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Home My WebLink AboutAPA2710I I HE 356 .A4 K55 no.20 KNIKARM CROSSING • TECHNICAL MEI\r10RANDUM f\Jo. 20 Biiological Secondary Impact Analysis • • • •\ ., p A... A or-. fiS\-l f' r-... I R~G c l or:::r:·ct: March 1, 1985 U.S. Department of Transportation Federal Highway Administrat~on · Alaska Department of Transportation and Public Facilities • ~ !"""- ' i. ' r I . ! ,, 1"'--: I. ' HE 35 6 . ,Itt.[ kb.~~ no,tP KNIKARM CROSSING''' ~~ TECHNICAL MEMORANDUM No. 20 n Biological Secondary n Impact Arialysis n I l j • ll } ('~ I, • ~ I : ('' I , \ ; r ' ' ,-, i ' ' \ ~ l : r, !"". I \ ~ ,..... I I. ' .f""" ,. !'larch 1, 1985 U.S. Department of Transportation Federal Highway Administration Alaska Department of Transportation and Public Facilities · ARLIS Alaska Resources Library & Information Servtces Anchorage, Alaska ""' I I "I ""' ., I ,, ).7 1"'1 ~ '"" """: I 'J ,......, r (' """' [~ r ~'""": i ' ' r·~ r ~' ! ', r t ,· ,- '1 /i i ' ,-., j: TABLE OF CONTENTS INTRODUCTION • METHODS •••• Induced Development Scenario • • • • • • • • • • Selection of Evaluation Species ••••••••••• Evaluation of Impact to Big Game and Upland Birds •••••• Evaluation of Impacts to Waterbirds ••••••••••••• Evaluation of Impacts to Aquatic Species RESULTS AND DISCUSSION • Big Game and·Upland Birds. Waterbirds • • • Aquatic Species. CAUTIONS •• REFERENCES • • APPENDIX A APPENDIX B Approach to Determining Likely Location for Matanuska-Susitna Borough Growth • • • • • • • Vegetation Types used by u.s. Soil Conservation Service in Willow Subbasin Study Program • . • iii Page 1· 1 1 2 2 6 9 12 12 17 17 25 25 A-1 B-1 Table 1 2 3 LIST OF TABLES Evaluation species for the Knik Arm Crossing Project Habitat evaluation matrix for moose and black bear- Knik Arm Crossing Project secondary impact analysis. Habitat evaluation matrix for spruce grouse- Knik Arm Crossing Project secondary impact analysis. ~ • • Cl • 4 Habitat evaluation for waterbird evaluation species- Knik Arm Crossing Project secondary impact analysis. 5 Habitat evaluation matrix for aquatic evaluation species- Knik Arm Crossing Project secondary impact analysis. • • 6 Surface area (acres) of terrestrial habitats potentially lost to moose productivity as a result of shifted or induced development from the Knik Arm Crossing Project • • 7 Surface area (acres) of terrestrial habitats potentially lost to black bear as a result of shifted or induced development from the Knik Arm Crossing Project • • • • • 8 Surface area (acres) of terrestrial habitats potentially lost to spruce grouse productivity as a result of shifted or induced development from the Knik Arm Crossing Project. 9 10 11 12 13 Surface area (acres) of various value habitats that could be lost to productivity for terrestrial evaluation species as a result of shifted or induced development from the Knik Arm Crossing Project •••• ~ • • • • • • • • • ••• Surface area (acres) of wetland and open water habitats potentially lost to productivity as a result of shifted or induced development from the Knik Arm Crossing Project. Surface area (acres) of various value waterbird habitats that would be lost to productivity as a result of shirted or induced development from the Knik Arm Crossing Project. Open water habitat units lost to productivity for terri- torial lake-oriented waterbirds as a result of shifted or induced development from the Knik Arm Crossing Project • • Littoral habitat (acres) potentially lost to productivity to aquatic organisms as a result of shoreline development on lakes and streams induced by the Knik Arm Crossing Project. . . . . . . . . . . . . . . . ., . . . . . . . . . iv Page 3 4 5 7 10 13 14 15 16 18 19 20 21 i... ..... \..,. I_ l, ~ f I - .... '-'" ! "I l..... ' •• 'I ... L c 'I I ' l..ol ! I u I' ..... i !: ""'" ,· 1 '.J .. il ,...J J ~ """' :. j i """" A ' ) '-.· r"" 1: r-'1 r ("", I 1 !""': I . I II r I . ~ lj rr"'l !(""\ u r l . . r--ll 1'""'1 I .. r~~ J Table 14 15 LIST OF TABLES (continued) Wetland fish rearing habitat (acres) potentially lost to productivity as a result of shifted or induced development from the Knik Arm Crossing Project. • • • • • • • • • • . • . Surface area (acres) of aquatic habitat that would be lost to productivity as a result of shifted or induced develop- ment from the Knik Arm Crossing Project according to Page 22 evaluation species and habitat value. • • • • • . • • • • • • 24 v : ,, I -, ' ... \ ""'1 ..,., ,J -1 ""' ,...... r" """" ,...., ~ ...... l ' ("'\ l I!'"' "'I I r i ,, .,.._, ! ! i t: /) BIOLOGICAL SECONDARY IMPACT ANALYSIS I NTRODU CT I ON Durtng the process of assessfng impacts to the natural environment from the proposed Knik Arm Crosstng Project, tt was determined that secondary tmpacts to bfologtcal resources could be greater than those caused directly by the crossfng and tts approach roads. For purposes of th r s study, secondary tmpacts are def r ned as Impacts that would be Induced by the crosst ng through Increased or shffted resldenttal, commerctal and lndustrtal development, Increased or shifted recreattonal use and other changtng human patterns. The area of prtmary concern Is located within the WII low Subbasin areas of the Matanuska-Susttna Borough. This study attempts to predict and quantify secondary Impacts that might occur to habitats used by key animal species. Because of budget and time limitations, existing Tnformation was utfllzed to the greatest degree possible. METHODS Induced Development Scenario A map (1 Tnch to the mile) del lneatlng probable locatfons of induced and shIfted development was prepared by the Kn I k Arm Cross r ng Project cons u I ta nt team. Thfs map plots on minimum 10 acre grid cell's the location of projected development Tn the year 2010 for possfble growth scenarfos associated with the Downtown and Elmendorf crossing alternatives. The procedures and assumptions used to develop the above growth scenarro ar·e described rn Appendfx A • -1- Se!ectlon of EyaJuatlon Specres Flfteen species <Table 1) were selected by the U.S. Fish and Wildlife Services CUSFWS> In cooperation wlth the Alaska Department of Fish and Game as the basts for evaluatlng impacts for the Knfk Arm Crossing Project. The rationale for species selection is explained In a Mitigation Statement prepared by USFWS (1984). Generally, species were selected because of high public Interest or economic value, or because they utll lze habitats having significant ecological values. Eya!uatlon of Impact to Big Game and Upl~d Birds Impacts to habitats used by the up! and eva! uatlon spec! es (moose, black ""' ( I,.. \.... i.- - I ( .... 1.- bear and spruce grouse) were eva! uated using two spec! al fzed maps produced ·~ by the Willow Subbasin study program (U.S. Department of Agr·lculture 1981): HEP Habitat Model for moose and snowshoe hare; and HEP Habitat Model for red squirrel and spruce grouse. These computer generated maps (1 inch to the mile) are based on groupings of vegetation types and model the habitat suftabfl tty for the above species on minimum 10 acre grid eel Is based on the abfl Tty of the habitats to satisfy I ffe requisites. The rationale for the models is described by USFWS (1981). A workshop attended by agency resource special fsts was held on September 12, 1984 to assfgn values to the habitat groupings used In the above models (Tables 2 and 3) and to establish assumptions to be used to quantify impacts from Induced development and Increased recreational use. Although there is no HEP habitat map for black bear, the moose model was adapted for the black bear by assigning habitat values relative to bear suttabfl Tty to the same habitat groupings used In the moose model. The basic procedure Involved overlaying the development scenario map over the habitat mode·! maps and observing the habitats that would be affected by the proposed development. Assumptions used In quantifying habitat withdrawal were as follows: -2- \_ - ~ ,~' '-" ...... '....... v -.I i' ,......, c· ~ ~ ..., ,, ~> """, I'"': """"· _, ri ~ I, . I, ' r I J f-! I \ I ,I '·v !'"'""' i: I I r-. I I 11. I n L J . ...., ! L J "' r\ { ; r~· 'i '!"": j I, L ) r TABLE 1 Evaluation species for the Knik Arm Crossing Project Common Name Moose Black bear Beaver Common loon Trumpeter swan Lesser Canada goose Mallard/Pintail Spruce grouse Lesser sandhill crane Yellowlegs Chinook Salmon Coho salmon Sockeye salmon Rainbow trout Dolly varden -3- Scienti fie Name Alces alces Ursus americanus castOr-c8nadensis Gav1a immer cygnus buccinator Branta canadensis parvipes Anas platyrhynchos /A acuta oendragapus canadensis Grus canadensis canadensis Triii'ga sp. Oncorhychus tshawytscha Oncorhynchus kisutch Oncorhynchus nerka Salmo gairdnerr- 5'8I'V81Inu8 malma - '·'., I -"" I ,- TABLE 2 Habitat evaluation3 matrix for moose and black bear- Knik Arm Crossing Project secondary impact analysis scs Percent Moose Vegetation Cover In Habitat Types 1 Willow Subbasin 2 Value -- Tundra 65 66, 67 15.09 M Grasslands 63, 64 14.38 M Low shrub 51' 62' 69 6.86 H Tall alder 60 2.67 M Tall alder-willow 61 2.45 H Closed cottonwood 28 0.35 M Closed mixed & spruce forests 26, 42 1. 97 M Other forests 21, 25, 31, 33' 41' 43' 22' 24' 27' M 29' 32' 34, 35' 36 44.21 Water, disturbed, non-vegetated 70-97 12.03 L 1 See Appendix B 2. from U.S. Dept. of Agriculture, 1981. 3. Value Ratinqs: H = High M = Medium L = Low N=Not utilized T~ I ---~ L_ ___ ; (_ ,{__ ~t L~c-; l --f .s-f ' ( (_ Black Bear Habitat Value L M H M H M M M L ,---, r ( f'\. ' f (""'"r / \lj,. ~ . ,, .• ~,,,._ .. .. .. ~,.-. ....... ........ .. }- I \..11 I ~BLE 3 Habitat evaluation3 matrix for spruce grouse- Knik Arm Crossing Project secondary impact analysis ~~ -SCS Percent Spruce Grouse Vegetation Cover In Habitat Habitat Type Types1 Willow Subbasin2 Spruce Grouse Suitability __ Value Shrub tundra Other Tundra and grasslands Willow/alder and Willow/birch shruplands Other shrublands 66 63, 64, 65 66, 67 61, 62 60, 69 0.13 not utilized N ~----------------------------.---------~------------------------- 29.34 not utilized N 6.03 not utilized N 5.95 not utilized N ·--------------·------------------------------------------------Mixed and black spruce forests 24, 26, 29 41, 43, 32 34, 35, 36 38.86 year-round food· & cover; reproduction H ------------~------------------------------------------------------ Deciduous forests Other coniferous forests 22' 27' 28 32, 34 21, 25,31 33, 42 3.68 3.98 not utilized winter food & cover; marginal spring/summer/fall food; reproduction -----------------·-----------·~----------------------------------------------------------------- Water, disturbed, non-vegetated 70-97 12.03 1see Appendix B 2rrom U.S.Dept. of Agriculture, 1981 3value. Ratinqs: H=Hiqh M=Medium L=Low N=Not utilized N M L I -. 1. In the situation were a development grid cell overlayed a habitat cell, the habitat beneath the cell was considered 100 percent with- drawn from productivity. 2. In the situation where an undeveloped cell(s) was completely surround- ed by developed cells, the undeveloped cell(s) was considered 100 percent withdrawn for black bear and 50 percent withdrawn for moose and spruce grouse. 3. To account for impacts to undeveloped areas adjoining development areas, an additional area factor -equal to 25 percent of developed surface area for moose and 50 percent of developed surface area for black bear and spruce grouse -was added to the above. Evaluation of Impacts to Waterbirds The impact analysis for water -and wetland-oriented evaluation species (common loon, trumpeter swan, lesser Canada goose, mallard/pintail, lesser sandhill crane and yellowlegs) was based on the development scenario map in combination with a computer-generated wetland map from the Willow Subbasin study program (U.S. Soil Conservation Service 1981). A workshop attended by resource specialists was again conducted to assign habitat values (Table 4) to each wetland type for each evaluation species and to establish assumptions to be used in quantifying impact. The map overlay procedure was again used and surface areas of impacted wetland habitats were estimated according to the following assumptions: 1. In the situation I'Alere residential or industrial development is projected to occur within wetland habitats, then the impacted area was considered as 100 percent of the developed area. -6- J I I I I I I I I I I II 1 'I I ·I rJ I ~ \ \ I -..,J I TABLE 4 Habitat evaluation matrix 1 for waterbird evaluation species - Knik Arm Crossing Project secondary impact analysis Evaluation Species Lesser Lesser Trumpeter Canada Mallard Sandhill Wetland Type2 Common Loon Swan Goose Pintail Crane Forested needle leaved evergreen N N N N N Forested broad - leaved deciduous N N N N N Forested mixed N N N N N Scrub/shrub broad 'leaved deciduous N L L M M Emergent persisten~ N L L L M Intertidal scrub N N L M M Intertidal emergent - Grassland N N M L M Intertidal emergent-- Marsh L M M L L Intertidal mud flat L L M M L Lower perennial streambed N L L M N Landlock Lakes L9rger than 10 acres Non -Landlocked Lakes M H L M N Larqer Than 10 Acres H H L M N Lakes Less Than 10 Acres L L 1.:-M N 1 Value Ratings: H = High M = Medium L = Low N = Not utilized 2From U.S.Department of Agriculture, 1981. Yellowleqs M L M M M M M M M N M N M 2. In the situation where development is projected to occur immediately adjacent to a wetland habitat, then 25 percent of the wetland block (10-acre cell) was considered withdrawn from productivity for each adjoining development block. In other .words, if a wetland block was surrounded on three sides by non-wetland development blocks, then 75 percent of the wetland was considered withdrawn from produc- tivity. Open water (lake) habitats were analyzed separately by overlaying the development scenario map on USGS topographic maps and noting the approximate proportion of the lake shore that would be developed. Lake surface area was estimated by superimposing a grid of 10 acre cells over the lake and counting the cells inside the lake boundary. All lakes less than 10 acres in size were considered to be 8 acres. Surface area of open water areas impacted was obtained by multiplying the total lake area by the percentage of developed shoreline. To provide a more realistic evaluation of impact to lake nesting habitat used by common loons and trumpeter swans, a supplemental analysis was performed that considered open water habitats only. Trumpeter swans are highly territorial and nearly always nest with one pair of adults to a lake, except on very large lakes with complex shorelines (Hanson et al. 1971). Swans are also very sensitive to human disturbance; periodic human activity such as canoeing or more than a few cabins on a lake greater than 10 acres will discourage the birds from nesting or interfere with reproductive success (Timm 1981; Bailey, personal communication). Therefore, any lake greater than 10 acres with more than 10 percent shoreline development and probable road access was considered lost to swan productivity. Each lake was assumed to provide habitat for only one pair of swans regardless of size; therefore, one open water "habitat unit" is equivalent to one lake. Common loons are also territorial, requiring about 100 acres of open water per reproducing pair in large lakes while smaller lakes from 15 to 100 acres are generally only occupied by one pair (Titus and Van Druff 1981). -8- - ..... ~ ·• lj i I ..... ( 'l i c,..J ic !I ·~ -!t ._,..~ u ~ ; . 'l. l_u . il j ' " I tl II ....,jl J :'I J J j j J I I ,, I I ,,- 1 I I I I I P3 ( t For purposes of this analysis, lakes less than 150 acres were considered as one loon "habitat unit" while lakes greater than 150 acres were considered to contain one "habitat unit" for each 100 acres of open water. Common loons will tolerate and/or adapt to substantial human disturbance but extensive shoreline development is detrimental (Titus and Van Druff 1981, Heimberger et al. 1983, and Sutcliffe 1978). Lakes·smaller than 150 acres (but greater than 10 acres) with less than 30 percent shoreline development were consid- ered to be adequate loon nesting habitat, while small lakes with greater than 30 percent shoreline development were considered to be 100 percent lost to loon productivity. Lakes of 150 acres or larger would incur no loss of productivity with up to 30 percent shoreline development; 30 to 60 percent shoreline development would result in a 50 percent reduction in productivity, and greater than 60 percent shoreline development would cause the lake to be entirely lost to loon production. For example, a 200 acre lake with 90 percent shoreline development would result in the loss of 2 open water loon nesting units. Evaluation of Impacts to Aquatic Species A third workshop was held on August 25 to categorize and assign values to the various aquatic habitats within the potential impact area (Table 5) and to establish approaches to quantifying secondary impacts. Three situations were identified that appeared to be quantifiable. 1. In the case of residential development of lakeshore property, it was concluded that an amount of littoral habitat would be lost to productivity (especially in regard to rearing fish). For any speci fie lake the surface area of habitat lost was assumed to be equal to 10 percent of the length of developed shoreline multi- plied by a band of littoral area 30 feet wide. Developed shoreline length was estimated by first estimating total shoreline length then multiplying by the percentage of the lake ~hare that would be developed as determined from the development scenario map. Total shoreline length of larger lakes was estimated from topographic maps using a map wheel measuring device. Total shoreline length of -9- Beaver ................ ,, ' ................. Spawning Rearing ~I'IIJI'IIl!ng R~llrinq ; ~llawning Rermng Spawmng Reann2 seawmng flearmg Streams little Susitna River N. of Parks Hwy. M M H H l l M M M M M 3 mi. below Mackenzie Rd, to Parks Hwy. M M l H l l l M l l H Inlet To Mackenne Rd. (J mi. below) N L N L N L N L N L M Little Susitna Tributaries My Creek N L N H N N ? M ? L H Hourglass Lake Outlet N L N H N N N M N L M Lake Creek N L N H L L M M L L H ---Other unnam·ed N L L H L L M M M M M I Goose Creek N N L M N N M M L L L ~ 0 Mule Creek N N M M N N N N L L L I Fish Creek L L M H L L M M L L M Meadow Creek N N M H L L M M L L L Lucille Creel< N N L H N N L L L L M Fish Creek (Susitna drainage) M M L H L L M M L L H Red Shirt Lake tributaries N N L H L L M M L L H Lakes Big Lake Complex N N L H H H N H H H L Red Shirt Lake Complex N N N H-M M N M L L L Landlocked lakes2 N N N N N N N N N N L Connected lakes N N L H L M N M L L L lvalue ratings: H = high M = medium L = low N = not utilized 2some specific lakes are stocked on a maintenance basis usually with rainbow trout. IIi .. .. -.. -~ .. .. \11iiit -·~ ... -. ... 'lllll .. -.. -- r: ' ' n r 1 1. n > I n r, r": > I n. ' > r. r: I " r\ i. ) ~n r I ; ~ t 1 1 r h ' ) ,..--.; J. I l ...---1 l i ~ ! L.-/ n il ' r~ smaller lakes was estimated from surface area (as measured for the waterbird analysts) by assuming that shore! lne length was equal to the circumference of a circle with the appropriate area plus20 percent. The above habitat Joss was Intended to Include tmpacts from shoreltne disturbance (boattng, swlmmtng, docks, etc., ), as wei I as Impacts from dredge and fll I of wetlands contiguous to lake shores. 2. In the case where stream bank and bed degradation are caused by heavy fishing pres.sure (Lfttle Susttna River only>, tt was concluded that wlthln an tmpact zone of 2 mlles upstream and downstream from probable access polnts, 20 percent of the rearlng productivity could be lost on the slde of the rtver used by fishermen. The Impact zone was assumed to be 10 feet wide. Possible future access points were tclentlfted by revlewtng land use and transportation plans and by selectlng potential corridors to the Little s~sltna Rtver from new roadways. 3. An additional lmpact factor relating to loss of wetland rearing habitat was considered as a result of activities that are not speclfical ly shore! lne related, such as road development and other land uses. Such Impacts were quantified by first 'Identifying the drainages In the study area where anadromo.us fish rearing was likely to occur (any waterbody connected to saltwater), and, second by ldentlfy"ng wetlands within these drainages from the Wll low Subbasin wetland map. Surface area loss of rearing wetlands was assumed to be equal to 25 percent of the wetland eel I for each contacting development eel I (same procedure as used for waterbird HabItats>. 4. Regarding beaver habitat, It was assumed that where streams potentially supporting beaver are Included within a grid eel I proJected for development the~ beaver habitat would be 100 percent lost within the development cell. If beaver habitat is present in an undeveloped cell adJacent to a developed cell then a -11- 25 percent loss of habitat would occur for each side of the undeve- loped cell that contacts a developed cell. The amount of habitat lost would be quantified according to the surface area ~f the affected cell (in the same way that the other species are con- sidered) even though the surface area concept is not as applicable to beaver as to other species that distribute themselves more uniformly. Loss of lake habitat to beaver use was computed usinq the same method described for quantifying impact to littoral fish habitat from shoreline development except that 100 percent of developed shoreline was used in the calculations rather than 10 percent and a 100-fo~t band of affected shoreline was assumed rather· than a 30-foot band. RESULTS AND DISCUSSION Big Game and Upl~nd Birds Tables 6, 7 and 8 provide estimates of the surface area of various habitats (per the HEP habitat maps) that could be withdrawn from produc- tivity as a result of development in the year 2010 for moose, black bear and spruce grouse respective! y. Acreage is provided for each of the four de- velopment scena~ios considered in this study. Table 9 provides surface area of habitats according to value to each of the evaluation species. The mixed spruce/birch forest is by far the most common upland habitat type in the study area (and in areas suitable for development). Tables 6-9 strongly reflect the dominance of this type. The mixed forests were considered to have medium value to moose and black bear. Relatively little of the shrub habitat types, important to both moose and black bear, would be impacted. Spruce grouse favor the mixed forest types and, consequent! y, nearly all the lqst habitat would be considered high value for this species. -12- j , I' ~ ' j ' J J J J J J ' J /J j ' ] I ~ ~ ) iJ i J ~ T "\ ' \ ' - 1 i ): ~ 1 1 I ...-1 'J I ~ VI I Table 6 Surface area (acres) of terrestrial habitats potentially lost to moose productivity as a result of shifted or induced development from the Knik Arm Crossing Project Habitat Type Omendorf-Low Development Scenario Elmendorf Mid-Downtown Mid-Dol'.rltol'.rl Hiqh range range Tundra 0 0 0 0 Grasslands 13 13 63 88 Low shrub 13 13 113 113 Tall alder 0 0 , 0 0 Tall alder-willow 20 20 20 20 Closed cottonwood .o 0 0 ·o Closed mixed & Spruce forests 743 843 888 1055 Other forests 6848 8110 10962 14982 ------------------------------------------------------------------~----------------------------------- Disturbed, non vegetated 105 235 272 542 \ TABLE 7 Surface area (acres) of terrestrial habitats potential! y lost to black bear as a result of shifted or induced development from the Knik Arm Crossing Project Development Scenario Habitat Type Elmendorf Low Elmendorf Mid-DoWltown Mid-Downtown High range range Tundra 0 0 0 0 Grasslands 15 15 115 165 I Low shrub 15 15 195 195 ~ -!>- I -~ Tall alder 0 0 0 0 ---- Tall alder-willow 40 40 40 40 - Closed cottonwood 0 0 0 0 - Closed mixed & Spruce forests 895 1015 1075 1280 - Other forests 8705 10240 13815 18815 -- Disturbed, non vegetated 130 290 345 745 r r : l · · --• • -·· ; · • --, 1 · ' / ---1-· ·-1 · ·-r ·---t --·--r --f' ·--~:---· ----• · ------- ----· -l=_-~ '==-be= "== ~ ~ ~-~ -... -. ~ J--~. / ~ 1--------o 1------= l----~ f-::.--k-----~ 1=--:__-~ f.-.: __ = I ~ IJ1 I TABLE 8 Surface area (acres) of terrestrial habitats potentially lost to spruce grouse productivity as a result of shifted .or induced development from the Knik Arm Crossing Project Development Scenario Habitat Type Elmendorf Low Elmendorf Mid- range Shrub tundra Other Tundra and grass! and s Willow/alder and Willow/birch shrub lands Other shrublands Mixed and black spruce forests Deciduous forests Other coniferous forests Water, disturbed, non-vegetated 15 15 75 90 9405 11395 +495* +290 * 0 0 0* 205 l:bWltown Mid- ranqe 55 205 15375 +245* 0 235 * Represents a gain in habitat area as a result of development shifting from one area to another. Downtown High 75 335 21020 190 180 625 J ,J TABLE 9 Surface area (acres) of various value habitats that could be lost to productivity for terrestrial evaluation species as a result of shifted or induced development from the Knik Arm Crossing Project Habitat Value High Medium Low Not Utilized Development Scenario Elmendorf Low Elmendorf Mid-range Downtown Mid-range Downtown High Elmendorf Low Elmendorf Mid-range Downtown Mid-range Downtown High Elmendorf Low Elmendorf Mid-range Downtown .Mid-range DowntoMl High Elmendorf Low Elmendorf Mid-range Downtown Mid-range l:bwntown High Moose 33 33 133 133 7604 8966 11913 16125 105 235 272 542 0 0 0 0 Evaluation Species Bleck Bear Spruce Grouse 55 9405 55 11395 235 15375 235 21020 S615 0 11270 0 15,005 0 20260 180 130 0 290 ' 205 345 235 745 625 - 0 +405* 0 +185* 0 15 0 600 * Represents a gain in habitat area as a result of development shifting from one area to another. -16- .... .... """ - ,_ ,_ - ._ 1 - ~ - -- , I - j : 1 I '-" 1 :_j ',,' 'I ,J I ~ I -~ ....., ......., L ...., !"""' ,I ,.-- I ,' r: r--, I I ' ' n 1 ' ( ; r i j ~) r r t r (' j i ,..-. I I '· \"""""1, ( 1.. ; r I > -J '! J~, \ Waterbirds Surface area of the various wetland types that could be lost to productivity for each of the development scenarios Is presented In Table 10. Table 11 translates the acreage into quantities of habitat lost to each waterbird evaluation species according to habitat value. It can be seen from the tables that, except for lake habitats, no high qual tty wetlands would be impacted. The I ow and med rum qual tty wet I and hab r tats that wou I d be affected would consist primarily of freshwater shrub and emergency types. High qual tty intertidal wetlands are primarily located within the state game refuge system and would be avoided by .development. High and medium qual tty lake habitats used for nesting and rearing by common loons and trumpeter swans are analyzed in more meaningful form in Table 12. Substantial numbers of lakes potentially used by these birds for nesting would probably be made unavailable because of development. AQyatJ c Species The surface area of littoral habitat that would be lost to productivity from shorel lne development Is presented In Table 13. Table 14 presents the area of additional wetland habitats (potentially used by rearing fish) that could be lost to productivity as a result o·f other development activities such as construction activities that require wetland fll 1. In addition to habitat withdrawals Itemized In Tables 13 and 14, 2.9 acres of stream habitat on the Little Susltna River was considered lost under all scenarios because of habitat destruction from fishing pressure adJacent to probable access points. This habitat loss was based on the assumption that three access points would be heavily utll !zed In the year 2010 south of the Parks Highway in addition to the one existing access point near the west end of Mackenzie Road. The estimate of access points Is based on a consideration of existing and probable future roadways, the presence of existing trails and seismic I lnes, and Judgement regarding the behavior of fishermen. The access scenario upon which this analysts Is based -17- ,~ ,-"' . f--~ -·\ ~ ~~~ :::-···.\ <~::~ tjj/-e ~ ·=-:;iif I ~ (X) I TABLE 10 Surface area (acres) of wetland and open water habitats potentially lost to prodLCtivity as a result of shifted or induced development from the Knik Arm Crossing Project Development Scenario ---- Wetland Type Elmendorf Low Elmendorf Mid-range Downtown Mid-range IXJwntown High Forested needle--__ ... -·-·- leaved evergreen 70 75 100 150 Forested broad -- leaved deciduous 0 0 0 0 - Forested mixed 98 1.20 158 207 Scrub/shrub broad --- leaved deciduous 100 127 227 349 Emerqent persistent 88 105 170 274 Intertidal scrub 0 0 o· 0 Intertidal emergent - Grassland 0 0 0 0 Intertidal emergent - Marsh 0 0 0 0 - Intertidal mud flat 7.5 15 27 27 Lower perennial streambed 0 0 0 0 ~ ' Landlock Lakes Larger than 10 acres 490 579 821 1001 Non-Landlocked Lakes Larger Than 10 Acres 323 343 347 497 Lakes Less Than 10 Acres 57 60 100 145 [~';~: L~ L~-~: r-.0 .: L~~ c·· L~~ t_: L~ [ -~~~ c -~ ( : ( _, c . { . ~ I • r -. c ... J J J '----: ) ) J 1 J J TABLE 11 Surface area (acres) of various value waterbird habitats that would be lost to productivity as a result of shifted or induced development from the Knik Arm Crossing Project Habitat Development Waterbird Evaluation 5 Value Scenario Common Trumpeter Lesser Sandh1l Loon Swan Guu!:ie Cuu1e Yellowlegs Elmendorf Low 323* 813* 0 0 0 0 Elmendorf Mid-range 343* 922* 0 0 0 0 High DoWI)town Mid-range 347* 1168* 0 0 0 0 Downtown High 497* 1498* 0 0 0 0 Elmendorf Low 490* 0 8 978 188 1234 Elmendorf Mid-range 579* 0 15 1124 232 1424 Medium Downtown Mid-range 821* 0 27 1522 397 1950 Downtown High 1001* 0 27 2019 623 2650 r Elmendorf Low 65 253 1058 88 8 0 Elmendorf Mid-range 75 307 1214 105 15 0 Low Downtown Mid-range 127 524 1665 170 27 0 Downtown High 172 795 2266 274 27 0 Elmendorf Low 356 168 168 168 1038 0 Not Elmendorf Mid-range 427 195 195 195 1177 0 Utilized · Downtown Mid-range 655 258 258 258 1526 0 Downtown High 980 357 357 357 2027 0 ·' I *Open water nesting and rearing habitat -see also Table 11 TABLE 12 Open water habitat units* lost to productivity for territorial lake-oriented waterbirds as a result of shifted or induced development from the Knik Arm Crossing Project Habitat Value High Medium Development Scenario Elmendorf Low Elmendorf Mid-range IXlwntown Mid-range IXlwntown High , Elmendorf Low Elmendorf Mid-range IXlwntown Mid-range IXlwntown High Evaluation S~ecies Co-mmon ---Trum-peter Loon Swan 9 9 10 13 11 14 21 24 20 26 32 37 0 0 0 0 * A Habitat unit represents the area of open water required by a pair of nesting loons or swans to achieve successful reproduction. In most cases 1 habitat unit is equivalent to 1 lake. -20- .... f' I ' ,_ '' \ ... r' ' ~ f' I '- /-, ,_ - ' ' ... ..... ... r-~ .,_,. -:"' '1 - f' I ~ j ~ 0 I I ...J ('I u ; n u ! :1 i) 'I J ~---J :~~"~J .--) ·=-:=1 ~ '~~~J I -::-:-J ~ ~-~~ J ; -_] --J :~~~~ J -~ J _) J J : '___:_] '------~ ----- TABLE 13 Littoral habitat (acres) potentially lost to productivity to aquatic organisms as a result of shoreline development on lakes and streams induced by the Knik Arm Crossing Project Development Scenario Elmendorf Low Elmendorf Mid-range Downtown Mid-range lliwntown Hiqh Little Susitna River (below Parks Highway) 0 0 0 0 Little Susitna Tributaries 0.1 0.1 0.1 0.3 I Goose Creek 0 0 0 0 N ~ I Mule Creek 0.05 0.05 0.1 0.15 Fish Creek 0.1 0.1 0.1 0.2 Meadow Creek 0 0 0 0 Lucille Creek 0 0 0 0 Fish Creek (from Red Shirt Lake) 0.23 0.23 0.23 0.23 Red Shirt Lake Tributaries 0 0 0.1 0.1 Big Lake Complex 0.3 0.3 0.3 0.3 Red Shirt Lake 0.4 0.4 0.4 0.4 Connected Lakes 0.8 0.9 0.9 1.7 Landlocked Lakes 6.1 7.0 10.2 12.8 I N N I TABLE 14 Wetland fish rearing habitat (acres) potentially lo'st to productivity as a result of shifted or induced development from the Knik Arm Crossing ~roject. Development Scenario Elmendorf Low Elmendorf Mid~range Do\'Klto\'61 Mid-range Little Susitna River (below Parks Highway 7.5 7.5 12.5 Little Susitna Tributaries 5.0 5.0 10.0 Goose Creek 2.5 2.5 5.0 Mule Creek 5.0 05. 10.0 fish Creek 5.0 5.0 5.0 Meadow Creek 0 0 0 n~-... -t>!<-·,.·•-onvr...,•L•>>r.">,o~"'<\1"~<-""'L Lucille Creek 0 0 0 fish Creek (from Red Shirt Lake) 27.5 27.5 27.5 Red Shirt Lake Tributaries 0 0 5.0 Rig Lake Complex 2.5 7.5 17.5 Red Shirt Lake 7.5 7.5 7.5 Connected Lakes o. 0 • I 2.5 . , Landlocked Lakes 0 0 o. Do\'KitO\'Kl High 15.0 20.0 7.5 10.0 22.5 0 0 27.5 10.0 25.0 15.0 20.0 0 [ _:~ C~ _ __: C =: (_ ~. L~~, L_:' f ft f ~ : t~~ ~ · I (' r f r--r f ., r-·--, ,f .., l, .. ,i, """' ...., I I : j ..., I """' .-, r ,..... r I""'"' ......, i l J 1....., i ,, ,r-. i :' r \ r l I~ Includes access to the Little Susftna River at the following points: 0 0 0 Bridge crossing from the proposed east-west corridor connecting the Knlk ~rm Crossing Houston Connector with the Fish Creek agricultural area near the west end of the existing Mackenzie Road • A trail access heading east to the river from the proposed Willow-Point Mackenzie Road <north-south corridor through the Fish Creek Management Unit) -access might logically occur several miles north of the ldftarod Trail crossing. Access via a seismic trail from.the northern portion of the Houston Connector w~st to the river near the Horseshoe Lake complex. Habitat w Tthdrawal s from the above sources are combined In Table 15 and presented accordlng to value to the key species. A separate analysis was performed for beaver and this species Is also Included In Table 15. To slmpl lfy the analysts, the habitat values assigned to waterbodles for specific species were those for the life stage which has the highest value, rather than separatl~g spawning and rearing habitat as In Table 5. With the exception of coho salmon, high qual tty fish habitats would not be greatly affected by the projected development activities relative to the other value categories. High value coho salmon rearing habitat Is associated with nearly alI the connected lakes and streams In the study area and, thus, appears to be the dominant f lsherles value that will be affected. Impact from shorel lne development alone would affect primarily the smal I, landlocked lakes near the road corridors. These fakes generally have I ow value to fIsh; however, they may have a high future recreation potential If development pressure justifies "put and take" fisheries supported by stocked fish. Therefore, habitat Impacts to landlocked Jakes might represent a loss to the enhancement potential to managed fisheries that are frequently developed fn suburban areas. -23- TABLE 15 Surface area (acres) of aquatic habitat that would be lost to productivity qs a result of shifted or induced development from the Knik Arm Crossing Project according to evaluation species and habitat value Evaluation Species Habitat Development ChTnooV ___ --Coho Sockeye Rainbow lXllly Value Scenario Salmon Salmon Salmon Trout Varden Beaver Elmendorf Low 0 59.8 2.8 2.a 2.8 55 Elmendorf Mid-range 0 64.9 7.8 7.8 7.8 55 High Downtown Mid-range 0 92.5 17.8 17.8 17.8 70 Downtown High 0 161.1 25.3 25.3 25.3 70 ElmendorF Low--------38.1 -7.6 8.7 59.5 . 5'. f )2.5 I Elmendorf Mid-range 38.1 7.6 8.8 59.6 5.1 32.5 N -!':> Medium Downtown Mid-range 43.1 15.1 11.3 84.7 10.1 35.0 I Downtown High 45.6 17.7 37.1 130.8 20.3 115.0 £fmendorf Low --10.2 0 47.3 0 59.5 -_---255.8 Elmendorf Nid-nmye 10.2 0 47.3 0 59.6 289.1 Low Do~<Jntown Nid-range 15.2 0 63.4 0 79.7 433.3 Downtown High 43.0 0 98.7 0 133.2 549.2 - Elm end or f Low 25.2 6.1 13.7 11.2 6.1 0 Not Elmendorf Nid-range 31.2 7.0 14.6 12.1 7.0 0 Utilized Downtown Mid-range 59.5 10.2 25.3 15.3 10.2 0 £bwntown High 103.0 11..8 30.5 35.5 12.8 0 [_: L: l .. { f r .. (-.. ,f -~ f ---r-· --f --f { --( r _, f--f f' -. ~ ' ' I '.l : ') l I .I """ '""'· -. r: ,..., l ·, I"""'· i l > I: ' ! n I \ I, ' r, l ' G ' ' I, \ n I' ' I, i n ,, I l .: r I l ) r I . ' I I . . CAUTIONS It should be strongly emphasized that the figures presented in this report are only intended to provide a suggestion of the kinds of habitat impacts that might result from future development stimulated by the Knik Arm Crossing. The results are on! y as accurate as the assumptions that went into developing them. While the development scenario map that served as the basis for this analysis was constructed on the basis of informed profes- sional judgement, the actual placement of individual "development cells" was to some extent arbitrary. The workshop approach that was used to help develop value ratings and impact assumptions provides some confidence in their reasonableness.-Never- theless, the decisions reached in the workshops were often based on scanty · background information and assumptions tended to emphasize resource values. Therefore, it is likely that the impacts described in this report represent a worst case situation. Additionally, existing laws and regulations will provide some degree of protection for habitats and associated species espec- ially when high values are involved. REFERENCES Hanson, H.A., P.E. Shepherd J.G. King and W.A. Troyer. 1971. The trumpeter swan in Alaska. Wild!. Monogr. No. 26. Heimberger, M., D. Euler, and J. Barr. 1983. The impact of cottage develop- ment on common loon reproductive success in central Ontario. Wilson bull. 95 (3): pp.431-439. ·Sutcliffe, S.A .1978. Changes in status and factors affecting common loon populations in New Hampshire. Trans. 35th N.E. Fish and Wild!. Conf., N.E. Sect. Wild!. Soc. pp. 319-224. Timm, D.E. 1981. Relationship between trumpeter swan distribution and cabins in the Susitna basin. Proc. Sixth Trumpeter Swan Society Con- ference: pp. 46-48. -25- Titus, J.R. and L.W. Van Druff. 1981. Response of the common loon to recreational pressure in the the Boundary Waters Canoe Area, north- eastern Minnesota. Wild!. Monogr. No. 79. U.S. Department of Agriculture. 1981. Susitna River Basin Study Alaska, Willow Subbasin Final Report. Anchorage. U.S. Fish and Wildlife Service. 1981. Technical Appendix -Fish and Wild- life Resources. Susitna River Basin Coopera:ive Study, Willow Subbasin Portion. -26- ·- 1.. '- ... ·- ! .... - ' ,_ ,_ .... - ._ - ...... , ..... J ' 'l u l>· , , CD ::s Q. -· >< l> ·---__ ] · ______ ) _ _I -, '""': I . I KNIKARM CROSSING INTEROFFICE CORRESPONDENCE TO: FILE FROM: John Page· LOCATION: LOCATION: ---~-------------------------------------------------------------------------------------------------------------, SUBJECT: Approach t:> Determining Likely Location for Mat-Su Borough Growth DATE: FILE: 10/17/84 -----------------------------------------------------------------.0--------------------------------------------~ I ) ~ I ......, r: r I I r n ! 1: : r . ' r t n I i I. ,r 't I r-, 'i ! J, : I r1 I ! This memo describes the approach and assumptions used in identifying the likely location of ·residential growth increases between 1983 and 2010 in· the Mat-Su Borough and the change that would result from a crossing. Seven areas of the Borough were considered: 0 0 0 0 0 0 0 Point MacKenzie Knik/Goose Bay Fish Creek Willow/Nancy Lake Big Lake/Houston Wasilla/Fishhook Palmer/Sutton These areas are illustrated on the attached map and are termed in the anaiysis "Sub-Regional Areas" (SRA's). The. approach to growth mapping was as follows: 1. -\. Dwelling Unit Growth a. No-Crossing. Total growth is similar to that forecast in the Matanuska-Susitn~ Borough Comprehensive Plan (draft) (DOWL Engineers, February 1983) for 2001. To this was added growth to 2010 assuming a growth rate slightly less than that before 2001. b. Elmendorf Crossing--Low. This low estimate of growth that ~ includes c:::-ossing related growth shifts from Anchorage to the Mat-Su Bor:>ugh was developed by the Institute of Social and Economic Research (ISER) for the Municipality of Anchorage (MOA). Holding capacity for development in the Mat-Su Borough in relation to regional holding capacity was the primary factor in determininc; the growth shift. This scenario assumed that only private a*d native lands would be available for development and densities· would pe 1 to 0.2 dwelling units per acre, a low holding capacity for development. c. Elmendorf Crossing--Medium. This estimate of shifted grow~.h .. was developed by the Knik Arm crossing team. fielding capacity in 'the Mat-Su Borough in relation to that in the region was· again a prime factor in the amount of growth shifted. Accessibility was another factor. Longer distances to central Anchorage tend to suppress development outside.the bowl. All lands with a medium A-1 2. d. e. to high capability for residential development (based on Willow Sub-basin grid-cell mapping) minus those set aside or to be set aside for agriculture or recreation were assumed to be available for development. Densities of one to two dwelling units per acre were assigned. The change in the definition of available lands and the greater densities increased the holding capacity in the Mat-Su Borough above that used in the low estimate. Downtown Crossing--Medium. This estimate was also made by the Knik Arm crossing team. The san:e assumptions as the Elmendorf--Medium were used except the distance to central Anchorage was shorter due to crossing location, increasing. accessibility and the amount of growth shifted to the Mat-Su Borough. Downtown Crossing--High. This estimate was prepared by ISER/MOA. It assumes that one-half of the Borough owned lands are available for development, as well as all private and native owned. A density of two dwelling units per acre with a small amount of land for multi-family housing at 15 dwelling units per acre was used. This scenario assumes the greatest holding capacity. The two estimates completed by the Knik Arm crossing team are believed by the team to properly reflect the differences between Elmendorf and Downtown crossing accessibility. The ISER estimates ·were developed for the Municipality of Anchorage and not for the -the crossing team. They are being included at the request of the ·Municipality as the most likely growth shift extremes. The decision to use these four sets of crossing forecasts was made jointly by the Municipality of Anchorage, Anchorage Metropo:itan Area Transportation Study, Mat~Su Borough, ISER, and the Knik Arm crossing team. The crossing team model breaks down the gror-rth shift estimates into the SRA's. See the attached map. The ISER forecasts were broken into these same areas by using the Elmendorf--Medium percentage distribution for Elmendorf--Low and the Do'll--ntown--Medium percentage distribution for Downtown--High. Development Density. Two sets of densities were used for mapping the forecasts. For residential growth that.would occur with No-Crossing, densities identified in the Borough Comprehensive Plan were used: Sub-Regional Area Point MacKenzie Knik/Goose Bay Fish Creek Willow/Nancy Lake Big Lake/Houston Wasilla/Fishhook Palmer /Sutton. A-2 Dwelling Units Per Acre 0.28 0.44 0.28 0.28 0.37 1.00 1.00 "" I ... 1.., ... ' .. . .... :.... '- '- \_. . .... -- .,.._ r I ...; :...J T I I -... " I I -..; J I , ,I ,~,.I ~ .., , I I 11 II} rr 'I: ~ } ..., i ~ J :1 r\ I ,......, I II ' I, ) r I' I r l ~ [ r r~ l ;' n I i n li ' \ ,' r~ I' L ) '~ \ r I : IL J r I , 3. 4. 0 0 0 0 0 0 A rural employment density of 0.087 acres per employee was also assumed for No-Crossing non-residential growth. Higher densities agreed to by the Mat-Su Borough and the Knik Arm cr9ssing team were used for crossing generated growth. The higher densities reflect the higher demand for land resulting from improved access to Anchorage • They are: Sub-Regional Area Point MacKenzie Knik/Goose Bay Fish Creek Willow/Nancy Lake Big Lake/Houston Wasilla/Fishhook Palmer/Sutton Dwelling Units Per Acre 2 1.5 1 1 2 2 1.5 For Crossing-related employment growth a rural density of 0.087 employees per acre was assumed except in Point MacKenzie, Wasilla/ Fishhook, and Palmer/Sutton where a suburban density similar to Eagle River of 0.048 employees per acre was assumed. Number of Grid Cells. This was determined by dividing the SRA forecasts (dwelling units) by anticipated average densities (dwelling units per acre). This result (acres) was divided by 10 acres per grid. Grid Cell Assignment. The no-crossing growth was first assigned to -grid cells on a "1 inch equals one mile" Willow Sub-basin grid-cell map. The purpose of the no-crossing grid assignment was to assure crossing-related development was not assigned to land likely to develop without a crossing. The additional growth with the Elmendorf--Low forecast was then marked using a different color. The Elmendorf--Medium, Downtown--Medium, and Downtown--High were then each in turn marked. The criterion used for assigning development to grid cells were: Highway access would be controlled. Growth was clustered around ·probable intersection locations. Grids were assigned only if they had a medium to high capability for residential development based on Willow Sub-basin grid-cell mapping. Development would occur in the Point MacKenzie are·a in areas designated in the Point MacKenzie Area Meriting Special Attention (AMSA) Phase II Report. Development would occur only in areas designated for residential development by ~e Mat-Su Borough Comprehensive Plan and in Fish Creek by the Fi~h Creek Management Plan. Only grids in road-served areas or areas planned for road service in the above plans were assigned. ... ...... --:"" : Lake-front property meeting all of the other criteria was generally assumed to develop. A-3 ,,,,~·## ,. 4>. ,,. ~~ •'' X ,•' .. (24) ~ ~ ~ .... .... ~ ~ '••· ••• •• ~ .. .... 404' .. ~ :I,IIIIIIIUIS -. ~ :!••••••e . --. ~ --. .... .... ~ .: ~ -. -. -. I • • ~·· ···························~····································: PALMERI 1.., .. .. .. .. -~ . .. . -4lt ... - WILLOW I ·~ .$ BIG LAKE/ = 5 NANCY LAKE ·~~ HOUSTON ~ ; ...... -······ ~ -: ~ : . ~ . : : ...... WASILLA I . : .talC' E .:> =I SHHOOK : .. • ~ =--~ ' . .. ..... ~ . -. hllllllllllll: : : :. ~ . .. . ........... -.. ~ ... ":;.,../": -~ ... ~ ~ FISH CREEK ,,,. : . -. 1.! ,,, :20 ~' .... :. • • .. .. • • S KNI K/ E GOOSEB - • . -. .. • -• . -.. . -. . . --. . 'f.. ~'l\-~ ~,'f.. ....-....... 9 ~c laG~~~,.,.. ·"!iii -., .. -:...•. ,-I : _..,_.,, I • ~w-JY· I 5 : AMATS: I : .. -.. ;+1 • : -~~ I : .... I • ~ . -~ I : ~ l : '#,#), I : ##" I • ~~ I : ~.; I : ~~ I : ~~ I : ~#L I : .'?: I : ~~ I : ~ I • ?,. ill falC111U I.; A-4 EAGLE RIVER SUBREGIONAL AREA ··BOUNDARIES ~1 l8 DISTRICT/SRA CENTROID LINK 10 NO. SUTTON X2 -(25) ,_ .. I I ' - ' I.. I 1... {'' I ~ ,_ ,_ '' ' '-' "· : T J J r · ~~ J ' '\ IJ u .:I> -a -a CD ::s· c. -· >< OJ VEGETATION TYPES USED BY U.S. SOIL 1. CONSERVATION SERVICE IN WI LLOW l I! "" ··' '"I ' .. ' I "'"" .., I I "": --- ,....,, ~ I !'""'1 11 ~ l. '"' \ ij SUBBASIN STUDY PROGRAM FOREST & ·T,.;OOUL~~D ( .::_ 10~ C::.-ovn ~aver) CLOSED :FO?-.EST ( ~ 50~ Cro;..-n Covet) CONIFEROUS FOREST ~nite Soruce Code 21 Short stands ~hite soruce-Main canopy usually less than 30·feet in ,. • height, usually found at higher elevations as isola::ed pockets in areas dominated by alder, grassland or. open mixed stands. Characteristic plants are: Trees -Yhite· spruce, paper birch; Shrubs -Yillows, high bush cranberry, ·prickly rose alder, rusty menziesia; Herbs -fireweed~ do~ood, starflo~er; Grasses· -blue- joint; Oth~rs -sedges, ferns. Total annual production of the understory is: 1000 -1500 lbs/acre 25 Tall stands Yhi-:e snruce -Main canopy usually greater than 30 f:eet in height, usually found at lower elevations on better sites, al~os~al~ays found mixed with old and decadent deciduous trees (very rarely foundps a pure type in Susitna Valley). 41 Characteristic plants are: Shrubs -willow, blueberry, dogwood, f:!.ve-lea.f bramb~e, ferns. Trees -white spruce, paper birch; dwarf birch, spirea; Herb~ -fireweed, lupine; Grasse$ -bluejoint; Others - Total annual production of the understory is: 400 -650 lbs/acre Black Soruce Short stands black soruce -Main canopy usually less than 30 feet in height, generally found on wet and/or cold (poor) sitei, ~ay be found mLxed with bir~h of poor quality but usually found ~s a pure type fo~ine isl~,ds and str~ngers in bog areas or transition zones between bog·area. and forest areas. Understory is uHu~lly a thick moss and/or sedge m~t. Ch~racteristic pl~nts are: Trees -bl3ck spruce, P~?er birch; Shrubs -uillows, spire~, lowbush cranberry, dwarf birch, labrador tea, crowperry, t~in-flower; Herbs -wintergreen; Gr~sses -bluejoint Others -horsetails. Total annu~l production of the understory is: 150 -400 lbs/acrc B-1 42 Tall stands black soruce -'Hain canopy usuall.y g·reater than JO fe".::t in height, can usually be identified as a fire formed stand, on relatively good sites, stands are remarkably pure and the stocking density is usually quite high, ~ay be found mixed ~ith ~ scattered birch • .,. Characteristic plants are: Trees -black spruce, paper birch; Shrubs -lo•.Jbush cranberry, blueberry, d:ogvood, crovberry > labrador. tea, currant, highbush cranberry, prickly rose, twin-flower, geocaul• Grasses -bluejoint; Others -horsetails. ·Total annual production of the understory is: 100 -300 lbs/acre Mountain Hemlock *45 Short stands hemlock -Main canopy less than 30 feet, geographically limited in Susitna Valley to higher ground -west of Tyonek, found as stringers mixed with other local types. *46 Tall stands hemlock -t~in canopy grea~er tha~ 30 feet, geogra?hically limit:ed in Susitna Valley to lo'tJ ground 1.1est of Tyon_ek, found as stringer stands mixed with other local types • ... Deciduous Forest ~ Closed deciduous, Closed mixed . 22 Young stand -deciduous/tlixed -Canopy is usually very finely· textured as seen from above, openings in stand are very rare. Composed Utostly of birch and/or aspen. This type very rarely mi~ed ~ith other types a~cept \.Then found as a re~nant condition in burned areas. Spruce is not usually . 24 . evident as a component· of the overs tory .in these young stands. 0-40 years old. Characteristic plants.are: Trees-paper birch, aspen; Shrubs- willows, alders, prickly rose, lo~bush cranberry, rusty menziesia, highbush cranberry, dog>:.Jood, twin-flo~er, devilsclub, spirea; Grasses -bluejoint; Herbs -cloudberry, starflo~er; Others -horse- tails, lichens. Total annual production of the understory is: 400 -700 lbs/acre Mediuc age stand -deciduous/mixed -Canopy is usually fine textured as seen from above, openings m~y be fairly co~~on but they are usually small. Ele~enis of this type include birch, spruce and aspen. Birch is usually found as a main component of this type but % composition may vary greatly depending on a number of factors, e.g •• as the type increases in age, the percentage of white spruce as a gro~~ conponent usually increase along ~ith the aoount of understory and number of st~nd openings. 40-100 year age. * Note these descri?tions are very tentative. -tkt \,Sl'-\.~ c.) vJ,\:o ~~" ,') I --.4 • .u .L . C:'._t .. I ... "-L '-\N-'-\\ · ... . +-...t.-.... a\ rv .............. , '- B-2 I. '" \, · .. l.o i.. 1.. I ... '- I '- 1...1. ;; n ! ' ,-. "' ':""" ....., i ,j " ~ r: ,, ' '·' r1 L: n t I n ' . ) n n •• J r"> i l ; n • J r I t r l . r l J r. l ; r-"1 1. l ' 26 Characteristic plants are: Trees -paper birch, ~bite spruce, black spruce, aspen; Shrubs -alders, willows, highbush cranberry, lowbush cranberry, prickly.rose, labrador tea, A.-:leric<ln red r<lspberry, bog blueberry, rusty menziesia, devils club; P.erbs -dog•.:ood, st:Lrflo·,.;er, fireweed; vin.tergreen, tall bluebell, cloudberry; Others -horset<lils, ferns. · Total annual production of the unde~story is: 200 -1000 lbs/acre : \ 'Old stand -dec:'.duous/c.i."<:ed -Canopy is usually SO::lewhat coarse textured . ·:~ as seen from above~ openings are USUally CC~-:'100 and may cover close to ·. r half of the stand area. Canopy may also appear smooth, but openL~gs appear. as definite holes in the crown. Deciduous trees in these old stands are usually decaden:. Spruce is usually becoming the dominant species. The _ understory-·-componen-c of the stand is usually visible from above and . i::~.cludes ·calcmagrostics and Alnus as its most co::::mon species. These .,! stands are al~ays greater than 100 years old. _ Cl1aracteristic plants are: Trees -paper birch, white spruce, black spruce; Shrubs -alders, tall blueberry, rusty menziesia, prickly rose~ lo-wbush cranberry, highbush cranberry, devilsclub, five-leaf brruuble, t:win-flowe.r; Grasses -bluejoint; Others -horsetails, ferns. Cottonwood Total annual ·production of the understory is: 400 -1500 lbs/acre ' 27 Young st<lnds -cottonwood -Host .comlnonly -found on new isl<lnds, dot."11St'l""eam ·ends of old islands and point bars of rivers. Cottonwood or popla1: is usually found nL~ed with l~rge alder and/or ~illow -(unde~s:ory is sparse to non~"'<istent). 40 years aid. 28 Characteristic plants are: Trees ·-cotton~ood; Shrubs -willows, alders; Grasses -bluejoint; Others -horsetails, ferns . Total annual production of the understory is: 100 -300 lbs/acre Mediu~ age stands -cottonwood -Host co~-:lonly fou~d in a riverine situatic· or within at: least one r.lile of a rivar (c'llluv:.~l soils). St:.::lncis ilre usuall pu~e cotton~ood or poplar, spacing is eve~ an~ ere~~ closure appro~ches 100 Understory in the Susitna Valley is do~in.:ltcd by alder and devilsclub. 40-100 years old. Characteristic plants are: Trees -cotton~ood, ~hitc spruce; Shrubs - devilsclub, highbush cranberry, alders, ~illo~s, Americ~n red rc'lspberr Gr~sses -bluejoint; Others -horsetc'lils, ferns. Total annual production of the un2erstory is: 600-lOOO.lbs/acrc B-3 29 ·old stands -cot:ton.,.ood -Most comr.lonly fou:1d in -riverin"e influence (alluvial soils). Stands rnay be mixed ,.,..ith young •..:hite sprue~. Cotton- wood are extremely large (30-40 inches in diameter) and decudent (larger trees may be only shells). Sta:1d appears sor.:ewnat clumpy due to openings appearing in stand. Understory includes large. quantit;es of ald~r, devilsclub. and willa...... Greater than 100 years old. Characteristic plants are: Trees -cotto~ood, white spruce; Shrubs -alders, ~illo,.,..s, prickly rose, devilsclub, highbush cranber.ry; American red raspberry; Grasses -bluejoint; Others -ferns, ho-rsetails Total annual production of the understo-ry is: 100 -1100 lbs/acre OPEN FOREST WOODL~~ (10-507. Crovn Cover) Coniferous Forest l\'h.ite Soruce 31 33 43 Short stands -white spruce -Usually found at higher elevations as a transition type between closed forest and high elevation nonforest areas. Usually found mixed with ~lements of the higher elevation type, i.e., if the higher elevation type is a mixture of alder and grass then the open ~ite spruce transition type will normally be forming a complex type witlt alder and grass. 30 feet tall. Characteristic plants are: Trees -white spruce, paper birch; Shrubs -alders, willows, ~~erican red raspberry, dwarf birch; Grasses -bluej oint, bromes; Herbs -starflover, dogwood, cow parsn:.t.p, false hellebore; Others -ferns, hor!:i.~tails. Total annual ·production of the understory is: 1200 -2000 l~s/acre Tall stands -white spruce -Same as type 31 except no~ally found at lower elevations or on better sites. Con~only found in creek bottoms mL~ed with alder/willow and grass. 30 feet tall. Characteriscic plants are: Trees -white spruce, paper birch; Shrubs -alders, willows, lovbush cranberry, twin-flovc~, labrador tea, spirea; Grasses -bluejoint; Herbs -dog~ood, starflouer; Others -fer:1s, horsetails. Total ann~al production of the underscory is: 300 -700 lbs/acrc Black Soruce Short stands-black spruce-Found in as~ociation with bog types. Black· soruce are usually of vc.r·y poor fon:1. Site is either vet or cold or both - t~ees usually less than 15 feet in heighc. B-4 f ·r I... L. 1... .... ._ ·- ''I' ..... -...l r' ' ~ ...... ......; ..... , I :..J 'I I ...... J ' j j :j ' l J J !' 1 n r l ' n r n r t ; r. I . L ; t:, r l j n. r l J r: t I l _,' n l ,: n [' n r. l ' ~ 1 ; J! l ... · Characteristic plants are: Trees -black. spruce, paper birch; Shrubs -dwarf birch, labrador tea, bog blueberry, bog ros~::tary, cro-wberry, alders, Yillows; Grasses -bluejoint:; Herbs -dogt;ood, geocaulon, cloudberry; Others -sedges, horsetails. . Total annual production of the understory is: 300 -900 lbs/acre Deciduous Fo~est Onen deciduous, Ooen mixed --.....-,_ .;...;..;;;=.;;..;;;..;;;. 32· -Mediu~ Age stands-deciduous mixed-Similar to type 31 except no~ally found at lower elevations (as elevation increases so does proportion of .; spruce in mi.'Ccd types). Although birch/aspen stands are not usually fo-:me as a transition type betYeen forest and high elevation nonforest areas, they are often found just belaY areas of type 31. 40 years old. 34 Characteristic plants are: Trees -paper birch, white spruce; Shrubs -dwarf birch, alder, prickly rose, highbush cranberry, ~illow, sweetgale, leatherleaf, rusty menziesia; Grasses -bluejointj Herbs -cloudberrJ, fireweed, bunchberry; Others -ferns, horsetails. Total annual production of the understory is: 1000 -1800 lbs/acre Old stands -Found in same general location as type 33. Found in associa- tion with grass and alder. Birch, in this type, is usually found growL~g in very small, tight clu:::lps. Spruce are usually found to have an open gro't.1n form and are nornally much younger thi:m the hardt;ood component of .the type. Characteristic plants are: Trees -paper birch, white spruce; Shrubs -alders, willows, highbush cranberry, rose, devilsclub, elderberry, tall blueberry; Grasses -bluejoint; Herbs -fire~eed, dog~ood, burnet, false hellebore, starflower, bluebell; Others - ferns, horsetails. Total annual production of the understory is:. BOO -1500 lbs/acre Cottonwood *35 HcdiuL:t ~·stands -Usually found at treeline just above cl2vational li::Ji:: of open white spruce. Found in pockets among low shrubs. Characteristic plants are: Trees -cott:om,•ood, ·..:hite spruce; Shrubs -alder, willa~, devilsclub; Gr;1sses -bluejoint; Her:,s - 'Wintcrgree!1, fire•,.>eed, bluebell; Others -ferns, horset<J.ils. Tot<J.l ;1nnual production of the und~rstory is: 400 -1000 lbs/~cre B-5 *36 Old stands -T'.;o el_e....-at:ional phases of this type seeCI to. occur. The high elevation phase, consisting of balsa:::t poplar, c-.ay be found mixed with streamside alder/willow along flowing water on high elevation flats. The lov elevation phase, consisting. of cottonwood, may be found on major river flood plair:s graving with a confusing mi.-.:ture of other types including open spruce, open birch, alder, grass, etc. . l ....J ' i I u I I u Characteristic plants are: Trees -cotton..:ood, birch~ white spruce; ' j Shrubs -alders, ~illo~s. rose, highbush cranberry, ~~erican red ·....~ raspberry, devilsclub; Grasses -bluejoint; Others -ferns, horsetails. : 1 Total annual production of the understory is: U 700 -1300 lbs/acre NON FOREST ( <107. Cro~~ Cover) Saitwater Wetlands *50 Grassland -El)~us dominated grassland in areas of tidal influence. Usually found at edge of normal high ~ater in sandy soil. No~ally this type is found in areas ~here the shoreline gradient is relatively steep, usually found as a belt of grass along the shore. Total annual production of the understory is: 800 -1500 lbs/acre *51 Lo~ shrub -rivrica dominated shrubland located on tidal flats. Water level is usually fluctuating seasonally. In are~s that are more continu~u .. sly w~t sedge replaced Hyrica. Total annual production of the understory is: 200 -800 lbs/acre *52 Tidal :Harsh -Usually found in areas with many shallov lakes and little topographic relief (within tidal influence). Vegetation is do~inated by various sedges. Woody plants may occur on the drier sedge and peat ridges that are common to this type. Total annual production of the understory is: 400 -1300 lbs/acre ~ Tall Shrub ' •I • I u r i I I ...... J ' 1 ~ ' 1 I J ' 1 I J ; 1 . ; ....J J ! 1 J *60 Alder -This type is do:::tinated by tall (10-15 feet) alder growing in dense u: thickets vith grasses, ferns, and a gre~t variety of forbs graving in the understory. Devilscl~~ can be found as a dominan~ unders~ory to the alder on vetter and steeper sites. Devilsclub ~ill nornally exclude other uncer-u story vegetation. The type is found at or above treeline. At treeline it is often found mixed with open white spruce and cott9n~ood types. Characteristic plants are: alder, devilsclub, spirea, Herbs -fire~eed; Others - Trees -~hitc spruce, cottonwood; Shrubs currant; c~as~es -bluejoint, hentgrass; fcr~s, horz~tnils. Total annual production of the u~derstory is: 2000-JOOO.lbs/acre B-6 I 1 I I u I "I . I u n n n n 1 I I (,, ·• rt I : (, _;: n l. J n ' ' n L ; r r I . ~ r t ' r n r r r -~ ~61 Alder-~illo~ (strea~side vegetation) -·This type is dominated by a mixture of very large alder and ~illo~. This type is normally found on frequently flooded ground such as ne....: islands, point bar~, etc. Understory is sparse but may include equiset~ and cala~agrostis. This type is often found mixed with young open cottonwood (in younger stands the cotton~..:ocd is *62 .al~ost indistinguishable from the willow and alder). Characteristic plants are: Trees -cottom-;ood; Shrubs -aders, willo·..: rose; Herbs -bluebells, lupines, fireweed; Grasses -bluejoint; Others -horsetails, ferns, sedges. -~Shrub- Total annual production of the understory is: 500 -1500 lbs/acre .·; Willo':-1 -resin b:..rch -This type i? dominated by either "~Jillor or resin birch or a combi:::ation thereof. The type is often found in shelter-ed situations at high elevations, e.g.,. dra"~Js in mountainocs· terrain. This type is found at and above the transition between tall shrubland and tundra. Characteristic plants are: Shrubs -dwarf birch, willows, tall blueberry, Grasses -bluejoint, bentgrass; Herbs -fire~•eed, lupines_ meadowrue; Others -ferns, sedges. · Grass l~nd Total annual production of the understory is: 750 -1000 lbs/aci-e · *63 Cala~ogrostis grassland -This type is do~inated by Calamagrostics 1 to 2 meters tall. Fireweed and various ferns are sometimes common. This type is ~ost often found as an understory in the more open forest types and ~oodland areas ~here it is commonly associated with alder patches. This type can also be found unassociated ~ith other types along small streams. Characteris:.ic plants are: Trees -Yhite spr1..1ce, birch, cottonwood; Shrubs -alder, Americ.:m red raspberry; Herbs -fire...:eed. cow parsnip false helleboie; Grnsses -bluejoint; Others -ferns, sedges. Tundra Total ann~al· producc:ion of t.he undersc:ory is: 2500 -3500 lbs/acre *64 Sedze -Grass Tu~dra -This type is found above treeline on relatively flz wet areas. Vegetation consists almost entirely of v~rious wet sedges .. Characteris:.ic plan~s arc: Shrubs -willo~s; Gr~sses -blt1ejoint, bentgrass; Others -sedges. Total zmnual production of tile unciersc·or;.· 200 -800 lbs/acrc B-7 l. , .. .. . *65 Herbacious Tundr~ -This type is found above treeline and is al~osc al~ays found mixed ~ith and above shrub tundra. The variety of species found in this type is i~~ense, consis:ing mainly of various grasses and forbs: Soil varies in depth and may be intermix~d wi~p rock outcroppings. Vegetation may not be continuous. Characteristic plants are: Shrubs -tall blueberry, dwarf birch, crowberry, willows, bearberry; Herbs -geranium, wintergreen, fireweed, dogwood; Grasses -brome, fescue, timothy; Others -sedges. ! Total annual production of the understory is: 300 -800 lbs/acre *56 Shrub Tundra -This type is dominated by dwarf arctic birch a~d other shrubs along with various short grasses and a large number ·of forbs. This t)~e is almost always found mixed with and below herbacious tundra. Density of the shrubs foun§ in this type varies considerably and may often appear quite patchy. Characteristic plants are: ·Shrubs -willo't-lS:o dwarf birch, _alder, labrador tea, ·tall blueberry, bearberry, burnet, wintergreen; Grasses -bluejoint, fescue, timothy, hairgrass; Others -sedges,. ferns. · Total annual production of the understory is: 500 -1200 lbs/acre *67 Mat-cushion tundra -This type is dominated by such plants as dryas, crowberry, bearberry, sedge, grass, lichen ~~d other rooted forbs. Climatic conditions are ~~treme at the elevation ~here this type is found~ Vegetation cover may be complete (closed mat cushion) or rela- tively sparse (scattered mat cushion) with a large percentage of the vegetation being_ lichen. This type is often mixed with rock. "Total annual production of the understo~f is: 50 -100 lbs/acre Fresh Water Wetlands *68 ~~ bog -Cover is domina ted by varying amount of sedge. equisetu.":l and woss (especially sphagnum). This type is usually found as a floating ma:: over several feet: of \."a;:er or as a thick mat directly over: satu:-a::ed or frozen soil. Shrubs and stunted trees (if present) may be found on drier peat ridses. (This type is sir-ilar to tidal marsh except that shallo\." lakes are less co~on, the peat ridges fo~ n more continuous and regular pattern and the type is found inland beyond tidal reach. Usually.!ound as a pure type. Characteristic plantz are: Trees -black spruce; Shrubs -dwarf birch, bog bluebe:::-ry, s·..:eetgale; Herbs -cloudber-:-y, buckbean; ~asses -bluejoin;:; Others -sedges, cottongrass .. TotZll annual production of the t:ncerstor:,· is: 300 -600 lbs/acre B-8 I ' : 1 u u r 1 J I 1 ·: I :....; ' "1 u : 1 :j J J r l ....,) u J ; 1 ....... J I l u r 1 ._j ' 1 ! ...J 1 ....I ' l i ....J I l "' lj ,J ., ,, i :j 'lj f, 'i 1 .. ') I I n 'I! :I 'l I I .i ~ ""' :I, I ""' .i ""; ""' l .., .., .., .., *69 S'ohagnu.r.:dS1;rub bog -Vegetation of this type is dominat~d by a thick moss mat (sphagnu:n) and/or sed?,e tussocks. Grass, eric<lceous shrubs, sali..~, blueberry and cranberry may also be present. Ground "'ater level usually varies seasonally but this type is usually never as "'et as sphagnuc bog. This type is usually mixed "'ith open st~nds of short black spruce. Man~ other types ~ay also be found in close association with sphagn~~ shrub bog. The associated types are usually found on glacia1 moraines and eskers Yithin the bog area. Characteristic. plants are: Trees -black spruce; Shrubs -d~arf birch, labrador tea, leatherleaf, Yillows, lowbush cranberry, bog ros~~ary, ~~eetgale; Herbs -cloudberry, buckbean; Grasses -blue- joint; Others -sedges, horsetails, cot~ongrass. ,.. Total ancual production of the understory is: 500 -1200 lbs/acre NON VEGETATED *70 Cultural influence -May be broadly defined as land that has been obviously affected by h~~an activity. Includes agricultural land, urban areas, and land developed to support or provide services to agricultural and urban land. This "type" may indeed be vegetated but vegetation that is present may not be natural in either cooposition or spacing. *80 *81 Bar-ren Mud Flats -Confined to tidal areas (Cook Inlet .•• ) anc! the mouths of major ri.vers (Susit:na, Y'.nik' ••• ). This "type" may appear vegetac~d on C. I. R. and , ' ' .t: h • h th II ' II • 1 1 co_or pnotog-rapny or ... ro::t t e a~r, O"to:ever, e vezetat:::..on lS usua-.y algal blooms, and/o~ other sea plants. ~!ud flncs are usually well patterned with ripple carks or water drainage pattersn. They are normally submersed during high tide. They r.1ay be used as resti~g and feeding areas by waterfo·..;l. Rock -Includes exposed bedrock and scree co~only found along vith mat cushion tundra at high elevations. This "type" is nlso used to describe large landslide areas -sooe corainal features and other natur<ll barren are.:1s. Pe~~nent Sno~ and Icc *82 Snov fields -High elevation sno~ acc.~~ulation areas. Appear~ to be a p;r;a::len.:-or nearly year round part of the landscape. ~lay be found as s~ll poc~ets on slcpes protected fro~ the sun, on lee slopes or in gulleys. Usually fou~d over bare ground. May also be found as large sno"' accurnulatio; areas at very high elevations. Often =ixed vith mat-cushion tundr<l and rock *83 Glaci~= -Includes bath icefields and glaciers. Usually found covering several square oiles. Considered a pe~anent part of landsc~pe. To dif- ferentiate 83 fro~ 82, note 83 covers r.1uch larger areas; crevasses, moraines and other glacial features are usually present . B-9 .