (EPA Reg. No. 524-308-AA), as manufactured by Monsento Company Agricultural Products, St. Louis MO 63167. A water based dY!l.

LANDSCAPE ~1MAGEMENT ACT I ON PLM FOR CRUJ-1 CREEK V,IOGDS

24


Control of Exotic Invasive Vegetation: Norway Maple (Acer QlatanoidesJ

Native t.o continental Europe, this illl';'lder is one of the tliggest t.hreats to the nortJleastenl deciduous forest. Escaped ft-orn cultivation in suburban and rut-al at-eas, Norway maple can be found throughout the region, displacing cornplex native forest plant communities 'i'fith monospecific wooljl ands. Prodi gi ous qUanti!. i es of rnobi 1e, \·vi ndborne seeds, reproducti on in sprouting, a tolerance for dense shade, fmd an ability to thrive in a broad range of soil conditions give U'le Norway maple a competitive edge over milny nBtive speCies, especially in areas of disturbance. Once established, Norway maple !'Iolds the ground for decades, releasing po\·. . et-ful chemicals . \''I'hich in!'libit U'le ger-rnination of other- species, In forested areas, this species is typically found at the edges and \·vithin the interior, follovl"ing roads, p8U'i'I,vays, and erosion channels, However, U'le vigorous spread of Not-vI'ay maple is not limited only to distur-bed for-ests, It is so \'videspread that (Jeres of abandoned fields thr-oughout the rnid-Atlantic states have been transfonrled into monospecific \'voodlands of I~on'l"ay r'naple ,/v·ithin a period of 30 to 40 ye(H-S, precluljing t.he succession of naUve habitat.s.

A d8n~;8 but Yieak wooded !.t"8e,

Non'ia~ !rp~p!8

is prone to

d;~!r!ag8

tilJ \'virpjs

and ice ;'lnd sno'l'v loads and rots quickly \Nhen U'I8 .,,\/Ounds are untreated, Like other rnep'les, itis SUbject to verticillium vvilt, Despite its many problerns and its inVasive behavior, Non,vay maple is still v,..-idely planted Ilnd Elppeat"s on mEiny lists of recommended stt-eet trees. The fall is the best time to monitor and evaluate Hie extent of NOt-way

mapl8 takeOV8r, as thes8 maples remain d;srk. green w!'!8n U!8 relj ;'lnd

~;I)g;'H­

maples are in full color, Only after the native trees !'la\i8 lost their leaves, will the Non. "ay maple turn a deep yellOW, easily visible in Hie leafless for-est.

LMD~:;CAPE

f1ANAGEf1ENT ACTION PLAN FOR CRUf1 CREEK ViOODS

25


Tretltment for Ertldictltion Nor-we~

maple sprouts vigor-ousl~, especially when cut, end can be ver-~ difficult to control mechanically., although r'epeatedly sprout cutting will eventually kill the tree. \~Iher'e numerous seedlings er-e present, hand pulling is effective in r-emoving them, tilJt the entir'e root system must be pulled up with the shoot, anlj ultimately, the major seed sources eliminated. Convincing an owner to cut down a lar-!~e specirnen tree which is deseminating seeljs Over a wide ar'ea eM tie the most intractable pr-otllem of all. However, recently, a nurntl8r' of horticultural and t,otaniceil institutions have teken niB lealj in effor-ts to remove serninal trees from trr8ir par-ks and campuses anlj to restr-ict the plernting of Norway maple in the wider cornrnunity. Since Ncrr-way rnaple is :::0 (ll~gr-essive, an approach cornbininl~ t'OUl mechanical and chemicalrnetJrods appears t.o tie most effective. BeCel):3e of the widely "iandinl~ sizes of 1.1"88:3 involved, two different treatment rnodes eil'e recommenljelj. In Ule first, the tr-ee is cut and removed end Hie hert,i ci de ir'eetrnent is confi nelj to the cut surf ace of the sturrlp. This rnethod is called 'notch and frill'. In other situations wrrere it is not possible or desirable to remove t.he tree., (j strip of l'I8rbicide in an oilrrledium is applied to the circumfer'ence of the trunk. This later t.reatment is rno:3t effective on younger c:mooth t,arkelj trees arllj is especiailid suit.ertlle for treating sites wher-s numerous small saplings have become established. This procedur'e is less effective on trees over 6 inches in caliper or 'Nhere (l plate~ t'ar-k has developed. It can t.'3ke ~:8v8rGI months for Ijeath of the I.r-ee to occur. Follow-up applications ere sorTIetirrl8S necessand. It i:3 critical to monit.or treated trees and '3pply (l foliar spray t.o.respr-out.s. Using either sturnp or trunk tr-eatments initiallrd, in~:tealj of a foliorsprard, rninirrliz8s the errlount of herbicide used while per-mitting very accurate application. Recommended Treatment Schedule

t'1id August through Septerntler -- Initiel hert,icide epplicetion on trunk or on sturnp immedietely after cutting. June through August -- Follow-up monitoring GI'Id folier' herbicide application. nle herbicide epplication is tin'led to effect maximum tninslocetion to the root zone. LAtWSCAPE t'lANAGEt'lENT ACTION PLAN FOR CRUI1 CREEf( "mODS

26


Safety Measures

Ttle herbicide applicator must be licensed bid the State and must possess necessary insurance as required by law. All precautions find environmental hflzard protections on pl-oduet lBbels must be otlserved. Only labelled herbicides, in original containers, obtclined from the basic manufacturers, must be used. Do not exceed use rates indicBted on the product label and be. sure not to exceed the amount of fictive ingredient per acre specified on the 1abe 1. Ttli s herbi ci de is an eff ecti ',Ie ki 11 el- of 'iI/oody speci es, however it is also extrelnelld Ijangerous to humans and must be used with extreme caution. Oil impel-vious gloves should be wom. The basal oil is combustible and shoul d not be used neal- fi reo To effect selective application, a vegetable dye should be Bdded to the mixture to pl-ovide an exact I-ecord of the ,a-ea treBted. \짜arm weatt-Ier during the application is necessary to ensure rapid uptBke by tile plant. A temperature between 75째 - 95째F is preferred. For sprey epplicl'ltions, the air must be calm, I,'yith winljs of less than 5 mph to a"loid spray drift. Do not applq herbicide to water. Effective contl-ol will be I-educed in wet weather. Lastlq, when trees are to tie cut, caution should be taken not to distl.wb adjacent vegetation. For larger trees topping may tie necessary, 1oweri ng the upper branches to the ground with ropes_ Recommended Herbi ci des and App! icati on Procedure

A Low Volume Besal (LVB) control treatrnent is recommended, using t'Bsal oil and a Triclop1dr ester herbicide, such as Doyy Chemical's "Garlon 4 Herbicj,je". Hie oil rneljiurn penetrates the bark and woodW tissue, tran<;porti ng the herbi ci Ije along with it, penrli tt i ng a very se 1ective app 1i cat ion anlj the use of 1ess herbi ci de than a f 0 1i ar spray, whi 1e reducing drift anlj. worker- 8xposw-e. A dye is also added to clearly delineate the area treated. A 25% concentnltion (1:3 I-atio) has been found to be effective. One gallon of hel-bicide should be mixed with three gcillons of bBsal oil and stirred for approximately ten minutes until a clear solution is obtained. Add up to OA ounces of basal dye per gallon of basal spray mix. Shake Dr stir until the liqui,j is unifol-mly mixed. Use a backpeck sprayer with e spray wand fitted with a sprey system 5500 nozzle end e '/-2 tip to achieve a precise, drip free, low-volume application. Only fl sma]] emount of the herbicide/ oi 1 mi x Sil0ul d be tlpp 1i ed. Li ghtl Y spray the lower ci rcumf el-ence of the LANDSCAPE nANAGEnENT ACTION PLAN FOR CRUt1 CREEK WOODS

27


stem, root, co 11 ar, end any exposed roots. Do not e11 ow the mi xture to puddle or drip eround the base. The height of the treeted band should be 2 to 4 times the caliper of the tree On a cut stump, the cambium leyer should be sprayed es soon es possible after cutting, as well as the rernaining bark and exposed roots to discourage resprouting. Again, puddling and dripping at the base should be avai ded. It is unnecessary to spray the he(lrt wood eree. Cont(lct with the cembium leyer C(ln be increesed with the "notch and frill" method. USB an axe to peel back the bark to i]llO'."1 greflter exposure of the cambi IJm t i SSUB. Products

Triclopyr, "GarJon 4 Herbicide" (EPA, Reg. No. 464-546), as manufactured by the Dow Chemical Company, Midland 1"11 48640. Basal Dye, "Automate BJue 8", as manufectured by f1cwton Thiokol Inc., f1ot-ton Chernical Division, 333 \~'est Vv'acker Drive, Chicego, ILL 60606 - 1292 Basii I oi I "Arborchem Basal Oil" (Hazerdous vI'aste No. DOO 1 Igni tabl e) as supplied bid P.O. Box 1567 . Fort Washington, PA 19103

ON AN UNCUT TREE SPRAY UP THE TRUNK TWO TO FOUR T I t1ES THE CAL I PER

/

ON CUT STUt1P SPRAY ALL STUMP AND ROOTS OR CUT AND FRILL AND SPRAY

Notch and Frill Detail LANDSCAPE f1MAGEf1ENT ACTION PLAN FOR CRUM CREEK V100DS

26


Replanting Strategies: Canopy Replacement

The ultimate goal of the forest management is to restore the diversity of the natural habitat. During the initial stages, howe'v'er, reestablishment of the forest canop1d is the most important environmental factor to implement. Tree replacement in U10se areas where canopy cover has been lost is the first effor-t. These areas may include forTner fill sites, new and active gullies 'Nhich have toppled trees, areas overYvi1elmed with vines, and stands of dead wood. In an effort to estatdish large numbers of trees for relatively little cost, bareroot planting is recommended. The trees should range in size from 6-12 feet in height and be planted in groups of 3, 5, Clnlj 7 in a loose clump and gap pattern in the opening in the canop1d. The trees can be secured with a sin1jle stake as illustrated. The method is both cost effective and re Iati v81 y safe from vanlja Ii sm and storrnwater. Bareroot trees ha''!e ad''!cmtages beyond their price. Because there is no soil, weight is not an issue. Transport is also cheaper and vehicles ere not necessery for getting the trees to forested sites. The bareroot tree also typically has a very reduced shoot system. New shoots, and tr,erefore a new drain on the tr'ee, tend to develop at the rate determined by root nrn'du'th 1 Innot- I-'vv nnnr l--f1nriitinnc ~ h:e.rerr'lnt nl~nt c-nrr"lcdln"loC' rlouolnnc' c·ln\Mlll VflU ....·1 '-''-'fIUI''-/ ..... '''... } U ,-,UI ..... / u ....'1. I-'IUIII.. ....'VIII .... I..IIII'..· .... \.I ..... y .... ,\..)I-' .... ""'WHitt

!dl ...·/1 \ . , .

but also stetjs·alive. The following species are recommended for use on the Swarthmore site: vy'hite oak (Quercus alba) Red oak (Quercus rubra) Sugar map 1e (Acer- saccharum) Arneri can linden (Ti Iia arneri cana) Tulip poplar (Liriodendron tuliQifera) 'w'ilite ash (Fraxi nus ameri cana)

LANDSCAPE J1ANAGEt'IENT ACTION PLAN FOR CRUM CREEK WOODS

29


1

/

1 These species ore all reesonobly available end occur in the oak/beech forests of the region. Other predominent species, such as beech end hickories, ere desireble, but ore not suitable for bereroot and ore recommended for planting et 0 later time.

1

II

In eddition to replecing cenoP!:J where it hos been lost, it is advisable to 'sea]' the edges of the forest with sapling size trees. The edges are often the most vulnerable to invosion by exotics, especially where existing tree cover is thin. \";here the edge of the forest is elsa the edge of the ploteolJ, the young trees planted to 'seol' the edge cen elso be used to help stobilize the low earthen storrnwater berm.

1 1

1 ,

1

1

1

1 1 1 1 1

"SCAPE

~1ANAGEMENT

ACTION PLAN FOR CRUM CREEK VVOODS

30


.'

',,~.

-: :,'.

NEW PLANT I NG TO 'SEAL' DISTURBED EDGE. SECTION AT EDGE OF WOODED SLOPE NEVI PLANTING TO FILL FOREST GAP -

... -. -.~ ~---.-~

.. -----.-------'-~----~---.---.---.--.--:--

NEW EDGE AND FOREST GAP PLANTING GROUPED INTO NATURAL LOOKING 'CLUMPS AND GAPS'

KEY PLAN

Canopy Re \

acernent

-~,."'.'"-.-~::::::::::::="-LANDSCAPE

MANAGE~1ENT

ACT ION PLAN FOR CRUM CREEK l'ilJODS

31


Replanting Strategies: Bareroot Trees

Bareroot trees and sht-ubs at-e plant matet-ials dug Ijonmmt out of tr,e field, usually in tf"le late fall or in the early spring, once U·,e gn:i1.H1lj is viorl,able. After bareroot plants are dug, tM soil is shaken from U·,8 roots. Hie plants are taken to a cold stot-age unit \,'here tlley are grade1j blJ sizes and species, and stored at temperatures just aMve freezing and at BvenJ high hurnidity. Hie plants are taken from cold storage the dalJ they are shipped or delivered to tl1e customer. Dur-ing shipping, tlle roots are kept moist with wet straw. Bareroot planting is a convenient method for planting large numt,et·s of trees at relatively little cost. Bareroot trees tHlve advantages beyond their price. Because tllere is no soil, weiqht is not an issue. Transport is cheaper and vehicles are not alv,/ays necessat-y to bring Hie trees to t.he site, anlj the plants i'it-e eCl'3Y for CI volunteer ere'l'\' to rJ(lndle. Hie t,aret-oot tree Cllso t.ypically t·,es e reljuced St·,oot system. Since new shoots tend to develop at Ule rete determined by t-oot growth, a smaller sMot system is less of e drain on the reduce root '3ystem of a ne'wly trensplanted tree. A1U"iOugtl t·,igt1losses can occur with t,ar8t-oot trees if U"18 tt-ees are impr-operly cared for before and Ijuring planting, nhwly 100% survi',,'al is possible wrlen larger sizes (6-12 feet) are US81j Clnlj vit·,et·e Ule trees are plante1j 8i'lt·liJ;and carefully, enlj 'watered frequent.ly. Use of a tlydro-gel wrlich meintains trlljisture around trle root zone 'will t·ielp t-eljuce losses, especially where it is Ijifficult to water. Recommended Species

Uplands: v-/hi I.e oak (Quercus a1be) Northern red oak (l)uercus boreelis) Sugar maple (AGer saccharum) Tulip poplar (Liriodendron tuliQifera) LANDSCAPE I1ANAGEMENT ACTION PLAN FOR CRUI1 CREEK ViOODS

32


Lowlands: Red mBple (Arer rubrum) V\lhite ash (Fraximus Americane) Pi n oak (QuetTus Ra 1ustt-i s) The species listed ere netive to the oek/beech fot-ests of ttle region and are reBdily aveileble at wholesele nurseries that specialize in bareroot matet-i ell. Other predominant speci es, such as beech and hi ckory, are desirable to enhance species diversity. These species are (lvailat,le in containers in smaller sizes (2 to 3 feet) etprices equivelent to the lerger (6 - 12 feet) bare root trees .

----

nll~.b6reroot

.-.~;:..:........--..~------

---

..,~---""-,,,.

trees should range in siZ;.e from 6-12 feet in heigrlt and be planted in groups of 3 to 9. Several tre'es may be placed in a single hole. /The o'.;erall planting pattern within ttle opening in the existing canopy ' should tie one of loose clumps with visible gaps t'etween each clump. ( Occasionell Single trees should function fJ!8 'outriders' drifting away from '\ the main clurnps anlj connecting it to thy!next clump. Thisylanting pattern '(eflects the spacing cheracteristic of seplings springing up in e gep phese

i lt1be~f.oFe st:--_·--_··-'··-···-_· ............ -- ....... --._-_.... _ ...... -.......... -.. -.-.----....-.-..-.-- ..........___ ~

Planting Time Ideellld, U'!ey should be planted as soon as the grounlj can be worked, but they mEild be planted up until the leeves emerge on the surrounding tt-ees-as long es the t'oreroot stock has been kept dormant. In the 11id-AtlEintic Region the season usually extends from early l'larch to 8Brly nay. Eerly 1"lerch planting has the clljvantege of col,jer temperatures end wetter soils.

Plenting Method· Upon errival to the site, the bareroot trees should be stored in the shade and their roots covered with wetted mulch such as straw or compost. As the weather warms, these measures become increesingly importllnt. Before planting, dip roots in a v'ietting agent solution, such as Liqua-ge1. Tllis solution will both rehydrate the root system and maintain an even moistut-e balance by releasing water into the soil es the soil dries. l1ix Liqua-Gel with water to form e gel thick enough to cling to the roots. Clip off any broken or dameged t'oots, dip the entire root system into the gel and then plant. It is especially important to spread th roots out evenly LANDSCAPE l'1ANAGEl1ENT ACT I ON PLAN FOR CRUM CREEK \'IIOODS

33


./

over e smell mound in the planting rlole or there will be tlir sptlces found in the soil eround the roots efter beckfilling. No roots cen develop in these ei r speces tlnd sett 1ement may occur 1ater.

Nursery Li st Princeton Nurseries P.O. Box 191 Princeton, New ~Iersey 08542 609-924-1776 Shermen Nursery Company Charles City, lowe 50616 515-228-1124

Hie Buddi es Nursery P.O. Box 14 Bi rdsboro., Pennsyl vani a 19508 215-582-2410

Products Li qua-Gel [C. Gei ger Box 285, Route 63 Her1 eysvi 11 e, Pennsy1 vilni a 19438-0332 (4 1bs. per 200 trees) P1 est i c Fiber Jr-e8 'w'rap Phillips 66 'Duon'. 4" x 50' (1 roll per 4 trees)

LANDSCAPE

MANAGE~lENT

ACTION PLAN FOR CRUM CREEK

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34


PRUNE UP TO ONE THIRD OF THE FOLIAGE OR AS DIRECTED

PLACE 1" X 2" WOODEN STAKE NEXT TO TREE AND WRAP TRUNK AND STAKE TOGETHER WITH TREE WRAP UP TO 4'- 0" HIGH

FORM SAUCER OF TOPSOIL 3" HIGH AND FILL WITH MULCH 2" DEEP ROOTS LAI D OVER OVER

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MIXTURE WELL COMPACTED ,\J::";":",,:",:", b~-:"70::0-:u..t .~'---_ _ _ UN D1ST URBED SUB - GRA DE

Bareroot Planting LANDSCAPE MANAGErlENT ACTION PLAN FOR CRUrl CREEK VmODS

35


Action Plan: Project Areas

Hie focus of trle Action Plen is to Bddress the most criticel problems on the eest side, thet is, ttw~nege side, of trle velley, impacting the Crum Creek \~Ioods, as described on, the Existing Conditions Map, including sites 'NiU'1 the rnost severe gullying, erosion, and loss of vegetation. The major project areas ere noted on theiaccompanying key mep. ,,-

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It is worth flOtlifg the'obvioy,s correlation betl'veen the plecernent of buildings and culverts at)t1e edge of trlB slope and trle sut1sequent gully format ions. It is also-clear ti"lataddit iona 1 bui 1di ng construct i on wi 11 continue. If statTn'I'Vater is notcot:liroired-r.nore effectively, extensive destruction will ensue. It is imperative, fo~xarnple, thi'lt responsible , desi gn of the Perf ormi ng Arts Center include slgnifi cant improvements in existing storrnwater management in the whole \q~.tershed area as vl"ell as adequate contt-ol of t-unoff from new constr1Jction\ It is clearly time for trle college to address these issues head at" ;."c;:",\ <:. i ,:\,.,< JT n ',Iv.. "

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It is elso recognized thet costly improvements )l'lvolving existing stormweter stt-uctures and ne'N constructi O[l,ere more complex and more di Hi cult to imp 1ement. Thet'ef ore, tJle AcHon F'l an descri bes botJI long and short-term t-ecommendtlUons, In general, Hie long term recommendations require both outside consultants and contractors, permits, and funding to implernent.

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Path Inventory. Beyond U1e runoff which is genenjted on U18 plete;ju, there is also some severe erosion on the slopes due to poor peth desi'jn i'It1lj eroded trails, A complete review of the cUtTent path system should be undertaken now to permit redesign where necessary to cont.l"ol erosion. All e~;isting paths sh6uld be notelj on the topogrephic map anlj current conditions notelt Trempled tt-ails througf1 the WOOljS, which inljicete some visitor Ijemand, shOUld also be noted, Stretches requiring redesign end reconstr-uction shOUld be notelt Special funding options for the cross-country treck should . i beinv8stigated, !, I': ;:.,,~ ' , L <" ,. ;Ie. k'; "ifU':)'j '2f t ',',-e c.J-r}\/) .. r9) ,;.f ~\('" ,{:'I,(;/(.. I :1. j-;,:J. '.):.,~. jl'l ,;;":.),::~;..e,, ~t;'·'(I'-/Ji"~J\~:·;-.':~~ t"~"~"'··t-\.~V,..:.fC, r

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low impoundment es with i ltration .trench

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Remove debris and dead wood

Area i: Faculty Housing Site LANDSCAPE I'1ANAGH1ENT ACTIDN PLAN FOR CRUI1 CREEK Vi[iDDS

41


Area 1: Faculty Housing Site Current Condi ti ons The laljolJt of the road to the housing site, the earlier filling for construction purposes, surfeee dreinege from the SPOt-ts fields, end a cul vert di set-large ha'.e eombi ned to create severe erosi on dovm the vall ey. Additional erosion is occurring down the central green space between the twin flanks of buildings, v,hich is further aggravated by a foot trail/gully do,yn to Crum Creek. Recommended Long-Term Actions Trle culvert v,hich discharges into the valley should be rebuilt. Significant reductions in flow should be accomplished in the redesign by providing alternate storage sites on the plateau and providing adequate retention of the hi gh frequenclj stann. Recommended Short-Term Actions Stormwater retention for surface flows from the playing fields should be provided on the lavm area between the bleachers and the woods, using a low em-then berm to create a shall ow i rnpollndment. Similar berms and impoundments should be placed at the head of the valley where e)<:cess road drainage now pours into the valley. A 101'l earthen berrnand i nfi lirat i on trench shoul d be created tllong the ri rn of Ule slope. In the housing complex itself, the inner court should be regraded to create shallow impoundment terraces with recharge trenches to reduce erosion. A stepped access path shoul d be bui 11. to pravi de appropri ate access to the woods. If access is not desirable at this point., e fence will be necessary Bnd adequate access prov'ided elsewhere, but within reasonable wfllking di stonce. Brush should be remo'.ed from the slopes. \ , ,. , . ( t._,j ,- \

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LANDSCAPE MANAGEMENT ACT I ON PLAN FOR

CRU~l

CREEK WOODS

40


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Repair current pipe break

Area 2: Amphitheatre Slope LAI'mSCAPE t1ANAGEMENT ACTION PLAN FOR CRU~l CREEK VIDODS

43


Area 2: Amphitheatre Slope Current Conditions This slope has been, until recently, relativelld stable with no severe gullies. Ho,vever-, it is present1~ deteriorating rapidl~. An old drainpipe has twoken 3nlj a new, thoul~h small, gull1d is presently forming. There are also numerous oUler small gullies across the slope. This network probably flas existed for yeel-s. Ho',vever, U"lese gullies ere now deepening dramatically. and likel~ have been ever since the construction of the t'lusic Library0'\v~ 4;;:cr:j~!/6 v~";::/; '/""J'~' These rivulets all drain to the main swale which has eroded deeply into ' "~;')' ~;.c'" .~:. the slope. This has established tl new hydraulic gradient which is reflected in these 'tributaries' which are adjusting commensurately.

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Recommended long-Term Actions The drainage to these culverts should be recaptured and stored higher on U"le plateau. The road drainage should be improved, possibly using a sequence of soak pi ts.

Recommended Short-Term Actions The I-ecent drainpipe break should be repaired. Check dams should be placed in the srnall gullies. A lm'v e6t-then berrnand infiltration trench should be created at the rim of tfle slope.

LANDSCAPE MANAGEMENT ACT ION PLAN FOR CRUM CREEK V100DS

42


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Area 3: Performing Arts Center LANDSCAPE ~lANAGEt1Er'n ACTION PLMJ FOR CRUJ'l CREEK 1-1ODDS

45


Area 3: Performing Arts Center Current Conditions

The slope immediately adjacent to the site of the proposed Performing Arts Center is, Bt pr-esent, relatively undisturbed. Existing drainage appecws to be directed largely to the storm drains in the r-oad and carried further along the plateau. This condition "'y'ould Change rapidly if past building practices ar-e continued in the new construction. Conventional stormwater management is completely inadequate to pr-otect the slope given the siting of the building at such a sensitive and risky site. Recommended long-Term Act ions

Continuous monitoring of the sl,ope and repair initiated as necessary. E,:otics control s]',ould begin. Recommended Short-Term Actions

The cu~rent building and site design should be reviewed and a stonrl\'later management plan deve loped bef are constructi on begins. The design criteria should include complete retention of the 100-year storm witr, no over-slope diSCharge. The grading s]',ould be reviewed and revis,ed to minimize damage to the existing tree", on the slope. The erosion and sedimentation controls durinq construction as well as U',e plans for the restoration of tr,e forest edge should also tie r-eviev,ed and rel'i sed as necessarl.j. A low earthen berm should be established at the edge of the plateau beyond the construction and disturbance zone.

LANDSCAPE 11ANAGEMENT ACTION PLAN FOR CRUt'l CREEK \,'mODS

44


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Area 4: Music Library Slope LANDSCAPE t'lANAGEI1ENT ACTION PLM~ FOR CF:UM CREEf< \~"OODS

47


Area 4: Music Library Slope Current Condit ions The s.,vale downslope from the new construction exhibits some of the worst conditions found in the Crum Creek ','loads. The most significant damage is initiated upslope at the main culvert from the plateau belov,.. the nusic Library. At this point, a large ravine has opened up and conditions at-e still deteriorating. Every small tributary swale is elsa being impacted and undercutting further upslope. The forest vegetation has also been severe lid di sturbed both by construct i on and tile subsequent di sturbence from stormwater. Fur-ther downslope, some path stretcfles are severely eroded and, in places, inappropriately designed and con',J8Y stormwater down steep slopes.

Recommended Long-Term Actions A me j Ot- restorat i on program is mandatory here and shoul d be the f DCUS of a serious funding effort. The stormwater rnanagernent system should be completely redesigne1j !,nd rebuilt. The primary goal should be to provide upslope storage of the 1OO-year storm. There appears to be adequate space to pr-ovide for a long tt~lin retention area. Additional soekpHs rneyalsobe required. Once the dischewge is eliminated, restoration of the swale and landscape shoul d be undertaken.

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Alow earthen berm and infiltration trench should be established at the rirrlofJhe plateau edge to provide lirnited retention of surface runoff overs lope.

.

Dead vv'ood and debri s shoul d be removed. Control of exotic

ve~etation

should be initiated.

Replanting of canopy trees should begin in existing open areas 'y'v'hicfl are not yet erodi ng. LANDSCAPE MANAGEI1ENT ACTION PLAN FOR CRUI1 CREEK \,'/OODS

46


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Log crJeck dams along gullies

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c~mposting/<

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LMJDSCAPE J1Af'JAGU1ENT ACT I ON PLM FOR CRUJ'1 CREEK V,/CiODS

49


Area 5: Building 18, Alligator Rock Slope Current Conditions

Extensi',18 debris has been pushed over the slope from the mulching openltion on the plateau. The curbs on the service area are too low to retain stonmvater ,vt-Jich then washes downslope. There are severely eroded gullies on the slope. Recommended Long-Term Actions

This site should be reviewed to develop a revised stonnwater retention plan. Site design criteria should include storage of surface runoff tly minor regrading in existing turf areas, soakpits, and other methods to reduce the volume of wBter IjischBt-ged dovms1ope. Recommended Short-Term Actions

Create several shallow temporary impoundments in lawn areas. Pull debris off trle slope and back onto the plateau. Stabi 1ize di sturbed slopes with check logs. Fence Hie composting operation to prevent 'y'y'oodchips, etc. from migrating dov'ms lope. Establish a 10,.,. earthen berm and infiltration trench at the edge of Ule p1eteau. Put checkdams in the gullies.

LANDSCAPE MANAGEMENT ACTION PLAN FOR CRUM CREEK VmODS

46


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Remove debris, brush, "nd ]"rce I irnbs \ "

Plant canopy tree rep 13cements in forest g3pS Control exotic vegetation Log check dams along gUll i es Check iogs for slope slabiliz3tion 1100 temporary impoundment I , "~_''-'" I

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Area 6: Dupont Parking Lot LANDSCAPE 1'1AIMGE~IHJT ACT ION PLAN FOR CPUI-1 CREEK WODDS

51


Area 6: DuPont Parking Lot Current Conditions Numerous ovenvash gullies extend frorn the parking lot wtlich holds ,vater for days after a rflin. Severe slope erosion has occurred. Large pieces of brush have been placed on the slope.

Recommended long-Term Actions Complete redesign of this whole area is required and likely should be accomplished when new construction occurs. Site design criteria should include retention of the 1OO-year storm on the plateau for the entire area, including runoff from buildings, paving, and turf.

Recommended Short-Term Actions Establish a low eBrthern berm Bnd infiltration trench at the plateau edge to limit runoff downslope. Replace the lower Quarter of the parking lot with a shallow berrned retent i on basi n. Remove the brush from the slope. Treat bare slope face with slope check logs. Plant edditional canopy replacement trees. Put check dams in tbe gUll i es. Initiate exotics control.

LANDSCAPE )'1ANAGE)'lENT ACT I ON PLAN FOR CRUM CREEK \'100DS

50


along gullies Control exotic vegetation

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Area 7: Elm Avenue Culvert LAND~;CAPE MANAGEMENT ACTION PLAN FOR [Rur"! CF:EEK WOODS

53


Area 7: Elm Avenue Culvert Current Conditions

A deep ravine has developed at the base of Elm Avenue culvert is collapsing.

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the existing

Recommended Long-Term Actions

Negotiations should be initiated with the Borough of Swarthmore to rebuild the end of the roadway and adjacent swales to provide adequate storm'yv8ter management. The design objective should be to eliminate excessive stormv,'ater discharges at the foot of Elm Avenue into the woods. Opportunities for storage might include soak trenches Bt the sides of end across the road,vay and at the foot of El m Avenue. Recommended Short-Term Actions

Place crleck darns in the gully. Remove dead wood and debri s. Initiate exotics control.

LANDSCAPE MANAGEt'1ENT ACTION PLAN FOR CRUM CREEK \,v'OODS

52


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