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NASA Technical Memorandum 83103 >

Effects Of Space Shuttle Launches STS-1 Through STSm9 On Terrestrial Vegetation Of John F. Kennedy Space Center, Florida

September 1985

(&AS&-TB-83103) E f P E C l S CF SEBCE SHUTTLE N8 7-2 06 58 LAONCEES S T S - I ' IEEGUGB S95-9 C b I E B f i E S T B I A L VEGETATICB Of JCHb F, K E N l i i E C Y S P A C E C E l T P B , E I C P I C B (Bionetics Cor&.) 40 & CSCZ 13B Unclas

G3/45 45444

National Aeronautics and Space Administration

NASA Technical Memorandum 83103

Effects Of Space Shuttle Launches STS4 Through STS9 On Terrestrial Vegetation Of John F. Kennedy Space Center, Florida Paul A. Schmalzer, Ph.D. C. Ross Hinkle, Ph.D. and David Breininger The Bionetics Corporation, Kennedy Space Center, Florida

September 1985

National Aeronautics and Space Administration

John F. Kennedy Space Center NASA

TABLE OF CONTENTS

i

Abstract

Space Shuttle launches cause acute vegetation damage in an area of about 2 2 ha near the launch pad. Damage results from exposure to the exhaust ground cloud which contains hydrochloric acid (HCl), aluminum oxide (A1203), and other substances; acidities of < 0 . 5 p H have been measured routinely in association with the launch cloud. Vegetation changes have been followed on 4 2 permanent 20 m vegetation transects within the impact zone. The vegetation changes which have occurred from STS-1 through STS-9 include loss of sensitive species, loss of plant community structure, reduction in total cover, and replacement of some species by weedy invaders. Community level changes define a retrogressive sequence.

Impacts t o strand and dune vegetation up to'1.2 km northeast of the launch pad occurred after the launches of STS-8 and STS-9. Acute vegetation damage in these areas occurred especially to sensitive species. Within six months, however, recovery was nearly complete as shown by examination of permanent plots. Sensitivity of strand and dune species to the launch cloud was partially predicted by previous laboratory studies.

Far-field acidic and dry fallout from the launch cloud as it rises to stabilization and moves with the prevailing winds causes vegetation spotting. Damage from this deposition is minor; typically at most 1% to 5% of leaf surface area is affected. No plant mortality or community changes have occurred from far-field deposition.

The area impacted by Shuttle launches will probably increase with increased launch frequency and operation of a second launch pad. Potential. problems requiring monitoring include dune stability and erosion, nutrient leaching, and wildlife effects .

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LIST OF FIGURES

F i g u r e 1 .

F i g u r e 2 .

F i g u r e 3 .

F i g u r e 4.

F i g u r e 5 .

F i g u r e 6 .

F i g u r e 7.

F i g u r e 8 .

F i g u r e 9 .

F i g u r e 10 .

Page Map of t h e Pad 39A s t u d y a r e a s h o w i n g t h e n e a r - f i e l d i m p a c t z o n e ( f r o m D r e s c h e l 2 e t a l . 1 9 8 5 ) .

I s o p l e t h map o f c h l o r i d e d e p o s i t i o n i n t h e n e a r - f i e l d e n v i r o n m e n t f r o m STS-11 3 ( 4 1 - B ) ( f r o m D r e s c h e l , H a l l , a n d H i n k l e 1 9 8 5 ) .

I s o p l e t h map o f p a r t i c u l a t e d e p o s i t i o n i n t h e n e a r - f i e l d e n v i r o n m e n t f r o m STS-11 4 ( 4 1 - B ) ( f r o m D r e s c h e l , H a l l , a n d H i n k l e 1 9 8 5 ) .

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L o c a t i o n of v e g e t a t l n r ! t r a c s e c t s ix t h e Pad 39A n e a r - f i e l d i m p a c t z o n e . C u m u l a t i v e n e a r - f i e l d l a u n c h d e p o s i t i o n f r o m STS-1 t h r o u g h STS-9 .

R e t r o g r e s s i v e c h a n g e s in p l a n t c o m m u n i t i e s i n t h e Pad 39A n e a r - f i e l d i m p a c t z o n e f r o m STS-1 - . t h r o u g h STS-9

Damage t o s t r a n d and d u n e v e g e t a t i o n f r o m STS-8 .

Damage t o s t r a n d v e g e t a t i o n f r o m STS-9 a n d s u b s e q u e n t r e c o v e r y .

Damage t o d u n e v e g e t a t i o n f r o m STS-9 and s u b s e q u e n t r e c o v e r y .

C u m u l a t i v e f a r - f i e l d l a u n c h d e p o s i t i o n f r o m STS-1 t h r o u g h STS-9 .

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LIST OF TABLES

Page

Table 1.

Table 2.

Table 3.

Table 4.

Table 5.

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Table 6.

Table 7.

Table 8.

Table 9.

Table 10.

Table 11.

Changes i n frequency (P) and percent cover of trees and shrubs from STS-1 through STS-9 in the near-f ield impact zone . Changes in frequency (F) and percent cover of grasses and sedges from STS-1 through STS-9 in the near-field impac't zone . Changes in frequency (F) and percent cover of herbs from STS-1 through STS-9 in the near-field impact zone . Changes in species richness and percent cover from STS-1 through STS-9 in the near- field impact zone,

Mean species richness and mean percent cover from STS-1 through STS-9 in the near- field impact area.

Sensitivity of species to damage based on transect data from strand vegetation - Zone of heavy damage from STS-8.

Sensitivity of species to damage based on transect data from strand vegetation - Zone of moderate damage from STS-8.

Sensitivity of species to damage based on transect data from dune vegetation - Zone of heavy damage from STS-8.

Sensitivity of species to damage based on transect data (N=1) from dune vegetation - Zone of moderate damage from STS-8.

Sensitivity of species to damage based on transect data from strand vegetation - Zone of heavy damage from STS-9.

Sensitivity of species to damage based on transect data from dune vegetation - Zone of heavy damage from STS-9.

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Acknowledgemen t s

T h i s p r o j e c t w a s c o n d u c t e d u n d e r t h e d i r e c t i o n o f D r . W i l l i a m M. K n o t t , 111, B i o l o g i c a l S c i e n c e s O f f i c e r and D r . A l b e r t M. K o l l e r , J r . , C h i e f , E n v i r o n m e n t a l S c i e n c e s O p e r a t i o n s and R e s e a r c h B r a n c h , The B i o m e d i c a l O f f i c e , J o h n F. Kennedy S p a c e C e n t e r (KSC) u n d e r NASA C o n t r a c t NAS10-10285. We t h a n k T e c h n i c o l o r G r a p h i c S e r v i c e s , I n c . , F l o r i d a O p e r a t i o n s f o r p h o t o g r a p h i c s u p p o r t a n d members of The B i o n e t i c s C o r p o r a t i o n E n v i r o n m e n t a l M o n i t o r i n g team, p a r t i c u l a r l y Lee A. M a u l l , f o r f i e l d a s s i s t a n c e , T e r r y L a y e r o f EGdG F l o r i d a , I n c . p r o v i d e d g r a p h i c s a s s i s t a n c e . Thomas W . D r e s c h e l , C h a r l e s T. G a e t z a n d C a r l t o n R. H a l l r e v i e w e d a n e a r l i e r v e r s i o n o f t h i s p a p e r . W e t h a n k A l i c e Hudson a n d T a m i S k i d m o f e for t y p i n g t h e m a n u s c r i p t .

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V

Introduction

Launches of the Space Shuttle from John F. Kennedy Space Center produce environmental impacts resulting from the formation of an exhaust cloud (Bowie 1981, Knott et al. 1983). Major constituents of the exhaust cloud are carbon dioxide (C02), water (H201, aluminum oxide (Al203), and hydrogen chloride (HCl) (NASA 1979). The formation of the exhaust cloud occurs as a result of the

(SRM), the Space Shuttle Main Engines (SSME) and- the simultaneous dumping of several thousand kiloliters of sound suppression and cooling water onto the launch pad. In the turbulence of the rocket exhausts, atomization of the deluge water occurs; these dro-plets coagulate with aluminum oxide particulates and rapidly

(Anderson and Keller 1983).

Typically this cloud, termed the ground cloud, is directed northward by the structure of the flame trench and begins to rise as the horizontal velocity decreases (Knott et al. 1983). As the cloud rises it entrains ambient air until reaching a stabilization height (Bjorklund et al. 1982). This cloud together with portions of the column cloud produced as the Space Shuttle ascends are carried by prevailing winds.

- combined effects of the ignition of the Solid Rocket Motors

scavenge hydrogen c h l c r i d e g2s p r e d u c i q a c i d i c depesition

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Near-field acute effects are produced by the ground cloud sweeping turbulently across the ground, vegetation, and lagoonal waters. Generally near-field effects occur within 0.5 km of the launch pad although they have extended up to 1.0 km away (Knott et al. 1983). Since the pH of droplets in this cloud can be <0.5 (Anderson and Keller 1983), near-field effects can be severe and include acute vegetation damage (Bowie 1981, Knott et al. 1983) and fish kills (Knott et al. 1983, Milligan and Hubbard 1983, Hawkins et al. 1984).

Far-field effects are produced after the cloud rises and moves with the prevailing winds. Deposition from this cloud occurs as spotting on vegetation and structures; spotting may include acid burns from “wet” deposition or may be dry residue, primarily A1203 (Knott et al. 1983, Anderson and Keller 1983). Deposition has been detected up to 22 km from the launch site.

Near-field deposition has been quantified for three launches, STS-11 (41-B), STS-13 (41-C) and STS-14 (41-D) (Dreschel and Hinkle 1984, Dreschel, Hall, and Hinkle 1985, Dreschel et al. 1985). In a typical launch such as STS-11 (41-B), approximately 3000 kg of chlorides and 7000 kg of particulates are deposited in the 22 ha near-field environment (Figure 1). Isopleths of this deposition indicate 100 g/m2 or more of chlorides (Figure 2) and 200 g/m2 or more of particulates (Figure 3) can be deposited in

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PAD 39A

Figure 1 . Map of the Pad 39A study area showing the near-field impact zone (from Dreschel et a l . 1985).

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the near-field environment (Dreschel, Hall, and Hinkle 1985). This typical pattern occurs under conditions of light surface winds. With stronger surface winds, particularly if from the north (e.g., during STS-13), the ground cloud is blown off its usual path (Dreschel, Hall, and Hinkle 1985).

This paper reports the effects on terrestrial vegetation of the first nine Space Shuttle launches in both the near-field and far-field environments. From the first launch on April 12, 1981 through the ninth launch on November 28, 1983 the near-field. environment was impacted. The frequency of these launches has increased and subsequently the time for vegetation recovery between launches has decreased. There were two launches in 1981, three in 1982, and four in 1983. Since the first launch in 1981,

been 6 3 days and the longest period has been seven months; therefore, this constituted a maximum recovery time of seven months and a minimum time of 63 days for vegetation exposed to the launch exhaust cloud.

t h e shortest i i i t i ~ r ~ a ? . betwee:: any t w ~ c ~ n s e ~ u t i ~ e - ~ = C E C ~ ? P _ S has

The launch exhaust cloud from two of nine launches, STS-8 (August 30, 1983) and STS-9 (November 28, 1983), crossed oyer nearby dunes which had previously not been impacted, These events. all'owed for the assessment of vegetation damage from a single launch onto previously unaffected areas of strand and dune vegetation. The launch of STS-8 occurred on August 30, 1983 at 2:32 a.m. At the time of the launch surface temperature was 23.9OC, relative humidity was 95.0%, surface wind speed was 3.09 m/sec and wind direction was 230.0" (Knott 1983a). Thunderstorms had occurred a few hours before launch. Vegetation damage was more extensive following this launch than from any previous one, perhaps due to the high humidity and wet condition of the vegetation. The launch of STS-9 occurred on November 28, 1983 at 11:OO a.m. At the time of launch, surface temperature was 21.4OC, relative humidity was 80.O%, surface wind speed was 6.18 m/sec, and wind direction was 180' (Knott 1983b). Vegetation damage was similar to that from STS-8.

Prior to any Space Shuttle launches several plant communities occurred in the near-field area. These communities included shrub dominated types, graminoid communities and mud flats. Specific types (named by dominant species) were sea oxeye (Borrichia frutescens), saltwort-glasswort (Batis maritima- Salicornia spp.), wax myrtle-groundsel (Myrica cerifera-Baccharis spp.), mixed grasses-sedge (e-g., Fimbristylis Castanea, Andropogon spp.), black mangrove (Avicennia germinans), mud flat-sea purslane (Sesuvium portulacastrum), sea oats-slender cordgrass (Uniola paniculata- Spartina patens), groundsel-sea oxeye and saw palmetto-sea grape (Serenoa repens - Cocoloba uvifera) types. (Unpublished vegetation map, M.J. Provancha).

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H e thods

Near-Field Vegetation

After the launch of STS-1 but before the launch of STS-2, sampling of the vegetation in the impact zone north of Pad 39A was conducted. A rectangular grid sampling system was established in an area approximately 427 m (1400 ft) along the east-west axis and 305 m (1000 ft) along the north-south axis. Eight north-south grid lines were established approximately 60 m (200 f t ) apart. These were labeled A,B,C,D,E,F,G, and H. Six east-west running grid lines were also established and labeled 1,2,3,4,5, and 6 (Figure 4). Grid coordinates were marked with metal posts except for those occurring in the lagoon. North- south and east-west trending vegetation transects were established along these transects. Transects were established in the central 20 m on the line between two grid posts. A total of 46 vegetation sampling transects were established with the grid system. Percent cover by species was determined along each transect using the line-intercept method. (Mueller-Dombois and Ellenberg 1974). The initial vegetation survey was conducted in October, 1981 (Breininger 1981).

In January, 1984 subsequent to the launch of STS-9 these transects were resurveyed. Percent cover by species was determined along each transect. Four of the original transects had been destroyed by groundskeeping operations leaving 42 for comparison to the original survey. Soil samples were taken at 0-15 cm and 15-30 cm depth. Frequency, percent frequency, mean cover and mean relative cover were determined for all plant species occurring in each transect. Species richness and the number of species lost, gained and persisting through the period were calculated. Total cover was also compared between the post-STS-1 and post-STS-9 periods.

The area receiving acute vegetation damage from the ground cloud was mapped after each launch. Maps showing cumulative impacts were prepared by overlaying maps of individual launches.

Dane and Strand Vegetation

Transects were established through the damaged strand and dune vegetation after the launch of STS-8. The dune transect established was 1150 m long and oriented northwest-southeast through the impacted area of dune vegetation. Along the sampling transect, 17 plots (1 m2) were located; of these 1 was in an area of no damage, 5 were in areas of light damage ( ( 5 % leaf area), 2 were in moderate damage (5-10% leaf area), and 9 were in heavily damaged areas 0 1 0 % leaf area). Within each plot, percent cover by species was estimated. Percent damage to each species was

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also estimated visually. Prior to launch this area was relatively undisturbed native dune vegetation dominated by sea oats in association with beach sunflower (Helianthus debilis), camphorweed (Heterotheca subaxillaris), sea grape, and other species.

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A transect 1050 m long was established through the strand vegetation after STS-8 and was oriented north-south through the damaged vegetation. Sixteen plots were established along this transect; meter square plots were used in open areas of grasses and herbs and .004 ha (.01 ac) circular plots were used to sample shrub vegetation with nested meter square plots for the herb layer. One plot was in an area of no damage, 4 in an area of light damage, 4 in an area of moderate damage and 7 in a heavily damaged area. Percent cover and percent damage by species were estimated visually on a continuous scale for each plot. Strand vegetation adjacent to the primary dune had previously been affected by road and railroad construction. Shrubs such as wax myrtle, sea oxeye, and groundsel dominate much of the area but openings dominated by grasses (e.g., Chloris petrae, Andropogon spp.) and herbs (e.g., Monarda punctata, Bidens pilosa) occurred.

A weighted mean percent damage was determined for each plot by multiplying .the percent cover of each species by the percent damage of that species, summing over all species, and dividing by the total cover. In order to determine the sensitivities of individual species, plots were divided into those in areas of moderate damage and those in areas heavily damaged. Mean percent damage for each species within these groups was calculated.

Assessment of STS-9 vegetation damage was made in a similar fashion to that from STS-8. In the dune vegetation a 450 m transect was established and 1 1 plots (1 m2) were distributed along it. Two plots were in undamaged areas, 2 in areas of light damage, 2 in moderate damage and 5 in heavily damaged areas. S i x of these plots were selected to be permanently marked and used to evaluate vegetation recovery. Percent cover and percent damage were recorded visually on a continuous scale by species on each plot . In the strand vegetation a 350 m transect was established and eight plots were placed along it; 0.004 ha plots with nested plots (1 m2) for the herb layer (if present) were used. S i x of these plots were permanently marked to follow recovery. Permanent plots were photographed initially and rephotographed in January, March, April and June. The original estimates of percent cover and percent damage were repeated in June, s i x months after the launch of STS-9.

F a r - F i e l d Vege ta t ion

A f t e r e a c h l a u n c h , t h e a r e a r e c e i v i n g f a r - f i e l d d e p o s i t i o n was mapped u s i n g d e p o s i t i o n s p o t t i n g on v e g e t a t i o n and s t r u c t u r e s ( K n o t t e t a l . 1 9 8 3 ) . C u m u l a t i v e m a p s s h o w i n g a r e a s r e p e a t e d l y h i t by t h e l a u n c h c l o u d w e r e p r e p a r e d by o v e r l a y i n g maps o f i n d i v i d u a l l a u n c h e s .

B e s u l t 8

Bear-Field Vegeta t ion

L a u n c h e f f e c t s h a v e n o t b e e n u n i f o r m a c r o s s t h e n e a r - f i e l d s t u d y a r e a i n terms of f r e q u e n c y of b e i n g h i t ( F i g u r e 5 ) o r i n t e n s i t y of t h e d e p o s i t i o n i f h i t ( F i g u r e s 2 and 3). Changes i n s p e c i e s and c o v e r a r e a p p a r e n t f o r t h e e n t i r e i m p a c t zone (22 h a ) . Among t h e t r e e s and s h r u b s , g r o u n d s e l , s e a o x e y e and s a l t w o r t h a v e d e c l i n e d in f r e q u e n c y and c o v e r ( T a b l e 1 ) . T h r e e s p e c i e s h a v e d i s a p p e a r e d f r o m t h e s t u d y t r a n s e c t s ; pers immon ( D i o s p y r o s v i r g i n i a n a ) and b e a u t y b u s h ( C a l l i c a r p a a m e r i c a n a ) w e r e r e l a t i v e l y uncommon t o b e g i n w i t h b u t l a n t a n a ( L a n t a n a c a m a r a ) was more common i n i t i a l l y . Wax m y r t l e a n d b l a c k mangrove h a v e m a i n t a i n e d t h e i r f r e q u e n c y and i n c r e a s e d i n c o v e r . T h e s e s p e c i e s a p p e a r more r e s i s t a n t t o t h e g r o u n d c l c u d t h a n many o t h e r s h r u b s . Wax- m y r t l e h a s b e e n l o s t o r ' damaged a t some s i t e s b u t is s t i l l d o m i n a n t a t o t h e r s ; i t s r e l a t i v e c o v e r h a s i n c r e a s e d f rom 20.3% t o 32 .2% p r o b a b l y d u e t o ' t h e d e c l i n e i n c o v e r of more s e n s i t i v e s h r u b s s u c h as g r o u n d s e l and sea o x e y e . B l a c k mangrove is a p p a r e n t l y v e r y r e s i s t a n t t o t h e e x h a u s t c l o u d b u t i t w a s damaged by t h e December 1983 f r e e z e . ( P r o v a n c h a , e t a l . 1 9 8 5 ) .

Grasses and s e d g e s h a v e u n d e r g o n e l e s s o b v i o u s c h a n g e s i n f r e - q u e n c y a n d c o v e r t h a n t h e s h r u b s ( T a b l e 2 ) . Some o f t h e more common s p e c i e s h a v e i n c r e a s e d i n f r e q u e n c y ( e . g . , F i m b r i s t y l i s C a s t a n e a , 17 .5% t o 3 5 . 0 % ) o r c o v e r w h i l e o t h e r s h a v e d e c r e a s e d somewhat ( e . g . , E r a g r o s t i s e l l i o t t i i , 10 .0% t o 2 .5% f r e q u e n c y ) . I n g e n e r a l , g r a s s e s and s e d g e s seem f a i r l y r e s i s t a n t t o e f f e c t s o f t h e l a u n c h c l o u d a n d h a v e i n some c a s e s i n c r e a s e d i n dominance as more s e n s i t i v e s p e c i e s have b e e n e l i m i n a t e d .

H e r b a c e o u s s p e c i e s w h i c h i n c l u d e s u c c u l e n t s and s u b s h r u b s c o n s t i t u t e t h e l a r g e s t s p e c i e s g r o u p i n t h e Pad 39A v i c i n i t y . R e s p o n s e s of t h e s e s p e c i e s a r e v a r i a b l e . Twenty o n e s p e c i e s h a v e d i s a p p e a r e d f rom t h e s t u d y t r a n s e c t s ( e - g . , Ambros i a s p p . ) w h i l e t e n o t h e r s ( e .g . , R i v i n a h u m i l i s ) h a v e d e c l i n e d i n f r e q u e n c y o r c o v e r ( T a b l e 3 ) . S e a s o n a l d i f f e r e n c e b e t w e e n t h e t i m e of t h e o r i g i n a l and t h e s e c o n d s u r v e y may h a v e had some i n f l u e n c e on the p r e s e n c e o r a b u n d a n c e o f some s p e c i e s , p a r t i c u l a r l y a n n u a l s . Some h e r b a c e o u s s p e c i e s h a v e i n c r e a s e d i n f r e q u e n c y and c p v e r ; P a r i e t a r i a f l o r i d a n a h a s a p p a r e n t l y i n v a d e d a n d become

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LAUNCH PAD 39A

CUMULATIVE NEAR-FIELD LAUNCH DEPOSITION > 5 [Wj . . .-.e.* .

Figure 5. Cumulative near-field launch deposition from STS-1 through STS-9.

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e s t a b l i s h e d on 2 5 % o f t h e t r a n s e c t s . Some d i f f e r e n c e s i n t axonomy a l s o i n f l u e n c e t h e r e s u l t s ; S a l i c o r n i a b i g e l o w i i ( a n n u a l g l a s s w o r t ) w a s n o t o r i g i n a l l y d i s t i n g u i s h e d f r o m S a l i c o r n i a v i r g i n i c a ( p e r e n n i a l g l a s s w o r t ) ; i t s p r e s e n c e i n t h e s e c o n d s u r v e y r e s u l t s f r o m t h i s and n o t f r o m new i n v a s i o n . T h e r e is a g r e a t e r l o s s o f s p e c i e s t h a n g a i n f r o m new i n v a s i o n .

O v e r a l l c h a n g e s i n s p e c i e s r i c h n e s s a r e a p p a r e n t ( T a b l e 4 ) . F o r a l l o f t h e t r a n s e c t s r e s u r v e y e d , t h e mean number o f s p e c i e s p e r t r a n s e c t d e c l i n e s f r o m 7.8 t o 5 .1 i n d i c a t i n g a s i g n i f i c a n t n e t l o s s o f s p e c i e s ( T a b l e 5 ) . T h i s is t h e r e s u l t o f b o t h s p e c i e s l o s s r a n g i n g f r o m 0 t o 1 4 s p e c i e s p e r t r a n s e c t (O-lOOX, x=4.3 s p e c i e s ) and s p e c i e s g a i n r a n g i n g f r o m O t o 7 s p e c i e s ( 0 - l o o % , x=1.7 s p e c i e s ) . I t is e v i d e n t t h a t c o n s i d e r a b l e t u r n o v e r , r e p i a c e m e n t , and l o s s o f s p e c i e s have nccrzrred; the number of s p e c i e s i n common r a n g e s f r o m 0 t o 9 ( T a b l e s 4 a n d 5 ) .

It is e v i d e n t t h a t t h e c h a n g e s i n s p e c i e s c o m p o s i t i o n a r e n o t u n i f o r m a c r o s s t h e s i t e and t h a t some a r e a s h a v e b e e n more h e a v i l y i m p a c t e d t h a n o t h e r s . Two i n d i c e s h a v e b e e n c a l c u l ' a t e d t o a t t e m p t t o q u a n t i f y t h e c h a n g e s i n s p e c i e s c o m p o s i t i o n . J a c a r d ' s i n d e x of s i m i l a r i t y ( I S ) was a p p l i e d t o t h e s e d a t a ( M u e l l e r - D o m b o i s and E l l e n b e r g 1 4 7 4 ) . As a p p l i e d t o t h e s e d a t a , a h i g h i n d e x o f s i m i l a r i t y i n d i c a t e s t h a t l i t t l e c h a n g e i n ' s p e c i e s c o m p o s i t i o n ( p r e s e n c e - a b s e n c e ) h a s t a k e n p l a c e . I n d i c e s c a l c u l a t e d r a n g e f r o m 0 t o 100% i n d i c a t i n g c h a n g e s f r o m c o m p l e t e t u r n o v e r t o no c h a n g e i n s p e c i e s c o m p o s i t i o n ( T a b l e 4 ) . The i n d e x of s i m i l a r i t y t e n d s t o be l o w f o r p l o t s i n t h e a r e a s h i t mos't o f t e n or m o s t s e v e r e l y by t h e l a u n c h c l o u d . F o r e x a m p l e , t r a n s e c t D E 1 ( F i g u r e 4 ) is i n a n a r ea f r e q u e n t l y h i t ( F i g u r e 5 ) ; i t s i n d e x o f s i m i l a r i t y is 7.7% ( T a b l e 4 ) w h i l e t r a n s e c t GH4 is a t t h e e d g e o f t h e i m p a c t zone ( F i g u r e 4 ) a 3 d i t s s i m i l a r i t y i n d e x is 100% ( T a b l e 4 ) .

I n o r d e r t o more c a r e f u l l y d e f i n e t h e c h a n g e s i n s p e c i e s c o m p o s i t i o n i n t h e s e t r a n s e c t s , a n i n d e x o f c h a n g e , 1, w a s d e v e l o p e d .

-13-

m c L al c

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-14-

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-16-

a VI

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-17-

It is defined as

IC - 100 - [.-. X

where T is the number'of species present at time one, L is the number of species lost, G is €he number of species gained, and P is the number of species persisting from time one to time two (C.T. Gaetz, pers. corn.). Thus, this index explicitly includes the numbers of species lost, gained, and persisting relative to the original.

This index was calculated for the sample transects (Table 4) and ranges from -50.0 through 0 to 82.0. The two negative indices occur in plots 34A and BC3 which gained species but did not lose any. An index of zero indicates no change in species composition while positive indices indicate species change. This index indicates considerable changes in species composition. Those transects with the largest positive indices are generally those nearest to the usual cloud path and most frequently or severely affected; f o r example, transect DE1 has an index of change of 82.0%. Transects with small indices are in areas less frequently or severely impacted by the cloud as, for example, transect GH4 which has an Ic=O.

All of the measures discussed so far depend totally on changes in species composition; changes in cover of a species without it being added or lost to the transect are not included. Total cover for the transects is given in Table 4. Mean total cover declined from 125.8% post-STS-1 to 78.6% post STS-9, a significant (p < . O S ) decline (Table 5). This indicates that there has been a loss of cover as well as a loss of species. This loss of cover results from the complete or partial killing of shrubs and small trees removing the shrub layer and changing the structure of the community.

In order to compare Individual transects on a basis which incorporates changes in cover, a quantitative modification of Sorensen's index was used (Mueller-Dombois and Ellenberg 1974). This index weights dominance more heavily than species presence - absence and so responds somewhat differently than the other two indices (Table 4). An example is transect DE1 which is in an

-18-

a r e a n e a r l y a l w a y s h i t by t h e e x h a u s t c l o u d . I t s s p e c i e s r i c h n e s s h a s d e c l i n e d f rom e l e v e n s p e c i e s t o t h r e e l o s i n g t e n of t h e o r i g i n a l e l e v e n s p e c i e s . J a c a r d ' s s i m i l a r i t y i n d e x r e f l e c t s t h i s c h a n g e , I S j - 7 . 7 % , as d o e s t h e i n d e x of c h a n g e , Ic-82.0X ( T a b l e 4 ) . However , t h e dominan t p l a n t i n t h i s t r a n s e c t , F i m b r i s t y l i s C a s t a n e a , had r ema ined t h e same s o t h a t t h e q u a n t i t a t i v e i n d e x r e f l e c t s g r e a t e r s i m i l a r i t y ( l e s s c h a n g e ) ,

I n g e n e r a l , t h e i n d e x o f change ( I c ) , w h i c h i n c o r p o r a t e s s p e c i e s l o s t , s p e c i e s g a i n e d a n d s p e c i e s p e r s i s t e n t , seems t o p r o v i d e t h e b e s t g e n e r a l i n d e x o f community c h a n g e s a t t h i s s i t e . The t r a n s e c t s may b e s e p a r a t e d i n t o two d i s t i n c t g r q u p s , o n e g r o u p w i t h I c > 4 0 % c a n be c o n s i d e r e d t h e a r ea o f " s e v e r e " i m p a c t and t h e s e c o n d g r o u p w i t i i I c < J O X is c o i i s i b e r e d t h e area cf " m o d e r a t e " i m p a c t . On ly two t r a n s e c t s had I c = O i n d i c a t i n g no c h a n g e and t h e s e were g r o u p e d w i t h t h e m o d e r a t e i m p a c t t r a n s e c t s .

The two g r o u p s show somewhat d i f f e r e n t r e s p o n s e s . The mean number of s p e c i e s p e r t r a n s e c t d e c l i n e d f rom 9.2 t o 5.2 i n t h e s e v e r e i m p a c t g r o u p w h i c h was s i g n i f i c a n t a t p <.05; t h e mean number d e c l i n e d i n t h e m o d e r a t e i m p a c t g r o u p f r o m 6.0 t o 4.9 bu t - t h i s d e c l i n e was n o t S i g n i f i c a n t ( T a b l e 5 ) . D e c l i n e s i n mean t o t a l c o v e r w e r e s i g n i f i c a n t i n b o t h g r o u p s .

Changes i n s p e c i e s c o m p o s i t i o n and d o m i n a n c e h a v e b e e n s u f f i c i e n t t o c h a n g e community t y p e s o f some of t h e s a m p l e t r a n s e c t s ( F i g u r e 6 ) . The wax m y r t l e - g r o u n d s e l t y p e i n t h e a r ea of s e v e r e i m p a c t h a s l o s t i t s s h r u b component and i s now d o m i n a t e d by g r a s s e s a n d s e d g e s ; i n t h e a r ea o f m o d e r a t e i m p a c t some s h r u b s p e r s i s t a l t h o u g h s h r u b c o v e r i s g e n e r a l l y r e d u c e d . G r o u n d s e l o r s e a o x e y e may be l o s t f r o m t h i s t y p e w h i l e wax m y r t l e p e r s i s t s . The g r a s s - s e d g e t y p e i s r e l a t i v e l y r e s i s t a n t t o t h e c l o u d i m p a c t s a n d h a s n o t c h a n g e d i n c l a s s i f i c a t i o n ; s e n s i t i v e h e r b a c e o u s s p e c i e s h a v e b e e n l o s t f r o m i t and p e r c e n t c o v e r h a s d e c l i n e d .

M o d e r a t e i m p a c t t o t h e sea oxeye t y p e h a s r e s u l t e d i n r e d u c t i o n of c o v e r o f sea o x e y e w h i l e s e v e r e i m p a c t h a s e l i m i n a t e d i t a l t o g e t h e r ( F i g u r e 6 ) . Where sea o x e y e i s e l i m i n a t e d h e r b a c e o u s s p e c i e s s u c h a s P a r i e t a r i a f l o r i d a n a and P h y s a l i s v l s c o s a h a v e become d o m i n a n t . The i n v a d i n g h e r b s a r e t y p i c a l o f d i s t u r b e d s i t e s .

I n summary, t h e community l e v e l c h a n g e s r e s u l t i n g f r o m r e p e a t e d e x p o s u r e t o t h e S h u t t l e e x h a u s t c l o u d a r e : 1 ) r e d u c t i o n i n s p e c i e s r i c h n e s s p a r t i c u l a r l y by t h e e l i m i n a t i o n o f s e n s i t i v e s p e c i e s , 2 ) loss of s h r u b s and s m a l l t r e e s w h i c h c a n n o t s u r v i v e r e p e a t e d d e f o l i a t i o n and t h e i r r e p l a c e m e n t by g r a s s e s and s e d g e s o r by weedy h e r b s , and 3 ) a d e c l i n e i n t o t a l c o v e r as s t r a t a and i n d i v i d u a l s p e c i e s a r e l o s t . As c o v e r d e c l i n e s , t h e a r ea of b a r e g r o u n d i n c r e a s e s , p o s s i b l y i n c r e a s i n g t h e p o t e n t i a l f o r e r o s i o n .

-19-

GROUNDSEL

CATTAIL

'- GRASS-S€DGE GRASS-SEDGE

* REDUCED COVER

CATTAIL

REDUCm covm

SALTWORT-

GLASSWORT

MIXED-HERB

SEA OXEYE

REDUCED COVER GLASSWORT

REDUCED COVER

MUD FLAT-

SEA PURSLANE

MUD FLAT-

SEA PURSLANE r *

Figure 6. Retrogressive changes i n plant communities in the Pad 39A near-f3& impact zone from STS-1 through STS-9.

-20-

Dune and Strand V e g e t a t i o n

A c u t e damage t o dune and s t r a n d v e g e t a t i o n o c c u r r e d u p t o 1 . 2 km n o r t h e a s t o f t h e l a u n c h pad from t h e l a u n c h e s o f STS-8 a n d STS-9. Mean t o t a l damage t o t h e s t r a n d v e g e t a t i o n f r o m STS-8 r a n g e d f rom 0% t o 8 1 % ; t h e mos t i n t e n s e damage w a s i n a s t r i p a b o u t 300 m w i d e ( F i g u r e 7 ) . S p e c i e s showed w i d e l y r a n g i n g s e n s i t i v i t i e s t o t h e l a u n c h c l o u d ( T a b l e s 6 and 7 ) . R e s u l t s f o r t h e a r ea o f h e a v y damage were p r o b a b l y more r e l i a b l e g i v e n t h e l a r g e r s a m p l e s i z e

, ( T a b l e 6 ) . I n g e n e r a l , h e r b a c e o u s s p e c i e s w i t h t h i n l e a v e s were v e r y s e n s i t i v e (e .g . , Monarda p u n c t a t a , B i d e n s p i l o s a ) w h i l e g ra s ses and s e d g e s w e r e f a i r l y r e s i s t a n t ( e . g . , C h l o r i s p e t r a e , Andropogon s p p . ) . S h r u b s v a r i e d i n t h e i r s e n s i t i v i t i e s w i t h B o r r i c h i a > B a c c h a r i s > Myr ica i n s e n s i t i v i t y .

-

Mean t o t a l damage t o t h e dune v e g e t a t i o n r a n g e d f rom 0% t o 2 7 % and t h e p a t t e r n w a s l e s s c o n s i s t e n t f r o m p l o t t o p l o t t h a n i n t h e s t r a n d ( F i g u r e 7 ) . T h i s p r o b a b l y r e s u l t s f r o m t h e d u n e s b e i n g f a r t h e r away f r o m t h e l a u n c h pad a n d f r o m t h e g e n e r a l l y g r e a t e r r e s i s t a n c e o f t h e d o m i n a n t dune g ra s ses t o l a u n c h c l o u d e f f e c t s . T h i n - l e a f e d h e r b a c e o u s s p e c i e s ( e . g . , camphorweed, b e a c h s u n f l o w e r ) were g e n e r a l l y s e n s i t i v e t o t h e c l o u d as were some s h r u b s w i t h s u c c u l e n t l e a v e s (e.g.-, S c a e v o l a p l u m i e r i , ( b e a c h b e r r y ) , - I v a i m b r i c a t a ( m a r s h e l d e r ) ) w h i l e t h e dune g r a s s e s ( e . g . , sea o a t s , b e a c h g r a s s (Pan icum amarum) , s l e n d e r c o r d g r a s s ) were q u i t e r e s i s t a n t ( T a b l e s 8 and 9 ) .

The l a u n c h of STS-9 p r o d u c e d a s i m i l a r p a t t e r n of damage f o l l o w e d b y r e c o v e r y . Mean p e r c e n t damage t o t h e s t r a n d v e g e t a t i o n r a n g e d f r o m 0% t o 7 6 % ; major damage was i n a s t r i p a b o u t 2 5 0 m w i d e . ( F i g u r e 8 ) . S p e c i e s s e n s i t i v i t i e s were s imi- lar t o t h o s e o f STS-8 ( T a b l e 1 0 ) . Some s p e c i e s had a l r e a d y become d o r m a n t a t t h e t i m e of l a u n c h and were t h u s u n a f f e c t e d ( e . g . , Monarda p u n c t a t a ) . Mean p e r c e n t damage t o t h e dune v e g e t a t i o n r a n g e d f rom O X t o 58%; h e a v y damage on t h e d u n e s was r e s t r i c t e d t o a s t r i p a b o u t 2 5 0 m w i d e ( F i g u r e 9 ) . S e n s i t i v e and r e s i s t a n t s p e c i e s were s i m i l a r t o t h o s e o f STS-8 ( T a b l e 11). I n i t i a l r e c o v e r y o f t h e damaged v e g e t a t i o n w a s s l o w p r o b a b l y due t o t h e s e a s o n o f t h e l a u n c h . I n f a c t , t h e s e v e r e f r e e z e of December 2 5 - 2 6 , 1 9 8 3 damaged s p e c i e s s u c h a s sea g r a p e and b e a c h b e r r y w h i c h were i n c o n t r o l p l o t s u n a f f e c t e d by l a u n c h ( P r o v a n c h a e t a l . 1 9 8 5 ) . By A p r i l , h o w e v e r , s u b s t a n t i a l r e g r o w t h w a s e v i d e n t and by J u n e c o n d i t i o n s a p p e a r e d c l o s e t o t h o s e p r e - l a u n c h . This w a s c o n f i r m e d by a r e s u r v e y of t h e p e r m a n e n t p l o t s w h i c h i n d i c a t e d o n l y a s m a l l r e m a i n i n g mean p e r c e n t damage ( 0 - 5 % ) a t t r i b u t a b l e t o l a u n c h ( F i g u r e s 8 a n d 9 ) . Not all s p e c i e s i n a l l p l o t s had y e t r e c o v e r e d t h e i r p r e - l a u n c h c o v e r . Some p l o t s a l s o had minor c h a n g e s i n s p e c i e s c o m p o s i t i o n ; s e a s o n a l d i f f e r e n c e s ( l a t e f a l l t o l a t e s p r i n g ) c o m p l i c a t e t h e i n t e r p r e t a t i o n of t h e s e r e s u l t s .

-21 -

W (3

n z 0 - 2 c W 45 W > W

(3

E P c z w 0 w P z

a a

a

a #

0 0 00

0 0 h

0 0 co

0 0 v )

03 I

rn z E 0 Fc ru

e 0 r( U m U 01 M 01 3 aJ C 9 U

a c m U C m Fc U

0 U

aJ M (d E m

rn

I-

aJ Fc 7 M rl cr

-22-

Table 6. Sensitivity of species to damage based on transect data from strand vegetation - Zone of heavy damage from STS-8

SPECIES

Monarda punctata

Bofrichia frutescens Conyza canadense Vitis rotundifolia Baccharis halimifolia Croton punctatus Myrica cerifera Lantana camara Catharanthus roseus Rubus sp. Solidago sp. Acrostichum danaeifolium Lippia nodiflora Opuntia stricta Chloris petrae Cyperus sp. Andropogon spp . Scirpus sp. Cenchrus longispinus

B i d e n s p i l c s a

Mean X Damage

97.5 Q 3 G

63.3 50.0 35.0 31 -0 20.0 17.5 10.0 10.0 10.0 10 -0 10.0 7.5 6.3 5.3 5.0 5.0 5.0 3.0

"&.A

Std . Dev. - N -

4 2 3 1 2 5 1 2 1 1 1 1 1 2 4 3 1 1 1 2

-23-

Table 7. Sensitivity of species to damage based on transect data from strand vegetation - Zone of moderate damage from STS-8

SPECIES

Borrichia frutescens Myrlca cerif era Baccharis hallmifolia Lantana camara Ambrosia artemissifolia . Heterotheca subaxillaris Monarda punctata Opuntia stricta Andropogon spp. Cyperus sp. Chloris petrae Lippia nodiflora Batis maritima Euphorbia sp . Mlkania scandens

Mean X Std. Dev . Damage N - -

7 . 5 5 .0 5 . 0

5 . 0 5 00 2 .5 1.0 1.0 1.0 1.0 1.0 0 0 0

5 . 0

-24-

Table 8. Sensitivity of species to damage based on transect data from dune vegetation - Zone of heavy damage from STS-8

SPECIES

Beterotheca subaxillaris s 2 a e .; 18 p I.:-, i e = i Helianthus debilis Iva imbricata Yucca aloifolia Chamaesyce bombensis Uniola panlculata Panicum amarum Andropogon spp. Croton punctatus Commelina diffusa Coccoloba uvifera Rapanea punctata Spartina patens

Mean X Damage

35.0 *a. 7 5 . 5

20.0 15.0 10.0 5.5 5.5 5.0 5.0 5.0 5;0 5.0 5.0 1.0

Std. Dev . - N -

8 1 1 2 1 2 9 4 1 1 1 1 1 1

-25 -

Table 9. Sensitivity of species to damage based on transect data (N=l) from dune vegetation - Zone of moderate damage from STS-8

SPECIES

Agave neglecta Scaevola plumier5 Heterotheca subaxillaris Lippia nodiflora Licania michauxii Gaillardia pulchella Ipomoea stolonifera . Uniola paniculata Opuntia stricta

-26-

Mean % Damage

15.0 10.0 5.0 5.0 5.0 3.0 2.0 2.0 1.0

I- o w v) 2

c z 4 c CH v) v) 0 a 0 q

a a n

a

W (3 a E a n c 2 W 0 pe w n 2 4 w E 0 00

n

E v

i a a c

.. h 8.4 aJ

V al 8.4

m I rn

-a 3

a C (d b u v)

0 u a M a s n co aJ & 1 M

7.1 &I

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Table 10. Sensitivity of species to damage based on transect data from strand vegetation - Zone of heavy damage from STS-9

SPECIES

Flaveria linearis Asteraceae-Unknown Unknown Herb I1 Baccharis halimifolia Lantana camara Hypericum sp. Solidago sp. Iresine diffusa Schinus terebinthifolius Myrica cerifera Serenoa ripens Smilax auriculata Quercus virginiana

var. geminata Rubus sp. Opuntia etricta Spartina patens C J p e r a c e a e- Unk no wn Juncus sp. Poaceae-Unknown Casuarina litorea

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Mean X Std. N - Dev. - Damage

96.7 92.5 90 83.3 75

5 0 40 22.5 19.0 15 15

74.0

11.7

8 .a 8.8 7.5 5 . 0 5 5 1

3 - 2

1 6 1 3 1

2 5 - 1 1 2

4 4 2 2 1 1 1

1 -__

c 0 w v) z a a c W z 3

v) v) 0 pc 0

n

W (3 a E a n c z W 0 W

2 W E

a n

a

0)

c v) c v) 0 n

ci, v) I c 2 0 t X v)

Q)

c v) c v) 0 e

<i,

I C

I ' 1: \

\ \ :i" \ c y

\ 0 v)

-29-

Table 11. Sensitivity of species to damage based on transect data from dune vegetation - Zone of heavy damage from STS-9

SPECIES

He 1 iant hus de bi 1 i s Heterotheca subaxillaris Iva imbricata Ipomoea stolonifera Croton punctatus Opuntia stricta Coccoloba uvifera Uniola paniculata - Chloris petrae

. Euphorbia sp.

Mean X Damage

70.4 53.3 45 .0 20.0 20 .0 16.7 10.0 5.0 5.0 1 .0

Std. Dev . N - -

-30-

A o n e - t i m e e x p o s u r e t o t h e s e v e r e n e a r - f i e l d e f f e c t o f t h e l a u n c h c l o u d c a n r e s u l t i n c o n s i d e r a b l e v e g e t a t i o n da-mage p a r t i c u l a r l y t o d u n e a n d s t r a n d t y p e s d o m i n a t e d by r e l a t i v e l y s e n s i t i v e s p e c i e s . However , i f t h i s i m p a c t is n o t r e p e a t e d c o n s i d e r a b l e r e c o v e r y w i l l o c c u r w i t h i n a b o u t s i x mon ths . No s t r u c t u r a l c h a n g e s o c c u r r e d i n t h e s e dune and s t r a n d c o m m u n i t i e s w i t h o n l y o n e e x p o s u r e t o t h e l a u n c h e x h a u s t c l o u d .

Par-field Vegetat ion

The map o f c u m u l a t i v e f a r - f i e l d d e p o s i t i o n ( F i g u r e 1 0 ) shows t h a t d i f f e r e n t a r e a s a r e a f f e c t e d by t h i s d e p o s i t i o n d e p e n d i n g on t h e c l o u d b e h a v i o r . The f r e q u e n c y o f i m p a c t f o r a r e a s > 3 km f r o m Pad 39A has b e e n low. Based on v i s u a l s u r v e y s o f v e g e t a t i o n a n d s t r u c t u r e s , d e p o s i t i o n h a s o c c u r r e d a s f a r a s 2 2 km f r o m t h e l a u n c h pad a n d t h e c l o u d t r a c k h a s b e e n up t o 3 km i n w i d t h . V e g e t a t i o n damage f r o m f a r - f i e l d d e p o s i t i o n c o n s i s t s o f a c i d s p o t t i n g and d r y d e p o s i t i o n o f a luminum o x i d e on l e a v e s . D e p o s i t i o n on a n y o n e s u r f a c e may be mixed s o t h a t a s p o t o f a luminum o x i d e w i l l i n c l u d e a r i n g o f a c i d b u r n a r o u n d i t on a l e a f . - T y p i c a l l y t h e amount o f l e a f s u r f a c e i n v o l v e d w i l l be a b o u t € - 5 % o - c c a s i o n a l l y r a n g i n g up t o 14%.

A l t h o u g h d e p o s i t i o n p e r s i s t s on l e a f s u r f a c e s f o r c o n s i d e r a b l e p e r i o d s , no m o r t a l i t y o f t h e s e p l a n t s h a s b e e n o b s e r v e d f r o m t h i s m i n o r l o s s o f p h o t o s y n t h e t i c t i s s u e . No c h a n g e s i n community c o m p o s i t i o n or s t r u c t u r e h a v e been o b s e r v e d i n t h e f a r - f i e l d r e l a t e d t o l a u n c h e f f e c t s . The c h r o n i c e f f e c t o f s u c h d e p o s i t i o n is unknown a t t h i s t i m e . E v a l u a t i o n o f t h e a c t u a l a m o u n t s of d e p o s i t i o n c o u l d p r o v i d e c o n s i d e r a b l e i n s i g h t i n t o p o t e n t i a l e f f e c t s .

Discussion

C o n s i d e r a b l e e x p e r i m e n t a l d a t a a r e a v a i l a b l e f r o m l a b o r a t o r y e x p o s u r e s o f p l a n t s t o h y d r o g e n c h l o r i d e ( H C l ) , a luminum o x i d e ( A l z O 3 ) , m i x t u r e s o f H C 1 and A l 2 O 3 , a n d t h e c o m b u s t i o n p r o d u c t s o f s o l i d r o c k e t f u e l (Heck e t a l . 1 9 8 0 ) . R a t i n g s o f t h e s e n s i t i v i t i e s of b o t h p l a n t s n a t i v e t o M e r r i t t I s l a n d a n d c u l t i v a t e d s p e c i e s t o H C l h a v e b e e n d e v e l o p e d . I n t h e l a u n c h c l o u d , h o w e v e r , h y d r o g e n c h l o r i d e g a s is q u i c k l y s c a v e n g e d by wa te r t o f o r m a h y d r o c h l o r i c a c i d a e r o s o l . E f f e c t s on p l a n t s d i f f e r somewhat b e t w e e n e x p o s u r e t o d r y H C 1 g a s and t o h y d r o c h l o r i c a c i d a e r o s o l s (Heck e t a l . 1 9 8 0 , G r a n e t t 1 9 8 4 ) . E n v i r o n m e n t a l f a c t o r s s u c h a s r e l a t i v e h u m i d i t y a n d s o i l m o i s t u r e a l s o i n f l u e n c e t h e amount of p l a n t damage. High r e l a t i v e h u m i d i t y o r m i s t i n g o f p l a n t s p r i o r t o e x p o s u r e t o H C 1 i n c r e a s e d p l a n t damage compared t o d r y e x p o s u r e t o H C 1 gas (Heck e t a l . 1 9 8 0 ) . T h u s , t h e h i g h r e l a t i v e h u m i d i t y o c c u r r i n g a t STS-8 and STS-9 a n d t h e r a i n w h i c h p r e c e d e d STS-8 would be e x p e c t e d t o i n c r e a s e v e g e t a t i o n damage.

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1

N

T 0 1 2 3 4 k m

CUMULATIVE FAR-FIELD LAUNCH DEPOSITION

2-3 1-1 > r e j .......... . .. . , . . .

Figure 10. Cumulative far-f i e l d launch deposition from STS-1 through STS-9,

-32-

The r e s p o n s e s o f p l a n t s r e s u l t i n g f r o m l a b o r a t o r y e x p o s u r e s t o H C 1 a n d f i e l d e x p o s u r e s t o t h e l a u n c h c l o u d a r e g e n e r a l l y c o m p a r a b l e . F o r e x a m p l e , sea o a t s a n d s l e n d e r c o r d g r a s s w e r e u n i n j u r e d by e x p o s u r e s o f >40 ppm €IC1 f o r one h o u r (Heck e t a l . 1 9 8 0 1 , and t h e s e s p e c i e s a r e v e r y r e s i s t a n t t o e x p o s u r e t o t h e l a u n c h c l o u d i n t h e f i e l d . On t h e o t h e r h a n d , camphorweed, s ea o x e y e a n d b e a c h s u n f l o w e r a p p e a r t o be much more s e n s i t i v e t o t h e l a u n c h c l o u d t h a n p r e d i c t e d by l a b o r a t o r y s t u d i e s . T h i s i s p r o b a b l y due t o t h e d i f f e r e n c e i n r e s p o n s e t o d r y H C l g a s ( u s e d i n l a b o r a t o r y e x p e r i m e n t s ) as compared t o a q u e o u s a e r o s o l h y d r o c h l o r i c a c i d . F i e l d d a t a a r e c o m p l i c a t e d somewhat by t h e l a c k o f c o n t r o l o f amount and t i m e o f e x p o s u r e , v a r y i n g e n v i r o n m e n t a l c o n d i t i o n s o f t e m p e r a t u r e , h u m i d i t y , and o t h e r f a c t o r s ; i n some c a s e s , t h e u p p e r s t r a t a o f t h e v e g e t a t i o n i n t e r c e p t s t h e l a u n c h c l o u d and p a r t i a l l y s h i e l d s t h e g rouhd- i e v e i v e g e t a t i o n .

Community a n d e c o s y s t e m l e v e l e f f e c t s a r e p r o d u c e d by t h e S h u t t l e e x h a u s t c l o u d . S m i t h ( 1 9 8 1 ) h a s d i v i d e d t h e ‘ i n t e r a c t i o n s b e t w e e n a i r c o n t a m i n a n t s and f o r e s t e c o s y s t e m s i n t o t h r e e c l a s s e s . A C l a s s I r e l a t i o n s h i p o c c u r s unde r c o n d i t i o n s o f low d o s e w h e r e t h e f o r e s t e c o s y s t e m f u n c t i o n s as a s i n k and s o u r c e f o r a i r p o l l u t a n t s . Under i n t e r m e d i a t e d o s e s , a C l a s s I1 r e l a t i o n s h i p , p a r t i c u l a r s p e c i e s o r i n d i v i d u a l s may b e s u b t l y and a d v e r s e l y a f f e c t e d . E x p o s u r e t o h i g h d o s e s , a C las s I11 r e l a t i o n s h i p , may r e s u l t i n a c u t e m o r b i d i t y o r m o r t a l i t y of p a r t i c u l a r p l a n t s . A l t h o u g h d e v e l o p e d o r i g i n a l l y f o r f o r e s t s , t h i s c l a s s i f i c a t i o n seems g e n e r a l l y a p p l i c a b l e t o i n t e r p r e t i n g l a u n c h e f f e c t s on t e r r e s t r i a l e c o s y s t e m s .

The n e a r - f i e l d a c u t e i m p a c t s of t h e S h u t t l e e - x h a u s t c l o u d c l e a r l y q u a l i f y as a Class I11 i n t e r a c t i o n g i v e n t h e p l a n t m o r t a l i t y and communi ty c h a n g e s w h i c h h a v e o c c u r r e d i n t h i s a r ea . O t h e r e x a m p l e s o f v e g e t a t i o n damage o f t h i s t y p e h a v e b e e n a s s o c i a t e d w i t h c e r t a i n p o i n t s o u r c e s o f p o l l u t i o n . S m e l t i n g o p e r a t i o n s f o r c o p p e r , n i c k e l , o r i r o n h a v e p r o d u c e d e x t e n s i v e z o n e s o f v e g e t a t i o n d e s t r u c t i o n a t Copper B a s i n , T e n n e s s e e , S u d b u r y , O n t a r i o and W a w a , O n t a r i o r e s u l t i n g f r o m s u l f u r d i o x i d e e m i s s i o n s ( S m i t h 1981 , Gordan a n d Gorham 1 9 6 3 ) . F l u o r i d e e m i s s i o n s f r o m a luminum o r e p r o c e s s i n g f a c i l i t i e s h a v e p r o d u c e d s i m i l a r p a t t e r n s o f v e g e t a t i o n damage ( S m i t h 1981) . Gordan a n d Gorham ( 1 9 6 3 ) , i n a d e t a i l e d s t u d y o f t h e Wawa, O n t a r i o s i t e , showed t h a t z o n e s o f d e c r e a s i n g i n t e n s i t y o f v e g e t a t i o n damage t o t h e b o r e a l f o r e s t e x i s t e d away f r o m t h e i r o n s i n t e r i n g p l a n t . Near t h e s o u r c e , n e a r l y a l l p l a n t s had b e e n e l i m i n a t e d . F a r t h e r away t h e g r o u n d l a y e r o f v e g e t a t i o n p e r s i s t e d b u t t r e e s a n d s h r u b s were e l i m i - n a t e d . I n t h e n e x t z o n e , t h e s h r u b l a y e r w a s d o m i n a n t b u t t h e c a n o p y had been n e a r l y e l i m i n a t e d . Next w a s a z o n e where t r e e s

-33-

were still present but showed signs of damage. Finally a zone of no apparent damage was reached. Species richness also declined on a gradient approaching the sintering plant. These zones of damage extended more than 20 miles (32 km) in the direction of the prevailing winds and affected thousands of acres of forest. In contrast, the effects of the Shuttle exhaust are localized.

Similar patterns of vegetation response have been described for chronic exposure to radiation (Woodwell 1967, 1970, Whittaker and Woodwell 1978) a very different kind of disturbance; Woodwell (1970) described common features that result from these and other disturbances to ecosystems. These changes are first a reduction in diversity by the elimination of sensitive species; then elimination of the tree canopy and survival of resistant shrubs and herbs, usually species recognized as "seral" or "generalist ." Along with this simplification in community structure, occurs a reduction in standing crop biomass and the amount of nutrients held within the system. Whittaker and Woodwell (1978) termed these sequence of changes retrogression and contrasted them to successional changes which typically add species and increase structure through time.

The effects of Shuttle launches differ from many environmental perturbations in that it is a pulsed system; major acute impacts are separated by some weeks or months which allow some recovery. More typical point sources (e.g., smelters) produce essentially continuous emissions. The early Shuttle flights (STS-1 to STS-9) were two to seven months apart; the shortest interval between launches in this period was 63 days.

Although there are unique 'features of Shuttle launch effects, the vegetation changes caused by the Shuttle exhaust cloud in the near-field area exhibit many of the characteristics associated with smelters and radiation sources. Sensitive species have been lost and reduction in species richness has occurred. No tree canopy existed at this site but the shrub layer has been removed in the most heavily damaged areas and reduced at the less impacted sites. Grasses, sedges and herbs. persist within the impact zone; many of these are typical of disturbed sites. Standing crop biomass has undoubtedly declined with elimination of the shrub layer.

The area influenced by the near-field exhaust cloud effects, about 22 ha, is much smaller than the hundreds to thousands of hectare$ damaged by large smelters. The interval between Shuttle launches has allowed some recovery and regrowth to occur; however, this interval is expected to decrease to perhaps two weeks in the future as launch rates increase.

- 3 4 -

The increased frequency will result in permanent removal or change of several plant communities. Changes can be expected to continue to occur within the impact zone. The area currently considered moderately damaged will become more like the area of severe damage. The area of severe damage will continue to be stressed; an endpoint cannot be predicted with complete certainty, but at some point all vascular plants may be eliminated, especially with increased exposure by frequent launches. The total area within the impact zone may increase with differing meteorological conditions at future launches. A n area larger than the present impact zone may eventually be damaged . With reduced cover and increased areas of bare ground, the potential for erosion will increase. Increased leaching nf sail nutrients may occur as plants are n o longer present to take them up. Runoff and leaching may contribute greater nutrient and sediment loads to nearby surface waters. Increased nutrient loading could contribute to eutrophication of the aquatic system while increased amounts of sedimentation could impact benthic organisms.

'Loss of the shrub layer from plant communities changes their value as wildlife habitat. The changes in habitat structure within the near-field impact area suggest that species requiring shrub vegetation will be replaced by species preferring graminoid vegetative cover. In addition, the interactions of wildlife with contaminants produced by Shuttle launches may be a major factor responsible for impacts on wildlife. Since the near-field terrestrial area at Pad 39A is limited in size and is not critical habitat for species of special concern, the effects on wildlife due to vegetational change are probably minimal.

Dune vegetation has been impacted by two launches, STS-8 and STS-9; if impacts to the dune system become frequent the loss of dune stability and erosion could occur. Since severe storms do occur along this coast, l o s s of the protecting dunes would pose a r i s k to areas and structures inland from them.

Long-term effects to dune vegetation are also of concern because of the mouse Peromyscus polionotus niveiventris. This sub- species of beach mouse is restricted primarily to dune vegetation along the central stretch of Florida's Atlantic coast. Given the rapid development along this coastline, lands of Kennedy Space Center and Cape Canaveral Air Force Station are likely to retain the only significant acreage for the survival of this animal (Jack Stout, pers. comm.). The effects on wildlife of contami- nants from Shuttle operations in near-field or far-field areas are unknown and may be as significant or more significant than changes in vegetation.

-35-

Far-field deposition is considered a much less serious environmental impact because of the much smaller amount of deposition which occurs over a relatively large area. No plane mortality or community changes have been associated with far- field deposition. However, absence of acute effects does not imply that long term chronic effects are not occurring. More careful quantification of far-field deposition is necessary to evaluate this potential.

For far-field areas, the magnitude of vegetation change has nsa appeared significant enough to perceive any permanent shifts ia habitat structure that would affect wildlife. However, the deposition rates have not yet been quantified for long term evaluation .

Conclusions and Recommendations

There have been significant acute vegetation changes in a 22 br near-field area resulting from Space Shuttle launches at Pad 39A. Launch effects are minor with respect to the whole barrier island system. Effects will increase in the near-field area depending on launch frequency which dictates vegetation recovery time, conditions at each launch and the sensitivity of the various species. The area affected will probably increase wit3 time to include more than 22 ha. Further monitoring is requi-red to determine if these changes are adversely impacting other components of this ecosystem and to determine the maximum extent of damage. More subtle chronic effects (e.g., leaching of s o i l nutrients, nutrient' loading to aquatic systems, etc.) are occurring and should be quantified.

Dune and strand vegetation exposed to the launch cloud on a& one-time basis can recover to a large degree in about six months. However frequent exposure of dune vegetation to the launch cloud could result in elimination of vegetation cover am& lead to serious erosion problems. Continued monitoring of dune vegetation should be conducted to evaluate these impacts and contingency plans for revegetation should be-established.

Far-field deposition also occurs with each launch. Acute efZfiects of this deposition are minor but continued monitoring is regailred t o determine long-term chronic effects. A more careful quantification of far-field deposition amounts is necessary Tor evaluating potential chronic effects.

The effects of contaminants from Shuttle launches on wildlife utilizing areas receiving deposition is currently unknown. m s issue requires further study.

-36-

Operation of Pad 39B can be expected to produce an area of acute impact similar to that of Pad 39A. More of the expected impact zone at Pad 39B is water than land but impacts to terrestrial vegetation will occur. It can be predicted that sensitive plant species will be eliminated from the near-field zone and shrubs will be eliminated. Additional areas of dune vegetation will be exposed to damage by launches from Pad 398. If the dune vegetation is repeatedly damaged a problem of dune stability and

- erosion will develop. Monitoring is required to determine these effects.

-37-

Literature Cited

Anderson, B.J. and V.W. Keller. 1983. Space Shuttle exhaust cloud properties. NASA Technical Paper 2258. Marshall Space Flight Center, Alabama.

Bjorklund, J.R., R.K. Dumbauld, C.S. Cheney and H.V. Geary. 1982. Users manual for the REEDM (Rocket Exhaust Effluent Diffusion Model) computer program. H.E. Cramer Co. NASA Contractor Report 3646. Marshall Space Flight Center, Alabama .

Bowie, W.H. 1981. Environmental effects of the STS-1 flight readiness firing and launch. Medical Directorate, NASA, Kennedy Space Center, Florida.

Breininger, D.R. 1981. Analysis of vegetation north of LC39A prior to STS-2. Unpublished paper.

Dreschel, T.W. and C.R. Hinkle. 1984. Acid deposition, pH and inorganic carbon interactions: Laboratory simulation of Space Shuttle launch cloud effects on estuarine systems. NASA TM 83094. John F. Kennedy Space Center, Florida. 13PP.

Dreschel, T.W., C.R.' Hall and C.R. Hinkle. 1985. Nea'r-field deposition patterns of chlorides and particulates resulting from launches of the Space Transportation System. In pr epara t i on.

Dreschel, T.W., C.T. Gaetz, C.R. Hall, and C.R. Hinkle. 1985. An evaluation of statistical relationships between the near-field atmospheric deposition patterns of Space Transportation System related substances. In preparation.

Gordan, A.G. and E. Gorham. 1963. Ecological aspects of air pollution from an iron-sintering plant at Wawa, Ontario. Can. J. Bot. 41:1063-1078.

Granett, A.L. 1984. The phytotoxicity of designated pollutants on plant species. Third Annual Report, AFAMRL-TR-83-96, Aerospace Medical Research Laboratory, Wright-Patterson AFB, Ohio. 81 pp.

Hawkins, W.E., R.M. Overstreet and M.J. Provancha. 1984. Pathological effects of Space Shuttle exhaust plumes on gills of some estuarine fish: A light and electron microscopic study of acute environmental stress. Gulf Research Reports 7:297-309.

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f

t Heck, W.W., W.M. Knott, E.P. Slahel, J.T. Ambrose, J.N. McCrimmon, M. Engle, L.A. Romanov, A.G. Sawyer and J.D. Tyson. 1980. Response of sele'cted plant and insect species to simulated solid rocket exhaust mixtures and to exhaust components from solid rocket fuels. NASA Technical Memorandum 74109. NASA, J.F. Kennedy Space Center, Florida. 146 pp.

Knott, W.M. 1983a. STS-8-Environmental effects: Quick look report. Biomedical Office, NASA, J.F. Kennedy Space Center, Florida.

Knott W.M. 1983b STS-9-Environmental effects: Quick look report. Biomedical Office, NASA, J.F. Kennedy Space Center, Florida.

Knntt5 W * M % $ l I I $ A * K n l l e r , Jr:, afid J e Pulec?, 1 9 8 3 , Environmental effects of STS-1 through STS-4 launches: Comprehensive report. pp.1-30. In: A. Potter (ed.) Space Shuttle Environmental Effects: The First Five Flights. NASA, L . B . Johnson Space Center, Houston, Texas.

Milligan, J.E. and G.B. Hubbard. 1983. STS-5 fish kill, Kennedy Space Center, Florida. pp.59-80. In: A. Potter (ed.) Space Shuttle Environmental Effects: The First Five Flights. NASA, L.B. Johnson Space Center, Houston, Texas.

Mueller-Dombois, D. and H. Ellenberg. 1974. Aims and methods of vegetation ecology. John Wiley & Sons, New York. 547 pp.

NASA. 1979. Final environmental impact statement for the Kennedy Space Center. NASA, J . F . Kennedy Space Center, Florida.

Provzncha, M.J., P.A. Schmalzer and C.R. Hall. 1985. Effects of the December 1983 and January 1985 freezing air temperatures on select aquatic poikilotherms and plant species of Merritt Island, Florida. Unpublished manuscript.

Smith, W.H. 1981. Air pollution and forests. Springer-Verlag, New York. 379 pp.

Whittaker, R.H. and G.M. Woodwell. 1978. Retrogression and coenocline distance. pp. 51-70. In: R.H. Whittaker (ed.) Ordination of plant communities. Dr. W. Junk. The Hague, The Netherlands.

Woodwell, G.M. 1967. Radiation and the patterns of nature. Science 156:461-470.

Woodwell, G.M. 1970. Effects of pollution on the structure and physiology of ecosystems. Science 168:429-433.

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1. Report No. 2. Government Accession No.

TM 83103 4. Tttle and Subtitle

E f f e c t s of Space S h u t t l e Launches STS-1 through STS-9 on Terrestrial Vegetat ion of John F. Kennedy Space Center , F l o r i d a

3. Recipnent's Cotolog N a

5. Report Date

September, 1985

BIO-1

I

6. Performtng ~ r g o n t r o t i o n code

I 12. Sponsoring Agency Nom. and Address

7. Author(s) Schmalzer, P .A. ,C.R. Hinkle a n d D. Breiningel ' Edi tor (s )Knot t , W.M., I11 and A.M. Ko l l e r , Jr . (2 ) (1 )

9. Performing Orgonizotion Nome ond Address

(1) The B ione t i c s Corp. (2) MD/Biomedical O f f i c e John F. Kennedy Space John F. Kennedy Space

Center Center KSC. FL 32899 KSC. FL 32899

NASA/John F. Kennedy Space Center F lo r ida 32899

8. P e r f o r m l n ~ O w n l z o t l o n Reporf No.

10. *ork Un i t No.

- 11. Contract or Gront No.

NAS10-10285

13. T v o e sf Reoort and Period Covered

I MD-RES

15. Abstroc?'

Space S h u t t l e launches produce a launch cloCid which con ta ins hydrochlor ic a c i d ( H C l ) , aluminum oxide (A1 0 ), and o t h e r subs tances . been measured rou t ine ly i n a s s o c i a t i o n w i t h ' t h e launch cloud. 22 ha r q u l a r l y exposed t o t h e exhaust cloud du r ing most S h u t t l e launches , acu te vegetation,damage has r e s u l t e d from t h e f i r s t n i n e S h u t t l e launches. Changes inc lude loss of s e n s i t i v e spec ie s , l o s s of p l a n t community s t i -uc ture , r educ t ion i n t o t a l cover , and replacement of some spec ie s by weedy invaders . Community l e v e l changes d e f i n e a r e t r o g r e s s i v e sequence. vege ta t ion ccurred a f t e r launches of STS-8 and STS-9. Acute vege ta t ion damage occurred e spec ia l ly t o s e n s i t i v e spec ies . Within s i x months, however, recovery w a s nea r ly qomplete. p red ic t ed by previous l abora to ry s t u d i e s . Far-f i e l d a c i d i c and dry f a l l o u t f rm t h e cloud a s ' i t rises t o s t a b i l i z a t i o n and moves wi th t h e p r e v a i l i n g winds causes vege ta t ion spot t ing . Damage from t h i s depos i t i on i s minor; t y p i c a l l y a t most 1% t o 5% of l e a f suyface area i s a f f e c t e d . No p l a n t ' m o r t a l i t y o r community changes have occurred from f _ a r 3 k l d depos i t ion .

A c i d i t i e s of C0.5 pH have 2 3 I n an area of about

One-time impacts t o s t r a n d and dune

P S e n s i t i v i t y of spec ie s t o t h e launch cloud w a s p a r t i a l l y

16. Key Words

Space S h u t t l e Launch, Hydrochloric Acid, Vegetat ion Damage, Environmental E f f e c t s

17. Btbliographtc Control 18. Distr tbut ion

14. Sponsoring Agency Code

19. Socurity Clossif.(of this report) 20. Security Clossif . (of th is page) 21. No. of Pages

Unclas s i f i ed Unc las s i f i ed 39 22. Pr ice

I I I I 1 YO *IC C O R Y te-27?.%5 I R E V . 7 / 1 8 )