Restoring Your Annual- Dominated Field to Conservation Prairie

Transcription

1 Restring Yur Annual- Dminated Field t Cnservatin Prairie

2 The authr f this Restratin Guide is Laura Phillips-Ma, University f Minnesta. Steve Chaplin, MN/ND/SD Chapter f The Nature Cnservancy, administered the prject and helped with prductin. Marybeth Blck, Minnesta Department f Natural Resurces, prvided review and editrial cmments. Susan Galatwitsch, University f Minnesta, cntributed t an earlier versin f this guide. The Nature Cnservancy January 1, 2017 Funding fr the develpment f this restratin guide was prvided by the Minnesta Envirnment and Natural Resurces Trust Fund as recmmended by the Legislative-Citizen Cmmissin n Minnesta Resurces (LCCMR) thrugh grant LCCMR092C. The Trust Fund is a permanent fund cnstitutinally established by the citizens f Minnesta t assist in the prtectin, cnservatin, preservatin, and enhancement f the state s air, water, land, fish, wildlife, and ther natural resurces. Currently 40% f net Minnesta State Lttery prceeds are dedicated t building the Trust Fund and ensuring future benefits fr Minnesta s envirnment and natural resurces. Additinal funding fr the update and redesign f the guide was prvided by a Wrking Lands Initiative grant frm the Minnesta Department f Natural Resurces. Cver pht taken at Bluestem Prairie by Justin Meissen.

3 Restring Yur Annual- Dminated Field t Cnservatin Prairie In this guide, yu will learn the basic steps t restre a field dminated by annual weeds t a cnservatin prairie. The precise restratin actins will depend n the particular features f yur site as well as yur budget, preferences and prject gals. When planning yur restratin, we recmmend yu cnsult with restratin prfessinals t evaluate yur site s unique characteristics. Please visit nature.rg/mnprairierestratinguides fr mre infrmatin n wh t cntact r ther publicatins that cver site assessment prtcls. Cnservatin benefits include imprved water quality, sil stabilizatin, and habitat fr birds, animals and insects. Cnservatin prairie can als buffer high-quality native prairies and supprt threatened and endangered plants and animals that depend n large cntiguus areas f grassland. Why restre annualdminated fields? Annual-dminated fields (>75% cverage by annual weeds) are ften previusly crpped fields that have been left fallw. They have been clnized by annual weeds, such as fxtail, barnyard grass and lambs-quarters. Native weedy annuals such as ragweed may als be present, but desirable native prairie species are either absent r very minimal. What is cnservatin prairie? Cnservatin prairie is designed t clsely mimic native prairie using a seed mix that has many different native species adapted t the restratin site. This diversity prvides habitat and fd fr native insects, including pllinatrs, and wildlife. A wide variety f flwering plants and grasses is als visually interesting t peple. Cnservatin prairie is nt suitable fr frage prductin, cmmercial uses r high-impact recreatinal activities such as driving ATVs. Cmpatible land uses include: Carefully managed grazing fr habitat gals Haying fr habitat gals Occasinal seed harvest Lw-impact recreatinal activities, such as hiking, phtgraphy, r hunting Cntrlling annual weeds and their seed bank will be an imprtant step in restratin, and seedbed preparatin is typically required prir t seeding. These fields are relatively straightfrward t restre t prairie, and they require less investment in weed cntrl than sites that have becme invaded by aggressive perennial weeds. This guide assumes that yur site has mderate t dry sil misture and has nt been drained. Relatively wet fields that have been drained via drainage tiles r ditches are better suited fr restring t wet meadw. This may require additinal steps t restre the hydrlgy 1. 1 Refer t the restratin guide Restring yur Crp Field t Cnservatin Wet Meadw fr mre infrmatin n hydrlgic restratin. 1

4 What will it invlve? Prairie restratin typically includes these basic steps: Site Assessment Identify the site characteristics and define gals fr the restratin. Vegetatin Remval Remve existing weeds and undesired vegetatin frm the site t prevent aggressive weedy species frm utcmpeting native prairie plants. Seedbed Preparatin Prepare a seedbed t ensure gd seed-sil cntact and prmte germinatin f planted seeds. Seeding/Planting Select seed mixes and seeding methds that are well suited t the site and prject gals. Or, in the case f small sites f less than half an acre, cnsider hand planting plugs fr quicker results 2. Establishment and Aftercare Cntrl weeds and prmte the establishment and grwth f prairie plants thrugh the first few years after seeding. Lng-term Management Maintain the health and diversity f native prairie int the future. actins are typically less frequent and intensive than during the establishment phase, but are critical fr maintaining the health and diversity f the prairie int the future. What will it cst? The cst f the restratin will be influenced by: Management level required t cntrl weeds Species and number f species selected fr the seed mix Cst f seed, which fluctuates frm year t year Labr and equipment available fr the prject The cst estimate in this dcument will give yu a baseline fr what yu can expect t spend thrugh the early establishment phase f yur restratin (i.e. thrugh three years after seeding). It may be tempting t cut csts by reducing the number f species planted r the frequency f weed cntrl activities. Be aware that these investments n the frnt end can actually save csts in the lng run. A healthy and diverse prairie will be mre resilient t disturbance, invasin by extic species, and extreme weather events such as drught. Hw lng will it take? On an annual weed-dminated field, the initial phases f site preparatin and seeding can be cmpleted within a single grwing seasn. After the year it s seeded, expect t spend at least three t five years n aftercare t ensure gd establishment f the cnservatin prairie. This perid is referred t as the establishment phase f restratin. After establishment, ften after year 5 fr cnservatin prairie, the lng-term management phase begins. Management Cattle n a cnservatin prairie near Sheepberry Fen TNC\Susan Chaplin 2 Plugs are yung plants sld in 4- r 6-packs. Plugs cst substantially mre than seed, but they establish rapidly and can prduce a resilient and visually appealing meadw mre quickly than seeding, s it is ften a preferred ptin fr smaller sites. 2

5 Annual dminated field in the Glacial Lakes area TNC\Steve Chaplin Annual-Dminated Field t Cnservatin Prairie Restratin Guidelines Site assessment A successful prairie restratin is highly dependent n specific characteristics f a site. Imprtant cnsideratins when planning a restratin include: Has the site had herbicide treatments that wuld prhibit seed frm germinating? Is there a risk f herbicide drift frm neighbring crpfields? Are the sils dry, mderate r wet? Are there steep slpes that may be vulnerable t ersin? What types f vegetatin are currently present n the site? If yu are new t prairie restratin, we strngly encurage enlisting smene wh has restratin experience t help yu assess the characteristics f the site and develp a restratin plan suited t yur site s specific features and yur prject gals. Vegetatin remval Annual weeds are cmmn in disturbed sites, such as fallw crp fields. If nt prperly managed, annual weeds can vertp and shade newly planted prairie seedlings, resulting in reduced survival and grwth. Cntrlling annual weeds and reducing their seed bank prir t seeding and in the early establishment phase will typically result in faster and mre cmplete establishment f planted natives. Annual weeds are cmmnly cntrlled with cmbinatins f mwing/burning and herbicide applicatins. Recmmended prtcl: Burn site t remve thatch. Or, if fuel lad cannt carry a fire, mw site instead. 3

6 Native seed mixes shuld be planted with equipment designed t handle different-sized seeds Justin Meissen. When weed regrwth reaches 4-6 inches (2-4 weeks), apply apprpriate herbicide, such as glyphsate. See Smith 2010 (Chapter 4) and Packard and Mutel 2007 (Chapter 16) fr lists f recmmended herbicides. Reapply herbicide (bradcast r spttreatment) t remaining green vegetatin after 2 weeks. Fr maximum weed cntrl, repeat herbicide applicatins as needed thrughut grwing seasn. Seedbed preparatins The best methd f seedbed preparatin is influenced by the intended seeding methd, as well as site cnditins. Fr this cnservatin prairie restratin plan, bradcast seeding is the recmmended seeding methd. Recmmended prtcl: Lightly harrw site, fr example with a spike-tth harrw, t lsen the sil and remve thatch. Wait at least 2 weeks fllwing herbicide applicatin t seed. An alternative t the abve sequence is t harrw r disk the site t bring seeds t sil surface and then apply repeated herbicide applicatins t emerging vegetatin and regrwth. This risks bringing the seeds f additinal undesired species such as invasive perennial weeds t the sil as well. If site was burned (thatch remved) and if planning t frst-seed, n additinal site preparatin is necessary. If sils are severely cmpacted, till t 4-inch depth and harrw with smething like a drag harrw r chain link fence t break up sil clds. Nte that sil disturbance may bring weed seeds t the sil surface. Herbicide applicatins may be required prir t native seed establishment. Nt recmmended fr highly erdible sites. 4

7 Seeding The key t establishing a successful prairie is t maximize seed-t-sil cntact during planting. Upland prairies can be seeded either using a n-till drill r bradcasting using a spreader munted t a tractr r ATV. Bradcast seeding is recmmended fr cnservatin prairies, because it prduces a mre natural appearance and favrs frb (flwering plant) species, which cntribute much f the diversity and value in a cnservatin prairie. prepared seedbed, with a n-till drill such as a Truax. Additinal mechanical incrpratin r packing is nt required when using a n-till drill. If bradcasting seed, native-seed bradcasters such as a Vicn seeder shuld be used. They are designed t spread mixes with different sized seeds. If planting with a drill, use a seed drill designed specifically t plant prairie grasses and flwers. Persistent drill rws can be minimized by drilling the site in tw passes at right angles t each ther, prducing a grid. Recmmended prtcl: Hw t seed: Bradcast seeds int prepared seedbed using an agitating spreader such as a Vicn seeder munted t a tractr r ATV. Incrprate the seeds int the sil with a light drag, such as a piece f chain link fence r packer pulled behind the tractr/atv while bradcasting. If frst r snw seeding (late fall thrugh early spring) r ash seeding (swing int ash immediately fllwing a burn), mechanical incrpratin may nt be needed. Freeze-thaw, snwmelt and rainfall actin may naturally incrprate seeds int the sil. An alternative seeding methd is t drill seeds directly int crp residue, r Drilling prairie seed int a prepared seedbed Matthew Traucht When t seed: Planting dates will vary depending n the weather and lcatin within the state. Cnsult with native seed suppliers r restratin specialists t determine the best planting dates fr the year. Grwing seasn plantings shuld ccur May 1 t July 1 OR when the sil temperature is at least 60 degrees F 3. Spring/early summer seeding prmtes warm seasn grasses. Drmant seeding shuld ccur Dec. 1 t April 30 OR after sil temperatures fall belw 50 degrees F fr a cnsistent perid f time 4. When pssible, timing the seeding befre a snwfall may help prevent lss f seed that is cnsumed by wildlife ver the winter mnths. Drmant seeding in late fall, als knwn as frst seeding, can be dne with a seed drill r until the grund is frzen. Seed can als be bradcast ver snw in winter/early spring, althugh results f snw seeding are mre variable and dependent n weather cnditins. 3 Summer seeding after July 1 leads t pr seedling survival and is nt recmmended fr prairies. 4 Early fall seeding is nt recmmended fr prairies, because seed may germinate t early and nt survive ver winter. 5

8 Drmant seeding prmtes cl seasn grasses and flwering plants. Seed mixes will vary but shuld take int accunt: Cnsider sil misture cnditins f the site. Seed rate: Plant at a minimum f 40 seeds/sq. ft t reduce risk f weed invasin. If there is minimal weed pressure and excellent site preparatin, the rate can be reduced t 30 seeds/sq. ft. Include species that prvide habitat value fr wildlife and insects, including mixed-height grasses and a diversity f flwering plants. Select a mix f bth warm- and clseasn species and species that blm in spring, summer, and early fall t encurage resilience t disturbances and ensure year-rund habitat resurces and visual interest 5. Cver/nurse crps such as ats are ptinal, but shuld be included with the seed mix when seeding steep slpes. Design: If the site has either dry r mesic sils thrughut, sw a single seed mix evenly acrss the site. If sil misture varies acrss the site, apply separate seed mixes suited t the different sil misture cnditins. Fr example: Sw a dry cnservatin prairie mix nt dry ridge tps. Sw a mesic mix int areas f mre mderate sil misture. If there are wet t wet-mesic sils n the site, select a wet prairie r meadw seed mix fr these seeding znes 6. Increase rate t 50 seeds/sq. ft n steep slpes (3:1 grade). Seeding rates may need t be increased by 25% fr drmant seedings t accunt fr lwer germinatin rates and lss f seed t wildlife. Pst-seeding aftercare and lng-term management Cnservatin prairie establishment generally takes 5 t 7 years, but will vary depending n sil misture and climate cnditins. Early management (aftercare) is critical t prevent re-invading weeds and wdy species frm ut-cmpeting and displacing establishing natives. Reinvading annual weeds are the biggest management prblem in the early stages f restratin frm annual-dminated fields. They can quickly vertp and shade prairie seedlings, resulting in decreased grwth and survival. Frequent mwing can prevent annuals frm frming a dense canpy and building up thatch that can further suppress native seedlings. Pst-seeding aftercare gals include discuraging weeds and encuraging rapid and rbust establishment f native species. The restratin site shuld be divided int management units fr burning n a rtatinal basis t maintain diversity and wildlife refuges. 5 See nature.rg/mnprairierestratinguides fr mre infrmatin n seed mix design and examples f cnservatin prairie seed mixes fr different regins and sil misture. 6 See nature.rg/mnprairierestratinguides fr examples f cnservatin meadw seed mixes apprpriate fr wetter sils. 6

9 Management strategies during the establishment phase include: Mwing annual weeds Selective use f herbicide t cntrl invasive perennials Prescribed fire t prmte native prairie species and discurage further invasin Mnitring vegetatin t evaluate establishment f prairie seedlings Thrughut the establishment phase and beynd, adjust management plans as necessary, including the ptin t reseed, t achieve the desired species cmpsitin and diversity. Years 3-5: Begin prescribed burns after three grwing seasns r as sn as bimass accumulatin is sufficient t carry a burn. Rtate burns in management units, burning n mre than ne third f site (ne half fr small sites) at a time t maintain diversity and a lcal refuge fr wildlife. Burn at an interval f every 3-5 years. If desired, burn each management unit mre frequently (every 1-2 years) thrugh the initial establishment phase in rder t prmte rapid establishment f prairie plants. Recmmended management prtcl: Year 1: Mw the field t a height f 4-6 inches when the annual weed canpy reaches a height f inches. Mst prairie plants will nt reach this height in first year and will nt be damaged by a mwer. The frequency f mwing will depend n the height and density f weeds, and hw much they are cmpeting with the prairie seedlings fr light and misture. Mwing shuld n lnger be needed. Spttreat weeds as necessary using drmant seasn applicatins and/r back-pack sprayer/wick applicatr t minimize damage t native species. Cnduct a stand evaluatin t assess seedling establishment utcmes. If native plant density is less than 1 plant per square ft, interseed t increase cver and diversity. Year 2: Mw the field t a 12-inch height as needed. If annual weeds are limited t individual patches, may spt-mw, perhaps even with a string trimmer, instead f mwing whle field. If there is flush f annual/biennial nxius weeds, mw, pull, r spt-treat prir t flwering t prevent seed-set. Mwing weeds n a restratin planting MN BWSR 7

10 Year 6 & beynd (lng-term management phase): Burn every 3-5 years t stimulate prductivity f native prairie plants and prevent invasin f herbaceus perennial weeds and wdy trees and shrubs. Interseed as needed t increase native cver and diversity if native species are declining. Adjust management plan, such as frequency and intensity f burning r grazing, if: Cntinue t burn in rtatins, up t ne third f site per seasn. Adjust seasnality f burning t maximize diversity. Fr example, alternate between spring and fall burns n individual management units. If cnservatin grazing is used, graze in rtatins at lw t mderate intensities, r at stcking rates prescribed by a grazing management plan written t meet the bjectives f the cnservatin prairie. Avid grazing in saturated cnditins. Every 1 t 3 years, mnitr vegetatin cmpsitin and diversity. cver f native species is declining desired cmpsitin is nt being maintained cver f invasive species is increasing Spt-treat weeds as needed by handpulling, back-pack sprayer, wickapplicatr r drmant-seasn applicatin. Temprarily increase burn frequency, such as annual burns fr 2 years, if wdy invasins increase in cver. Nte that sustained burn intervals f less than 3 years will negatively impact cl-seasn natives and wildlife. Prescribed fire is an imprtant tl in maintaining a cnservatin prairie Chris Helzer/TNC 8

11 Restred cnservatin prairie at Glacial Ridge TNC Cst Estimate The estimated cst t restre an annualdminated field t cnservatin prairie is $1707 per acre, based n 2013 prices. Csts assciated with site assessment and prject planning are excluded frm this estimate. This cst estimate assumes vegetatin remval includes tw bradcast herbicide applicatins and ne cntrlled burn, and the site is bradcast-seeded and cultipacked. Pst-seeding management csts include a ttal f eight mwing treatments and three cntrlled burns (burning n mre than ne third f the site per seasn). Actual prject csts will be lwer if a less-frequent mwing schedule is required. Lng-term management csts are nt included in this cst estimate but can be quite variable depending n site needs. Csts assume services and seed are purchased frm restratin cntractrs and native seed nurseries. Useful references Ging Native: A prairie restratin handbk fr MN Landwners MN Dept. f Natural Resurces rd/prairierestratin/gingnative.pdf Native Vegetatin / Seed Mixes MN Bard f Water & Sil Resurces Prairie Seedling and Seeding Evaluatin. Bckenstedt, P Bnestr Rsene Anderlik & Assciates. The Tallgrass Prairie Center Guide t Prairie Restratin in the Upper Midwest. Smith, D University f Iwa Press, Iwa City, IA. The Tallgrass Restratin Handbk fr Prairies, Savannas, and Wdlands. S. Packard and C. F. Mutel, editrs Island Press, Washingtn, D.C. 9